Neurological Manifestations of MTHFR-related Hyperhomocysteinemia

Methylene-tetrahydrofolate reductase (MTHFR) is a homocysteine metabolism-related enzyme and defects of MTHFR is a risk factor for hyperhomocysteinemia and related various neurological disease. Among them, 665C>T polymorphism is the most common form. We report a 48 years old man presenting with progressive psychiatric problems along with severe demyelinating polyneuropathy due to homozygous c.665C>T homozygote polymorphism superimposed by compound heterozygous mutation (c.1417C>T, p.Arg473Trp) in the MTHFR gene, without thromboembolic changes.

A Diagnostic Dilemma: Normal Repetitive Nerve Stimulation in Lambert-Eaton Myasthenic Syndrome

It is important for the diagnosis of Lambert-Eaton myasthenic syndrome (LEMS) to confirm the incremental response at high-rate stimulation or after brief exercise in the repetitive nerve stimulation (RNS) test. Therefore, it may be difficult to diagnose LEMS if the RNS test is normal initially. We report a patient with LEMS whose diagnosis was delayed due to normal RNS findings. We believe that anti-P/Q-type voltage-gated calcium channel antibody testing is crucial in the diagnosis of LEMS.

Finger Drop-Dominant Variant of Guillain-Barre Syndrome in a Patient With COVID-19: A Case Report

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 that may trigger Guillain-Barre syndrome (GBS) in selected patients. We describe a case of GBS presenting as marked finger extensor weakness in a 73-year-old woman with COVID-19. Her clinical and electrophysiological findings were consistent with a diagnosis of acute motor axonal neuropathy subtype of GBS with prominent finger dropping. Treatment with intravenous immunoglobulin for 5 days completely resolved her finger extension weakness after 19 months, although other involved extremities recovered earlier at 3 months. This study highlights that COVID-19-associated GBS can present in various forms aside from the classic variant, even in patients without any COVID-19 symptoms. Therefore, it is important to always consider the diagnosis of GBS in patients with COVID-19.

A Little-Known Brain Imaging Feature in Neuromyelitis Optica Spectrum Disorder: A Leukodystrophy-Like Pattern

No abstract available.

Neuromyelitis Optica Spectrum Disorder Presenting with Pseudoathetosis

No abstract available.

Patterns of Orthostatic Blood Pressure Changes in Patients with Orthostatic Hypotension

BACKGROUND AND PURPOSE: The objective of this study was to determine the patterns of blood pressure (BP) changes during the head-up tilt (HUT) test, particularly in terms of its clinical significance for patients with orthostatic hypotension (OH). METHODS: OH was divided into four categories based on systolic BP changes occurring within the first 10 minutes of the HUT test: sustained orthostatic hypotension (SOH), progressive orthostatic hypotension (POH), orthostatic hypotension with partial recovery (OHPR), and transient orthostatic hypotension (TOH). RESULTS: In total, 151 patients were analyzed: 65 with SOH, 38 with POH, 21 with OHPR, and 27 with TOH. POH patients exhibited the greatest reduction in systolic BP after HUT and were also the most likely to develop symptoms requiring early termination of the HUT test (42.1%, p < 0.001). Additionally, SOH patients exhibited smaller heart-rate variation with deep breathing values (p=0.003) and Valsalva ratios (p=0.022) compared to POH patients. The sweat volume was greatest in OHPR patients. CONCLUSIONS: Clinical characteristics, including the findings of autonomic function tests, differed between the OH patient groups. This might reflect differences in the underlying pathophysiologic mechanisms. Determining the patterns of BP changes during the HUT test may facilitate the development of effective management strategies in patients with OH.

Clinical Heterogeneity of Anti-GM2-Ganglioside-Antibody Syndrome

BACKGROUND AND PURPOSE: Antiganglioside antibodies are known to play a pathogenic role in Guillain-Barré syndrome (GBS). Either an immunoglobulin (Ig)G- or IgM-type anti-GM2 antibody is detected in rare cases in GBS patients. However, the specific pathogenic role of these antibodies in GBS has not been reported previously. This study aimed to define and characterize the clinical spectrum of GBS with anti-GM2 positivity. METHODS: We reviewed the database of the Dong-A University Neuroimmunology Team, which has collected sera of GBS and its variants from more than 40 general and university-based hospitals in Korea. Detailed information about the involved patients was often obtained and then corrected by the charge doctor applying additional questionnaires. RESULTS: Four patients with acute monophasic peripheral neuropathy or cranial neuropathy with isolated IgM-type anti-GM2-antibody positivity were recruited. In addition, IgG-type anti-GM2 antibody was solely detected in the sera of another four patients. The IgM-positive group comprised heterogeneous syndromes: two cases of acute motor axonal neuropathy, one of acute inflammatory demyelinating polyneuropathy, and one of isolated facial diplegia. In contrast, all of the cases enrolled in the IgG-positive group manifested with dizziness with or without oculomotor palsy due to cranial neuropathy syndrome. CONCLUSIONS: This study has identified that anti-GM2 antibody can be found in various subtypes of GBS and its variants in rare cases. Compared to the clinical heterogeneity of the IgM-positive group, the IgG-positive group can be characterized by cranial-dominant GBS variants presenting mainly with oculomotor and vestibular dysfunctions.

Surfer's Myelopathy Mimicking Infectious Myelitis

No abstract available.

