Alterations in 18F-FDG PET/MRI and 15O-Water PET Brain Findings in Patients With Neurological Symptoms After COVID-19 Vaccination: A Pilot Study.

PURPOSE: This study aimed to investigate functional abnormalities in the brain of patients with neurological adverse effects following COVID-19 (coronavirus disease 2019) vaccination using 18F-FDG PET/MRI and 15O-water PET. METHODS: Eight patients (1 man and 7 women, aged 26-47 years [median age, 36.5 years]) who experienced neurological symptoms after the first COVID-19 vaccination underwent CT, MRI, 18F-FDG PET/MRI, and 15O-water PET of the brain. After 7 days, each patient underwent a follow-up 18F-FDG PET/MRI and 15O-water PET of the brain. Imaging data were analyzed using visual and semiquantitative analyses, which included a cluster subtraction workflow (P = 0.05). RESULTS: There was no evidence of vascular abnormalities, acute infarction, or hemorrhage on the CT or MRI scans. On the 15O-water PET images, 1 patient had mildly significant decreases in perfusion in the bilateral thalamus and bilateral cerebellum, and another patient showed a diffuse increase in perfusion in the cerebral white matter. The visual and semiquantitative analyses showed hypometabolism in the bilateral parietal lobes in all 8 patients on both the first and follow-up 18F-FDG PET/MRI scans. Metabolic changes in the bilateral cuneus were also observed during the first visit; all patients exhibited neurological symptoms. Moreover, 6 patients showed hypometabolism, and 2 patients showed hypermetabolism. CONCLUSION: All regions of metabolic abnormality were part of the fear network model that has been implicated in anxiety. Our study findings support the concepts of and provide evidence for the immunization stress-related response and the biopsychosocial model.

A comparative crossover study on the treatment of hemifacial spasm and blepharospasm: preseptal and pretarsal botulinum toxin injection techniques.

Hemifacial spasm (HFS) and benign essential blepharospasm (BEB) are chronic and disabling abnormal craniofacial movements that produce involuntary eyelid twitching and closure. The efficacy and safety of botulinum toxin type A (BoNT-A) injections have been accepted and widely used for the treatment of HFS and BEB. However, different injection sites may influence the effectiveness, doses, and side effects. The aim of this study is to compare the efficacy, patient satisfaction, and complications of low-dose BoNT-A injections between injection at the preseptal (PS) and the pretarsal (PT) portion of the orbicularis oculi muscle. A total of 40 patients, 31 patients with HFS and 9 patients with BEB, participated in this study. Each patient received both PS and PT BoNT-A injections in a crossover design study. Latency to response, duration of improvement, the Jankovic Rating Scale (JRS), self-response scale, patient satisfaction scale, and complications were compared. Low-dose injections of BoNT-A at the PT portion produced a significantly higher response rate in terms of latency to response, duration of improvement, JRS, self-response scale, and patient satisfaction scale than the PS injections. Major side effects including ptosis and droopy eyelid were observed only after the PS injections. These findings confirmed that low-dose injections of BoNT-A at the PT portion provide more efficacy, patient satisfaction, and fewer complications than the PS injections for the treatment of involuntary eyelid twitching and closure in patients with HFS and BEB.