Case Presentation: 66 year old male with past medical history of hypertension presented with complains of tingling sensations & weakness involving his hands for 2 weeks. His initial symptoms began with weakness involving bilateral feet, legs & hamstrings that started about 10 weeks prior to this presentation. He received moderna vaccine 1 month prior to the onset of this weakness & had a breakthrough COVID-19 infection 15 days later when he developed cough and congestion. Denied dysphagia, dysphonia, bowel or bladder dysfunction.His vitals were stable. He was AO x 3, 2-12 cranial nerves were intact, motor examination was abnormal with strength of 0/5 throughout in lower extremities & decreased at biceps (4/5) & triceps (4/5) muscles bilaterally. Sensations were decreased to vibrations at ankles and decreased proprioceptions at toes bilaterally. Basic labs were normal except for serum glucose of 172 mg %. SARS-CoV-2 was not detected on routine nasopharyngeal PCR testing. MRI Cervical and Thoracic spine were remarkable for focal increased T2 signal throughout the lateral corticospinal tracts of cervical and thoracic spinal cord extending up to the level of T12. Spinal tap was done and cerebrospinal fluid (CSF) findings were as shown in the table 1. Paraneoplastic antibodies and autoimmune encephalitis panel was negative. Anti-aquaporin 4 (AQP4) antibody and anti-MOG (myelin oligodendrocyte glycoprotein) antibodies were also negative. He was admitted to the hospital with the impression of Longitudinally Extensive Transverse Myelitis (LETM) & was underwent plasma exchange with partial improvement in his symptoms.

Discussion: Various neurological manifestations have been reported following COVID-19 infection varying from encephalopathy, meaning-encephalitis, acute necrotizing hemorrhagic encephalopathy, stroke, Guillain-Barré syndrome, acute necrotizing hemorrhagic encephalopathy, infectious and inflammatory syndromes involving central nervous system. On the other hand, cases of myelitis post COVID-19 vaccination are also reported. LETM, a subtype of Transverse Myelitis involving spinal cord spanning three or more vertebral segments on MRI, itself a rare entity. Only handful number of cases have been reported following COVID-19 infection. There are no known case of LETM following breakthrough COVID-19 infection after m-RNA 1273 vaccination.Direct neural invasion through angiotensin converting enzyme 2 (ACE2) receptors and post-COVID-19 hyper-activation of innate immunity with overproduction of inflammatory cytokines and chemokines such as interleukins (IL) 2, 6, 7, and 10, and tumor necrotizing α factor, causing damage to myelin are some of the pathophysiologies that can explain the CNS manifestations related to COVID-19 infection. [1-3]Although it is difficult to ascertain if the LETM in the above case was associated with COVID-19 vaccine or the COVID-19 infection, the temporal sequence of the events suggest that this is post-infectious in origin. It is also possible that the augmented immune response from COVID-19 vaccine and theCOVID-19 infection may have played a role in the development of LETM.

Conclusions: It is known that the severity & risk of hospitalizations due to COVID-19 infections are low following adequate vaccination. However, this case indicates that potential serious neurological complications, although rare, can still occur following a breakthrough infection despite vaccination with an m-RNA vaccine.

IMAGE 1: Image 1: Sagittal Sections of MRI Cervical (A) and Thoracic Spines (B) showing Hyperintense T2 Lesions Within Spinal Cord

IMAGE 2: Table 1: Results of Cerebrospinal Fluid Analysis