Friday, May 17, 2024

Abnormality of early white matter development in tuberous sclerosis complex and autism spectrum disorder

Srivastava S, Yang F, Prohl AK, Davis PE, Capal JK, Filip-Dhima R, Bebin EM, Krueger DA, Northrup H, Wu JY, Warfield SK, Sahin M, Zhang B; TACERN Study Group. Abnormality of Early White Matter Development in Tuberous Sclerosis Complex and Autism Spectrum Disorder: Longitudinal Analysis of Diffusion Tensor Imaging Measures. J Child Neurol. 2024 May 15:8830738241248685. doi: 10.1177/08830738241248685. Epub ahead of print. PMID: 38751192.

Abstract

Background: Abnormalities in white matter development may influence development of autism spectrum disorder in tuberous sclerosis complex (TSC). Our goals for this study were as follows: (1) use data from a longitudinal neuroimaging study of tuberous sclerosis complex (TACERN) to develop optimized linear mixed effects models for analyzing longitudinal, repeated diffusion tensor imaging metrics (fractional anisotropy, mean diffusivity) pertaining to select white matter tracts, in relation to positive Autism Diagnostic Observation Schedule-Second Edition classification at 36 months, and (2) perform an exploratory analysis using optimized models applied to all white matter tracts from these data. Methods: Eligible participants (3-12 months) underwent brain magnetic resonance imaging (MRI) at repeated time points from ages 3 to 36 months. Positive Autism Diagnostic Observation Schedule-Second Edition classification at 36 months was used. Linear mixed effects models were fine-tuned separately for fractional anisotropy values (using fractional anisotropy corpus callosum as test outcome) and mean diffusivity values (using mean diffusivity right posterior limb internal capsule as test outcome). Fixed effects included participant age, within-participant longitudinal age, and autism spectrum disorder diagnosis. Results: Analysis included data from n = 78. After selecting separate optimal models for fractional anisotropy and mean diffusivity values, we applied these models to fractional anisotropy and mean diffusivity of all 27 white matter tracts. Fractional anisotropy corpus callosum was related to positive Autism Diagnostic Observation Schedule-Second Edition classification (coefficient = 0.0093, P = .0612), and mean diffusivity right inferior cerebellar peduncle was related to positive Autism Diagnostic Observation Schedule-Second Edition classification (coefficient = -0.00002071, P = .0445), though these findings were not statistically significant after multiple comparisons correction. Conclusion: These optimized linear mixed effects models possibly implicate corpus callosum and cerebellar pathology in development of autism spectrum disorder in tuberous sclerosis complex, but future studies are needed to replicate these findings and explore contributors of heterogeneity in these models.

Preventative treatment of tuberous sclerosis complex with sirolimus

Capal, J.K., Ritter, D.M., Franz, D.N., Griffith, M., Currans, K., Kent, B., Martina Bebin, E., Northrup, H., Koenig, M.K., Mizuno, T., Vinks, A.A., Galandi, S.L., Zhang, W., Setchell, K.D.R., Kremer, K.M., Prada, C.M., Greiner, H.M., Holland-Bouley, K., Horn, P.S. and Krueger, D.A. (2024), Preventative treatment of tuberous sclerosis complex with sirolimus: Phase I safety and efficacy results. Ann Child Neurol Soc. https://doi.org/10.1002/cns3.20070

Abstract

Objective

Tuberous sclerosis complex (TSC) results from overactivity of the mechanistic target of rapamycin (mTOR). Sirolimus and everolimus are mTOR inhibitors that treat most facets of TSC but are understudied in infants. We sought to understand the safety and potential efficacy of preventative sirolimus in infants with TSC.

Methods

We conducted a phase 1 clinical trial of sirolimus, treating five patients until 12 months of age. Enrolled infants had to be younger than 6 months of age with no history of seizures and no clinical indication for sirolimus treatment. Adverse events (AEs), tolerability, and blood concentrations of sirolimus measured by tandem mass spectrometry were tracked through 12 months of age, and clinical outcomes (seizure characteristics and developmental profiles) were tracked through 24 months of age.

Results

There were 92 AEs, with 34 possibly, probably, or definitely related to treatment. Of those, only two were grade 3 (both elevated lipids) and all AEs were resolved by the age of 24 months. During the trial, 94% of blood sirolimus trough levels were in the target range (5–15 ng/mL). Treatment was well tolerated, with less than 8% of doses held because of an AE (241 of 2941). Of the five patients, three developed seizures (but were well controlled on medications) at 24 months of age. Of the five patients, four had normal cognitive development for age. One was diagnosed with possible autism spectrum disorder.

Interpretation

These results suggest that sirolimus is both safe and well tolerated by infants with TSC in the first year of life. Additionally, the preliminary work suggests a favorable efficacy profile compared with previous TSC cohorts not exposed to early sirolimus treatment. Results support sirolimus being studied as preventive treatment in TSC, which is now underway in a prospective phase 2 clinical trial (TSC-STEPS).

Depression and euthanasia

A physically healthy, 28-year-old Dutch woman has decided to legally end her life due to her struggles with crippling depression, autism and borderline personality disorder, according to a report.

Zoraya ter Beek, who lives in a small village in the Netherlands near the German border, is scheduled to be euthanized in May — despite being in love with her 40-year-old boyfriend and living with two cats.

Ter Beek, who once aspired to be a psychiatrist, has been dealing with mental health struggles throughout her life.

She said she decided to be euthanized after her doctors told her, “There’s nothing more we can do for you. It’s never gonna get any better,” according to the Free Press.

“I was always very clear that if it doesn’t get better, I can’t do this anymore,” ter Beek said.

She is just one of the growing number of people in the West who have decided to die rather than continue living in pain that, unlike a terminal illness, could be treated.

More people are deciding to end their lives while suffering from a slew of other mental health problems like depression or anxiety amplified by economic uncertainty, climate change, social media and other issues, the Free Press reported.

Ter Beek said she will be administered the life-ending drug on her couch with her boyfriend by her side.

“I’m seeing euthanasia as some sort of acceptable option brought to the table by physicians, by psychiatrists, when previously it was the ultimate last resort,” Stef Groenewoud, a health care ethicist at Theological University Kampen, in the Netherlands, told the outlet.

“I see the phenomenon especially in people with psychiatric diseases, and especially young people with psychiatric disorders, where the health care professional seems to give up on them more easily than before,” she added.