Does Diabetes Mellitus Influence Carpal Tunnel Syndrome?

BACKGROUND AND PURPOSE: Diabetes mellitus (DM) has been proposed as a risk factor for carpal tunnel syndrome (CTS), but this remains controversial. We investigated the association between DM and CTS using both ultrasonography (US) and nerve conduction study (NCS) data. METHODS: We analyzed a prospectively recruited database of neuromuscular US and medical records of subjects who had undergone NCSs and electromyography for symptoms suggestive of CTS. Subjects were assigned to the follow groups: Group I, CTS with DM; Group II, CTS without DM; Group III, no CTS with DM; and Group IV, no CTS without DM. US cross-sectional area (CSA) and NCS measurements at the median nerve (MN) were compared among groups. We used a general linear mixed model to adjust for statistically significant covariates. RESULTS: The 230 participants comprised 22, 83, 19, and 106 in Groups I–IV, respectively. In multivariate analyses, the MN action potential amplitude in females was the only variable that was significantly associated with DM (p<0.001). Groups with DM tended to have a longer latency, smaller amplitude, and lower conduction velocity in the NCSs compared to groups without DM. The measured US CSA values did not differ significantly among the groups. CONCLUSIONS: NCS measurements of the MN tended to differ between DM and non-DM patients regardless of the presence or absence of CTS. However, US did not reveal any statistically significant relationship between CTS and DM.

The Impacts of Influenza Infection and Vaccination on Exacerbation of Myasthenia Gravis

BACKGROUND AND PURPOSE: Upper respiratory infection (URI), including influenza, may exacerbate the symptoms of myasthenia gravis (MG), which is an autoimmune disease that causes muscle weakness. There is also concern that the influenza vaccine may trigger or worsen autoimmune diseases. The objective of this study was to determine the impacts of influenza infection and vaccination on symptom severity in MG patients. METHODS: Patients diagnosed with MG were enrolled from 10 university-affiliated hospitals between March and August 2015. Subjects completed a questionnaire at the first routine follow-up visit after enrolling in the study. The patient history was obtained to determine whether a URI had been experienced during the previous winter, if an influenza vaccination had been administered before the previous winter, and whether their MG symptoms were exacerbated during or following either a URI or vaccination. Influenza-like illness (ILI) was defined and differentiated from the common cold as a fever of ≥38℃ accompanied by a cough and/or a sore throat. RESULTS: Of the 258 enrolled patients [aged 54.1±15.2 years (mean±SD), 112 men, and 185 with generalized MG], 133 (51.6%) had received an influenza vaccination and 121 (46.9%) had experienced a common cold (96 patients) or ILI (25 patients) during the analysis period. MG symptoms were aggravated in 10 (40%) patients after ILI, whereas only 2 (1.5%) experienced aggravation following influenza vaccination. The rate of symptom aggravation was significantly higher in patients experiencing an ILI (10/25, 40%) than in those with the common cold (15/96, 15.6%, p=0.006). CONCLUSIONS: The results of this study suggest that the potential risk of aggravating autoimmune disease is higher for ILI than for influenza vaccination, which further suggests that influenza vaccination can be offered to patients with MG.

Application of Near-Infrared Spectroscopy in Neurological Disorders: Especially in Orthostatic Intolerance

Near-infrared spectroscopy (NIRS), a noninvasive optical method, utilizes the characteristic absorption spectra of hemoglobin in the near-infrared range to provide information on cerebral hemodynamic changes in various clinical situations. NIRS monitoring have been used mainly to detect reduced perfusion of the brain during orthostatic stress for three common forms of orthostatic intolerance (OI); orthostatic hypotension, neurally mediated syncope, and postural orthostatic tachycardia syndrome. Autonomic function testing is an important diagnostic test to assess their autonomic nervous systems for patients with symptom of OI. However, these techniques cannot measure dynamic changes in cerebral blood flow. There are many experimentations about study of NIRS to reveal the pathophysiology of patients with OI. Research using NIRS in other neurologic diseases (stroke, epilepsy and migraine) are ongoing. NIRS have been experimentally used in all stages of stroke and may complement the established diagnostic and monitoring tools. NIRS also provide pathophysiological approach during rehabilitation and secondary prevention of stroke. The hemodynamic response to seizure has long been a topic for discussion in association with the neuronal damage resulting from convulsion. One critical issue when unpredictable events are to be detected is how continuous NIRS data are analyzed. Besides, NIRS studies targeting pathophysiological aspects of migraine may contribute to a deeper understanding of mechanisms relating to aura of migraine. NIRS monitoring may play an important role to trend regional hemodynamic distribution of flow in real time and also highlights the pathophysiology and management of not only patients with OI symptoms but also those with various neurologic diseases.

Transient Increase in Intrathoracic Pressure as a Contributing Factor to Cardioembolic Stroke

BACKGROUND: The hemodynamic effects of increased intrathoracic pressure (ITP) have been the focus of many investigations. However, very little is known about the effects of elevated ITP on the occurrence of stroke. CASE REPORT: Four young patients with a cardioembolic source of stroke were examined. In all cases the stroke was preceded by an increase in ITP that occurred during coughing, vomiting, or sexual intercourse. CONCLUSIONS: We suggest that cardioembolic stroke is facilitated by situations in which ITP is elevated.