Demyelination and remyelination play key roles in spinal cord injury (SCI), affecting the recovery of motor and sensory functions. Research in rodent models is extensive, but the study of these processes in non-human primates is limited. Therefore, our goal was to thoroughly study the histological features of demyelination and remyelination after contusion injury of the cervical spinal cord in Macaca fascicularis. In a previous study, we created an SCI model in M. fascicularis by controlling the contusion displacement. We used Eriochrome Cyanine staining, immunohistochemical analysis, and toluidine blue staining to evaluate demyelination and remyelination. The results showed demyelination ipsilateral to the injury epicenter both rostrally and caudally, the former mainly impacting sensory pathways, while the latter primarily affected motor pathways. Toluidine blue staining showed myelin loss and axonal distension at the injury site. Schwann cell-derived myelin sheaths were only found at the center, while thinner myelin sheaths from oligodendrocytes were seen at the center and surrounding areas. Our study showed that long-lasting demyelination occurs in the spinal cord of M. fascicularis after SCI, with oligodendrocytes and Schwann cells playing a significant role in myelin sheath formation at the injury site.
Animals ; Spinal Cord Injuries/physiopathology* ; Demyelinating Diseases/etiology* ; Remyelination/physiology* ; Macaca fascicularis ; Disease Models, Animal ; Myelin Sheath/pathology* ; Oligodendroglia/pathology* ; Schwann Cells/pathology* ; Female ; Spinal Cord/pathology* ; Axons/pathology*

Myelin is an essential structure that facilitates rapid saltatory conduction in the nervous system. Discrepancies in myelin microstructure are a hallmark of numerous neurological disorders, rendering the assessment of myelin integrity and content an indispensable tool in clinical diagnostics and neuroscience research. Extensive research has been dedicated to scrutinizing its biochemical makeup and morphology under normal, pathological, and experimental conditions over the years. In this review, we present an updated summary of the myelin sheath's structure, composition, and developmental trajectory. We systematically enumerate and contrast eight prevalent myelin staining techniques across dimensions of sensitivity, specificity, and resolution, delving into their underlying staining principles. With an initial application of myelin histology on the mouse demyelination model, our review accentuates the accurate delineation of myelination and the microstructural analysis of the myelin sheath. Such insights are anticipated to significantly contribute to the evaluation and understanding of white matter pathologies.
Myelin Sheath/metabolism* ; Animals ; Humans ; Demyelinating Diseases/pathology* ; Staining and Labeling/methods*

Leukodystrophy (LD) is a group of genetic heterogeneous diseases characterized by primary abnormalities in glial cells and myelin sheath, and it is a common nervous system disease in children and has significant genotype-phenotype correlation. In recent years, the improvement in high-throughput sequencing has changed the diagnostic and therapeutic mode of LD, and elaborative phenotype analysis, such as the collection of natural history and multimodal neuroimaging evaluation during development, also provides important information for subsequent genetic diagnosis. This article reviews LD from the perspective of clinical genetics, in order to improve the awareness of this disease among pediatricians in China.
Demyelinating Diseases ; High-Throughput Nucleotide Sequencing ; Humans ; Myelin Sheath ; Neurodegenerative Diseases ; Phenotype

Biopsies of suspected lymphoma cases with history of pre-biopsy corticosteroid therapy present several diagnostic issues, such as the inability to demonstrate the neoplastic hematolymphoid cells, the similarity of post-corticosteroid changes with inflammatory demyelinating lesions, and the possibility of a demyelinating lesion preceding a central nervous system lymphoma. This report presents the case of a 51-year-old immunocompetent male with a solitary callosal mass, with immunomorphologic features suggestive of a demyelinating lesion on initial biopsy, and upon re-biopsy after three months revealed a diffuse large B-cell lymphoma. Awareness of these issues in post-corticosteroid stereotactic biopsy specimens, together with adequate clinical and radiologic data, is important for proper diagnosis and further therapeutic guidance.
Adrenal Cortex Hormones ; Demyelinating Diseases ; Lymphoma

OBJECTIVE: To explore the clinical features and genetic variant in a child featuring megalencephalic leukoencephalopathy with subcortical cyst (MLC) type 2B. METHODS: Clinical and imaging data of the child was collected. Potential variant of hepatocyte adhesion molecule (HEPACAM) gene was detected by Sanger sequencing. The growth and development of her mother and uncle was also reviewed. RESULTS: The patient, a 1-year-and-7-month female, presented with convulsion, mental retardation and abnormally increased head circumference. Cranial MRI revealed extensive long T1 long T2 signals in the white matter of bilateral cerebral hemisphere, right anterior sac cyst, cerebral gyrus widening, and shallow sulcus. Sanger sequencing identified a c.437C>T missense variant in exon 3 of the HEPACAM gene. The same variant was detected in her mother but not father. Her mother and maternal uncle both had a history of increased head circumference when they were young. In their adulthood, the head circumference was in the normal range but still greater than the average. CONCLUSION The heterozygous variant of the HEPACAM gene probably underlies the MLC2B in this child. The variant has derived from her asymptomatic mother, which suggested incomplete penetrance of the MLC2B.
Adult ; Cell Cycle Proteins ; genetics ; Cerebrum ; diagnostic imaging ; Cysts ; diagnostic imaging ; genetics ; Female ; Genetic Variation ; Hereditary Central Nervous System Demyelinating Diseases ; diagnostic imaging ; genetics ; Humans ; Infant

