Movement Disorders Moment: Parkinson Disease in the COVID-19 Era

Although no medical specialty is immune to the impact of the COVID-19 pandemic, in the field of movement disorders, we can’t help but wonder if this highly contagious pulmonary infection is planting a seed that will blossom into a secondary neurologic pandemic in a few years. We are all familiar with postinfectious parkinsonism and the notoriety that came after the influenza pandemic of the early 20th century. Are we now watching something similar unfold in real time, and if so, are we any better prepared for what may come next? These are not simply academic questions, but they also are not the most pressing questions that plague clinical practice on a daily basis. Our patients already have Parkinson disease (PD) and want to know what navigating the pandemic means for them and what their risks may be.

PD and COVID-19 Risk

Individuals with PD who contract COVID-19, as with any infection that upsets the delicate balance of PD, may have a much more severe clinical course. A recent study in Italy showed no increased risk of hospitalization for people with PD who contracted COVID-19 compared with the general population. For those with parkinsonism who developed COVID-19, however, there was increased risk of hospitalization.¹ This is all the more reason to counsel our patients regarding the vaccine against SARS-CoV-2, which does not prevent infection or COVID-19, but does prevent a worsening of symptoms of COVID-19 and reduces the rates of hospitalization, intubation, and death caused by COVID-19. This important real-time statistical analysis of morbidity and mortality has shown as high as a 30% increased risk of mortality for people with PD compared with a demographically matched population.² After accounting for the confounding factor of age, people with PD were 1.3 times more likely to die if they got COVID-19 than people without PD.²

Effects of Pandemic on People With PD

To reassure our patients, we have said from the start of the public health emergency that having PD does not increase your risk of developing COVID-19. As we have collected data in real time, this fact has held true. It has also become clear, however, that the morbidity of COVID-19 extends far beyond those with a positive antibody titer for SARS-CoV-2, which causes COVID-19. Even those without infection have been affected–the isolation, disruption in daily routines, lack of physical activity because of gym closures and limited rehabilitation center access–have taken a mental and physical toll on our patients that may be difficult to reverse.

Although quantitative data are limited, there seems to be comorbidity worsening in people with PD during the pandemic–notably anxiety, depression and cognition. Any clinician managing PD can anecdotally tell you the disruption of routine and isolation has wreaked havoc on the motor and nonmotor symptoms of PD. A larger study of 358 people with PD showed those who had a higher COVID-related stressor load experienced more PD symptoms, and this effect was mediated by the degree of psychologic distress. Almost half (46.6%) of people with PD were less physically active since the pandemic began, and reduced physical activity correlated with worsened PD symptoms. Symptoms that worsened most were rigidity, fatigue, tremor, pain, and concentration. The presence of neuropsychiatric symptoms (eg, anxiety and depression) before the pandemic, as well as cognitive dysfunction and several personality traits predicted increased psychologic distress during the COVID-19 pandemic.³ A study from Italy corroborates this and highlights the impact on caregiver burden. Although this was a much smaller study of 34 patients, all groups showed a worsening of cognitive symptoms (39.6%), pre-existing (37.5%) and new (26%) behavioral symptoms, and motor symptoms (35.4%) during the COVID-19 lockdown, resulting in an increased caregiver burden in 26% of cases.⁴

Virtual Care for People With PD

To try to combat this disruption of care and companionship, implementation of virtual strategies has blossomed. From telemedicine visits to virtual physical, occupational, and speech therapies, to virtual support groups and classes—all of this has been implemented with great gusto and varying degrees of success, although it does not replace face-to-face care. To assist in making these virtual options as effective as possible, the Movement Disorder Society’s Telemedicine Study Group has a working document of strategies and suggestions (Box).⁵ Although many are advocates for the inclusion of telehealth in care paradigms going forward, with the introduction of the vaccine, it is the goal that interactions can slowly transition from virtual to traditional.

What Next?

As availability of a vaccine allows us to consider transitioning to more in-person care, it also leaves us to ask what comes next? Will our care landscape shift from maintaining stability for patients with PD during the pandemic to seeing a new cohort of patients developing PD or parkinsonism because of SARS-CoV-2? Although there is much postulation and speculation of how SARS-CoV-2 infection and parkinsonism/PD may interact (Figure), currently an association of SARS-CoV-2 infection and the development of parkinsonism is not supported by robust evidence.⁶ There have been numerous anecdotal reports, and past experience has shown us, that acute or subacute parkinsonism can develop as the result of a viral infection with central nervous system (CNS) penetrance. We know that there is evidence of CNS penetrance of SARS-CoV-2 because of the multiple neurologic symptoms reported in people with COVID-19—from encephalitis to hyposmia.⁷ It should be noted, however, that this association of a respiratory virus with postinfectious parkinsonism has inconsistencies when pathology is investigated; there is no evidence of substantia nigra damage or Lewy bodies. With SARS-Cov-2 specifically, cerebrospinal fluid (CSF) studies fail to detect SARS-Cov-2 most of the time, meaning that there may be a secondary immune-mediated mechanism rather than a direct CNS involvement.⁶

For now, our role as clinicians is to continue serving as guideposts for our patients as we continue to weather this storm. Reassure where we can, be realistic when we must, and be hopeful that their efforts and our efforts are effective. Encourage continuity of care through telehealth and safely reintroduce in-person activities with appropriate precautions when we can, encourage continued diligence with appropriate safety measures of distancing, handwashing, and masking, and educate on the importance of the vaccine and its expectations of protection. As doctors and patients, we are all feeling the fatigue of COVID-19, but fatigue is nothing new to those who deal with and live with PD, so we may be better equipped to persevere than most.