We present the case of a 56-year-old male whose symptoms started in late November 2023 after a holiday in Australia. He noticed sudden onset sharp shooting pain over the back of his right arm and similar shooting pain in the flexor aspect of the right arm and forearm. Similar symptoms appeared shortly afterwards in the flexor aspect of the left arm and forearm. The patient kept emphasising on his difficulty with shaving the angle of his jaw. Few days following onset of the pain, he noticed weakness of the right thumb and became unable to press his key fob with his right thumb. Clinical examination showed impaired “OK sign” bilaterally. The overall pattern was consistent with bilateral anterior interosseous nerve palsy. 
  No peripheral nerve deficits were demonstrable on routine nerve conduction studies. In view of the clinical deficits which pointed to anterior interosseous nerve palsy, we proceeded to do concentric needle EMG sampling of the flexor pollicis longus and pronator quadratus muscles bilaterally. These muscles showed profuse fibrillation potentials and positive sharp waves. No voluntary motor units were seen in the pronator quadratus muscles. Occasional discrete low amplitude motor units were seen in the flexor pollicis longus muscles. These findings confirmed bilateral anterior interosseous nerve syndrome.
The patient was emphasising on his difficulty with shaving the angle of his jaw. We told him to mimic the movement in the clinic setting. It turned out that this difficulty was a result of his inability to sustain hyper-pronation of his hand when shaving the ipsilateral jaw (Fig.1). Weakness of the pronator quadratus muscle often manifests as weakness of pronation with a flexed elbow (1,2). Abnormal “Okay sign” is the most commonly known sign of anterior interosseous nerve lesion, but many people are not aware of the pronator quadratus hyper-pronation sign, or inability to sustain hyper-pronation of the forearm and hand when the elbow is flexed. This can present with beard shaving difficulty. The patient tested positive for Hepatitis-E virus infection. This reminds us of the current understanding that about 10% of cases of neuralgic amyotrophy are associated with ongoing hepatitis E virus infection. In such cases, neuralgic amyotrophy affects multiple nerves, and could be bilateral. Hepatitis-E is an emergent pathogen that has been reported in several acute monophasic neurologic disorders including neuralgic amyotrophy, Bell’s palsy, Guillain Barres Syndrome, Transverse myelitis and encephalitis (3).