Charcot-Marie Tooth disease type 1A (CMT1A), the major type of CMT, is caused by duplication of peripheral myelin protein 22 (PMP22) gene whose overexpression causes structural and functional abnormalities in myelination. We investigated whether miRNA-mediated regulation of PMP22 expression could reduce the expression level of PMP22, thereby alleviating the demyelinating neuropathic phenotype of CMT1A. We found that several miRNAs were down-regulated in C22 mouse, a CMT1A mouse model. Among them, miR-381 could target 3′ untranslated region (3′UTR) of PMP22 in vitro based on Western botting and quantitative Real Time-PCR (qRT-PCR) results. In vivo efficacy of miR-381 was assessed by administration of LV-miR-381, an miR-381 expressing lentiviral vector, into the sciatic nerve of C22 mice by a single injection at postnatal day 6 (p6). Administration of LV-miR-381 reduced expression level of PMP22 along with elevated level of miR-381 in the sciatic nerve. Rotarod performance analysis revealed that locomotor coordination of LV-miR-381 administered C22 mice was significantly enhanced from 8 weeks post administration. Electrophysiologically, increased motor nerve conduction velocity was observed in treated mice. Histologically, toluidine blue staining and electron microscopy revealed that structural abnormalities of myelination were improved in sciatic nerves of LV-miR-381 treated mice. Therefore, delivery of miR-381 ameliorated the phenotype of peripheral neuropathy in CMT1A mouse model by down-regulating PMP22 expression. These data suggest that miRNA can be used as a potent therapeutic strategy to control diseases with copy number variations such as CMT1A.
Animals ; Demyelinating Diseases ; In Vitro Techniques ; Mice ; MicroRNAs ; Microscopy, Electron ; Myelin Sheath ; Neural Conduction ; Peripheral Nervous System Diseases ; Phenotype ; Sciatic Nerve ; Tolonium Chloride ; Tooth Diseases ; Untranslated Regions

Trigeminal neuralgia is caused by compression of trigeminal nerve root and it leads to demyelination gradually. It was almost idiopathic and occurred unexpected. The upper cervical spinal cord contains the spinal trigeminal tract and nucleus. Fibers with cell bodies in the trigeminal ganglion enter in the upper pons and descend caudally to C2 level. We experienced a rare patient with facial pain, which was paroxysmal attack with severe pain after a clear event, cervical spinal injury (C2). So, this case reminds us of a possible cause of trigeminal neuralgia after a trauma of the head and neck.
Cell Body ; Cervical Cord ; Demyelinating Diseases ; Facial Pain ; Head ; Humans ; Neck ; Odontoid Process ; Pons ; Spinal Cord ; Spinal Injuries ; Trigeminal Ganglion ; Trigeminal Nerve ; Trigeminal Neuralgia

No abstract available.
Demyelinating Diseases ; Hyponatremia

Extrapontine myelinolysis is a demyelinating disorder usually caused by rapid correction of chronic hyponatremia. We present an 82-year-old female patient with general weakness, and severe hyponatremia (103 mEq/L) which was corrected 14 mEq/L during 21 hours. She was stuporous and presented status epilepticus. Brain T2-weighted image showed high signal intensities of bilateral thalami and electroencephalogram monitoring indicated right hemisphere lateralized periodic discharges, maximal in the right frontal region. This case shows that status epilepticus can occur in a patient of extrapontine myelinolysis involved bilateral thalami without pontine lesions.
Aged, 80 and over ; Brain ; Demyelinating Diseases ; Electroencephalography ; Female ; Humans ; Hyponatremia ; Myelinolysis, Central Pontine ; Status Epilepticus ; Stupor

The obstacle to successful remyelination in demyelinating diseases, such as multiple sclerosis, mainly lies in the inability of oligodendrocyte precursor cells (OPCs) to differentiate, since OPCs and oligodendrocyte-lineage cells that are unable to fully differentiate are found in the areas of demyelination. Thus, promoting the differentiation of OPCs is vital for the treatment of demyelinating diseases. Shikimic acid (SA) is mainly derived from star anise, and is reported to have anti-influenza, anti-oxidation, and anti-tumor effects. In the present study, we found that SA significantly promoted the differentiation of cultured rat OPCs without affecting their proliferation and apoptosis. In mice, SA exerted therapeutic effects on experimental autoimmune encephalomyelitis (EAE), such as alleviating clinical EAE scores, inhibiting inflammation, and reducing demyelination in the CNS. SA also promoted the differentiation of OPCs as well as their remyelination after lysolecithin-induced demyelination. Furthermore, we showed that the promotion effect of SA on OPC differentiation was associated with the up-regulation of phosphorylated mTOR. Taken together, our results demonstrated that SA could act as a potential drug candidate for the treatment of demyelinating diseases.
Animals ; Apoptosis ; drug effects ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Demyelinating Diseases ; prevention & control ; Encephalitis ; prevention & control ; Encephalomyelitis, Autoimmune, Experimental ; prevention & control ; Female ; Mice, Inbred C57BL ; Myelin Basic Protein ; metabolism ; Neuroprotective Agents ; administration & dosage ; Oligodendrocyte Precursor Cells ; drug effects ; metabolism ; Rats ; Remyelination ; drug effects ; Shikimic Acid ; administration & dosage ; TOR Serine-Threonine Kinases ; metabolism