No significant increase in Guillain-Barré syndrome after COVID-19 vaccination in adults: A vaccine adverse event reporting system study.

OBJECTIVE: To investigate the association between Guillain-Barré syndrome (GBS) and COVID-19 vaccination. BACKGROUND: On July 13, 2021, the US Food and Drug Administration (FDA) released a new warning that Johnson & Johnson COVID-19 vaccine could increase the risk of developing GBS. METHODS: The reporting rate of adult GBS after COVID-19 vaccination, ascertained with Brighton criteria, was compared with the reporting rate after other vaccinations during the same time period, and also compared with the reporting rate during control periods. Statistical methods such as proportion tests, and Pearson's chi-squared test were utilized to identify significant relationships. Self-controlled and case centered analyses were conducted. A machine learning model was utilized to identify the factors associated with a worse outcome defined as emergency room (ER) or doctor visits, hospitalizations, and deaths. RESULTS: The reporting rate of GBS after COVID-19 vaccination was significantly higher than after influenza and other vaccinations (49.7, 0.19, 0.16 per 10 million, p < 0.0001). However, the reporting rate was within the incidence range of GBS in the general population. Using self-controlled and case centered analyses, there was a significant difference in the reporting rate of GBS after COVID-19 vaccination between the risk period and control period (p < 0.0001). There was an estimated 0.7-1.7 per million excess reports of GBS within 6 weeks of COVID-19 vaccination. Machine learning model demonstrated that female gender and age between 18 and 44 are associated with worse outcome. No association was found between the onset interval of GBS and its prognosis. CONCLUSIONS: Although the reporting rate of GBS after COVID-19 vaccination was not statistically different than that of the general population, the increased reporting of GBS within the first 6 weeks after COVID-19 vaccination, more so than with other vaccinations, suggests that some cases of GBS are temporally associated with COVID-19 vaccination. However, there is a reduction in the reporting rate of GBS after other vaccines, compared to reporting rates pre-COVID-19, highlighting limitations inherent in any passive surveillance system. These findings warrant continuous analysis of GBS after COVID-19 vaccination. Further improvement of the machine learning model is needed for clinical use.

Abnormal spontaneous muscle activity in plegic limb appears to initiate distal to the upper motor neuron: a case report in a stroke patient.

OBJECTIVE: To study the effect of the cutaneous silent period (CSP) on spontaneous muscle activity occurring after an upper motor injury from stroke, with a goal of developing an insight into the origin of the pathological activity. METHODS: A patient with an acute right centrum semiovale ischemic stroke had left hemiparesis. Fibrillation potentials and positive sharp waves were recorded in several left arm muscles. CSP silent period studies were performed in both arms. RESULTS: The CSP inhibited the volitional activity in the unaffected right arm. In the plegic left arm, fibrillation potentials and positive sharp waves persisted during the time period during which the CSP would have been expected, based upon the right-sided studies. CONCLUSIONS: Spontaneous activity after a cerebrovascular accident was resistant to inhibition from CSP. These findings suggest that the localization of the origin of the spontaneous activity is distal to the upper motor neuron. A confirmatory study with more patients and in a variety of stroke subtypes would strengthen this conclusion.

Effect of intravenous immunoglobulin on cerebellar ataxia and neuropathic pain associated with celiac disease.

BACKGROUND: Cerebellar syndrome and small fiber neuropathy may complicate celiac disease (CD) and may be resistant to a strict gluten-free diet. METHODS: Case series. RESULTS: We report three patients with biopsy-proven CD who developed cerebellar ataxia and neuropathic pain despite strict adherence to a gluten-free diet. A small fiber neuropathy was suggested by skin biopsy findings in two patients. All patients' symptoms, including small fiber neuropathy symptoms, responded to treatment with intravenous immunoglobulin (IVIG). Discontinuation of IVIG in two patients resulted in worsened ataxia that reversed after resumption of IVIG. CONCLUSION: Intravenous immunoglobulin may be effective in treating cerebellar ataxia and small fiber neuropathy associated with CD, suggesting an immune pathogenesis. Further prospective, controlled studies are necessary to determine the long-term response to IVIG or other immunomodulation therapy.

Posterior antebrachial cutaneous nerve conduction study technique.

PURPOSE: This paper describes an improved electrodiagnostic methodology for posterior antebrachial cutaneous nerve (PABC) neuropathy based on retrospective analysis. METHODS: Results of PABC nerve conduction studies in 14 control patients and 3 patients with left PABC neuropathy are included. Stimulation was performed 0.5 to 2.0 cm above the lateral epicondyle, and the recordings were acquired at 12 cm, 15 cm and 20 cm distally. Data was evaluated using the mean A+/- standard deviation, calculated for descriptive analysis of continuous variables whereas frequencies and percentages were determined for categorical variables. Abnormal cutoff values including side-side comparison values were established so that all normal control values would fall within the normal range. RESULTS: PABC conduction studies with 20 cm recording distance demonstrated abnormal electrodiagnostic findings in all 3 patients, while more proximal recordings failed to document the neuropathy. CONCLUSION: The recording of PABC responses at 12 cm, 15 cm and 20 cm distal to the stimulating electrode offers a more comprehensive evaluation and may be a more sensitive test for evaluation of suspected PABC neuropathy, in comparison to traditional 12 cm recording.

Severe botulism after focal injection of botulinum toxin.

We report a 34-year-old woman who developed clinical botulism after the cosmetic use of an unapproved botulinum toxin type A. Electrophysiologic findings demonstrated complete denervation with complete electrical silence. She had a lengthy recovery but was able to ambulate by discharge.

Hepatitis C virus acute quadriparetic vasculitic neuropathy responsive to cyclophosphamide.

PURPOSE: Hepatitis C viral [HCV] infection is a chronic multisystem disorder that may have an indolent course initially. Peripheral neuropathy associated with cryoglobulinemia and a systemic vasculitis is a well-described complication of HCV infection. But this neuropathy is not known to have a late-onset acute fulminant phase. This acute fulminant phase is characterized by quadriparesis associated with pulmonary and/or renal insufficiency, and it may occur despite adequate treatment for HCV infection. The purpose of this study is to report that patients treated for chronic HCV infection may manifest a secondary progressive acute fulminant neuropathy associated with respiratory and/or renal insufficiency that is responsive to cyclophosphamide. METHODS: Case series retrospective data analysis. RESULTS: Three patients with biopsy-proven HCV associated vasculitic neuropathy manifested a secondary progressive acute fulminant course resulting in quadriparesis within 5 years of the initial diagnosis. Complete remission was achieved with cyclophosphamide therapy such that all patients became ambulatory. CONCLUSIONS: HCV-associated vasculitic neuropathy may manifest a secondary phase, which is acute, fulminant and progressive that is superimposed on an otherwise slowly progressive disorder. Cyclophosphamide therapy may abort progression and induce remission of this acute fulminant phase.