P7-20 Central and peripheral sensory pathway function in familial amyotrophic lateral sclerosis

Aim: To assess the clinical and neurophysiological features of the peripheral neuropathy associated with Fabry disease (FD) and to examine the function of the VIII cranial nerve. Methods: We prospectively examined 38 adults with FD (17 male, 21 female; mean age, 35.6 years. Each patient was assessed clinically. Nerve conduction studies (NCS) and quantitative sensory testing (QST) were performed: cold, warmth, vibratory, cold pain and heat pain detection thresholds were evaluated in one hand and one foot. Neurootologic signs and symptoms were evaluated in a subgroup of 20 consecutive patients with FD (6 male, mean age, 32 years; 14 female, mean age, 37 years) from within the cohort studies using: head thrust test and conventional caloric testing. The VIII cranial nerve was investigated using vestibular evoked myogenic potentials, pure tone audiometry and BAER. Results: All patients had signs or symptoms of FD. The most frequent manifestation was acroparaesthesia. In total, 92.1% of patients with FD presented with abnormal QST results: 73.7% showed increased cold detection thresholds and 65.8% had altered warmth detection thresholds. NCS were normal. Neuro-otologic manifestations: 80% of the patients were affected by auditory manifestations, 13/19 patients (68%) had both cochlear and vestibular symptoms Neuro-otologic involvement was peripheral in 15 cases and central in one case. Only 2/15 patients showed a congruent peripheral unilateral involvement of the superior and inferior vestibular tests with compromise of the ipsilateral cochlea. The main finding was that in 15 patients there was a lack of neural or vascular pattern in the involvement of the peripheral labyrinth. Conclusion: We identified signs and symptoms of peripheral neuropathy in both heterozygous and hemiyzygous patients with Fabry disease. Neuropathy predominantly affects small A-delta and C fibers. Neuro otologic involvement is frequent in Fabry disease, affecting the vestibular cochlear labyrinth in the majority of patients.