Backpack palsy

Rose K, Davies A, Pitt M, Ratnasinghe D, D'Argenzio L. Backpack palsy: A rare

complication of backpack use in children and young adults - A new case report.

Eur J Paediatr Neurol. 2016 Sep;20(5):750-3.

Abstract

Backpack palsy is a well-recognised, albeit rare, complication of carrying backpacks. Although it has been mostly described in cadets during strenuous training, sporadic cases of brachial nerve impairment have been reported in children and young adults. Here we reported the case of a 15-year-old girl who presented with a left-side brachial palsy with axonal denervation of C5C7 motor roots following a school challenge for the Duke of Edinburgh Award. Her symptoms began soon after starting the challenge and included weakness of shoulder abduction and elevation, as well as forearm, wrist and fingers extension. After 6 months of physiotherapy her motor function was completely restored. Backpack palsy can sometimes present in children and young adults. This disorder should be taken in consideration when planning for daily, as well as more challenging, physical activities in these age groups.

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From the article

A 15-year-old female student took part in the 2015 challenge for the Duke of Edinburgh Silver Award Expedition. The girl had been otherwise healthy with no previous symptoms of peripheral neuropathy and with unremarkable personal and family medical history. She was of Indo-Asian ethnicity, post-menarche and weighed 36.1 kg with a BMI of 14.2.

The exact weight of her backpack was not checked at the time but based on items included it was estimated to be about 10 kg. She used a soft shell backpack with a waist strap. During the expedition she walked with her classmates for 8–10 h/day for two consecutive days. Short rests were taken several times each day. At the end of the first day, she began to develop numbness in her left hand, which did not improve after rest. She subsequently developed a profound left arm weakness during the second day with inability to extend it against gravity at the elbow, wrist or fingers with minimal shoulder abduction; of significance she did not experience any painful symptoms. After 10 days of no improvement, her primary care physician referred her to the local paediatric team for an urgent review.

The neurological examination of her left arm showed no reduced muscle bulk or fasciculations. There was full range of passive movements; however, active movements were markedly reduced when compared to the contralateral arm. The most marked limitations were seen at wrist, fingers (MRC 0) and elbow extension (MRC 1). Less marked deficit was detected at shoulder elevation and abduction (MRC 3), elbow flexion, finger flexion and thumb abduction and adduction (MRC 4) ( Fig. 1 a,b). Brachial, triceps and brachioradial deep tendon reflexes were absent. Sensory examination was normal. Coordination could not be tested for the left arm but was normal on the right side and lower limbs. The rest of her neurological examination was normal. The overall findings were suggestive of a peripheral motoneuropathy involving the lateral and posterior chords of the brachial plexus 

(C5 C7)…

Electromyography (EMG) and nerve conduction studies were performed approximately 2 and 6 weeks after the onset of initial symptoms. The initial results showed normal sensory conduction with EMG showing a mixture of conduction block, seen in triceps, and active denervation found prominently in deltoid and to a lesser extent, extensor digitorum communis (EDC). Evidence of involvement outside of the posterior cord was suggested by abductor pollicis brevis (APB) and adductor digiti minimi, demonstrating F-wave abnormalities. The repeated study at 6 weeks post injury confirmed axonotmesis had taken place with reinnervation in deltoid and EDC. Triceps appeared still only affected by conduction block. F-waves had returned when APB was studied. EMG of biceps was normal.

The patient was managed conservatively. She was reviewed by the community physiotherapy team and instructed with daily exercises. She gradually started to recover her motor function about 4 months after the injury. A follow-up visit 6 months after the initial presentation revealed a complete recovery.

Courtesy of:  http://www.mdlinx.com/neurology/medical-news-article/2016/08/11/rucksack-palsy-backpack-palsy-brachial-plexus/6779729/?category=sub-specialty&page_id=3&subspec_id=317