F-Wave Features in Most Common Chinese Spinocerebellar Ataxias.

The use of F-wave study may help to gain insight into electrophysiological significance of spinocerebellar Ataxias (SCAs). Particularly, the difference of F-wave features between Chinese SCA1, SCA2 and SCA3 patients were scarcely reported. 20 SCA1, 20 SCA2, 46 SCA3 patients and 30 healthy controls underwent nerve (median, ulnar, tibial) conduction and F-wave studies, and electrophysiology parameters were compared between them. Clinical data including ataxia and non-ataxia features was recorded. The study revealed peripheral neuropathological involvement in 80% of SCA1, 100% of SCA2, and 50% of SCA3 Chinese patients. Most patients of all subtypes presented with sensory neuropathy, and F-wave changes. We observed that SCA1 patients had prolonged F-wave latency as well as increased maximum F-wave amplitude and F/M amplitude ratio compared to controls for the first time. Besides, SCA2 patients had decreased F-wave persistence as well as increased maximum F-wave amplitude, F/M amplitude ratio and frequency of giant F-wave. The maximum amplitude of SCA1 correlated positively with disease severity and disease duration. The value of F/M amplitude ratio of SCA2 correlated positively with disease duration. In all subtypes, F-wave of the tibial nerve was the most sensitive measurement index. This study exhibits F-wave characteristics and inter-group differences of the most common Chinese SCAs. F-wave may be a potential biomarker for evaluating the progression of SCAs.