Electrodiagnostic methods to verify Guillain-Barré syndrome subtypes in Istanbul: A prospective multicenter study.

BACKGROUND AND AIMS: This study aimed to identify the clinical characteristics and electrodiagnostic subtypes of Guillain-Barré syndrome (GBS) in Istanbul. METHODS: Patients with GBS were prospectively recruited between April 2019 and March 2022 and two electrodiagnostic examinations were performed on each patient. The criteria of Ho et al., Hadden et al., Rajabally et al., and Uncini et al. were compared for the differentiation of demyelinating and axonal subtypes, and their relations with anti-ganglioside antibodies were analyzed. RESULTS: One hundred seventy-seven patients were included, 69 before the coronavirus disease 2019 pandemic (April 2019-February 2020) and 108 during the pandemic (March 2020-March 2022), without substantial changes in monthly frequencies. As compared with the criteria of Uncini et al., demyelinating GBS subtype diagnosis was more frequent according to the Ho et al. and Hadden et al. criteria (95/162, 58.6% vs. 110/174, 63.2% and 121/174, 69.5%, respectively), and less frequent according to Rajabally et al.'s criteria (76/174, 43.7%). Fourteen patients' diagnoses made using Rajabally et al.'s criteria were shifted to the other subtype with the second electrodiagnostic examination. Of the 106 analyzed patients, 22 had immunoglobulin G anti-ganglioside antibodies (14 with the axonal subtype). They had less frequent sensory symptoms (54.5% vs. 83.1%, p = 0.009), a more frequent history of previous gastroenteritis (54.5% vs. 22.9%, p = 0.007), and a more severe disease as compared with those without antibodies. INTERPRETATION: Serial electrodiagnostic examinations are more helpful for accurate subtype diagnosis of GBS because of the dynamic pathophysiology of the disease. We observed no significant increase in GBS frequency during the pandemic in this metropolis.

Increased neuropil antibody prevalence in COVID-19 patients with acute ischemic stroke.

OBJECTIVES: COVID-19 infection is associated with an increased risk of acute ischemic stroke (AIS). Although the underlying mechanisms are largely unknown, autoimmunity has been implicated as a potential role player. METHODS: To investigate the presence and clinical impact of neuronal cell surface antibodies in COVID-19 associated AIS, patients with COVID-19 pneumonia and AIS (n = 30), COVID-19 pneumonia without AIS (n = 32) and AIS without COVID-19 infection (n = 27) were recruited. Serum anti-neuronal antibodies directed against well-characterized and novel cell surface antibodies were evaluated by cell-based assays and indirect immunohistochemistry, respectively. RESULTS: None of the recruited patients displayed well-characterized neuronal cell surface antibodies. Ten patients in the COVID-19 pneumonia with AIS group and three patients in the COVID-19 pneumonia without AIS group exhibited antibodies to neuropil of hippocampus and cerebellum. Neuropil-antibody positive patients showed trends towards milder clinical severity and reduced blood levels of inflammation factors. CONCLUSION: Our results confirm the presence of neuropil antibodies in patients with COVID-19 infection and identify a putative antibody-driven association between AIS and COVID-19. The antigenic targets and potential pathogenic action of these antibodies need to be further explored.

The First Electrophysiological Abnormality in New-onset DM: Autonomic Tests.

Introduction: Conventional nerve conduction studies (NCS) are used in the electrodiagnosis of diabetic neuropathy. The aim of our study was to investigate diabetic small fiber neuropathy in newly diagnosed type 2 diabetes mellitus (DM) patient group by using autonomic tests. Methods: Our study was conducted on 49 patients (24 female, 25 male) who were newly diagnosed with type 2 DM in the last 3 months and a control group of 25 volunteers. In addition to conventional NCS, sympathetic skin response (SSR) and RR interval variability (RRIV) tests were performed. Results: The mean upper limb SSR latency of the patient group was more prolonged than that of the control group, whereas the mean lower limb SSR amplitude of the patient group was lower than that of the control group (p=0.002, p<0.001; respectively). The mean resting (R) and deep inspiration (D) RRIV values of the patient group were lower than that of the control group (p=0.037, p<0.001; respectively). In the patient group, the mean R-RRIV and D-RRIV values were found to be positively correlated with the lower limb SSR amplitude (r=0.006, r=0.011; respectively). The mean R-RRIV and D-RRIV change rate of the patient group (D-R)/R was found to be lower than that of the control group (p=0.002). Conclusion: In our study, we showed that autonomic function tests were impaired in newly diagnosed type 2 DM patients who were found not to have diabetic polyneuropathy by standard electrophysiological study. These findings suggest that standard electrophysiological tests are not sufficient in the early stages of the disease.

