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Case Study Suggests Possible Link Between Drop Foot And COVID-19 

By Clay Shumway, DPM, AACFAS, Jason Miller, DPM, FACFAS and Benjamin Marder DPM, AACFAS 

Here one can see photos of the foot of the patient in question upon presentation to the ER for symptoms of COVID-19 (left) and a few days later (right).A 21-year-old female presented to the emergency room on April 23, 2020 with red streaking starting on her right second toe and tracking proximally along the dorsum of the foot (see left photo to right). She also had a mild fever and cough for two days prior to arriving at the ER. Due to the patient having asthma, the ER staff and the patient herself did not believe the cough was anything more than a mild asthma exacerbation. She received oral antibiotics and was discharged. 

The erythema spread to the entire dorsum of the foot (see right photo to right) before resolving three days later. Her cough and fever also resolved in that same time frame. She ultimately received a call a few days later as she had tested positive for COVID-19 during her visit to the emergency room. 

She presented to our office eight weeks later on June 24, 2020 with a history of recurrent ankle sprains, most recently a grade 2 injury on May 20, 2020. She ambulated with a speed lace ankle brace and reported “tightness” and “discomfort” in her anterior ankle. We palpated what seemed to be a mobile mass at the anterior ankle along the peroneal nerve. 

Subsequent magnetic resonance imaging (MRI) showed no evidence of a ganglionic cyst or other mass. The only remarkable finding was mild thickening of the anterior talofibular ligament (ATFL). We relayed this information to her via telemedicine contact and we had a discussion regarding physical therapy for her ankle. She returned on July 8, 2020 complaining of progressive weakening of her ankle and her foot “slapping the floor.” She denied any recent reinjury of the right ankle in the previous six weeks. 

Her physical exam demonstrated a three-plus out of five muscle strength to the anterior tibial tendon of the right ankle with mild local edema. She reported her ankle pain as dull and achy. She additionally described pain beginning in her right hip flexors over the past week. Upon gait evaluation, she demonstrated a steppage gait and minor foot slap consistent with drop foot (see video at end of blog). 

Due to these findings, we ordered an in-house electromyography (EMG) test, which illustrated isolated, prolonged distal onset latency of the right peroneal motor nerve with no evidence of fibular head impingement, demonstrating a mononeuritis of the right distal peroneal nerve consistent with drop foot.

What About Guillain-Barre Syndrome?

Neurologists are investigating a connection between COVID-19 and Guillain-Barre syndrome as researchers have seen an increased incidence of the syndrome during previous pandemics such as Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS).1 There is a concern that patients with neurologic symptoms do not seek timely treatment because of the fear associated with contracting COVID-19 in the hospital setting, making case studies like this even more rare and important to evaluate for any suspected correlations.

Guillain-Barre syndrome is a disease of the patient’s immune system, which attacks the myelin sheath of peripheral nerves. This slows down the conduction signals being sent along the nerve, weakening the muscles. To accurately diagnose patients, physicians may perform lumbar punctures to sample spinal fluid. Treatment may include plasma exchange or donated blood to infuse the body with antibodies that will fight the disease process. For most patients, symptoms will improve in several weeks and they are able to fully recover long-term. Some patients, however, have long-term weakness or abnormal sensation in the arms or legs. A few patients may even become bedridden or have long-term disability. 

There is a known connection between Guillain-Barre syndrome and bacterial infections from food poisoning as well as from viral infections such as Zika virus, influenza viruses and coronaviruses.2 One possible hypothesis is that this link occurs because of the immune response to the virus, which goes on to attack the peripheral nervous system.2

In connection with COVID-19, there have been reports of Guillain-Barre syndrome emerging in multiple countries.1,3 In some states, there may be a limited access to EMG testing due to the current pandemic. It is currently more likely that a neurologist makes the diagnosis of Guillain-Barre syndrome via a thorough clinical exam as opposed to specific testing. Most patients with Guillain-Barre syndrome and a common viral and bacterial etiology go on to a full recovery, albeit with a sometimes slow recovery process.2 We do not yet know if the recovery will be the same for patients who have Guillain-Barre syndrome in association with COVID-19.

Recognizing The Potential Link Between Coagulopathy And COVID-19

Another potential theory leading to our patient’s peripheral mononeuropathy could be the coagulopathy linked with COVID-19.4 Systemic vasculitis as a disease process in itself can lead to infarcts of the vasa nervorum in 25 percent of patients, leading to acute or subacute axonal painful and multifocal neuropathy.5 Researchers have demonstrated that COVID-19 can produce vasculitis-type symptoms via binding of proteins to receptors expressed in the lungs, heart, kidney and endothelial cells.6 These proteins can bind to the vasa nervorum of the nervous system, leading to inflammation and the disassociation of the neurologic conduction system downstream.  

In Conclusion

There is a sparse amount of data to refer to in this situation. Our aim in presenting this case study is to increase awareness of the possible correlation of neurologic symptoms with COVID-19 so patients can get the proper treatment and education they deserve. Since the drafting of this case presentation, the patient reports mild improvement in her drop foot symptoms that we continue to monitor. Since there is such scant information regarding this particular dropfoot etiology, patient support and monitoring comprise the only suggested protocol at this time. Hopefully, this etiology will follow the resolution patterns demonstrated by other patients with Guillain-Barre syndrome.

Dr. Shumway is a Fellow with the Pennsylvania Intensive Lower Extremity Fellowship in Malvern, Pa. 

Dr. Miller is the Director of the Pennsylvania Intensive Lower Extremity Fellowship at Premier Orthopaedics in Malvern, Pa.

Dr. Marder is a former Fellow with the Pennsylvania Intensive Lower Extremity Fellowship in Malvern, Pa. 

References

1. Galassi G, Marchioni A. Facing acute neuromuscular diseases during COVID-19 pandemic: focus on Guillain–Barré syndrome. Acta Neurol Belg. 2020;1-19. Doi: 10.1007/s13760-020-01421-3 . 

2. Mayo Clinic. Guillain-Barre Syndrome. Available at: https://www.mayoclinic.org/diseases-conditions/guillain-barre-syndrome/symptoms-causes/syc-20362793.  Accessed July 29, 2020.

3. Toscano G, Palmerini F, Ravaglia S, et al. Guillain-Barre syndrome associated with SARS-CoV-2. N Eng J Med. 2020;382:2574-2576.

4. Guan WJ, Ni ZY, Hu Y, et al. Clinical characteristics of coronavirus disease 2019 in China. N. Engl J Med. 2020;382:1708-1720. 

5. Pagnoux C, Guillevin L. Peripheral neuropathy in systemic vasculitides. Curr Opin Rheumatol. 2005;17(1):41-48.

6. Hanafi R, Roger P-A, Perin G, et al. COVID-19 neurologic complications with CNS vasculitis-like pattern. Am J Neuroradiol. 2020. Available at: https://doi.org/10.3174/ajnr.A6651 . Accessed July 22, 2020.

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