Ter Beek plans to be cremated after she’s euthanized on the couch in her living room.

“No music,” she said.

https://nypost.com/2024/04/02/world-news/28-year-old-woman-decides-to-be-euthanized-due-to-mental-health-issues/

The genetic cause of spinocerebellar ataxia 4

Spinocerebellar ataxia 4 is a devastating progressive movement disease that can begin as early as the late teens. Now, a multinational research team led by University of Utah researchers has conclusively identified the genetic difference that causes the disease, bringing answers to families and opening the door to future treatments.

Some families call it a trial of faith. Others just call it a curse. The progressive neurological disease known as spinocerebellar ataxia 4 (SCA4) is a rare condition, but its effects on patients and their families can be severe. For most people, the first sign is difficulty walking and balancing, which gets worse as time progresses. The symptoms usually start in a person's forties or fifties but can begin as early as the late teens. There is no known cure. And, until now, there was no known cause.

Now, after 25 years of uncertainty, a multinational study led by Stefan Pulst, M.D., Dr. med., professor and chair of neurology, and K. Pattie Figueroa, a project manager in neurology, both in the Spencer Fox Eccles School of Medicine at University of Utah, has conclusively identified the genetic difference that causes SCA4, bringing answers to families and opening the door to future treatments. Their results are published in the peer-reviewed journal Nature Genetics.

Solving a genetic enigma

SCA4's pattern of inheritance had long made it clear that the disease was genetic, and previous research had located the gene responsible to a specific region of one chromosome. But that region proved extraordinarily difficult for researchers to analyze: full of repeated segments that look like parts of other chromosomes, and with an unusual chemical makeup that makes most genetic tests fail.

To pinpoint the change that causes SCA4, Figueroa and Pulst, along with the rest of the research team, used a recently developed advanced sequencing technology. By comparing DNA from affected and unaffected people from several Utah families, they found that in SCA4 patients, a section in a gene called ZFHX3 is much longer than it should be, containing an extra-long string of repetitive DNA.

Isolated human cells that have the extra-long version of ZFHX3 show signs of being sick -- they don't seem able to recycle proteins as well as they should, and some of them contain clumps of stuck-together protein.

"This mutation is a toxic expanded repeat and we think that it actually jams up how a cell deals with unfolded or misfolded proteins," says Pulst, the last author on the study. Healthy cells need to constantly break down non-functional proteins. Using cells from SCA4 patients, the group showed that the SCA4-causing mutation gums up the works of cells' protein-recycling machinery in a way that could poison nerve cells.

Hope for the future

Intriguingly, something similar seems to be happening in another form of ataxia, SCA2, which also interferes with protein recycling. The researchers are currently testing a potential therapy for SCA2 in clinical trials, and the similarities between the two conditions raise the possibility that the treatment might benefit patients with SCA4 as well.

Finding the genetic change that leads to SCA4 is essential to develop better treatments, Pulst says. "The only step to really improve the life of patients with inherited disease is to find out what the primary cause is. We now can attack the effects of this mutation potentially at multiple levels."

But while treatments will take a long time to develop, simply knowing the cause of the disease can be incredibly valuable for families affected by SCA4, says Figueroa, the first author on the study. People in affected families can learn whether they have the disease-causing genetic change or not, which can help inform life decisions such as family planning. "They can come and get tested and they can have an answer, for better or for worse," Figueroa says.

The researchers emphasize that their discoveries would not have been possible without the generosity of SCA4 patients and their families, whose sharing of family records and biological samples allowed them to compare the DNA of affected and unaffected individuals. "Different branches of the family opened up not just their homes but their history to us," Figueroa says. Family records were complete enough that the researchers were able to trace the origins of the disease in Utah back through history to a pioneer couple who moved to Salt Lake Valley in the 1840s.

Since meeting so many families with the disease, studying SCA4 has become a personal quest, Figueroa adds. "I've been working on SCA4 directly since 2010 when the first family approached me, and once you go to their homes and get to know them, they're no longer the number on the DNA vial. These are people you see every day… You can't walk away. This is not just science. This is somebody's life."

This work was performed in collaboration with researchers from University of Tübingen, University of Lübeck and Kiel University, University Hospital Hamburg-Eppendorf, and Veterans Administration Medical Center, Albany, NY.

The study was supported by the National Institute of Neurological Disorders and Stroke of the National Institutes of Health under award number R35127253 and the DFG-funded INST 37/1049-1.

https://www.sciencedaily.com/releases/2024/04/240429103023.htm

Figueroa KP, Gross C, Buena-Atienza E, Paul S, Gandelman M, Kakar N, Sturm M, Casadei N, Admard J, Park J, Zühlke C, Hellenbroich Y, Pozojevic J, Balachandran S, Händler K, Zittel S, Timmann D, Erdlenbruch F, Herrmann L, Feindt T, Zenker M, Klopstock T, Dufke C, Scoles DR, Koeppen A, Spielmann M, Riess O, Ossowski S, Haack TB, Pulst SM. A GGC-repeat expansion in ZFHX3 encoding polyglycine causes spinocerebellar ataxia type 4 and impairs autophagy. Nat Genet. 2024 Apr 29. doi: 10.1038/s41588-024-01719-5. Epub ahead of print. PMID: 38684900.

Abstract

Despite linkage to chromosome 16q in 1996, the mutation causing spinocerebellar ataxia type 4 (SCA4), a late-onset sensory and cerebellar ataxia, remained unknown. Here, using long-read single-strand whole-genome sequencing (LR-GS), we identified a heterozygous GGC-repeat expansion in a large Utah pedigree encoding polyglycine (polyG) in zinc finger homeobox protein 3 (ZFHX3), also known as AT-binding transcription factor 1 (ATBF1). We queried 6,495 genome sequencing datasets and identified the repeat expansion in seven additional pedigrees. Ultrarare DNA variants near the repeat expansion indicate a common distant founder event in Sweden. Intranuclear ZFHX3-p62-ubiquitin aggregates were abundant in SCA4 basis pontis neurons. In fibroblasts and induced pluripotent stem cells, the GGC expansion led to increased ZFHX3 protein levels and abnormal autophagy, which were normalized with small interfering RNA-mediated ZFHX3 knockdown in both cell types. Improving autophagy points to a therapeutic avenue for this novel polyG disease. The coding GGC-repeat expansion in an extremely G+C-rich region was not detectable by short-read whole-exome sequencing, which demonstrates the power of LR-GS for variant discovery.

