Neuromagnetic responses to multimodal stimuli in Friedreich's ataxia.

OBJECTIVE

This study explores the utility of various evoked fields in elucidating the pathophysiology of Friedreich's ataxia (FA) and potentially contributing to developing more targeted diagnostic and therapeutic strategies.

METHODS

Thirty-seven patients with FA aged 27.6 ± 7.4 years and a control group of 17 healthy subjects were enrolled in the study. The neuromagnetic response to auditory, tactile, visual, somatosensory, auditory and tactile oddball stimulation were acquired. For all the components of interest, latency and amplitude were measured and correlated with clinical data.

RESULTS

Neuromagnetic responses were identifiable in more than 90% of cases. A significant response delay was observed in all tested modalities (auditory, somatosensory, tactile and visual responses). P300 responses were comparable in patients and healthy subjects. Latencies of visual and auditory responses correlated with SARA scores. Moreover, latencies of auditory responses correlated with disease onset age, whereas latencies of visual responses correlated with disease severity.

CONCLUSIONS

Auditory and visual responses correlated with the severity of the disease, whereas alterations in somatosensory responses represent an intrinsic characteristic of the disease.

SIGNIFICANCE: In FA the study of evoked visual fields could provide a possible biomarker of disease progression and treatment efficacy.