Increased serum citrullinated histone H3 levels in COVID-19 patients with acute ischemic stroke.

Background and purpose: Prevalence of acute ische-mic stroke (AIS) is increased in patients with coronavirus disease 2019 (COVID-19). A proposed hypothesis is increased virus-induced propensity to hypercoagulation resulting in arterial thrombosis. Our aim was to provide evidence regarding the involvement of neutrophil extracellular trap (NET) formation (NETosis) in COVID-19 related AIS. Methods: Twenty-six consecutively enrolled COVID-19+ pneumonia patients with AIS, 32 COVID-19+ pneumonia patients without AIS and 24 AIS patients without COVID-19 infection were included to the study. Clinical characteristics of recruited patients were collected. Serum levels of citrullinated histone H3 (H3Cit; a factor of NETosis), IL-8 and C5a (mediators associated with NETosis) were measured by ELISA (enzyme-linked immunosorbent assay). Results: H3Cit levels were significantly higher in COVID-19+ AIS patients, whereas all study groups showed comparable IL-8 and C5a levels. There were no significant differences among etiological subgroups of AIS patients with or without COVID-19. AIS patients with COVID-19 showed relatively increased white blood cell, lymphocyte, neutrophil, D-dimer, C-reactive protein and procalcitonin levels than control groups. H3Cit levels did not correlate with clinical/prognostic features and inflammation parameters. H3Cit and IL-8 levels were correlated in COVID-19 patients without stroke but not in COVID-19 positive or negative AIS patients. Conclusion: Increased levels of inflammation parameters and H3Cit in COVID-19 related AIS suggest that NETosis may cause susceptibility to arterial thrombosis. However, H3Cit levels do not correlate with clinical severity measures and inflammation parameters diminishing the prognostic biomarker value of NETosis factors. Moreover, the link between IL-8 and NETosis appears to be abolished in AIS.

Leucine-Rich Glioma-Inactivated Protein 1 Antibody-Positive Polyradiculopathy Associated with Epstein-Barr Virus Infection.

Epstein-Barr virus (EBV) has been associated with a plethora of neurological manifestations including polyneuropathy and polyradiculopathy. A 27-year-old man with a recent upper respiratory system infection presented with difficulty in walking. His neurological examination revealed reduced muscle strength in both proximal and distal lower limb muscles without sensory and autonomic signs. Needle electromyography showed abnormal spontaneous activity and reduced recruitment of motor units in muscles innervated by multiple lumbo-sacral roots. Cerebrospinal examination showed increased protein levels with normal cell counts. While spinal MRI was normal, whole-body CT and PET examination showed disseminated lymph node enlargement. Anti-EBV viral capsid antigen and anti-nuclear antigen IgG but not IgM was positive, whereas EBV PCR was negative in blood. Analysis of inguinal lymph node biopsy showed reactive lymphoid hyperplasia and EBV DNA. Leucine-rich glioma-inactivated protein 1 (LGI1) antibody was found in serum but not in CSF. All clinical, imaging, and electrophysiological findings improved following steroid and intravenous immunoglobulin treatment. These findings suggested the acute involvement of lumbo-sacral spinal roots and/or motor neurons. Purely motor polyradiculopathy has been reported in both EBV-positive and LGI1 antibody-positive patients, and EBV infection is known to precede different autoimmune manifestations. Whether EBV infection may trigger LGI1 autoimmunity and cause involvement of spinal motor roots and/or motor neurons needs to be further studied.

Holter Monitorisation Results in Early Period of Acute Ischemic Stroke.

INTRODUCTION: Paroxysmal atrial fibrillation (PAF) has a similar risk with persistent AF for ischemic stroke. Holter monitorization (HM) and other long-term monitorization methods increased the detection of PAF and short-lasting runs of tachyarrhythmias. Their classification as PAF and roles in the etiology of ischemic stroke is controversial. In this study, we aimed to investigate the frequency of any duration of PAF and clinical characteristics of the patients with acute ischemic stroke who have undergone 24-hrs HM. METHODS: Patients with acute ischemic stroke and transient ischemic attack (TIA) hospitalized in the Neurology ward and undergone 24-hrs of HM during their hospital stay were included in the study. HM reports, clinical, and laboratory characteristics were analyzed, retrospectively. Patients were grouped into three based on HM: 1st group, without PAF; 2nd group, PAF >30 seconds (s) and 3rd group, PAF<30s. RESULTS: PAF of any duration was detected in 18.8% (n=49) of 261 patients. The duration of PAF was <30s in 16.1% (n=42) and >30s in 2.7% (n=7) of the patients. The mean age, left atrium diameter and CHA2DS2-VASc scores of the second group were significantly higher than the first group (p<0.001, p<0.001 and p=0.007; respectively). The mean age, left atrium diameter, modified Rankin Scores (mRS), and CHA2DS2-VASc scores of the third group were significantly higher than the first group (p<0.001; for all). There was no difference between the second and the third groups in means of mean age, left atrial diameter, MRS, and CHA2DS2-VASc scores (p<0.017, for all). CONCLUSION: In this study, 24-hrs HM in the early period of acute ischemic stroke results yielded a high frequency of PAF<30s and predictive features were in parallel with the literature.

