Cognitive profiles and clinical factors in type III spinal muscular atrophy: a preliminary study

Cognitive abilities are often affected in progressive neurodegenerative disorders, but there is a lack of understanding about whether spinal muscular atrophy (SMA) patients experience cognitive deficits and, if so, whether they are associated with clinical factors. A sample of 22 type III SMA patients and 22 healthy controls completed a comprehensive neuropsychological battery, including tests in memory, executive function, language, visuospatial, and global cognitive functioning. Clinical severity was assessed using the Hammersmith Functional Motor Scale, the Revised Upper Limb Module and the Six Minute Walk Test. SMA patients showed poorer performance in visuospatial abilities, executive functions and language as compared to healthy controls. In the SMA sample, patients with greater motor difficulties had lower performance in attention, but higher performance in measures of language, verbal fluency, and memory. In men, but not women, cognitive test performance was associated with motor functioning. Our findings showing cognitive changes in SMA type III may reflect the presence of intrinsic brain pathology and cognitive adaptation mechanisms following physical dysfunction, which may be mediated by other factors, such as sex.