Covid-19 / A different disease for Orthotists; but also some very familiar sequela.

“We are facing a secondary pandemic of neurological disease…“

Since the start of this pandemic it has become ever clearer that Sars-CoV-2 is not just a turbo-charged common cold, it’s quirky, unusual and at times has terrifying traits. Most viruses have U shaped mortality curves, killing young and old alike. But Sars-CoV-2 typically only causes mild symptoms in children. The novel coronavirus also disproportionately affects men: up to 70% of people admitted to ICUs worldwide are male. However, 3 female children have already been through my clinic with multiple organ dysfunction secondary to Covid-19 complications, leading to PNS issues and more specifically, complete peroneal palsy.

Some early data on manifestations show that Encephalopathy, Encephalitis and Guillain-Barré syndrome, and additionally SARS-CoV-2 has been detected in the CSF of some patients. More recently the media have revealed more quirks, with many Covid-19 patients whose only symptom is confusion without cough or fatigue. Another anomaly is ‘Happy Hypoxia’. A typical blood saturation is 98%, below 85% should lead us to a loss of consciousness, coma or death and yet many Covid-19 patients present with saturation levels below 70% to 60%, yet are fully conscious and cognitively functional. Anosmia and ageusia are common and can occur in the absence of other clinical features.

It can be said with some certainty that the last months have led us to believe that Covid-19 is extremely heterogeneous in presentation. Alarmingly, published evidence reveals that Sars-CoV-2 could cross the blood-brain barrier, often thought to be coincidental as it is extremely rare; are now deemed not so. The brain is normally shielded from infectious diseases by the blood-brain barrier – a lining of specialised cells inside the capillaries running through the brain and spinal cord. These block microbes and other toxic agents from infecting the brain. If Sars-CoV-2 can cross this barrier, it suggests that not only can the virus get into the core of the central nervous system, but also that it may remain there, with the potential to return years down the line.

‘The virus’s impact on the nervous system could be far larger and more devastating than its impact on the lungs’.

Predominantly a respiratory disease, neurological manifestations are being recognised increasingly. On the basis of knowledge of other coronaviruses, especially those that caused the severe acute respiratory syndrome and Middle East respiratory syndrome epidemics, cases of CNS and peripheral nervous system disease caused by SARS-CoV-2 might have been expected to be rare, but this is not the case.

We have to be careful to log what is either direct or indirect causation from the Virus, hypoxic encephalopathy and critical care neuropathy spring to mind, but it is still worth including infectious, para-infectious, and post-infectious encephalitis, hypercoagulable states leading to stroke and acute neuropathies such as Guillain-Barré syndrome, as these are all going to fall into needing some form of treatment by an AHP. To date I have had to deal with 2 GBS patients and complete Brachial plexus injuries due to central line complications.

The challenges are recognising neurological disease associated with SARS-CoV-2 in patients who are mild or asymptomatic, especially if the primary COVID-19 illness occurred weeks earlier. The proportion of infections leading to direct neurological disease will probably remain small, but these patients may be left with severe neurological sequelae.

With so many people infected, the overall number of neurological patients and their associated health burden, social and economic costs might indeed be large. Although neurological complications are rare in SARS, MERS and COVID-19, the sheer scale of the current pandemic means that even a small proportion could build up to a significant number of cases.

The minimum prevalence of CNS complications ranged from 0·04% for SARS to 0·20% for MERS, whilst PNS complications ranged from 0·05% for SARS to 0·16% for MERS. Extrapolate these numbers of cases with neurological complications of COVID-19 with the approximate 12.5 - 15 million cases of COVID-19 globally at time of writing, then prevalence runs at around 6 - 30k patients with CNS complications and 7.5 – 24k with PNS complications. These numbers, which do not include the increasingly important syndromes of stroke-associated COVID-19 infection, will rise as the pandemic continues and we are looking at the Americas here in particular!

NHS planners should take note and policy makers must prepare for this eventuality. I’ll be completing my 3rd weekly ‘Covid clinic’ this week of in-patients requiring Orthotics on our specialist neurological rehab wards. This is one relatively small hospital in the UK that can sustain a clinic just from the Covid-19 fall out weekly. It's a sobering experience. Not everyone is ‘walking out’ a survivor on discharge day.

The biggest shock is acute cerebrovascular disease emerging as an important complication, with cohort studies reporting stroke in 2 – 6% of patients hospitalised with COVID-19, which takes us to around 60 - 180k. Again, I have personally had 2 of these cases in the past week.

In one national registry of 125 patients with COVID-19, neurological or psychiatric disease was reported over a 3 week period, 31% patients had altered mental status and 18% with a neuropsychiatric diagnosis, including psychosis and dementia-like syndrome. Notably, 62% of patients had a cerebrovascular event: 46% ischaemic strokes, 7% intracerebral haemorrhages, <1% CNS vasculitis and 8% other cerebrovascular events. Hypercoagulable states and cerebrovascular disease which are seen rarely for some acute viral infections, are an important neurological complication of COVID-19. An expectation that 50–80% of the world’s population might be infected before herd immunity develops could easily see patients with neurological disease increase. Neurological complications, particularly encephalitis and stroke, can cause lifelong disability, with associated long-term care needs and that inevitably means Orthotists along the way.

We would like to broaden the conversation and hear from other clinicians who have had interesting Covid cases to treat….