Título

NEUROLOGICAL AND OPHTHALMOLOGICAL CHARACTERISTICS OF A CASE SERIES OF CARRIERS OF SPINOCEREBELLAR ATAXIA TYPE 7 (SCA 7)

Objetivo

To describe the neurological and ophthalmological findings in a case series of symptomatic (Scarriers) and asymptomatic carriers (Acarriers) of SCA 7 - rare SCA that stands out from other SCA by the appearance of a retinal dystrophy with progressive loss of central vision.

Método

Scarriers and their at 50% risk relatives were evaluated by ataxia (SARA, CCFS, PATA and 8-MW) and neurological scores (NESSCA and INAS); a visual functioning questionnaire (NEI-FVQ 25); evaluation of visual acuity (VA), average loss of vision in Humphrey automated campimetry (ALVC) and macular thickness in swept source optical coherence tomography (SS-OCT). Molecular analysis of the ATXN7 was done blindly.

Resultado

Six carriers were studied up to now: 2 were Acarriers. Ages and CAGexp of S and Acarriers were 29-58 and 24-27 years of age (yo), and 39-44 and 39 repeats. Mean of age at onset of gait ataxia (AO) and disease duration (DD), among Scarriers, were 34.25 yo and 12.5 years. Completely separated profiles were obtained between S and Acarriers. Mean of ALVC obtained in S and Acarriers were -13.35dB and -1.99dB. One Acarrier already presented losses in visual fields and a borderline macular thickness in SS-OCT. After that, we looked for correlations (p <0.05, Spearman) between the gold-standard variables of disease severity (SARA and VA) and the other clinical variables, in order to explore which will be probably validated in a study with power. SARA correlated (rho) with NESSCA (0.94), CCFS (0.88), PATA (0.92), 8-MW (0.98), and ALVC (0.89). Visual acuity (VA) correlated with INAS (0.85), ALVC (0.81) and NEI-FVQ 25 (0.89). INAS also correlated with ALVC (0.88).

Conclusão

ALVC stood out as the best candidate for a biomarker of disease progression in SCA7, since it was the first first clinical alteration detected in still an asymptomatic carrier. Macular thickness in SS-OCT seems to be another good candidate. ALVC also correlated well with both gold-standards of disease progression (SARA and VA).