Thursday, May 16, 2024

One chip challenge

A Massachusetts teenager who participated in a social media challenge where users eat a spicy tortilla chip died from eating a large quantity of chile pepper extract and also had a congenital heart defect, according to autopsy results.

Harris Wolobah, from the city of Worcester, died on Sept. 1, 2023, after eating the chip manufactured by Paqui, a Texas-based subsidiary of the Hershey Co.

Wolobah died of cardiopulmonary arrest "in the setting of recent ingestion of food substance with high capsaicin concentration," according to the autopsy from the Chief Office of the Medical Examiner.

Capsaicin is the component that gives chile peppers their heat.

"Capsaicin consumption can also cause more serious health problems including chest pain, heart palpitations, and even heart attacks. Consumption of larger amounts of capsaicin can also cause repeated vomiting that can lead to life-threatening esophageal damage. Because of this, people should use caution when consuming foods or products that contain capsaicin," she wrote in an article about the Paqui challenge on the website Poison.org.

Paqui pulled the chips off of shelves shortly after Wolobah's death.

The autopsy also said that Harris had an enlarged heart and a congenital defect described as "myocardial bridging of the left anterior descending coronary artery."

Wolobah died after participating in the so-called "One Chip Challenge," a marketing campaign by Paqui. It involves eating a single spicy tortilla chip seasoned with Carolina Reaper and Naga Viper peppers, and then waiting as long as possible before eating or drinking anything else.

"Any time you're sort of testing the body to its maximum, bad things can happen," Bradford Holland, M.D., an otolaryngologist in Central Texas, previously told Fox News Digital.

After Wolobah's death, Paqui said its product clearly states it is not intended for children or anyone sensitive to spicy foods.

"While the Pacqui One Chip Challenge is intended for adults only, we have seen an increase in teen usage of the product," the company said at the time.

https://www.foxbusiness.com/fox-news-us/massachusetts-teen-died-eating-spicy-chip-social-media-challenge




The genetic facets of Dravet syndrome: Recent insights

Mouhi HE, Abbassi M, Jalte M, Natiq A, Bouguenouch L, Chaouki S. The Genetic Facets of Dravet Syndrome: Recent Insights. Ann Child Neurol. 2024;32(2):67-82.

Abstract

Dravet syndrome (DS), previously known as severe myoclonic epilepsy of infancy, is a severe epileptic syndrome affecting children, with an incidence of 1/22,000 to 1/49,900 live births annually. Characterized by resistant and prolonged seizures, it often leads to intellectual impairment, with males being twice as susceptible as females. Its clinical features include recurrent seizures triggered by fever initially, but later occurring spontaneously, developmental delays, behavioral issues, and movement disorders. Sodium voltage-gated channel alpha subunit 1 (SCN1A) mutations, observed in about 90% of cases, are usually de novo, while mutations in other genes, such as protocadherin 19 (PCDH19), gamma-aminobutyric acid type A receptor subunit gamma 2 (GABRG2), and sodium voltage-gated channel alpha subunit 2 (SCN2A), can also contribute to the condition. Next-generation sequencing aids in identifying these genetic abnormalities. First-line treatments include anticonvulsant drugs such as valproate, clobazam, stiripentol, topiramate, and bromide. Second-line treatments for drug-resistant DS include stiripentol, fenfluramine, and cannabidiol. This literature review provides a comprehensive update on the genetic underpinnings of DS, highlighting SCN1A's predominant role and the emerging significance of other genes. Moreover, it emphasizes novel therapeutic approaches for drug-resistant forms, showcasing the efficacy of newer drugs such as stiripentol, fenfluramine, and cannabidiol. This synthesis contributes to our understanding of the genetic landscape of DS and informs clinicians about evolving treatment strategies for enhanced patient care.

Tuesday, May 14, 2024

Recovery potential in patients who died after withdrawal of life-sustaining treatment

Sanders WR, Barber JK, Temkin NR, Foreman B, Giacino JT, Williamson T, Edlow BL, Manley GT, Bodien YG. Recovery Potential in Patients Who Died After Withdrawal of Life-Sustaining Treatment: A TRACK-TBI Propensity Score Analysis. J Neurotrauma. 2024 May 13. doi: 10.1089/neu.2024.0014. Epub ahead of print. PMID: 38739032.

Abstract

Among patients with severe traumatic brain injury (TBI), there is high prognostic uncertainty but growing evidence that recovery of independence is possible. Nevertheless, families are often asked to make decisions about withdrawal of life-sustaining treatment (WLST) within days of injury. The range of potential outcomes for patients who died after WLST (WLST+) is unknown, posing a challenge for prognostic modeling and clinical counseling. We investigated the potential for survival and recovery of independence after acute TBI in patients who died after WLST. We used Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) data and propensity score matching to pair participants with WLST+ to those with a similar probability of WLST (based on demographic and clinical characteristics), but for whom life-sustaining treatment was not withdrawn (WLST-). To optimize matching, we divided the WLST- cohort into tiers (Tier 1 = 0-11%, Tier 2 = 11-27%, Tier 3 = 27-70% WLST propensity). We estimated the level of recovery that could be expected in WLST+ participants by evaluating 3-, 6-, and 12-month Glasgow Outcome Scale-Extended (GOSE) and Disability Rating Scale outcomes in matched WLST- participants. Of 90 WLST+ participants (80% male, mean [standard deviation; SD] age = 59.2 [17.9] years, median [IQR] days to WLST = 5.4 [2.2, 11.7]), 80 could be matched to WLST- participants. Of 56 WLST- participants who were followed at 6 months, 31 (55%) died. Among survivors in the overall sample and survivors in Tiers 1 and 2, more than 30% recovered at least partial independence (GOSE ≥4). In Tier 3, recovery to GOSE ≥4 occurred at 12 months, but not 6 months, post-injury. These results suggest a substantial proportion of patients with TBI and WLST may have survived and achieved at least partial independence. However, death or severe disability is a common outcome when the probability of WLST is high. While further validation is needed, our findings support a more cautious clinical approach to WLST and more complete reporting on WLST in TBI studies.

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It must be one of the hardest decisions people ever have to make: whether to let their loved one go, switching off their life support if signs suggest they won't recover from a traumatic brain injury that happened just days ago.

But recovery is unpredictable, so doctors don't really know which patients could possibly recover from severe head trauma if given more time, and who, if they were to live, would experience lasting brain damage and disability, compromising their quality of life.

