Combined Central and Peripheral Demyelination: Two Case Reports.

Combined central and peripheral demyelination (CCPD) is a rare disease characterized by demyelinating lesions in both the central nervous system (CNS) and peripheral nervous system (PNS). CCPD can present with acute, subacute, or chronic onset. The initial symptom may be of CNS origin, PNS origin, or both. The clinical manifestations of CCPD are quite heterogeneous, and there are no well-defined diagnostic criteria. In MRI imaging of CCPD cases, demyelinating lesions can be seen in areas such as the brain, cerebellum, brainstem, optic nerve, and spinal cord. Common electromyography (EMG) findings in patients with CCPD include decreased motor nerve conduction velocities, decreased or absent sensory nerve action potentials, prolonged F-wave latency, and decreased amplitude of compound muscle action potentials. Neurofascin (NF) is a transmembrane protein and anti-neurofascin (anti-NF) antibodies directed against NF can be positive in cases of CCPD. Four main NF polypeptides are produced by alternative splicing: NF 186, NF 180, NF 166, and NF 155. The investigation of anti-NF in CCPD cases is therefore important for etiological considerations. Here, we discussed three cases diagnosed with CCPD based on clinical, neuroimaging, EMG, and anti-NF antibody results in light of the literature.

Reconsidering the Relationship Between Hand Preference and Cerebral Vascular Dominance: A Computed Tomography (CT) Angiography Study.

Background: To date, it has been suggested that there may be many genetic, environmental, and vascular factors that affect hand preference. In previous studies evaluating the relationship between cerebral dominance and hand preference, carotid and vertebral artery (VA) Doppler ultrasonography (USG) was generally preferred; and these studies only measured VA diameters. Unlike other studies, we aimed to reevaluate the relationship between hand preference and cerebral vascular dominance by measuring VA and internal carotid artery (ICA) diameters. In addition, we used carotid and VA computed tomography (CT) angiography instead of Doppler USG. Methods and Material: A total of 345 participants were included in the study. The results of carotid and VA CT angiography taken during hospitalization were retrospectively evaluated by two radiologists, and the Edinburgh Hand Preference Questionnaire was applied to these patients. Results: In right-handed patients, the diameter of the left VA was significantly larger than the diameter of the right VA (p = 0.005). In left-handed patients, the diameter of the left ICA was larger than the diameter of the right ICA, but the difference was not statistically significant (p = 0.055). There was no significant difference between the diameter of the right and left ICA in right-handed patients (p = 0.771). Conclusions: In our study, we found a correlation between the dominant hemisphere VA diameter and hand preference. Using CT angiography, we were able to eliminate many challenges of ultrasonography that make radiological evaluation difficult, such as differences of opinion between radiologists, and technical and anatomical reasons.

Use of CMAP, MScan fit-MUNE, and MUNIX in understanding neurodegeneration pattern of ALS and detection of early motor neuron loss in daily practice.

BACKGROUND: The pattern of lower motor neuron (LMN) degeneration in amyotrophic lateral sclerosis (ALS), i.e., dying-back (from the nerve ending to cell body) or dying-forward (from the cell body to nerve ending), has been widely discussed. In this study, we aimed to evaluate LMN loss using compound muscle action potential (CMAP), motor unit number index (MUNIX), and MScan-fit-based motor unit number estimation (MUNE) to understand the pattern of neurodegeneration in ALS. METHODS: Twenty-five patients were compared with 25 controls using CMAP amplitude and area, MUNIX, and MScan-fit MUNE in three proximal and distal muscles innervated by the ulnar nerve. RESULTS: Unlike the controls, the CMAP area, MScan-fit MUNE, and MUNIX recorded in ALS patients showed more neurodegeneration in distal muscles than proximal muscles. In ALS patients with unaffected CMAP amplitudes (n = 13), the CMAP area, MScan-fit MUNE, and MUNIX showed subtle motor unit loss of 30.7 %, 53.8 %, and 38.4 %, respectively. CONCLUSION: The CMAP area, MScan-fit MUNE, and MUNIX showed neurodegeneration earlier than the reduction in CMAP amplitude. These tests confirmed dying-back neurodegeneration, while only MUSIX showed re-innervation in ALS.