Unilateral oculomotor palsy in Charcot-Marie-Tooth disease 1A (CMT 1A)

Charcot-Marie-Tooth disease (CMT) type 1A is the most common form of CMT 1 and one of the autosomal dominant demyelinating hereditary motor and sensory neuropathies (HMSN). Cranial nerves may be frequently subclinically affected in CMT disease. However manifest clinical signs of cranial nerve involvement are rare.

This case comprise neurological, ophthalmological, internal medicine and ear-nose-throat investigation, motor and sensory nerve conduction velocity, auditory evoked potentials and orbicularis-oculi reflex measurements, lumbar puncture and blood examination, inclusive molecular genetic testing, as well as electrocardiogram and cranial imaging such as computer tomography and magnetic resonance imaging RESULTS: The present case shows a Charcot-Marie-Tooth (CMT) 1A patient with complete unilateral oculomotor palsy in combination with predominant ipsilateral subclinical trigeminal demyelination. A combined of third and fifth cranial nerves as in our patient has not been reported yet.

This case shows cranial nerve involvement as an unusual leading symptom of CMT 1A. It may remind us that hereditary neuropathies have to be taken into consideration in patients with slowly progressing unilateral or asymmetric cranial neuropathies.