It's a delicate balance of unthinkable probabilities that no one wants to consider.

Now a team of researchers have tried: William Sanders, a medical researcher at Massachusetts General Hospital in Boston, and colleagues compared the outcomes of 212 brain trauma patients, to try to understand the impossible – what might have happened to patients if life support was left on.

Their findings, from 18 trauma centers across the United States, suggest that some patients with brain injuries who died after life support was withdrawn may have survived and even recovered some level of independence six months after injury.

"Our findings support a more cautious approach to making early decisions on withdrawal of life support," says Yelena Bodien, a neurologist at Massachusetts General Hospital and senior author of the study.

Given the complexities, some guidelines recommend doctors refrain from making judgements about a patient's prognosis too early. Research has only faintly begun to understand different patterns of consciousness within comatose patients. No guidelines or algorithms exist to help clinicians identify which patients might make a meaningful recovery.

Yet families are often asked to make the call within 72 hours of someone sustaining a severe brain injury. Unless patients make a rapid recovery in the first few days, it's thought they are unlikely to survive or recover much at all.

The data Sanders and colleagues analyzed tentatively suggest otherwise.

From a cohort of 1,392 patients admitted to intensive care units with a traumatic brain injury, the researchers created a mathematical model to group patients based on their likelihood to have life support withdrawn, and their age, sex, health background, injury characteristics, and clinical features.

From there, Sanders and colleagues could match 80 people who died after their life support was turned off with 132 people who had a similar health trajectory up until and briefly after their brain injury, but didn't have life-sustaining treatment withdrawn.

This allowed the researchers to estimate the level of recovery that might have been possible at three, six, and 12 months for the 80 people who died soon after life support was withdrawn.

Of course, we'll never know what could have happened had the machines stayed on, but based on follow-up data of those in a similar, heart-wrenching position, we can glean some hazy insights.

The data revealed that 31 of the 56 brain trauma patients who stayed on life support died within six months; and 45 percent survived. Of the 25 patients who survived, more than 30 percent recovered enough in that same six-month period to have at least some independence in daily activities.

Just four patients recovered 'fully' to how they functioned before their injury.

While that's a remarkable outcome for a lucky few, the findings show that overall severe disability is common, although a lifetime in a vegetative state is unlikely and recovery to some degree is possible, even after a very serious injury.

"Traumatic brain injury is a chronic condition that requires long-term follow-ups to understand patient outcomes," Bodien says. "Delaying decisions regarding life support may be warranted to better identify patients whose condition may improve."

In this study, the researchers couldn't estimate potential outcomes for the oldest and most severely injured group, because no comparable patients were found among those whose life support stayed switched on.

Larger studies of more patients are needed to fill in the blanks and plot the recovery trajectories of these and other brain trauma patients.

The research has been published in the Journal of Neurotrauma.

https://www.sciencealert.com/study-more-patients-could-survive-brain-injuries-if-life-support-not-switched-off

Monday, May 13, 2024

Alexander disease 2

Inspired by a patient

Paprocka J, Nowak M, Machnikowska-Sokołowska M, Rutkowska K, Płoski R. Leukodystrophy with Macrocephaly, Refractory Epilepsy, and Severe Hyponatremia-The Neonatal Type of Alexander Disease. Genes (Basel). 2024 Mar 11;15(3):350. doi: 10.3390/genes15030350. PMID: 38540409; PMCID: PMC10970303.

Abstract

Introduction: Alexander disease (AxD) is a rare neurodegenerative condition that represents the group of leukodystrophies. The disease is caused by GFAP mutation. Symptoms usually occur in the infantile age with macrocephaly, developmental deterioration, progressive quadriparesis, and seizures as the most characteristic features. In this case report, we provide a detailed clinical description of the neonatal type of AxD.

Method: Next-Generation Sequencing (NGS), including a panel of 49 genes related to Early Infantile Epileptic Encephalopathy (EIEE), was carried out, and then Whole Exome Sequencing (WES) was performed on the proband's DNA extracted from blood.

Case description: In the first weeks of life, the child presented with signs of increased intracranial pressure, which led to ventriculoperitoneal shunt implementation. Recurrent focal-onset motor seizures with secondary generalization occurred despite phenobarbital treatment. Therapy was modified with multiple anti-seizure medications. In MRI contrast-enhanced lesions in basal ganglia, midbrain and cortico-spinal tracts were observed. During the diagnostic process, GLUT-1 deficiency, lysosomal storage disorders, organic acidurias, and fatty acid oxidation defects were excluded. The NGS panel of EIEE revealed no abnormalities. In WES analysis, GFAP missense heterozygous variant NM_002055.5: c.1187C>T, p.(Thr396Ile) was detected, confirming the diagnosis of AxD.

Conclusion: AxD should be considered in the differential diagnosis in all neonates with progressive, intractable seizures accompanied by macrocephaly.

Joung J, Gallison K, Sollee JJ, Vigilante N, Cooper H, Liu GW, Ballester L, Faig W, Waldman AT. Acquisition and Loss of Developmental Milestones and Time to Disease-Related Outcomes in Cerebral Alexander Disease. J Child Neurol. 2023 Dec;38(13-14):672-678. doi: 10.1177/08830738231210040. Epub 2023 Nov 3. PMID: 37920915.

Abstract

Objective: To determine the ages at acquisition of developmental milestones, loss of motor function, and clinical symptoms in Alexander disease. Methods: Patients with confirmed cerebral Alexander disease were included. Data abstraction of developmental and disease-specific milestones was performed from medical records, physical exams, and questionnaires. Mixed effects logistic regression was used to determine if key clinical features were associated with milestone achievement, controlling for patient age. Results: 51 patients with cerebral/infantile Alexander disease were evaluated at a mean age of 10.96 years (range 2.29-31.08 years). Developmental milestones in Alexander disease were often achieved but delayed. Ambulation was achieved in 44 subjects (86%); 34 (67%) subjects walked independently (mean age 1.9 years, range 0.91-3.25 years) and an additional 10 (20%) subjects walked with assistance (mean age 3.9 years, range 1.8-8 years) but did not progress to independent ambulation. Developmental delay was the earliest and most prevalent symptom (N = 48 [94%], mean age 0.58 years), compared to an initial seizure (N = 41 [80%], mean age 2.80 years), and macrocephaly (N = 28 [55%], mean age 4.04 years), P < .0001 between these ages of onset. Loss of independent ambulation occurred in 11 of the 34 (32%) children who had acquired ambulation (range 3.41-15.10 years). Presence of seizures or macrocephaly did not predict the achievement or loss of ambulation. Conclusions: The clinical triad of developmental delay, seizures, and macrocephaly are not universally present in cerebral Alexander disease. Clinicians should have a high index of suspicion for Alexander disease in patients with mild delays and a first seizure.

