While cognitive functions in patients with Parkinson disease were only slightly impacted by the coronavirus disease 2019, notable effects on urinary issues and fatigue may warrant adjustments to therapy, according to study findings.
While cognitive functions in patients with Parkinson disease were only slightly impacted by the coronavirus disease 2019 (COVID-19), notable effects on urinary issues and fatigue may warrant adjustments to therapy, according to study findings published in Movement Disorders.
In studies on those with PD, an observed increased risk of higher mortality was attributed to older patients and those with longer disease duration. COVID-19’s impact on older populations is well known, but what are the distinct implications for those with PD?
As researchers note, the impact of COVID-19 on clinical features of PD has been poorly characterized so far. They sought to investigate the virus’ effects on motor and non-motor symptoms by reviewing 1092 records of patients with idiopathic PD in the Lombardy region of Italy.
From this cohort, 141 patients agreed to be interviewed by a neurologist experienced in movement disorders. Of those interviewed, 12 were found to be diagnosed with COVID-19, and were then compared with a selected control group of 36 patients from the remaining 129 in the original PD cohort.
Both the control group and COVID-19 group exhibited similar mean age (65.5 years) and disease duration (6.3 years). Both groups were examined for changes in clinical features from January 2020 to April 2020 using the clinical impression of severity index for PD, the Movement Disorders Society Unified PD Rating Scale Parts II and IV, and the nonmotor symptoms scale.
Compared with the control group, those with COVID-19 experienced more daily OFF episodes, which required higher doses of dopaminergic therapies in 1-third of patients. Researchers pointed to a greater incidence of diarrhea among those with the virus as a potential reason for increased doses as it can impact how medicine moves through the body, which is known as pharmacokinetics.
Moreover, they note that heightened incidence of diarrhea may explain why patients experienced increased motor fluctuations, but not significant worsening of motor disability or motor aspects. Patients with PD diagnosed with COVID-19 were also more likely to experience fatigue and urinary issues, but none experienced autonomic failure.
Independent of age and disease duration, the study authors highlighted COVID-19’s impact on motor and non-motor symptoms, which they speculate may be caused by systemic inflammatory response rather than a direct invasion of the central nervous system.
“Further studies in larger PD populations are warranted to clarify the cause—effect relationship among clinical changes and the severity of COVID-19 illness, cytokine levels, and virus detection in the cerebrospinal fluid,” concluded the study authors.
Cilia R, Bonvegna S, Straccia G, et al. Effects of COVID-19 on Parkinson disease clinical features: A community-based case-control study. Mov Disord. Published online May 25, 2020. doi:10.1002/mds.28170