A 52-year-old right-handed female experienced a first attack of NMOSD after vaccination with the first dose of BNT162b2. She had a mild fever the day after vaccination but no other inflammation reactions, including local reactions in her left arm around the injection site for thirteen days. Fourteen days after vaccination, she began to feel pain ranging from the neck to the left shoulder, weakness of the left arm, numbness of the left hand, and impaired temperature sensation of the right leg. Seventeen days after vaccination, she complained of weakness of the left leg.
Twenty-one days after vaccination, she was admitted to our department. On admission, she had no visual impairment. Ophthalmological checkups showed no remarkable findings suggesting optic neuritis. The other cranial nerves were intact. Distal-dominant moderate to severe weakness of the left upper extremity, mild weakness of the left lower extremity, and hypesthesia of the abdomen and the right thigh were found. Her left grasp power was 4.5 kg compared with 19.0 kg for her right. Lhermitte sign was positive. Neither nausea nor hiccups were observed.
Magnetic resonance imaging (MRI) of the spinal cord showed that T2-weighted (T2WI) and fluid-attenuated inversion recovery (FLAIR) hyperintense lesions reached from the C1 to C6 level. Gadolinium (Gd)-enhancement lesion was located from the C3 to C5 level and, especially, left lateral fasciculus was enhanced predominantly (Figure 1). Cerebral MRI showed T2-weighted and double inversion recovery (DIR) hyperintense lesions in the area postrema and the obex of the medulla (Figure 2). These lesions were not enhanced. No other remarkable signal changes were detected in the cortices or the optic nerves.
Routine blood tests detected no remarkable abnormal values. Cell-based assays showed that anti-AQP4 antibody (AQP4Ab) was positive. Other autoantibodies were absent. On cerebrospinal fluid (CSF) analysis, mild pleocytosis (9 cells/µL), in which mononuclear cells dominated (7 cells/µL), mildly increased protein (49 mg/dL), and elevated myelin basic protein (MBP) (1550 pg/mL) were found. IgG index was normal (0.54), and oligoclonal bands were negative.
We ruled out SARS-CoV-2 infection by a negative polymerase chain reaction (PCR) test and the absence of antibodies against the SARS-CoV-2 N protein. In addition, she had no complaints of fever, cough, or other known COVID-19 symptoms before admission during the pandemic periods.
The patient had a history of chronic inflammatory demyelinating polyneuropathy (CIDP). At the age of 35, she developed weakness of the bilateral lower extremities. The onset was about a month after suffering a cervical sprain because of a car accident. These symptoms progressed slowly for about a month until her admission to our department. On admission, a nerve conduction study (NCS) showed temporal dispersion findings and other demyelinating patterns at multiple nerves. MRI showed no remarkable signal changes in the spinal cord. We diagnosed CIDP, and after intravenous immunoglobulin therapy, she fully recovered. She had experienced no CIDP relapses until the present admission. The present MRI showed no enlargements of nerve roots or enhancement lesions in the cauda equina, and NCS showed no demyelinating patterns in the bilateral median nerves and no other findings suggesting CIDP relapse. The family history was negative for any neurologic disorders and autoimmune diseases.
After other differential diagnoses were excluded, following the 2015 International Consensus Diagnostic Criteria, we diagnosed AQP4-IgG-positive neuromyelitis optica spectrum disorder. We conducted two cycles of high-dose glucocorticoid therapy (each 1000 mg methylprednisolone i.v. for three days; the first cycle was initiated at 21 days after vaccination; the second cycle was at 28 days) and oral administration of 40 mg prednisolone for 16 days and a tapering dose for about two weeks.
Twenty-eight days after vaccination, T2WI hyperintense lesions shrank to locate from the C3 to C5 level in the cervical spinal cord, and lateralization pattern at the left lateral column remained (Figure 3). Currently, the patient is taking 25 mg of prednisolone orally and showing improved symptoms.