Anis S, Fay-Karmon T, Lassman S, Shbat F, Lesman-Segev O, Mor N, Barel O, Dominissini D, Chorin O, Pras E, Greenbaum L, Hassin-Baer S. Adult-onset Alexander disease among patients of Jewish Syrian descent. Neurogenetics. 2023 Oct;24(4):303-310. doi: 10.1007/s10048-023-00732-w. Epub 2023 Sep 2. PMID: 37658208.

Abstract

Alexander disease (AxD) is a rare autosomal dominant leukodystrophy caused by heterozygous mutations in the glial fibrillary acid protein (GFAP) gene. The age of symptoms onset ranges from infancy to adulthood, with variable clinical and radiological manifestations. Adult-onset AxD manifests as a chronic and progressive condition, characterized by bulbar, motor, cerebellar, and other clinical signs and symptoms. Neuroradiological findings typically involve the brainstem and cervical spinal cord. Adult-onset AxD has been described in diverse populations but is rare in Israel. We present a series of patients diagnosed with adult-onset AxD from three families, all of Jewish Syrian descent. Five patients (4 females) were diagnosed with adult-onset AxD due to the heterozygous mutation c.219G > A, p.Met73Ile in GFAP. Age at symptoms onset ranged from 48 to 61 years. Clinical characteristics were typical and involved progressive bulbar and gait disturbance, followed by pyramidal and cerebellar impairment, dysautonomia, and cognitive decline. Imaging findings included medullary and cervical spinal atrophy and mostly infratentorial white matter hyperintensities. A newly recognized cluster of adult-onset AxD in Jews of Syrian origin is presented. This disorder should be considered in differential diagnosis in appropriate circumstances. Genetic counselling for family members is required in order to discuss options for future family planning.

Friday, May 10, 2024

Pediatric palliative epilepsy surgery

M. Jeno, B. Zimmerman, S. Shandley, L. Wong-Kisiel, R. Singh, N. McNamara, E. Fedak Romanowski, Z. Grinspan, K. Eschbach, A. Alexander, P. McGoldrick, S. Wolf, S. Nangia, J. Bolton, J. Olaya, D.W. Shrey, S. Karia, C. Karakas, P. Tatachar, A.P. Ostendorf, S. Gedela, P. Javarayee, S. Reddy, C. Manuel, E. Gonzalez-Giraldo, J. Sullivan, J. Coryell, D. Depositario-Cabacar, J.S. Hauptman, D. Samanta, D. Armstrong, M.S. Perry, A. Marashly, M. Ciliberto. Pediatric palliative epilepsy surgery: a report from the Pediatric Epilepsy Research Consortium (PERC) Surgery Database. Pediatric Neurology (2024), doi: https://doi.org/10.1016/j.pediatrneurol.2024.04.028.

Introduction

Epilepsy is common, occurring in 0.5-1.5% of the pediatric US population, with drug-resistant epilepsy (DRE) occurring in nearly one-third of persons with epilepsy under 18 years of age. The International League Against Epilepsy (ILAE) defines DRE as “failure of adequate trials of two tolerated, appropriately chosen and used, antiepileptic drug schedules to achieve sustained seizure freedom”. After two anti-seizure medications (ASMs) have failed, the likelihood that an additional ASM will lead to seizure freedom is around 4-5%. These statistics have not changed despite increasing pharmaceutical options for the treatment of epilepsy over the last 20 years, highlighting the need for other treatment options for DRE. However, surgery continues to be an underutilized therapy, particularly when seizure freedom is not expected.

Definitive (or curative) surgical treatment for epilepsy is determined after identification of a seizure focus, followed by neurosurgical resection, disconnection, or ablation with the goal of achieving seizure freedom. Palliative epilepsy surgeries have a goal other than seizure freedom, including reduction of seizure severity, reduction in seizure frequency, or alleviation of a particular seizure type to improve quality of life. A palliative approach may be indicated when the epileptogenic zone cannot be fully resected due to failure of localization or lateralization, overlap with eloquent cortex, the presence of multiple epileptogenic zones, or the presence of generalized epilepsy. Corpus callosotomy, neuromodulation, and multiple subpial transections are procedures traditionally considered palliative procedures, though any surgical procedure can be considered a palliative treatment based on the preoperative goal of therapy including traditionally definitive procedures such as hemispherotomy, lobectomy, and lesionectomy.

Palliative epilepsy surgery can improve outcomes beyond what is captured with available surgical outcome measures, such as QOL in patients undergoing palliative hemispherotomy. Some palliative surgical procedures also have diagnostic utility that may lead to more definitive surgery later. For example, corpus callosotomy can help lateralize the seizure onset in frontal lobe epilepsies which can be difficult to lateralize on surface EEG. Responsive neurostimulation (RNS) allows long-term limited invasive EEG recording and can potentially lateralize or localize the most active seizure onset zone in suspected multifocal epilepsy leading to more definitive subsequent therapies.

Reducing seizures via epilepsy surgery, even without achieving seizure freedom, can help maximize neurodevelopmental potential and quality of life, as refractory seizures can lead to cognitive decline, impaired social outcomes, and higher risk of sudden unexplained death in epilepsy (SUDEP). This highlights the need to redefine surgical success as it relates to palliative procedures. In this paper, we evaluate the characteristics of children in the US offered palliative pediatric epilepsy surgery using a multicenter database to compare patient selection, evaluation, surgical treatment and outcomes of patients ultimately undergoing palliative epilepsy surgery.

Epilepsy surgery in children with genetic etiologies

Coryell J, Singh R, Ostendorf AP, Eisner M, Alexander A, Eschbach K, Shrey DW, Olaya J, Ciliberto MA, Karakas C, Karia S, McNamara N, Romanowski EF, Kheder A, Pradeep J, Reddy SB, McCormack MJ, Bolton J, Wolf S, McGoldrick P, Hauptman JS, Samanta D, Tatachar P, Sullivan J, Auguste K, Gonzalez-Giraldo E, Marashly A, Depositario-Cabacar DF, Wong-Kisiel LC, Perry S. Epilepsy surgery in children with genetic etiologies: A prospective evaluation of current practices and outcomes. Seizure. 2023 Dec;113:6-12. doi: 10.1016/j.seizure.2023.10.011. Epub 2023 Oct 25. PMID: 38189708.

