Objective: To describe a 46 year-old woman with the syndrome of facial onset sensory and motor neuronopathy.
Methods: Case description.
Results: A 46 year-old woman noticed numbness in the left upper lip seven years earlier. The numbness gradually spread into both sides of the face, neck and arms. In the last two years she developed dysphagia and dysarthria. There was no family history of neurological disease. Examination showed wasting and weakness of the facial and masseter muscles, absent corneal reflexes, loss of small fibre sensory function on both sides of the face and inside the mouth, absent pharyngeal sensation, absent gag reflex, weakness of neck flexion and reduced pain and temperature sensation over the neck, arms and upper trunk. Lower limb sensation was normal. Routine blood tests, lipids and serum immunofixation were normal. Autoantibodies and cryoglobulins were not detected. Sensory action potentials were reduced in both arms. Blink reflexes were absent. EMG showed chronic partial denervation of the tongue, masseter and facial muscles, but the muscles in the arms and legs were normal. There were no fibrillations. CSF examination and MRI of the brain and cervical spine were normal. Histological examination of the superficial radial nerve did not show vasculitis or amyloid infiltration. High dose methylprednisolone and intravenous immunoglobulin were unhelpful.
Conclusions: The clinical and neurophysiological findings were consistent with the syndrome of facial onset sensory and motor neuronopathy, which was first described by Vucic et al in 2006. This is a rare, progressive degenerative disorder of unknown pathogenesis.