Title : Circadian rhythms and neurological disorders
Abstract:
Introduction: Circadian rhythms are biological processes that are crucial to maintain homeostasis, regulate the sleep-wake cycle, and other physiological functions in a 24-hour cycle. Disruptions in the circadian rhythm along with neurological disorders like Parkinson’s disease, epilepsy, and Alzheimer’s disease can worsen quality of life of affected individuals.
Purpose: The purpose of this study is to explore the relationship between neurological disorders and the circadian rhythm, emphasizing the potential for circadian-aligned interventions for treatment and improving patient outcomes.
Methodology: A systematic review was performed using PubMed, Scopus, and Google Scholar, focusing on articles from 2010 to 2024 with keywords like “circadian rhythm,” “Alzheimer’s,” “Parkinson’s,” “epilepsy,” and “treatment.” Approximately 40-55 articles meeting the inclusion criteria on circadian rhythm disruptions related to these disorders were analyzed, excluding non-English articles and those without valid Information.
Results: This review shows the link between circadian rhythm disruptions and neurological diseases. PDs disrupts the sleep-wake cycle, leading to significant dopamine depletion up to 60-80% by the time symptoms become evident, thereby worsening motor symptoms. ADs affects circadian rhythms, impairing protein clearance and leading to elevated levels of amyloid-beta and tau proteins. Compared to healthy aging brains, beta-amyloid clearance is reduced by approx. 30-50%, while tau protein clearance is decreased by 20-30%, contributing to the accumulation of tangles and accelerated cognitive decline. Circadian rhythms also influence epilepsy, affecting seizure patterns through alterations in neurotransmitter levels and neuronal excitability. For PDs, while no cure exists, 60-70% of patients see significant symptom improvement with medication. ADs also lacks a cure but can benefit from medications that may slow progression or offer some improvement. In epilepsy, approx. 70% of patients achieve effective seizure control with medication, and 60-70% of drug-resistant cases can attain seizure freedom through surgical techniques.
Conclusion: Overall, this study identified notable connections between neurological disorders and circadian rhythms. By aligning therapeutic interventions with circadian cycles, healthcare providers can enhance treatment efficacy and patient outcomes.