Abstract

Objective: This study assesses current practices and outcomes of epilepsy surgery in children with a genetic etiology. It explores the pre-surgical workup, types of surgeries, and post-surgical outcomes in a broad array of disorders.

Methods: Patients ≤18 years who completed epilepsy surgery and had a known genetic etiology prior to surgical intervention were extrapolated from the Pediatric Epilepsy Research Consortium (PERC) surgery database, across 18 US centers. Data were assessed univariably by neuroimaging and EEG results, genetic group (structural gene, other gene, chromosomal), and curative intent. Outcomes were based on a modified International League Against Epilepsy (ILAE) outcome score.

Results: Of 81 children with genetic epilepsy, 72 % had daily seizures when referred for surgery evaluation, which occurred a median of 2.2 years (IQR 0.3, 5.2) after developing drug resistance. Following surgery, 68 % of subjects had >50 % seizure reduction, with 33 % achieving seizure freedom [median follow-up 11 months (IQR 6, 17). Seizure freedom was most common in the monogenic structural group, but significant palliation was present across all groups. Presence of a single EEG focus was associated with a greater likelihood of seizure freedom (p=0.02).

Significance: There are meaningful seizure reductions following epilepsy surgery in the majority of children with a genetic etiology, even in the absence of a single structural lesion and across a broad spectrum of genetic causes. These findings highlight the need for expedited referral for epilepsy surgery and support of a broadened view of which children may benefit from epilepsy surgery, even when the intent is palliative.

Wednesday, May 8, 2024

Acquired savant syndrome

In 2002, two men savagely attacked Jason Padgett outside a karaoke bar, leaving him with a severe concussion and post-traumatic stress disorder. But the incident also turned Padgett into a mathematical genius who sees the world through the lens of geometry.

Padgett, a furniture salesman from Tacoma, Washington, who had very little interest in academics, developed the ability to visualize complex mathematical objects and physics concepts intuitively. The injury, while devastating, seems to have unlocked part of his brain that makes everything in his world appear to have a mathematical structure.

"I see shapes and angles everywhere in real life" — from the geometry of a rainbow, to the fractals in water spiraling down a drain, Padgett told Live Science. "It's just really beautiful."

Padgett, who just published a memoir with Maureen Seaberg called "Struck by Genius" (Houghton Mifflin Harcourt, 2014), is one of a rare set of individuals with acquired savant syndrome, in which a normal person develops prodigious abilities after a severe injury or disease. Other people have developed remarkable musical or artistic abilities, but few people have acquired mathematical faculties like Padgett's.

Now, researchers have figured out which parts of the man's brain were rejiggered to allow for such savant skills, and the findings suggest such skills may lie dormant in all human brains.

'Struck by genius'

Before the injury, Padgett was a self-described jock and partyer. He hadn't progressed beyond than pre-algebra in his math studies. "I cheated on everything, and I never cracked a book," he said.

But all that would change the night of his attack. Padgett recalls being knocked out for a split second and seeing a bright flash of light. Two guys started beating him, kicking him in the head as he tried to fight back. Later that night, doctors diagnosed Padgett with a severe concussion and a bleeding kidney, and sent him home with pain medications, he said.

Soon after the attack, Padgett suffered from PTSD and debilitating social anxiety. But at the same time, he noticed that everything looked different. He describes his vision as "discrete picture frames with a line connecting them, but still at real speed." If you think of vision as the brain taking pictures all thes the frames without the smoothing. In addition, "everything has a pixilated look," he said.

"I see this image in my mind's eye, now in 3-D, every time imagine how my hand moves through space-time."

With Padgett's new vision came an astounding mathematical drawing ability. He started sketching circles made of overlapping triangles, which helped him understand the concept of pi, the ratio of a circle's circumference to its diameter. There's no such thing as a perfect circle, he said, which he knows because he can always see the edges of a polygon that approximates the circle.

Padgett dislikes the concept of infinity, because he sees every shape as a finite construction of smaller and smaller units that approach what physicists refer to as the Planck length, thought to be the shortest measurable length.

After his injury, Padgett was drawing complex geometric shapes, but he didn't have the formal training to understand the equations they represented. One day, a physicist spotted him making these drawings in a mall, and urged him to pursue mathematical training. Now Padgett is a sophomore in college and an aspiring number theorist.

Padgett's remarkable abilities garnered the interest of neuroscientists who wanted to understand how he developed them.

Beautiful mind

Berit Brogaard, a philosophy professor now at the University of Miami, in Coral Gables, Florida, and her colleagues scanned Padgett's brain with functional magnetic resonance imaging (fMRI) to understand how he acquired his savant skills and the synesthesia that allows him to perceive mathematical formulas as geometric figures. (Synesthesia is a phenomenon in which one sense bleeds into another.)

"Acquired savant syndrome is very rare," Brogaard said, adding that only 15 to 25 cases have ever been described in medical studies.

Functional magnetic resonance imaging measures changes in blood flow and oxygen use throughout the brain. During scans of Padgett, the researchers showed the man real and nonsense mathematical formulas meant to conjure images in his mind.

The resulting scans showed significant activity in the left hemisphere of Padgett's brain, where mathematical skills have been shown to reside. His brain lit up most strongly in the left parietal cortex, an area behind the crown of the head that is known to integrate information from different senses. There was also some activation in parts of his temporal lobe (involved in visual memory, sensory processing and emotion) and frontal lobe (involved in executive function, planning and attention).

But the fMRI only showed what areas were active in Padgett's brain. In order to show these particular areas were causing the man's synesthesia, Brogaard's team used transcranial magnetic stimulation (TMS), which involves zapping the brain with a magnetic pulse that activates or inhibits a specific region. When they zapped the parts of Padgett's parietal cortex that had shown the greatest activity in the fMRI scans, it made his synesthesia fade or disappear, according to a study published in August 2013 in the journal Neurocase.

Brogaard showed, in another study, that when neurons die, they release brain-signaling chemicals that can increase brain activity in surrounding areas. The increased activity usually fades over time, but sometimes it results in structural changes that can cause brain-activity modifications to persist, Brogaard told Live Science.

