Electrophysiological features in patients and presymptomatic relatives with spinocerebellar ataxia type 2.
Motor and sensitive nerve conduction studies, visual (VEP), brainstem auditory (BAEP) and somatosensory (SSEP) evoked potentials in 82 patients with spinocerebellar ataxia type 2 (SCA2), 62 presymptomatics relatives and 80 controls, correlating it with CAG repeat, disease duration and ataxia score were assessed. All the groups showed differences in the amplitude of sensory action potentials in median and sural nerves. Sural amplitude was negatively correlated with disease duration and ataxia score. Differences among patients and controls in the mean latency and conduction velocity of sensory action potentials were found. Abnormal morphology and replicability of SSEPs and BSAEPs were found in patients and presymptomatics. Moreover, consistent increase in latencies of P40 component of SSEPs, III and V peaks and I-III interpeak of BSAEPs was found in patients. A positive correlation was found between latency of III and V waves, I-III and III-V interpeak latencies of BSAEPs and disease duration. CAG repeat and electrophysiological markers assessed were not correlative. Electrophysiological alterations in the SCA2 appeared in presymptomatic stages. These alterations are consistent markers which could be used to evaluate the progression of the disease.
Velázquez Pérez
Luis
L
Center for the Research and Rehabilitation of Hereditary Ataxias "Carlos J. Finlay "Holguín, Cuba, Carretera Central Km 51/2 (Vía Habana). Reparto Edecio Pérez, 80100, Holguín, Cuba. ataxia@cristal.hlg.sld.cu
Sánchez Cruz
Gilberto
G
Canales Ochoa
Nalia
N
Rodríguez Labrada
Roberto
R
Rodríguez Díaz
Julio
J
Almaguer Mederos
Luis
L
Laffita Mesa
José
J
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D004594:Electrophysiology; D005071:Evoked Potentials / Q000502:physiology*; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology* / Q000528:radiation effects; D020754:Spinocerebellar Ataxias / Q000235:genetics* / Q000503:physiopathology*; D018709:Statistics, Nonparametric