Worsening Motor Function Tied to Post-COVID Syndrome in Parkinson's

Daniel M. Keller, PhD

September 30, 2021

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

Decreased motor function, as well as other adverse outcomes, are linked to post-COVID-19 syndrome in patients with Parkinson's disease (PD), new research suggests.

Results from a small, international retrospective case study show that about half of participants with PD who developed post-COVID-19 syndrome experienced a worsening of motor symptoms and that their need for anti-Parkinson's medication increased.

"In our series of 27 patients with Parkinson's disease, 85% developed post COVID-19 symptoms," lead investigator Valentina Leta, MD, Parkinson's Foundation Center of Excellence, Kings College Hospital, London, United Kingdom, told Medscape Medical News.

The most common long-term effects were worsening of motor function and an increase in the need for daily levodopa. Other adverse effects included fatigue; cognitive disturbances, including brain fog, loss of concentration, and memory deficits; and sleep disturbances, such as insomnia, Leta said.

The findings were presented at the virtual International Congress of Parkinson's Disease and Movement Disorders (MDS) 2021.

Long-term Sequelae

Previous studies have documented worsening of motor and nonmotor symptoms among PD patients in the acute phase of COVID-19. Results of these study suggest that mortality may be higher among patients with more advanced PD, comorbidities, and frailty.

Leta noted that long-term sequelae with so-called long COVID have not been adequately explored, prompting the current study.

The case series included 27 patients with PD in the United Kingdom, Italy, Romania, and Mexico who were also affected by COVID-19. The investigators defined post-COVID-19 syndrome as "signs and symptoms that develop during or after an infection consistent with COVID-19, continue for more than 12 weeks, and are not explained by an alternative diagnosis."

Because some of the symptoms are also associated with PD, symptoms were attributed to post-COVID-19 only if they occurred after a confirmed severe acute respiratory infection with SARS-CoV-2 or if patients experienced an acute or subacute worsening of a preexisting symptom that had previously been stable.

Among the participants, 59.3% were men. The mean age at the time of PD diagnosis was 59.0 ± 12.7 years, and the mean PD duration was 9.2 ± 7.8 years. The patients were in Hoehn and Yahr stage 2.0 ± 1.0 at the time of their COVID-19 diagnosis.

Charlson Comorbidity Index score at COVID-19 diagnosis was 2.0 ± 1.5, and the levodopa equivalent daily dose (LEDD) was 1053.5 ± 842.4 mg.

Symptom Worsening

"Cognitive disturbances" were defined as brain fog, concentration difficulty, or memory problems. "Peripheral neuropathy symptoms" were defined as having feelings of pins and needles or numbness.

Table. Symptom Prevalence in Post-COVID-19 Syndrome

Adverse outcome Prevalence (%)
Respiratory symptoms  
Breathlessness 3.7
Cough 11.1
Generalized symptoms  
Fatigue 40.7
Fever 18.5
Pain 11.1
Neurologic symptoms  
Cognitive disturbances 22.2
Headache 18.5
Sleep disturbances 22.2
Peripheral neuropathy symptoms 11.1
Dizziness 14.8
Delirium 7.4
Musculoskeletal symptoms  
Joint pain 11.1
Muscle pain 7.4
Psychological/psychiatric symptoms  
Depression 7.4
Anxiety 14.8
Ear, nose, and throat symptoms  
Loss of taste or smell 14.8
PD-specific aspects  
Motor worsening 51.9
Increased LEDD requirement 48.2


By far, the most prevalent sequelae were worsening motor symptoms and increased need for anti-Parkinson's medications. Each affected about half of the study cohort, the investigators note.

Leta added the non-PD-specific findings are in line with the existing literature on long COVID in the general population. The severity of COVID-19, as indicated by a history of hospitalization, did not seem to correlate with development of post-COVID-19 syndrome in PD patients.

In this series, few patients had respiratory, cardiovascular, gastrointestinal, musculoskeletal, or dermatologic symptoms. Interestingly, only four patients reported a loss of taste or smell.

The investigators note that in addition to viral illness, the stress of prolonged lockdown during the pandemic and reduced access to healthcare and rehabilitation programs may contribute to the burden of post-COVID-19 syndrome in patients with PD.

Study limitations cited include the relatively small sample size and the lack of a control group. The researchers note the need for larger studies to elucidate the natural history of COVID-19 among patients with PD in order to raise awareness of their needs and to help develop personalized management strategies.

Meaningful Addition

Commenting on the findings for Medscape Medical News, Kyle Mitchell, MD, movement disorders neurologist, Duke University, Durham, North Carolina, said he found the study to be a meaningful addition in light of the fact that data on the challenges that patients with PD may face after having COVID-19 are limited.

"What I liked about this study was there's data from multiple countries, what looks like a diverse population of study participants, and really just addressing a question that we get asked a lot in clinic and we see a fair amount, but we don't really know a lot about: how people with Parkinson's will do during and post COVID-19 infection," said Mitchell, who was not involved with the research.

He said the worsening of motor symptoms and the need for increased dopaminergic medication brought some questions to mind.

"Is this increase in medications permanent, or is it temporary until post-COVID resolves? Or is it truly something where they stay on a higher dose?" he asked.

Mitchell said he does not believe the worsening of symptoms is specific to COVID-19 and that he sees individuals with PD who experience setbacks "from any number of infections." These include urinary tract infections and influenza, which are associated with worsening mobility, rigidity, tremor, fatigue, and cognition.

"People with Parkinson's seem to get hit harder by infections in general," he said.

The study had no outside funding. Leta and Mitchell have disclosed no relevant financial relationships.

International Congress of Parkinson's Disease and Movement Disorders (MDS) 2021. Abstract 332. Presented September 17–22, 2021.

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