Scientists don't know whether the changes in Padgett's brain are permanent, but if he had structural changes, it's more likely his abilities are here to stay, Brogaard said.

The savant in everyone

So do abilities like Padgett's lie dormant in everyone, waiting to be uncovered? Or was there something unique about Padgett's brain to begin with?

Most likely, there is something dormant in everyone that Padgett tapped into, Brogaard said. "It would be quite a coincidence if he were to have that particular special brain and then have an injury," she said. "And he's not the only [acquired savant]."

In addition to head injuries, mental disease has also been known to reveal latent abilities. And Brogaard and others have done studies that suggest zapping the brains of normal people using TMS can temporarily bring out unusual mathematical and artistic skills.

It's always possible that having savant skills may come with trade-offs. In Padgett's case, he developed fairly severe post-traumatic stress disorder and obsessive-compulsive disorder, and he still finds it difficult to appear in public.

Yet Padgett wouldn't change his new abilities if he could. "It's so good, I can't even describe it," he said.

https://www.livescience.com/45349-brain-injury-turns-man-into-math-genius.html

See: https://www.youtube.com/watch?v=qX6ONPQGBfo
https://www.youtube.com/watch?v=GDU7lEmiiD8

See: Treffert DA, Treffert DA. The Sudden Savant: A New Form of Extraordinary Abilities. WMJ. 2021 Apr;120(1):69-73. PMID: 33974770.

Abstract


Introduction: Savant Syndrome previously has been characterized as either congenital or acquired. This report describes sudden savant syndrome in which neurotypical persons have the sudden emergence of savant skills without underlying disability or brain injury and without prior interest or ability in the newly emerged skill areas.

Case presentation: Eleven cases are described in which savant abilities suddenly and unexpectedly surfaced in neurotypical persons with no special prior interest or ability in the new skills, accompanied by an obsessive interest with and compulsive need to display the new abilities. All participants completed an online survey to record their demographics and skill characteristics.

Discussion: The acquired savant, and now the sudden savant, raise questions about the dormant potential for such buried skills in everyone. The challenge is to be able to tap such latent abilities without head injury or other precipitating events.

Conclusion: This paper documents 11 cases of sudden savant syndrome, which is a new and additional form of savant abilities surfacing in neurotypical persons without developmental disabilities (such as autism) or head or other brain injury (acquired savant syndrome). It opens new paths of inquiry for exploration of extraordinary abilities perhaps within everyone.

Clinical review of juvenile Huntington’s disease

Oosterloo, Mayke, Touze, Alexiane, Byrne, Lauren M., Achenbach, Jannis, Aksoy, Hande Coleman, Annabelle Lammert, Dawn, Nance, Martha, Nopoulos, Peggy, Reilmann, Ralf, Saft, Carsten, Santini, Helen, Squitieri, Ferdinando, Tabrizi, Sarah,Burgunder, Jean-Marc, Quarrell, Oliver. Clinical Review of Juvenile Huntington’s Disease. Journal of Huntington's Disease, vol. Pre-press, no. Pre-press, pp. 1-13, 2024. DOI: 10.3233/JHD-231523

Abstract: Juvenile Huntington’s disease (JHD) is rare. In the first decade of life speech difficulties, rigidity, and dystonia are common clinical motor symptoms, whereas onset in the second decade motor symptoms may sometimes resemble adult-onset Huntington’s disease (AOHD). Cognitive decline is mostly detected by declining school performances. Behavioral symptoms in general do not differ from AOHD but may be confused with autism spectrum disorder or attention deficit hyperactivity disorder and lead to misdiagnosis and/or diagnostic delay. JHD specific features are epilepsy, ataxia, spasticity, pain, itching, and possibly liver steatosis. Disease progression of JHD is faster compared to AOHD and the disease duration is shorter, particularly in case of higher CAG repeat lengths. The diagnosis is based on clinical judgement in combination with a positive family history and/or DNA analysis after careful consideration. Repeat length in JHD is usually >  55 and caused by anticipation, usually via paternal transmission. There are no pharmacological and multidisciplinary guidelines for JHD treatment. Future perspectives for earlier diagnosis are better diagnostic markers such as qualitative MRI and neurofilament light in serum.

Monday, May 6, 2024

Neurofilament light chain to monitor nerve cell injury

An experimental method developed to detect nerve injury in multiple sclerosis (MS) in adults also works for children with MS and other neurological conditions, even when they are symptom-free, according to an international team of researchers. In MS, early intervention with more recently approved treatments may be required to prevent new symptoms and eventual disability.

The adult method was developed last year and has already received breakthrough status from the Food and Drug Administration for consideration as a clinical tool to monitor the disease in patients over 18. It measures neurofilament light chain (NfL), which is found in blood and reflects injury to nerve cells.

The new study in children, which appears July 28, 2023, in The Lancet Neurology, creates reference ranges of this biomarker in children with and without neurological diseases. It could help expand the tool’s approval for use in children.

If NfL is high in a child, even if they appear well, it suggests the disease is not stable and other treatment strategies should be considered.”

“NfL can tell doctors how to manage MS after a diagnosis is made and treatment is started,” said Ahmed Abdelhak, MD, clinical instructor of neurology at UC San Francisco, a member of the Weill Institute for Neurosciences and a first author of the paper. “If NfL is high in a child, even if they appear well, it suggests the disease is not stable and other treatment strategies should be considered.”

The study examined 2,667 healthy children and 220 pediatric neurological patients, 142 of whom had MS. Others had epilepsy, traumatic brain injury, bacterial infections of the nervous system and MOGAD, a condition with some similarities to MS. Children with neurological disease had elevated NfL levels, indicating ongoing injury to nerve cells.

The researchers measured NfL values in two cohorts of healthy children: the Coronavirus antibodies in Kids from Bavaria (CoKiBa) study and participants without neurological diseases who had served as the control group in the U.S. Pediatric Multiple Sclerosis Network study, led by UCSF co-author Emmanuelle Waubant, MD, PhD.

Participants with MS and other neurological conditions were patients at the UCSF Pediatric Neuro-Immunology and Multiple Sclerosis Program and at the Children’s Hospital of the University of Regensburg in Germany.

