Poster
# 80
Poster |
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6th Internet World Congress for Biomedical Sciences |
Alberto Pizarro Gallardo(1)
(1)Facultad de Medicina U.A.N. - Tepic. Mexico
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[Neurology] |
[Pathology] |
The term neuropathy is used in referring to any degenerative or inflamatory changes in peripheral nerves. Sometimes, the term neuritis is used.
When many nerves are involved, the condiction is described as polyneuropathy or polineuritis, if one nerve is involved, as mononeuropathy or mononeuritis.
Various changes that may be found include hyperemia of the nerve sheath, transudation and swelling and fragmentation of axis-cylinders. Once continuity of fibers is broken, secundary Wallerian degeneration.
The neuropathy peripheral can appear after the exposition to drugs.
This is a polineuropathy symmetrical sensory - motor. There is degenerative axonal.
The axonal degeneration is characterized by primary destruction of the axon and with secondary pod sheath of mielina (demyelinizating proccess). In a day the axón is demoted, and the cells of affected Schwann begin to catabolizar the mielina and thereinafter fagocitan fragments of the axón forming structures oval-shaped. The muscular fibers lose its aferency neural and suffer atrophy by denervación. (1)
The myopaty for dexametazone is characterized by the weakness of the proximal muscle of arms and legs. (2)The ultrastructural alterations is non specifics through toxic damage for drugs through treatment with chemotherapy to the cancer. (2)
Vincristine is a vinca alkaloid widely utilized in cancer chemotherapy. Major pathological lesions were focal axonal swellings (giant axon formations) due to maligned accumulations of neurofilaments and secondary demyelination of the paranodal type. These were primarily confined to the proximal portions of the peripheral nerves. The distal portions of the peripheral nerves contained only a few giant axon formations. Wallerian degeneration was noted to involve a small number of nerve fibers in the distal regions.
The biopsies processed by the methods of routine of the outlying nerves could provide information diagnosis in some illnesses selected like poliartheritis nodos, amyloidosis, sarcoidosis, leprosy and leukodystrophy metacromática. The sural nerve it is particularly capable for the biopsy, due to their frequent commitment in the illnesses outlying neural.
In the pathological exam the neuropathieses are classified in two groups:
1. Degeneration Wallerian axonal. the primary localization of the illness is in the central axon, this leads to a collapse of the sheath of mielin.
2. segmental Demyelinization of the sheath of mielin. The cell of Schwann is the place of the degeneration. The illness begins near the nodules of Ranvier, taking the disappearance of the sheath of mielin in all one segment internodal. The axon this normal.
In a great amount of cases of polineuropathy, the cause etiologic of the illness is uncertain.
clinical record
36 years-old woman to diagnosis from non specific chronic dermatitis into hands 10 years than evolution. She was treated to dexametazone for two years. one previous months at her biopsy presented swellinge into face, arterial tension 190/ 100 myalgia and neuritis on the various extremities nerves than she doesn´t give with analgesics. The patient is recupered two months after for eliminated dexametazone treatment. The doctors take single biopsy of sural nerve.
The biopsy was reported as minimal changes neuropathy. Electromyographic changes was identified. a new biopsy for electron microscopy was taken.
Muscle was fixed glutaraldehyde 5% buffered, osmium tetroxide postfixed. rutine methods for electron microscopy and photografied in TEM Philips EM 300.
our analized the photografies.
Ultrastructure:
Swelling Schwann cells were present in different grades of alteration:
a. Cytoplasm: large and many lipid inclusions, swelling of mitochondria, dilated rugous endoplasmic reticulum(rer) some crystalloid. abundant microtubules. fig. 1,2)
b. Axon: small swelling degenerative and necrotic changes.fig3,4
c. Myelin fibers: swelling, fig3 separation of membranes,fig8,9 rupture of membranes, fig5 disociated membranes, fig6 onion bulb figures, fig8-9 image fingerpint dactilar fig10
The unmyelinated fibers without changes.
We identified demylination of nerve with secundary diffuse damage of Schwann cells associated at toxity for dexametasone drug.
It is one interesting case. The patient has multiple symptoms of toxicity of dexametazone: swelling of face, hypertension, myalgia and neuritis . (1)
The ultrastructural alterations is inespecifics through toxic damage for drugs through treatment with chemotherapy to the cancer. (2)
The image onion bulb figures into layers for onion into separation than its cellular membranes and decrease on phospholipids for the cellular membrane are suggestive for the peripheral neuropaty secondary desmielinizanteing probably at the dexametazone.
Our case had a polineuropathy associated with dexametasone durg. I dont know if this neuropathy is an idiosyncratic reaction or immune - mediated alteration and occured after years of treatment. The patient was health after eliminated the dexametasone drug.
In our case was secundary neuropathy with specific damage in myelin with alteration of swelling membranes, onion bulb figures and finger print dactilars image.
This is the first case demostrated with ultrastructure of neuropathy for dexametasone.
We presented one case for secundary demyelinizating peripheral neuropaty associated at the dexametazone drug.
The damage was myelin membranes with: swelling membranes, onion bulb figures and fingerprints dactilars image.
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[Neurology] |
[Pathology] |
