Abordagem das polineuropatias periféricas

2015 ◽  
pp. 6-8
Author(s):  
Lívia Almeida Dutra
Keyword(s):  
Vasa Nervorum

A polineuropatia periférica é uma afecção neurológica frequente, de apresentação clínica e etiologia variada. O nervo periférico é constituído por fibras nervosas mielínicas (grossas e finas) e amielínicas, organizadas em fascículos nervosos recobertas pelo perineuro. Externamente, o nervo é recoberto pelo epineuro e nutrido por vasos sanguíneos denominados vasa nervorum. As fibras mielínicas são constituídas por axônios de neurônios envolvidos pelas células de Schwann, que desempenham papel fundamental na formação da bainha de mielina, importante na velocidade da condução nervosa através da condução saltatória. Quanto maior o diâmetro da fibra nervosa, maior a velocidade da condução. Desta forma, as fibras mielínicas grossas estão envolvidas na transmissão de estímulos motores e propriocepção, enquanto fibras finas mielinizadas estão envolvidas na condução de estímulo tátil, dor e função autonômica pré-ganglionar. As fibras amielínicas estão envolvidas na dor e na função autonômica pós-ganglionar. Devido a esta compartimentalização da transmissão nervosa, os pacientes podem apresentar sintomas puramente sensitivos ou motores, ou ainda envolvimento predominante da sensibilidade profunda, levando ao desequilíbrio e à incoordenação, fenômeno denominado ataxia sensitiva. Pacientes portadores de polineuropatias podem apresentar sintomas positivos descritos como queimação, dor, parestesia, formigamento, alodinia, hiperalgesia; ou ainda sintomas negativos, como anestesia e ataxia. Também é importante avaliar a função autonômica questionando na história clínica a presença de saciedade precoce, constipação, diarreia, incontinência, impotência sexual, hiper-hidrose, anidrose, hipotensão postural, extremidades frias, alterações tróficas em membros e disautonomia.

Innervation of endoneurial microvessels in human sural nerve

1992 ◽  
Vol 50 (1) ◽  
pp. 920-921
Author(s):  
John L. Beggs ◽  
Peter C. Johnson ◽  
Astrid G. Olafsen ◽  
C. Jane Watkins
Keyword(s):  
Blood Flow ◽  
Blood Vessels ◽  
Blood Supply ◽  
Peripheral Nerves ◽  
Sural Nerve ◽  
Nerve Fibers ◽  
Arterial Supply ◽  
Autonomic Nerve ◽  
Vasa Nervorum ◽  
Endoneurial Blood Flow

The blood supply (vasa nervorum) to peripheral nerves is composed of an interconnected dual circulation. The endoneurium of nerve fascicles is maintained by the intrinsic circulation which is composed of microvessels primarily of capillary caliber. Transperineurial arterioles link the intrinsic circulation with the extrinsic arterial supply located in the epineurium. Blood flow in the vasa nervorum is neurogenically influenced (1,2). Although a recent hypothesis proposes that endoneurial blood flow is controlled by the action of autonomic nerve fibers associated with epineurial arterioles (2), our recent studies (3) show that in addition to epineurial arterioles other segments of the vasa nervorum are also innervated. In this study, we examine blood vessels of the endoneurium for possible innervation.

Do Denervated Peripheral Nerve Trunks Become Ischemic? The Impact of Chronic Denervation on Vasa Nervorum

2001 ◽  
Vol 172 (2) ◽  
pp. 398-406 ◽  
Author(s):  
Ahmet Höke ◽  
Hong S. Sun ◽  
Tessa Gordon ◽  
Douglas W. Zochodne
Keyword(s):  
Peripheral Nerve ◽  
Vasa Nervorum ◽  
Chronic Denervation ◽  
The Impact

Tangier disease. A case with sensorimotor distal polyneuropathy and lipid accumulation in striated muscle and vasa nervorum

1985 ◽  
Vol 67 (1-2) ◽  
pp. 121-127 ◽  
Author(s):  
A. Marbini ◽  
F. Gemignani ◽  
G. Ferrarini ◽  
S. Maccari ◽  
B. Lucci ◽  
...  
Keyword(s):  
Lipid Accumulation ◽  
Striated Muscle ◽  
Tangier Disease ◽  
Vasa Nervorum

Vasa nervorum of epicardial nerves and valves of small veins investigated in porcine heart by two types of vascular injections

2021 ◽  
Author(s):  
Vladimir Musil ◽  
Josef Stingl ◽  
Tomas Vanek ◽  
Jitka Riedlova ◽  
Zdenek Suchomel ◽  
...  
Keyword(s):  
Porcine Heart ◽  
Vasa Nervorum

Imaging of the Vasa Nervorum Using Contrast-Enhanced Ultrasound

2017 ◽  
Vol 27 (6) ◽  
pp. 583-588 ◽  
Author(s):  
Adnan I. Qureshi ◽  
Muhammad A. Saleem ◽  
Asad Ahrar ◽  
Faisal Raja
Keyword(s):  
Contrast Enhanced Ultrasound ◽  
Vasa Nervorum ◽  
Contrast Enhanced

Abstract 241: Direct Injection of Bone Marrow Mononuclear Cells Reversed Experimental Diabetic Neuropathy by Augmenting Neovascularization and Providing Angio-neurotrophic Cytokines

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Hyongbum Kim ◽  
Yong Jin Choi ◽  
Jong-seon Park ◽  
Masaaki Ii ◽  
Marcy Silver ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Diabetic Neuropathy ◽  
Neurotrophic Factors ◽  
Mononuclear Cells ◽  
Motor Nerve ◽  
Therapeutic Option ◽  
Direct Injection ◽  
Saline Group ◽  
Vasa Nervorum ◽  
Sciatic Nerves

