Respiratory symptoms are the hallmark of infection with COVID-19 but while some infected patients also experience neurological symptoms and altered mentation, the impact of these symptoms on disease outcomes is poorly characterised.
The absence of a recognised link between neurological symptoms on admission and subsequent mortality in patients with COVID-19, prompted a study by a team from the Department of Neurological Surgery, Albert Einstein College of Medicine, New York, US, to retrospectively examine this relationship in more detail.
Their retrospective study was undertaken in four hospitals in the New York area between March and April 2020 and focused on patients admitted to hospital with COVID-19 and who had neurological symptoms of sufficient severity to warrant radiographic imaging, e.g., computed tomography, magnetic resonance imaging, diagnostic cerebral angiography. Among those where there were no obvious abnormalities detected on imaging, the team further divided patients into two groups: individuals either with or without altered mentation. Altered mentation was determined from a review of the medical notes generated on admission and defined in terms of altered cognition, i.e., evidence of disorientation, confusion, agitation or delirium or impaired arousal, i.e., drowsiness or somnolence. The group without altered mentation, i.e., normal orientation and arousal, still had neurological symptoms but these were consistent with those known to be associated with COVID-19 such as headache, anosmia, ageusia, chemesthesis, vertigo. The primary outcome measure of interest was in-hospital mortality and patients identified with neurological symptoms were age-matched on a 1:3 ratio with patients admitted with COVID-19 with equal disease severity but no documented neurological manifestations.
A total of 4711 patients were admitted to hospital with COVID-19 during the study period including 581 (12%) with neurological manifestations. This cohort comprised 258 with altered mentation, 216 with normal mentation and recognised COVID-19 neurological symptoms while the remainder had either a stroke (55), seizures (26) or other brain lesions (26). Multivariate analysis revealed that patients with altered mentation, but no imaging abnormalities, had a statistically significant increased risk of in-hospital mortality (odds ratio, OR = 1.39, 95% CI 1.04 – 1.86, p = 0.04), as did those with a radiologically confirmed stroke (OR = 3.1, 95% CI 1.65 – 5.92, p = 0.001). The authors were unable to explain why those with altered mentation and a normal imaging result had an increased mortality risk, and suggested that this might be due to some yet-to-be determined mechanism.
They concluded that altered mentation might represent a different clinically important expression of COVID-19 infection that carries a greater risk of mortality beyond the severity of the underlying illness.
Eskandar EN et al. Neurologic syndromes predict higher mortality in COVID-19. Neurology 2020 DOI: 10.1212/WNL.0000000000011356