At the 15th International Virtual Conference on Alzheimer’s disease (AD) and Parkinson’s disease (PD) 2021, physicians and researchers analysed the impact that the ongoing Covid-19 pandemic has on neuropathology, clinical trials as well as social implication on neurodegenerative disorders.
It is well known that mortality rates of other respiratory illnesses are even higher in people with dementia. In a study published in 2020, it was demonstrated that elderly people with Covid-19 present almost three times higher mortality if they also have dementia. Most patients with dementia have comorbid medical conditions that could increase the severity of infections. Delirium can develop at the beginning of Covid-19, making a worse prognosis, and these atypical presentations may impede the early recognition of the disease and increase Covid-19’s spread and mortality. Neuropathology studies on people with dementia who died from the virus showed significant vascular injuries, with both ischemic or hemorrhagic and inflammatory pictures, including immune-induced meningoencephalitis. Immune hyperactivation involving the innate immune system inside the brain, namely microglia, appears as a key factor in the pathogenesis of neurological damage, particularly in elderly individuals affected by neurodegenerative phenomena recruiting inflammation. However, more research is needed to confirm the mechanism of nervous system damage in relation to Covid-19.
The pharmaceutical industry has been as affected as any other industry by the pandemic. Most countries’ research sites have put clinical trial studies on hold due to the inability to have dosing and in-person clinic visits for treatment and prevention trials, and pharmaceutical companies have shifted their overall priorities away from some current indications towards the coronavirus.
With the full or partial lockdown situation in most of the countries, people aged 65 and older are not able to participate in clinical trials or receive care. However, physicians are staying in contact with their patients and carers remotely to minimise visits to hospitals. The disruption of important clinical research by the pandemic is also linked to the particular vulnerability of older adults, who are most at risk from Covid-19. The number of deaths in the elderly population worldwide has already reached significant numbers and participants of neurodegenerative disease trials dying from the disease can significantly affect the outcomes of studies.
During the pandemic, Roche Holding continued both enrollment and dosing in the company’s Phase III GRADUATE trial of gantenerumab in AD due to the utilisation of home nursing to mitigate the Covid-19 impact on trial data. The benefits of home administration in the trial setting firstly include maintaining the number of participants continuing treatment and studying dosage, thereby mitigating Covid-19-related challenges. Secondly, the benefits allow the flexibility of care settings for the patient and their carers, and lastly, they reduce the time spent travelling to clinic visits. However, this trial adaptation was possible as gantenerumab is an anti-Aβ monoclonal antibody administered subcutaneously. Such an initiative would be more difficult for other therapies requiring on-site administration, such as intravenous therapies. Furthermore, according to the company, at the moment Covid-19-vaccinated people are still enrolled in the trial but they must have a gap between the dose of the vaccine and the dose of the drug to avoid potential vaccine side effects from being attributed to gantenerumab.
The social implications of the Covid-19 impact on neurodegenerative diseases include confinement, which might lead to social isolation. They also include impaired memory, which could limit understanding of the situation, inability to participate in face-to-face activities, which can worsen cognitive function, and limited understanding, which might increase the risk of exposure. Due to the nature of their cognitive decline, people with dementia require the carers’ support to follow healthcare and preventive measures. However, the availability of caregivers becomes limited during the pandemic due to the increased risk of transmission to and from people with dementia.
To mitigate the disruption caused by the coronavirus, new interventions need to be implemented. With the new technologies available, researchers and physicians can remotely screen potential participants rather than conduct in-person visits, and they can support their families and carers during these difficult and uncertain times.