Friday, May 20, 2016

The "round the houses" sign as a clinical clue for Niemann-Pick disease type C

Eggink H, Brandsma R, van der Hoeven JH, Lange F, de Koning TJ, Tijssen MA. Teaching Video NeuroImages: The "round the houses" sign as a clinical clue for Niemann-Pick disease type C. Neurology. 2016 May 10;86(19):e202.

A 58-year-old man presented with progressive involuntary jerky movements. In addition to a cortical myoclonus, supported by polymyographic evaluation, we saw a “looping” trajectory of the vertical saccades, also referred to as the “round the houses” sign (video on the Neurology® Web site at

This sign has been reported as an early indicator of vertical supranuclear gaze palsy in progressive supranuclear palsy. However, vertical supranuclear gaze palsy is not disease specific and in our patient led to the genetically confirmed diagnosis of Niemann-Pick disease type C.2 This shows that the presence of the “round the houses” sign should raise suspicion of a treatable diagnosis of Niemann-Pick disease type C.

[-may perform vertical saccades by performing a lateral arc movement = "round the houses" sign-

In some patients in whom the range of ocular movements are still preserved, the so-called “round the houses” sign can be observed early, denoting a laterally curved trajectory of vertical saccades."]

1 comment:

  1. A classic: Grover WD, Naiman JL. Progressive paresis of vertical gaze in lipid storage disease. Neurology. 1971 Sep;21(9):896-9.

    From the article (no abstract):

    The isolated finding of a progressive impairment of vertical gaze in childhood usually suggests the presence of a pinealoma or some other tumor in the area of the midbrain. In association with other signs, paresis of vertical gaze may be seen in brainstem encephalitis and myasthenia gravis. In neuronal storage disease there are usually alterations within the optic fundus but intact ocular motility. The two brothers described in this report have an unusual lipid storage disease and progressive paresis of vertical gaze. Except for a single case report by Norman et al., a review of the literature has shown no similar examples of gaze palsies in lipid storage disease. In sphingomyelinosis, which shares many features of our patients' illness, neuropathologic findings have not included changes in the pretectal area. Experimental data suggest impaired functioning at this site. It is our purpose to suggest that metabolic diseases of this type may also cause paresis of vertical gaze in childhood...

    As shown in the table, sphingomyelinase assay performed on fibroblast culture indicated an enzyme level of 10 units (normal, over 20 units). This value, though low, is above the levels found in type A and B Niemann-Pick disease; it may represent secondary impairment of enzyme activity by an accumulation of lipids of unknown type...

    Paresis of vertical gaze, progressive in nature, has been described in two brothers with find¬ings suggestive of a lipid storage disease. Lat¬eral gaze mechanisms are intact but there is impaired convergence and vertical opticoki-netic nystagmus and abnormal ocular response to horizontal rotation. These findings suggest that the pretectal area is a site of impaired function. We suggest that a central nervous system defect of metabolic origin should be considered in the evaluation of paresis of verti-cal gaze in childhood.