Facial Onset Sensory and Motor Neuronopathy-Like Syndrome: A Case Report.

Abstract

Objectives: Facial onset sensory and motor neuronopathy syndrome (FOSMN) is a rare motor neuron disorder characterized by facial sensory and motor aberrations that progress to the upper limbs. We present a case of FOSMN-like syndrome that has characteristics of FOSMN but is confined to the craniofacial region.

Methods: Retrospective chart review and review of the literature.

Results: A 70-year-old woman presented with a 1-month history of progressive bilateral facial sensory loss and weakness affecting the trigeminal and hypoglossal nerves. Within 12 months, she developed debilitating weakness affecting her lower and midface bilaterally. After an extensive workup, a diagnosis of FOSMN-like syndrome was made, as symptoms failed to progress to the upper extremities.

Conclusions: This case demonstrates a unique presentation of FOSMN that we classify as FOSMN-like syndrome. Clinicians must maintain a high index of suspicion when a patient presents with clinical features characteristic of FOSMN syndrome without progression of symptoms distal to the craniofacial region because it may represent a FOSMN-like syndrome.