Pathognomonic amyotrophic lateral sclerosis (ALS) symptoms which are typically attributed to other anatomical regions, such as pseudobulbar affect, may be modulated, exacerbated, or partially driven by cerebellar changes in amyotrophic lateral sclerosis (ALS), according to a study published in the Journal of Neurology, Neurosurgery, and Psychiatry.

In this prospective imaging study of 271 participants, researchers sought to systematically evaluate cerebellar grey and white matter alterations, cerebellar peduncle integrity, and cerebro-cerebellar connectivity in patients with ALS.

The population of interest were stratified into four groups: patients testing positive for GGGGCC repeat expansions in C9orf72; patients carrying an intermediate-length repeat expansion in ATXN2; patients without established ALS-associated mutations; and healthy controls.

According to the results, cerebellar pathology was confined to lobules I-V of the anterior lobe in study subjects with sporadic ALS in contrast to the considerable posterior lobe and vermis disease burden identified in C9orf72 mutation carriers. Patients with intermediate ATXN2 expansions did not exhibit significant cerebellar pathology.

“Focal, rather than global, cerebellar degeneration characterizes ALS,” the researchers concluded. “Pathognomonic ALS symptoms which are typically attributed to other anatomical regions, such as dysarthria, dysphagia, pseudobulbar affect, eye movement abnormalities and cognitive deficits, may be modulated, exacerbated or partially driven by cerebellar changes in ALS.”

Link: https://pubmed.ncbi.nlm.nih.gov/34168085/

Keywords: amyotrophic lateral sclerosis, multiple sclerosis, pseudobulbar affect