The Role of the Cerebellum in Alzheimer's Disease: More Than Just a Bystander?

               In their article titled "Cerebellar EEG source localization reveals age-related compensatory activity moderated by genetic risk for Alzheimer's disease", Elizabeth R. Paitel and Kristy A. Nielson study the genetic risks that come with Alzheimer's disease (AD). Through an EEG study of cerebellar activity, Paitel and her associate concluded that those with a predisposition to AD (specifically older individuals in this paper specifically) demonstrate increased cerebellar activity. This research raises an important question to understand: Is cerebellar activity a cause of AD? Or is it merely a symptom?

            The role of cerebellar activity in the development of neurodegenerative diseases is still widely unknown. As noted by Paitel in her paper, the cerebellum is implicated to have a role in many other neurological diseases, such as Huntington’s disease and Parkinson’s disease. Beyond these correlations, the causes and effects of cerebellar dysfunction are widely unknown.

            In a paper published to the Oxford Academic, titled “The cerebellum in Alzheimer’s disease: evaluating its role in cognitive decline”, various researchers seek to understand the role of the cerebellum in AD beyond just a correlation. This is done through review of various other scientifically published papers that study various parameters of AD. They note many microscopic and macroscopic findings. A microscopic finding noted to be important in the study is the indication that frequent depositing of b-amyloid in the cerebellum is frequently noted in the discovery of early-onset AD. An example of a macroscopic finding would be that the cerebellums of those with early-onset AD are often lighter than those without AD. Through the analysis of such studies, the authors conclude that the cerebellum is ”more than a silent bystander in the pathophysiology of Alzheimer’s disease”. Also noted is that more research must be done into the pathology of AD in the cerebellum, as even still, so little is understood about the connection demonstrated here. Despite this, current findings indicate that the cerebellum may have a more prevalent role in the development of AD than once thought.

References

1. 2. Heidi I L Jacobs, David A Hopkins, Helen C Mayrhofer, Emiliano Bruner, Fred W van Leeuwen, Wijnand Raaijmakers, Jeremy D Schmahmann, The cerebellum in Alzheimer’s disease: evaluating its role in cognitive decline, Brain, Volume 141, Issue 1, January 2018, Pages 37–47, https://doi.org/10.1093/brain/awx194

2. Paitel ER, Nielson KA. Cerebellar EEG source localization reveals age-related compensatory activity moderated by genetic risk for Alzheimer's disease. Psychophysiology. 2023 Dec;60(12):e14395. doi: 10.1111/psyp.14395. Epub 2023 Jul 26. PMID: 37493042; PMCID: PMC10720653.