Background: Bone marrow (BM)-derived mononuclear cells (MNCs) have been shown to effectively treat ischemic cardiovascular diseases. Recent evidence suggested that diabetic neuropathy (DN) is causally related to impaired angio-vasculogenesis in vasa nervorum and deficiency of angiogenic and neurotrophic factors. Accordingly, we sought to investigate whether DN can be ameliorated by local injection of BM-derived MNCs. Methods and Results: A severe peripheral neuropathy, characterized by significant slowing of motor nerve conduction velocities (MCV) developed 12 wks after the induction of diabetes with streptozotocin in Fisher rats (vs normal rats; 46.6±2.6 vs 32.0±2.5 m/s, P < 0.05). These rats were randomly assigned to MNC or saline injection groups (n = 9, each group) and received either 5x106 MNCs or saline intramuscularly around the sciatic nerves. In the MNC group, MCV were significantly improved within 4 wks after treatment (MNC vs Saline, 41.9±3.2 vs 32.7±2.8 m/s, P < 0.01). Microvascular circulation of sciatic nerve, measured by laser Doppler perfusion imaging was markedly increased only in the MNC group. Capillary density at 4 wks was significantly higher in the MNC group than in the saline group (68±5.9 vs 37±4.4 /cross section, P < 0.01). Robust engraftment of MNCs were observed in sciatic nerves, which sustained over 4 wks. A fraction of engrafted MNCs expressed endothelial markers suggestive of transdifferentiation into endothelial cells in the vasa nervorum. Intriguingly, a large number of the engrafted MNCs are following the course of vasa nervorum in close proximity. Real-time RT-PCR on sciatic nerves revealed that the expression of angio-neurotrophic factors were significantly increased in the MNC group compared to the saline group: VEGF (2.1 fold), FGF-2 (2.4), eNOS (18.1), Brain-derived neurotrophic factor (35.1), IGF-1 (25.5) (all P < 0.05). The protein levels were well correlated with mRNA expression levels. Conclusion: Local transplantation of BM-derived MNCs could improve experimental DN by augmenting neovascularization and increasing angiogenic and neurotrophic factors in peripheral nerves. These findings suggest that BM-MNC transplantation may represent a novel therapeutic option for treating DN.

scholarly journals Vasculitis and the peripheral nervous system

Rheumatology ◽  
2020 ◽  
Vol 59 (Supplement_3) ◽  
pp. iii55-iii59 ◽  
Author(s):  
Lionel Ginsberg
Keyword(s):  
Lower Limb ◽  
Vessel Wall ◽  
Early Recognition ◽  
Systemic Vasculitis ◽  
Nerve Biopsy ◽  
Chronic Neuropathic Pain ◽  
Vasculitic Neuropathy ◽  
Vasa Nervorum ◽  
Sensory Recovery ◽  
Systemic Process

Abstract Peripheral neuropathy is a common feature of systemic vasculitis and can also occur when vessel wall inflammation is confined to the vasa nervorum, as a tissue-specific condition—non-systemic vasculitic neuropathy (NSVN). Typically, the clinical picture in both systemic and non-systemic cases is of a lower limb predominant, distal, asymmetric or multifocal neuropathy, which is painful and subacute in onset. For NSVN, nerve biopsy is required to make the diagnosis, and nerve biopsy also has a role when vasculitic neuropathy is suspected and a systemic process has not yet declared itself. Early recognition of the disorder is important, because it is treatable, and without treatment potentially disabling, or even lethal if part of an undiagnosed systemic process. Treatment is generally with combination therapy (glucocorticoid plus other immunosuppressant), after which motor and sensory recovery are likely to occur, albeit slowly, but the patient may be left with chronic neuropathic pain.

Cochlear nerve injuries caused by cerebellopontine angle manipulations

1987 ◽  
Vol 67 (2) ◽  
pp. 244-249 ◽  
Author(s):  
Tetsuji Sekiya ◽  
Aage R. Møller
Keyword(s):  
Cerebellopontine Angle ◽  
Morphological Changes ◽  
Cochlear Nerve ◽  
Histological Changes ◽  
Content Type ◽  
Eighth Nerve ◽  
Vasa Nervorum ◽  
Electrophysiological Responses ◽  
Compound Action Potentials ◽  
Fine Print

✓ Changes in the response from the cochlear nerve in dogs resulting from cerebellopontine angle (CPA) manipulations were correlated with histological changes in the nerve. The aim of this study was to determine the mechanisms underlying hearing deficits incurred as a result of manipulations in the CPA. Compound action potentials (CAP) were recorded from the cochlear nerve in response to click stimulation before, during, and after cerebellar and eighth nerve retractions were performed under anesthesia. The retractions were carried out to elicit different degrees of change in the latency and waveform of the CAP. About 30 minutes after completion of the manipulations, the dogs were perfused with a fixative and their cochlear nerves and brain stems were prepared for histological studies. The results showed that retraction of the eighth nerve caused a disintegration of the myelin sheath, and there were multiple and extensive foci of petechial hemorrhage and thromboses of the vasa nervorum of the cochlear nerve. In two dogs in which retraction was carried to a point at which the N2 peak of the CAP was abruptly obliterated, there was a separation of the central and peripheral myelin junction (Obersteiner-Redlich (OR) zone) and bleeding from the vasa nervorum at the OR zone. In the dogs in which the changes in the CAP had almost recovered before fixative perfusion, there were petechial hemorrhages within the cochlear nerve trunk, thus showing that improvement of electrophysiological responses may not always correlate with the absence of morphological changes.

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