Clinical and diagnostic characteristics of Hashimoto's encephalopathy: a single-center, retrospective study.

BACKGROUND AND PURPOSE: Diagnosing Hashimoto's encephalopathy (HE) is challenging. In contrast to other types of autoimmune encephalitis, HE shows an excellent response to steroid treatment. We aimed to investigate the rates of antithyroid antibodies (ATAs) and probable HE in patients with unexplained mental dysfunction and compare the clinical characteristics between the good- and poor-outcome groups. METHODS: We retrospectively reviewed the medical records and electroencephalography (EEG) and neuroimaging findings of patients admitted to the Department of Neurology of our hospital from March 1, 2006, to February 28, 2023. Using our proposed diagnostic criteria for probable HE, we compared the clinical characteristics between the good- and poor-outcome groups. We also investigated the rates of ATA positivity and probable HE. RESULTS: In total, 198 patients exhibited altered mentation, rapidly progressive cognitive decline, or myoclonus. ATA tests were performed on 86 patients, and the detection rates of ATAs and probable HE were 29.1% and 25.6%, respectively. Of the 22 patients enrolled, the good- and poor-outcome groups comprised 19 and 3 patients, respectively. Clinical seizures occurred in seven patients. Nonconvulsive status epilepticus on EEG was observed in six patients, all of whom were intractable to antiepileptic drugs. Nineteen of 21 patients (90.5%) treated with immunosuppressants showed good outcomes. CONCLUSIONS: HE is a rare clinical disorder, but not as rare as previously thought. When HE is suspected, steroids should be considered the first-line treatment. Early diagnosis and adequate treatment are critical to achieve good outcomes in HE.

Herpes simplex encephalitis initially presenting without fever or cerebrospinal fluid pleocytosis and with typical neuroimaging findings: a case report.

Herpes simplex encephalitis (HSE) is a common viral encephalitis that can be fatal if not adequately treated. Fever, cerebrospinal fluid (CSF) pleocytosis, and typical neuroimaging findings are commonly observed in HSE cases. We encountered a patient with HSE who did not exhibit these classic clinical features. A 63-year-old male presented with his first-ever seizure. Fever did not develop until the fourth day of admission, and neither neuroimaging nor CSF analysis revealed abnormalities. Under suspicion of autoimmune encephalitis, methylprednisolone was administered. Subsequently, when the patient developed fever, a follow-up neuroimaging study was performed and revealed abnormalities consistent with HSE. The patient was promptly treated with acyclovir, which led to a full recovery. Diagnosing HSE in patients who present without fever or CSF pleocytosis and with typical neuroimaging findings poses a challenge. Therefore, prior to initiating immunosuppressive treatment, it is crucial to closely observe patients and to conduct follow-up tests, including neuroimaging and CSF analysis.

Therapeutic Outcomes and Electrophysiological Biomarkers in Anti-Myelin-Associated Glycoprotein Neuropathy: A Multicenter Cohort Study in South Korea.

BACKGROUND AND PURPOSE: Unlike other immune-mediated neuropathies, anti-myelin-associated glycoprotein (MAG) neuropathy is often refractory to immunotherapy. It is necessary to compare the relative efficacies of various immunotherapies and develop objective biomarkers in order to optimize its clinical management. METHODS: This study recruited 91 patients with high anti-MAG antibody titers from 7 tertiary hospitals in South Korea. We analyzed the baseline characteristics, therapeutic outcomes, and nerve conduction study (NCS) findings of 68 patients and excluded 23 false positive cases. RESULTS: The rate of positive responses to treatment was highest using zanubrutinib (50%) and rituximab (36.4%), followed by corticosteroids (16.7%), immunosuppressants (9.5%), intravenous immunoglobulin (5%), and plasma exchange (0%). Disability and weakness were significantly associated with multiple NCS parameters at the time of diagnosis, especially distal compound muscle action potential (CMAP) amplitudes. Moreover, the longitudinal trajectory of the average CMAP amplitudes paralleled the clinical courses, with a 16.2 percentile decrease as an optimal cutoff for predicting a clinical exacerbation (area under the receiver operating characteristic curve=0.792). CONCLUSIONS: Our study supports the use of NCS as an objective marker for estimating disease burden and tracking clinical changes in patients with anti-MAG neuropathy. We have described the beneficial effects of rituximab and a new drug, zanubrutinib, compared with conventional immunotherapies.

