ABSTRACT
SUMMARY: Endoneurial oedema is a salient feature of all types of neuropathy. Its elimination is crucial during the complications of nerve recovery. The objective was to study a possible role of the endoneurial fibroblasts in the resolution of nerve edema. Forty-two albino male rats aged between 30 and 40 days (weight 200 g to 250 g) were used in this study. The left sural nerves of 36 rats were subjected to crush injury at one to three-week intervals with six animals per interval. The right and left sural nerves of the remaining six rats were used as controls. At the end of the second week after crush injury, the endoneurium showed channel-like spaces that were lined by fibroblast-like cells and collagen bundles that contained degenerated myelin, and were connected to the subperineurial spaces. Flattened fibroblast-like cells were arranged in several layers in the subperineurial, forming barrier-like cellular sheets localizing to the endoneurial oedema in the space. Fibroblast-like cells also wrapped around the regenerating nerve fibres with their branching cytoplasmic processes. During the third week, the flattened fibroblast-like cells formed nearly continuous cellular sheets in the subperineurial spaces. Macrophages were frequently observed between these cellular barrier-like sheets and in the subperineurial. The endoneurial fibroblast-like cells form barrier-like cellular sheets that probably localise the endoneurial oedema in the subperineurial space. It also appear to create endoneurial channel-like spaces containing degenerated myelin and endoneurial oedema, which may be helpful in localizing and resolving such oedema.
RESUMEN: El edema endoneural es una característica destacada de todos los tipos de neuropatía. Su eliminación es importante durante las complicaciones de la recuperación nerviosa. El objetivo fue estudiar un posible papel de los fibroblastos endoneurales en la resolución del edema nervioso. En este estudio se utilizaron 42 ratas macho albinas con edades entre los 30 y 40 días (peso 200 a 250 g). Los nervios surales izquierdos de 36 ratas se sometieron a lesiones por aplastamiento en intervalos de una a tres semanas con seis animales por intervalo. Se usaron los nervios surales derecho e izquierdo de las seis ratas restantes como controles. Al final de la segunda semana después de la lesión por aplastamiento, el endoneuro mostró espacios en forma de canal que estaban revestidos por células similares a fibroblastos y haces de colágeno que contenían mielina degenerada y se conectaron a los espacios subperineurales. Las células aplanadas de fibroblastos se dispusieron en varias capas en el subperineuro, formando láminas celulares de tipo barrera que se localizaban en el espacio del edema endoneural. Las células similares a fibroblastos también envolvían las fibras nerviosas regeneradoras con sus procesos citoplásmicos ramificados. Durante la tercera semana, las células aplanadas de fibroblastos formaron láminas celulares casi continuas en los espacios subperineurales. Los macrófagos se observaron con frecuencia entre estas láminas similares a barreras celulares y en el subperineuro. Las células de tipo fibroblasto endoneural formaban láminas celulares de tipo barrera que probablemente localizan el edema endoneural en el espacio subperineural. También parece que crea espacios en forma de canal endoneural que contienen mielina degenerada y edema endoneural, que pueden ser útiles para localizar y resolver este edema.
Subject(s)
Animals , Male , Rats , Sural Nerve/ultrastructure , Edema/therapy , Fibroblasts/physiology , Crush Injuries/therapy , Peripheral Nerves , Rats, Sprague-Dawley , Microscopy , Nerve CrushABSTRACT
OBJECTIVE: Although prevailing spinal nerve involvement has been recognized in a few detailed Guillain-Barré syndrome (GBS) autopsy reports, imaging studies addressing this question in cervical nerves are lacking. METHODS: We describe clinical, electrophysiological, ultrasonographic (US) and pathological findings in six consecutive early GBS patients, evaluated within 10 days of onset. RESULTS: Patients' ages ranged from 37 to 80 years. Five patients required mechanical ventilation, two of them having died 9 and 28 days after onset. Upper- and lower-limb nerve US showed abnormal findings in just 8.8% of scanned peripheral nerves. In comparison with 46 aged-matched control subjects, US of the fifth to seventh cervical nerves showed changes in four cases, which consisted of significant nerve enlargement, blurred boundaries of the corresponding ventral rami, or both. Autopsy study in one case demonstrated that pathology, consisting of demyelination and endoneurial inflammatory oedema, mainly involved cervical and lumbar nerves. CONCLUSIONS: In early GBS inflammatory oedema of spinal nerves is a pathogenically relevant feature to understanding the mechanism of ascending paralysis, particularly when conventional electrophysiological studies are normal or not diagnostic. SIGNIFICANCE: Findings advocate the use of cervical nerve US in early GBS.
