Electroneuromyographic Features in Fabry Disease: A Retrospective Review.

Introduction: Fabry disease (FD) is an X-linked recessive inherited disorder characterized by lysosomal alpha-galactosidase deficiency. The purpose of our study was to assess and compare the electroneuromyographic (ENMG) findings of 15 patients with Fabry disease and the electroneurographic (ENG) findings of 15 healthy controls. We have not encountered any similar study in the medical literature of our country. Therefore, we believe that our study will contribute to national literature.

Methods: Fifteen patients with Fabry disease, 13 females and 2 males and 15 healthy controls, 13 females and 2 males, were included in the study. The definite diagnosis of patients with Fabry disease was made based on the enzyme level and genetic mutation. The patients with Fabry disease were examined with ENMG, while the healthy control group was examined with ENG. In the patients with a normal ENMG examination, neuropathic pain was attributed to the small fiber involvement.

Results: Patients with Fabry disease had neuropathic pain (LANSS score≥12). While neurological examination was normal in eight patients, glove- and stocking-type hypoesthesia and decreased deep tendon reflexes were observed in five and two patients, respectively. Axonal polyneuropathy was detected in one patient. The ENMG examinations of the other patients were normal. Enzyme replacement therapy could not be initiated in one patient because of pregnancy. The neurological examination of the healthy control group was normal. There was no statistically significant difference between the ENMG features of both groups (p>.05). As in other studies, a routine ENMG examination was normal in our patients with early-stage Fabry disease. Neuropathic pain, seen in patients with Fabry disease in literature, is thought to be due to small fiber involvement.

Conclusion: Fabry disease should be considered in the differential diagnosis of patients with neuropathic pain at young ages. It should be kept in mind that ENMG examination can be normal at the early stages. Quantitative sensory test, autonomic tests (R-R interval and sympathetic skin response) and skin biopsy should be performed in such cases. In our country, pediatric physicians work on Fabry disease more than physicians dealing with Fabry disease in adults. Therefore, in this retrospective study, we aimed to draw adult and pediatric neurologists' attention to Fabry disease.