Ischemic Stroke in the Elderly: Septuagenarians Versus Octogenarians.

INTRODUCTION: Stroke prevalence is known to increase with age. Approximately 50% of acute ischemic stroke patients are aged between 70 and 89 years. METHODS: In this study, records of 770 ischemic stroke patients who were 70-89 years old were retrospectively examined (407 septuagenarians and 363 octogenarians). The demographics, comorbid conditions, ischemic stroke type, and stroke outcome for the two age groups were analyzed. RESULTS: Comorbid hypertension, diabetes mellitus, and HbA1c levels of ≥6.5% more frequently occurred in septuagenarians than in octogenarians (80.6% versus 70.8%, p=0.002; 32.2% versus 21.8%, p=0.001; and 35% versus 23.2%, p=0.003, respectively), whereas atrial fibrillation was significantly higher in octogenarians (49.3% versus 41.5%, p=0.03). Hypercholesterolemia, previous stroke history, and antiaggregant and/or anticoagulant use were not significantly different between the two age groups. Based on the Oxfordshire Community Stroke Project classification, the most common stroke subtype in the septuagenarian group was a lacunar infarction and in the octogenarian group, it was a partial anterior circulation infarct. According to the Modified Ranking Score, the number of patients living independently was higher for septuagenarians (42.8% versus 27.8%, p<0.001). CONCLUSION: The present findings indicate that the clinical characteristics of ischemic stroke differed between septuagenarians and octogenarians. Therefore, elderly stroke patients cannot be accepted as a homogeneous group. Because this is a hospital-based study, our findings need to be tested via additional epidemiological studies.

The second lumbrical-interosseous latency comparison in carpal tunnel syndrome.

Carpal tunnel syndrome (CTS) is the most common nerve entrapment syndrome. Electromyogram (EMG) is beneficial in supporting the diagnosis of CTS. We compared standard nerve conduction studies of EMG with median and ulnar motor nerve conduction studies from recordings of second lumbrical and interosseal muscles in supporting the diagnosis of CTS. In this study, a total of 242 patients were included, and a total of 375 hands were involved. Electrophysiologic CTSs were diagnosed in 283 hands of 161 patients. A significant association between second lumbrical-interosseal distal motor latency difference (2LI-MDLD) and CTS was found in this study. Statistically, every 0.1 increment in the 2LI-MDLD value was observed to increase the risk of disease by 1.74. When a cut-off of ≥ 0.5 for 2LI-MDLD is taken for predicting CTS, the sensitivity of the test is found to be 89.4% and specificity 84.4%. When the cut-off value for motor distal latency of second lumbrical of the median nerve (2L-MDL) was taken as ≥ 3.15 milliseconds in the diagnosis of CTS, the sensitivity of the test was 87.3%, and specificity 70.7%. Previous reports and our findings suggest that in CTS diagnosis, not only 2LI-MDLD value but also 2L-MDL value are easy and rapidly obtainable and offer additional information in very severe cases where compound muscle action potentials (CMAP) cannot be recorded from the abductor pollicis brevis (APB) muscle.

Motor and occipital cortex excitability in migraine patients.

OBJECTIVE: We evaluated motor and occipital cortex excitability in migraine patients using transcranial magnetic stimulation. METHODS: In this study, we included 15 migraine patients with aura (MwA), 15 patients without aura (MwoA) between attacks, and 31 normal healthy controls. Motor thresholds at rest, amplitudes of motor evoked potentials, central motor conduction time and cortical silent period were measured by stimulation of the motor cortex by using 13.5 cm circular coil and recording from abductor digiti minimi muscle. Additionally, phosphene production and the threshold of phosphene production was determined by stimulation of the visual cortex with the same coil. RESULTS: No significant differences were observed between the groups with respect to the motor thresholds, Motor evoked potential max/compound muscle action potential max (MEPmax/Mmax) amplitudes, central motor conduction times and duration of cortical silent period. Although not statistically significant, the proportion of the migraineurs with phosphene generation (90%) was found to be higher than that of normal controls (71%). Phosphene threshold levels in migraine patients, however, were significantly lower than those of the controls with MwA patients having the lowest levels. CONCLUSION: Our findings indicate that the occipital cortex, but not the motor cortex, is hyperexcitable in migraine patients.