NfL levels fall as healthy children grow older

The researchers found that in healthy children, NfL was very high after birth, likely related to relatively low blood volume in the first years of life. It decreased by 6.8% every year until the age of 10 and then plateaued. The average NfL for a healthy child was 4.8, versus 21.2 for a child with MS. NfL levels were elevated in the other neurological conditions, although not as much as in MS.

“NfL blood tests are much cheaper than MRI and might be repeated every few months if needed, while an MRI might be done at longer intervals,” said co-senior author Jens Kuhle, MD, of University Hospital and University of Basel in Switzerland, who was also senior author of the adult study.

While relapses or progression was the norm for older MS drugs, pediatric patients are now treated with disease-modifying drugs (DMTs), which have led to long-term stability, said Waubant, director of the UCSF Regional Pediatric Multiple Sclerosis Center, and also a member of the Weill Institute for Neurosciences.

“Testing NfL may help monitor disease activity in patients who are not yet on these high-efficacy DMTs, as well as in future clinical trials, in which it might one day partially replace MRIs,” she said. “This would simplify the study and decrease costs.”

In adults, NfL increases as they age

In the adult MS study, which published in 2022, researchers found that high levels of the biomarker were associated with more severe disease and a poor response to treatment. In adults, NfL went up as people grew older, rising exponentially after 50.

“Use of age-adjusted NfL concentrations in children and adults means that we do not have to limit the wide-scale application of NfL in clinical settings to a specific age-group,” said Kuhle. “For MS patients, we have a sensitive test that can measure disease activity and quantify treatment response.”

https://www.ucsf.edu/news/2023/07/425901/blood-test-may-reduce-risk-disability-kids

Abdelhak A, Cordano C, Boscardin WJ, Caverzasi E, Kuhle J, Chan B, Gelfand JM, Yiu HH, Oertel FC, Beaudry-Richard A, Condor Montes S, Oksenberg JR, Lario Lago A, Boxer A, Rojas-Martinez JC, Elahi FM, Chan JR, Green AJ. Plasma neurofilament light chain levels suggest neuroaxonal stability following therapeutic remyelination in people with multiple sclerosis. J Neurol Neurosurg Psychiatry. 2022 Jun 16:jnnp-2022-329221. doi: 10.1136/jnnp-2022-329221. Epub ahead of print. PMID: 35710320; PMCID: PMC9984688.

Abstract

Background: Chronic demyelination is a major contributor to axonal vulnerability in multiple sclerosis (MS). Therefore, remyelination could provide a potent neuroprotective strategy. The ReBUILD trial was the first study showing evidence for successful remyelination following treatment with clemastine in people with MS (pwMS) with no evidence of disease activity or progression (NEDAP). Whether remyelination was associated with neuroprotection remains unexplored.

Methods: Plasma neurofilament light chain (NfL) levels were measured from ReBUILD trial's participants. Mixed linear effect models were fit for individual patients, epoch and longitudinal measurements to compare NfL concentrations between samples collected during the active and placebo treatment period.

Results: NfL concentrations were 9.6% lower in samples collected during the active treatment with clemastine (n=53, geometric mean=6.33 pg/mL) compared to samples collected during treatment with placebo (n=73, 7.00 pg/mL) (B=-0.035 [-0.068 to -0.001], p=0.041). Applying age- and body mass index-standardised NfL Z-scores and percentiles revealed similar results (0.04 vs 0.35, and 27.5 vs 33.3, p=0.023 and 0.042, respectively). Higher NfL concentrations were associated with more delayed P100 latencies (B=1.33 [0.26 to 2.41], p=0.015). In addition, improvement of P100 latencies between visits was associated with a trend for lower NfL values (B=0.003 [-0.0004 to 0.007], p=0.081). Based on a Cohen's d of 0.248, a future 1:1 parallel-arm placebo-controlled study using a remyelinating agent with comparable effect as clemastine would need 202 subjects per group to achieve 80% power.

Conclusions: In pwMS, treatment with the remyelinating agent clemastine was associated with a reduction of blood NfL, suggesting that neuroprotection is achievable and measurable with therapeutic remyelination.

Ketogenic diet

Amelia Lavenski is a child with a bright personality who loves laughing and Mickey Mouse. “Every day, she smiles at something new,” says Amelia’s mother, Stephanie. Amelia started having seizures when she was 15 months old, and was diagnosed with epilepsy — a neurological condition that causes seizures. She was also diagnosed with a rare gene mutation (mitochondrial disorder) that causes prolonged seizures, and would experience one or two seizures every year that would require hospitalization.

But in August 2023, an uncontrollable seizure led to a life-changing event. 

Four-year-old Amelia was rushed to the emergency room, and then admitted to the Johns Hopkins Children’s Center pediatric intensive care unit (PICU). Despite efforts to stop her seizure with medication, it continued. “This seizure was really hard to control, and lasted a week,” Stephanie says. To prevent further complications, Amelia was intubated and monitored by an electroencephalogram, or EEG — a test that detects the electrical activity of the brain.

Implementing the Ketogenic Diet

Days later, Amelia’s condition improved, and she woke up from the prolonged seizure, after doctors adjusted her medication and implemented the ketogenic diet, one of the oldest treatments for epilepsy. The high-fat, very low-carb diet can be used to help control seizures. Ultimately, Amelia’s prolonged seizure led to inflammation in her brain, creating severe complications. She was no longer able to walk, move one side of her body, or sit or hold up her head on her own. She remained in the PICU for two weeks, and eventually moved to a step-down unit, where her care team, including Pediatric Ketogenic Diet Center Director Eric Kossoff, formulated a treatment plan. In combination with medication, Amelia would continue the ketogenic diet for now.

“The keto diet can be very beneficial, but it does not work for everyone,” says Kossoff. “In Amelia’s case, implementing this was a lifesaving treatment.”  

Amelia was discharged from Johns Hopkins after three weeks. She then spent five weeks at Kennedy Krieger Institute for additional inpatient rehabilitation. Since then, Amelia has remained mostly seizure-free. She initially continued on the ketogenic diet before transitioning back to a regular diet. She also completes therapy at home and at an outpatient clinic, and is relearning to walk in addition to other social and motor skills.

Amelia’s doctors are hopeful she will keep making strides as her recovery continues. “She is making good progress,” says Stephanie. “And we are slowly getting back to things.”

https://www.hopkinsmedicine.org/health/conditions-and-diseases/epilepsy/epilepsy-amelias-story

See: https://childnervoussystem.blogspot.com/2016/04/ketogenic-diet-in-refractory-childhood_12.html