A comparative study of the clinical and electrophysiological features between Friedreich ataxia and Ataxia with isolated vitamin E deficiency in Tunisia (P1.064)

Objective: To compare the clinical and electrophysiological features of FRDA and AVED patients. Background: Friedreich ataxia(FRDA) and Ataxia with isolated vitamin E deficiency(AVED)are the most common recessive hereditary ataxia in Tunisia. Even if they have a resembling phenotype, clinical and electrophysiological differences have been reported. Design/Methods: From March 2017 to September 2017,we prospectively included in our study 30 patients affected by FRDA and 30 patients affected by AVED. We examined, analyze and compared the clinical electrophysiological and molecular features. Results: We collected 30 FRDA patients : 28 carried a biallelic GAA expansion and 2 had a compound heterozygous. All AVED patients had the 744del mutation. The sex ratio was 0,87 for FRDA patients and 1,5 for AVED patients. The mean age of examination was 31years for FRDA and 32years for AVED patients. The mean age in which the disease began was 17,3years for FRDA and 14,6years for AVED patients. The main presenting symptom was gait disturbance for both group (96,7%FRDA,86,7% AVED). The mean SARA scale was 24,01 for FRDA and 13,6 for AVED patients with a significant difference(p=0,000). FRDA patients were wheelchair-bound in 46,7% at a mean age of 21,7 years, while only 6,7% AVED patients were wheelchair-bound at a mean age of 50years. Neurological examination revealed significant differences: amyotrophy and muscle weakness were more frequent in FRDA patients(53,7%,60%) than in AVED patients(6,7%,0%);in contrast cervical dystonia and head tremor were more frequent in AVED patient(83,3%,70%) than FRDA patients(6,7%,6,7%). Electrophysiological study revealed a higher frequency of neuropathy in FRDA group(P=0,000). Conclusions: The clinical and electrophysiological features of our FRDA patients showed differences from our AVED patients :The SARA scale was higher for FRDA patients ;amyotrophy, motor weakness and neuropathy were more frequent in FRDA patients. In contrast; cervical dystonia and head tremor were more frequent in AVED patients. The progress of the disease was faster and more severe for FRDA patients. Those differences could help the clinical diagnosis of these ataxia. Disclosure: Dr. Jridi has nothing to disclose. Dr. Kharrat has nothing to disclose. Dr. Sassi has nothing to disclose. Dr. Nabli has nothing to disclose. Dr. Blel has nothing to disclose. Dr. Hentati has nothing to disclose.