The density of myelinated fibres in the superficial peroneal nerve was studied in 41 samples from 24 control human subjects. Photographic montages of the whole nerve fascicle were made from semithin and ultrathin transverse sections and used for a statistical analysis of sampling procedures, range of variations and relations between density and other variables. The results indicate that the spatial distribution of myelinated fibres within a nerve is often non-uniform. Therefore, it was not possible to define a statistically valid sampling system. The study of relations between variables shows the lack of any correlation between density and age and a considerable variation in the density. In contrast, there is a strong positive linear correlation between the surface area of the nerve fascicle and its content of myelinated fibres. That is, the fibre density of a given normal nerve is related to its diameter and can be predicted within a narrow range of error. We propose the term "derived density" for this value, and its application as a tool in the diagnosis of peripheral neuropathies is now being studied.
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http://dx.doi.org/10.1016/0022-510x(85)90036-x | DOI Listing |
Clin Neurophysiol
January 2025
Department of Clinical Neurophysiology, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine and Neuroscience, University of Copenhagen, Denmark; Department of Neurology, Rigshospitalet, Copenhagen, Denmark.
Objective: To investigate motor axonal excitability in multifocal motor neuropathy (MMN) associated with involuntary muscle activity.
Methods: Two MMN patients with continuous involuntary finger movements (MMNifm) were compared to 11 patients without movements (MMNnfm). Clinical examination, EMG of the abductor pollicis brevis muscle, nerve conduction studies, motor unit number estimation, excitability studies, and mathematical modeling were conducted in the patients with MMN and compared to controls.
ASN Neuro
January 2025
Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA.
In light of the increasing importance for measuring myelin ratios - the ratio of axon-to-fiber (axon + myelin) diameters in myelin internodes - to understand normal physiology, disease states, repair mechanisms and myelin plasticity, there is urgent need to minimize processing and statistical artifacts in current methodologies. Many contemporary studies fall prey to a variety of artifacts, reducing study outcome robustness and slowing development of novel therapeutics. Underlying causes stem from a lack of understanding of the myelin ratio, which has persisted more than a century.
View Article and Find Full Text PDFFront Neuroanat
January 2025
Department of Anatomy, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates.
Neuropathic pain is a pervasive health concern worldwide, posing significant challenges to both clinicians and neuroscientists. While acute pain serves as a warning signal for potential tissue damage, neuropathic pain represents a chronic pathological condition resulting from injury or disease affecting sensory pathways of the nervous system. Neuropathic pain is characterized by long-lasting ipsilateral hyperalgesia (increased sensitivity to pain), allodynia (pain sensation in response to stimuli that are not normally painful), and spontaneous unprovoked pain.
View Article and Find Full Text PDFFront Cell Neurosci
January 2025
Laboratório de Neurodegeneração e Reparo - Departamento de Anatomia Patológica, Hospital Universitário Clementino Fraga Filho, HUCFF/UFRJ, Rio de Janeiro, Brazil.
Background: Following transection, nerve repair using the polylactic acid (PLA) conduit is an effective option. In addition, inosine treatment has shown potential to promote nerve regeneration. Therefore, this study aimed to investigate the regenerative potential of inosine after nerve transection and polylactic acid conduit repair.
View Article and Find Full Text PDFEgypt J Immunol
January 2025
Department of Clinical Pathology, Faculty of Medicine, Assiut University, Assiut 71515, Egypt.
Multiple sclerosis (MS) is a disease of the central nervous system, characterized by progressive demyelination and inflammation. MS is characterized by immune system attacks on the myelin sheath surrounding nerve fibers. Genome-wide association studies revealed a polymorphism in the signal transducer and activator of transcription 4 (STAT4) gene that increases risk for MS.
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