Patient with Epilepsy Showing Psychiatric Symptoms after Remission of Seizures and Normalization of Electroencephalography: The Phenomenon of Forced Normalization?

Psychiatric disorders are commonly observed in patients with epilepsy. Among them, the phenomenon known as forced normalization is scarce. Herein, we report the case of a 41-year-old patient who showed long-term first-onset psychiatric symptoms after seizure remission and normalization of electroencephalography. After changing the antiepileptic drug regimen and psychiatric treatment, the patient's symptoms regressed. However, the exact pathological mechanisms remain to be elucidated. Changing the regimen of antiepileptic drugs and long-term psychiatric treatment may help control this phenomenon.

Aphasic Status Epilepticus Associated with Alzheimer's Disease: Clinical and Electrographic Characteristics.

In aphasic status epilepticus (ASE), aphasia is the sole manifestation of seizure in patients with this disorder. Alzheimer's disease (AD) is one of neurological disorders causing ASE. Herein, we report two cases of ASE associated with AD, and discuss their clinical characteristics. Patient 1 presented Broca's aphasia, and patient 2 presented global aphasia during the ictal period. Both patients exhibited atypical ictal electroencephalographic (EEG) patterns, which improved after antiepileptic drug administration. ASE was the presenting symptom of AD in patient 1. ASE can develop at any stage of AD. Alterations in clinical symptoms and EEG patterns after treatment with antiepileptic drug are the key to diagnosis. Prompt diagnosis and treatment are critical for preventing further consciousness dysfunction.

Residual one-dimensional convolutional neural network for neuromuscular disorder classification from needle electromyography signals with explainability.

BACKGROUND AND OBJECTIVE: Neuromuscular disorders are diseases that damage our ability to control body movements. Needle electromyography (nEMG) is often used to diagnose neuromuscular disorders, which is an electrophysiological test measuring electric signals generated from a muscle using an invasive needle. Characteristics of nEMG signals are manually analyzed by an electromyographer to diagnose the types of neuromuscular disorders, and this process is highly dependent on the subjective experience of the electromyographer. Contemporary computer-aided methods utilized deep learning image classification models to classify nEMG signals which are not optimized for classifying signals. Additionally, model explainability was not addressed which is crucial in medical applications. This study aims to improve prediction accuracy, inference time, and explain model predictions in nEMG neuromuscular disorder classification. METHODS: This study introduces the nEMGNet, a one-dimensional convolutional neural network with residual connections designed to extract features from raw signals with higher accuracy and faster speed compared to image classification models from previous works. Next, the divide-and-vote (DiVote) algorithm was designed to integrate each subject's heterogeneous nEMG signal data structures and to utilize muscle subtype information for higher accuracy. Finally, feature visualization was used to identify the causality of nEMGNet diagnosis predictions, to ensure that nEMGNet made predictions on valid features, not artifacts. RESULTS: The proposed method was tested using 376 nEMG signals measured from 57 subjects between June 2015 to July 2020 in Seoul National University Hospital. The results from the three-class classification task demonstrated that nEMGNet's prediction accuracy of nEMG signal segments was 62.35%, and the subject diagnosis prediction accuracy of nEMGNet and the DiVote algorithm was 83.69 %, over 5-fold cross-validation. nEMGNet outperformed all models from previous works on nEMG diagnosis classification, and heuristic analysis of feature visualization results indicate that nEMGNet learned relevant nEMG signal characteristics. CONCLUSIONS: This study introduced nEMGNet and DiVote algorithm which demonstrated fast and accurate performance in predicting neuromuscular disorders based on nEMG signals. The proposed method may be applied in medicine to support real-time electrophysiologic diagnosis.

Increased pulsatility index of the basilar artery is a risk factor for neurological deterioration after stroke: a case control study.

