Trigeminal sensory neuropathy: anatomico-physiological correlation

The widespread use of MRI, allowing accurate localisation of brain lesions, particularly within the brainstem, tends to overshadow the usefulness of electrophysiology in evaluating functional loss. This is the case of the blink reflex which explores trigeminal and facial nerves, and the brainstem. Discrete lesions at sites along the structures involved in the reflex arc are associated with particular abnormalities of the blink reflex.1 Here we describe a patient with an isolated trigeminal sensory neuropathy in whom an abnormal blink reflex predicted the localisation of a brainstem lesion. A 35 year old man reported acute onset of painless paraesthesiae …