Neurophysiological study in cerebrotendinous xanthomatosis.

INTRODUCTION: Cerebrotendinous xanthomatosis (CTX) is a rare autosomal-recessive disease due to mutations of the 27α-hydroxylase. It is characterized by cataracts, xanthomas, and neurological manifestations. Polyneuropathy has been reported, although it is unclear whether it is axonal or demyelinating.

METHODS: We report clinical and neurophysiological results of 13 patients with CTX diagnosed in Spain.

RESULTS: In 8 patients (62%), peripheral neuropathy was demonstrated (4 demyelinating, 3 axonal, and 1 mixed; 3 predominantly motor and 5 sensorimotor). All patients had clinical signs/symptoms of peripheral neuropathy. Upper limb somatosensory evoked potentials (SSEPs) were affected in 38% of patients, and lower limb SSEPs in 67%. Fifty percent of patients had delayed brainstem auditory evoked potentials, and 43% had affected visual evoked potentials.

DISCUSSION: In this series, polyneuropathy was predominantly sensorimotor and demyelinating. Neurophysiological studies correlated only partially with clinical follow-up. Therefore, we recommend neurophysiological follow-up studies only if clinical symptoms are present.