BACKGROUND: Higher pulsatility of the middle cerebral artery (MCA) is known to be associated with stroke progression. We investigated whether pulsatility index (PI) of the basilar artery (BA) can predict neurological deterioration (ND) after acute cerebral infarction. METHODS: A total of 708 consecutive patients with acute ischemic stroke who had undergone transcranial Doppler (TCD) ultrasonography were included. ND was defined as an increase in the National Institutes of Health Stroke Scale scores by two or more points after admission. The patients were categorized into quartiles according to BA PI. Multivariable logistic regression analysis was performed to examine whether BA PI is independently associated with ND. RESULTS: BA PI was well correlated with the right (n = 474, r2 = 0.573, P < 0.001) by Pearson correlation analysis although MCA PI could not be measured from right MCA (n = 234, 33.05%) and left MCA (n = 252, 35.59%) by TCD owing to insufficient temporal bone window. Multivariable logistic regression analysis including age, sex, cerebral atherosclerosis burden, National Institutes of Health Stroke Scale at admission, and the proportion of patients with current smoking status, hypertension, diabetes mellitus, atrial fibrillation revealed that the higher BA PI (odds ratio, 3.28; confidence interval, 1.07-10.17; P = 0.038) was independently associated with ND. CONCLUSIONS: BA PI, which would be identified regardless of temporal window, could predict ND among acute stroke patients.

Anti-N-Methyl-D-Aspartate Receptor Encephalitis after BNT162b2 COVID-19 Vaccination.

After the coronavirus disease 2019 (COVID-19) pandemic emerged, the development of vaccines was accelerated. Neurologic complications of COVID-19 vaccination had been reported, which included encephalitis. In this study, we report a very rare case of a female with anti-N-methyl-D-aspartate receptor encephalitis associated with ovarian teratoma that would be triggered by BNT162b2 m-RNA COVID-19 vaccination.

Incidence and mechanism of early neurological deterioration after endovascular thrombectomy.

BACKGROUND: We investigated the prevalence and mechanisms of neurological deterioration after endovascular thrombectomy. METHODS: Between January 2011 and October 2017, acute ischemic stroke patients treated by endovascular thrombectomy in a tertiary university hospital were included. Early neurological deterioration (END) was defined as an increase of 2 or more National Institute of Health Stroke Scale (NIHSS) compared to the best neurological status after stroke within 7 days. The END mechanism was categorized into ischemia progression, symptomatic hemorrhage, and brain edema. RESULTS: A total of 125 acute ischemic stroke patients received endovascular thrombectomy. Neurological deterioration was detected in 44 patients, and 38 cases (86.4% of END) occurred within 72 h. The END mechanism included 20 ischemia progression, 16 brain edema and 8 hemorrhagic transformation cases. Multivariable logistic regression analysis revealed that the patients who experienced END were more likely to have poor functional outcome defined as modified Rankin scale 3-6 at 90 days than neurologically stable patients (odds ratio (OR) = 4.06, confidence interval (CI) = 1.39-11.9). The risk factor of END due to ischemia progression was stroke subtype of large artery atherosclerosis (OR = 6.28, CI = 1.79-22.0). Successful recanalization (OR = 0.11, CI = 0.03-0.39) and NIHSS after endovascular thrombectomy (OR = 1.15 per one-point increase, CI = 1.06-1.24) were significantly associated with END due to hemorrhage or brain edema. CONCLUSION: Neurological deterioration frequently occurs after endovascular thrombectomy, and the risk factors of END differ according to the mechanism of END.

Eosinophilic Granulomatosis with Polyangiitis Presented as Acute Polyneuropathy and Cerebral Vasculitis.

Eosinophilic granulomatosis with polyangiitis (EGPA) is an immune related systemic disease that is caused by vasculitis affecting multiple organ systems. It is characterized by asthma, fever, eosinophilia, cardiac problems, renal injury, and peripheral neuropathy. In this report, we describe a patient with EGPA with concurrent cerebral infarction and acute polyneuropathy mimicking a Guillain-Barre syndrome (GBS). A 46-year-old man presented with rapidly progressing gait disturbance, muscular weakness, and tingling sensation in all four limbs. A nerve conduction study revealed sensorimotor polyneuropathy in all four limbs, and a test of the cerebrospinal fluid showed an albumin-cytologic dissociation. In addition, brain magnetic resonance imaging (MRI) using fluid-attenuated inversion recovery and diffusion weighted MRI revealed high signal intensity lesions with gadolinium enhancement on T1-weighted MRI in the right caudate nucleus. After performing laboratory tests, paranasal sinus computed tomography, and a nasal smear, the patient was diagnosed with EGPA and treated with high dose glucocorticoid and oral cyclophosphamide. In conclusion, our findings indicate that a diagnosis of EGPA should be considered when a patient presents with rapidly progressing polyneuropathy mimicking a GBS along with unusual systemic symptoms or brain lesions.