Information continues to accrue on the potential neurological effects of infection with SARS-Cov-2, the virus that causes Covid-19. In the last few days, three papers have appeared detailing cases of acute inflammatory neuropathies associated with Covid-19. A paper in the New England Journal of Medicine presents five Italian patients with Guillain-Barré syndrome (GBS),(1) a condition in which the body produces antibodies that damage the fatty myelin sheath that surrounds nerves, protecting them and improving their ability to conduct impulses. GBS is a rare complication of certain viral or bacterial infections. It is usually self-limiting, but in rare cases can be severe enough to cause problems with walking, swallowing, or breathing. Most district general hospitals in the UK will see four or five cases a year, and it is not particularly surprising to see cases appearing in association with Covid-19. The Italian cases, in combination with previously published case from China, and another single case report of a patient from Iran,(2) bring the total published number of cases to seven, though it is highly likely that there are many more cases that have not been written up for publication: when I highlighted these new cases on Twitter, for example, one of my colleagues in Spain replied to tell me that she had one such case on her ward.
There are other, even rare, ways in which acute inflammation of peripheral nerves can present. One such is the Miller Fisher syndrome (named after the great American neurologist C Miller Fisher (and not, as commonly supposed by junior neurologists, two separate neurologists of those names)), in which the changes of GBS are accompanied by dysfunction of the cranial nerves, causing problems such as double vision, inco-ordination, and gait instability. Two such cases associated with Covid-19 have been published by a team from Madrid. It is striking that in neither of these cases, and in none of the published cases of GBS, evidence has been found of central nervous system (CNS) infection with SARS-Cov-2. The Spanish neuro-ophthalmologists conclude that their patients’ problems are likely ot be due to “increased levels of plasma pro-inflammatory cytokines that could be involved in the damage induced by SARS-Cov-2”.(3)
On the question of CNS effects of Covid-19, one piece of apparently good news has emerged from a study done in China, looking at whether the infection is associated with new onset seizures. The answer seems to be no, the authors finding “no evidence suggesting an additional risk of acute symptomatic seizures in patients with COVID-19”.(4) Against this, however, one has to balance the media reports of a 5 year old child from Detroit dying of meningoencephalitis associated with the infection.(5) Further details of this sad case, if they can be published, would be of great value.
References
- Toscano G, Palmerini F, Ravaglia S, et al. Guillain-Barré Syndrome Associated with SARS-CoV-2. New Eng J Med 2020. Published online, 17 April, 2020. doi: 10.1056/NEJMc2009191
- Seaghat Z, Karimi N. Guillain-Barré Syndrome Associated with COVID-19 Infection. A Case Report. J Clin Neurosci 2020. doi: 10.1016/j.jocn.2020.04.062
- Gutiérrez-Ortiz C, Méndez A, Rodrigo-Rey S, et al. Miller Fisher Syndrome and polyneuritis cranialis in COVID-19. Neurology 2020. Published online, 17 April, 2020. doi: 10.1212/WNL.0000000000009619
- Lu L, Xiong W, Liu D, et al. New-onset acute symptomatic seizure and risk factors in Corona Virus Disease 19: a retrospective multicenter study. Epilepsia 2020. Published online, 18 April, 2020. doi: 10.1111/epi.16524
- Barmore J. 5-year-old with rare complication becomes first Michigan child to die of COVID-19. https://amp.detroitnews.com/amp/5163094002