Brachial palsy after deep sleep

Abstract

A young student presented with left forearm numbness and proximal arm palsy after awaking from benzodiazepine and alcohol consumption-induced deep sleep. The patient had fallen asleep while sitting with the neck leaning on a laptop screen and head tilted left (figure 1). Prior medical history was negative for diabetes mellitus, trauma, neuropathy, chronic alcohol consumption, renal failure or autoimmune disorders. There was no family history of neuropathy. Examination revealed paralysis of the left deltoid, biceps and brachioradialis muscles, mild triceps weakness (4/5 MRC scale), absent biceps tendon reflex and C5-C6 dermatomal hypoesthesia suggesting involvement of the C5-C6-C7 roots or the upper and middle primary trunks of the brachial plexus. Electromyography, performed 3 days after the onset of symptoms, showed no motor unit voluntary recruitment in deltoid, biceps or brachioradialis, and reduced recruitment in triceps. Bilateral upper limb sensory, including lateral antebrachial cutaneous nerve, and motor nerve conduction studies (NCS) were unremarkable. The amplitudes and latencies of compound muscle action potentials recorded from left and right biceps and deltoid muscles were normal and symmetrical even after brachial plexus stimulation at Erb's point.