Received Jan 9, 2026
| Type | Name | Manufacturer | Dose | Lot | Route / Site |
|---|---|---|---|---|---|
| COVID19 | COVID19 (COVID19 (PFIZER-BIONTECH)) | PFIZER\BIONTECH | 3 | — | — |
paroxysmal hyperkinetic movements; hyperkinetic movements related to COVID 19 vaccine/antibody mediated hyperkinetic movements; This is a literature report for the following literature source(s). A 73-year-old male patient received BNT162b2 (BNT162B2 NOS), as dose 3 (booster), single (Batch/Lot number: unknown) for covid-19 immunisation. The patient's relevant medical history and concomitant medications were not reported. Vaccination history included: Covid-19 vaccine (DOSE 1, SINGLE), for COVID-19 Immunization; Covid-19 vaccine (DOSE 2, SINGLE), for COVID-19 Immunization. The following information was reported: PAROXYSMAL DYSKINESIA (medically significant), 2 weeks after the suspect product(s) administration, outcome "recovered", described as "paroxysmal hyperkinetic movements"; DYSKINESIA (medically significant), 2 weeks after the suspect product(s) administration, outcome "recovered", described as "hyperkinetic movements related to COVID 19 vaccine/antibody mediated hyperkinetic movements". The patient underwent the following laboratory tests and procedures: Antibody test: presence of the antibody; elevated; presence of the antibody, notes: reduced titer in the serum in conjunction with the improved symptoms; Cognitive test: became impaired, notes: with poor memory and slow mentation; Electroencephalogram: unremarkable.; Malignancy work-up: negative.; Labs: significant for elevated LGI1 antibody in the, notes: serum; Magnetic resonance imaging head: unremarkable.. Therapeutic measures were taken as a result of paroxysmal dyskinesia, dyskinesia. Clinical course: A 73 year-old man developed paroxysmal left sided arm/leg involuntary movements, with speech arrest and impaired attention. Each episode lasted for several seconds, with abrupt onset multiple times a day, without residual deficits in between the episodes. He also developed slow involuntary oral-buccal-lingual (OBL) movements around the same time. In tandem with these movements, his cognitive function became impaired, with poor memory and slow mentation. These symptoms started 2 weeks after his third dose of Pfizer-BioNTech COVID-19 vaccine. He had no abnormal reaction to the vaccine, nor COVID-19 or flu symptoms during or before that period of time. The symptoms peaked within 3 to 5 months and started getting better on their own. Labs were significant for elevated LGI1 antibody in the serum. MRI brain and EEG were unremarkable. Malignancy work-up was negative. IVIG and clonazepam further improved the symptoms. Our patient had paroxysmal hyperkinetic movements, including dystonia, hemichorea and myoclonus, with seizure-like activity as suggested by speech arrest and impaired attention during the episode. This is a typical presentation of LGI-1 antibody mediated movement disorders manifesting as paroxysmal faciobrachial dystonic seizures (except that the movements in our case also involved the leg, which is uncommon but reported 1-3). The presence of the antibody in the serum and CSF, and the reduced titre in the serum in conjunction with the improved symptoms also support its causality. Our case however was most likely related to the vaccination itself, rather than the infection, given the onset 2 weeks after the vaccination, the spontaneous improvement prior to any treatment being initiated, and the absence of COVID-19 infection from the history. Our case is the first report of antibody mediated hyperkinetic movements related to this commonly used vaccine, with a benign course.; Sender's Comments: Based on the information available and plausible temporal association, the causal relationship between the reported events PAROXYSMAL DYSKINESIA, DYSKINESIA and suspect drug BNT162B2 cannot be excluded. The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to Regulatory Authorities, Ethics Committees and Investigators, as appropriate.
Test Name: CSF anctibody; Result Unstructured Data: Test Result:presence of the antibody; Test Name: LGI1 antibody; Result Unstructured Data: Test Result:elevated; Test Name: serum antibody; Result Unstructured Data: Test Result:presence of the antibody; Comments: reduced titer in the serum in conjunction with the improved symptoms; Test Name: cognitive function; Result Unstructured Data: Test Result:became impaired; Comments: with poor memory and slow mentation; Test Name: EEG; Result Unstructured Data: Test Result:unremarkable.; Test Name: Malignancy work-up; Result Unstructured Data: Test Result:negative.; Test Name: Labs; Result Unstructured Data: Test Result:significant for elevated LGI1 antibody in the; Comments: serum.; Test Name: MRI brain; Result Unstructured Data: Test Result:unremarkable.