Background: Research on amyotrophic lateral sclerosis (ALS) reveals that the disorder is not restricted to motor neurons.
Objectives: This neuroimaging study aimed to investigate the presence of cerebellar damage in adult ALS patients.
Material and methods: The study retrospectively analyzed magnetic resonance imaging (MRI) examinations performed on a 1.5T MR unit of 33 patients (17 men and 16 women with a mean age of 59.3 years) diagnosed with ALS. Cerebellar and posterior fossa dimensions were calculated using plain MR images. In addition, diffusion tensor imaging (DTI) was used to obtain white matter integrity measurements, represented as fractional anisotropy (FA) values, in the posterior limbs of internal capsules (PLIC) and middle cerebellar peduncles (MCPs). These measurements were compared to 36 healthy volunteers (11 men and 25 women with a mean age of 55.3 years). The study also assessed clinical data for correlations with cerebellar imaging findings.
Results: The linear measurements of the cerebellum did not differ between groups. However, the transverse cerebellar dimension (TCD) ratio to the maximum length of the posterior fossa (0.973 compared to 0.982, t = -2.76, p < 0.01) and FA value in both MCPs (0.67 compared to 0.65 and 0.69 compared to 0.67, p < 0.05) were significantly lower in ALS patients. No significant differences were found in FA value in the PLIC, and no significant correlations were observed between patient clinical characteristics and cerebellar damage.
Conclusion: This study provides evidence of cerebellar damage in adult ALS patients. These findings contribute to ALS understanding and highlight the importance of considering cerebellar involvement in the disease process. The results suggest that measuring the TCD ratio and FA value in both MCPs could be potential biomarkers for cerebellar damage in ALS patients.
Keywords: amyotrophic lateral sclerosis; cerebellum; fractional anisotropy; magnetic resonance imaging; transverse cerebellar diameter.