This information is provided by the National Institutes of Health (NIH) Genetic and Rare Diseases Information Center (GARD).
Facial onset sensory and motor neuronopathy (FOSMN) is a rare and slowly progressive motor neuron disorder. Affected people initially experience facial tingling and numbness which eventually spread to the scalp, neck, upper trunk and upper limbs. These sensory abnormalities are later followed by the onset of motor symptoms such as cramps, muscle twitches, difficulty swallowing, dysarthria, muscle weakness and atrophy. The hallmark of FOSMN is a reduced or absent corneal reflex (the reflex to blink when something touches the eye). The underlying cause is currently unknown. Most cases appear to occur sporadically in people with no family history of the condition. Although there is no consensus regarding the best treatment options for FOSMN, some affected people have temporary improvement in response to intravenous immunoglobulin or plasmapheresis.
For more information, visit GARD.