Hereditary Neuralgic Amyotrophy with a Lesion Distal to the Brachial Plexus on Magnetic Resonance Imaging.

A 35-year-old woman first experienced left upper limb weakness at 17 years old, after which it repeatedly recurred and then remitted. She was diagnosed with carpal tunnel syndrome with median nerve hyperintensity by magnetic resonance imaging (MRI). Surgical treatment was ineffective. We suspected hereditary neuralgic amyotrophy because of enlargement distal to the brachial plexus on MRI and administered steroid therapy, after which the weakness improved. Genetic testing revealed a point mutation in SEPT9. Because lesions outside the brachial plexus can be seen in hereditary neuralgic amyotrophy, the diagnosis should be based on typical characteristics and the family history.

Anti-glycine receptor antibody-positive progressive encephalomyelitis with rigidity and myoclonus initially presenting with one-sided stiff face: A case report.

Background: Progressive encephalomyelitis with rigidity and myoclonus (PERM) is a subtype of stiff-person syndrome, a rare cerebrospinal disease that causes brainstem symptoms, myoclonus, muscle rigidity, and hyperekplexia. Case presentation: A 71-year-old man experienced left-sided stiff face, and was subsequently admitted to our hospital because of the appearance of left-dominant lower limb myoclonus. Muscle rigidity followed 3 days later. Magnetic resonance imaging revealed no abnormality. An electrophysiological examination showed a toughness of the antagonistic muscle following evocation of the Achilles tendon reflex, and a tonic phenomenon affecting the left facial muscles during the blink reflex. The patient's serum was positive for anti-glycine receptor (anti-GlyR) antibody, suggesting PERM. The patient was administered steroids, immunoglobulin therapy, and immunosuppressive drugs. He gradually improved after these therapies and became able to walk using a walker. Conclusions: We conclude that this was a rare case of anti-GlyR antibody-positive PERM with unilateral brainstem symptoms, myoclonus, and muscle rigidity.