Patients with spinal muscular atrophy (SMA) may have deficiencies in specific cognitive abilities which may be affected by variables such as motor difficulties or sex, as published in a novel paper in the Neuromuscular Disorders journal.
The study included 44 patients; half were patients with SMA type 3 and the other half were controls. They were assessed clinically for motor and cognitive functions, with researchers evaluating cognitive areas such as executive function, memory, language, visuospatial, and overall cognitive function.
“We observed a lower performance in individual tests assessing executive function, language and visuospatial abilities in SMA as compared to healthy controls,” the authors noted.
Although differences in education level within treatment and control groups could distort the results, the associations were still statistically significant after the authors controlled variables such as age or education.
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Furthermore, the authors found that cognitive function was also associated with disease severity and motor impairment. “SMA patients with greater motor difficulties had lower performance in attention, but higher performance in measures of language, verbal fluency, and memory,” they explained.
Sex stratification was also a significant element influencing cognitive function. In male patients, increased disease severity was associated with low attention and working memory abilities, but with a better score on language and verbal fluency tests. This finding was consistent with previous studies that suggest sex as a possible variable for clinical severity, the authors noted.
Overall, patients SMA patients exhibited better performance in some cognitive areas but worse function in others, and those measurements correlated with motor symptoms’ severity. The authors suggest that this may be due to structural or functional brain changes influenced by coping strategies but not in the overall brain structures, as specific areas improve while others deteriorate.
Although this study suggested cognitive impairment, due to the small sample, it is not strong enough to establish a clear cognitive pattern. Therefore, further research with a larger sample should explore these aspects, the authors concluded.
Lenzoni S, Semenza C, Calligaro D, et al. Cognitive profiles and clinical factors in type III spinal muscular atrophy: a preliminary study. Neuromuscul Disord. Published online May 11, 2022. doi:10.1016/j.nmd.2022.05.005