Demyelination of peripheral nerves

Paralysis -demyelination of peripheral nerves Buckthorn, coyotillo, tullidora (US, Mexico) Anthracenones - attack the myelin that surrounds the peripheral nerves... 

Follis and Wintrobe have found demyelinization of peripheral nerves in the pig on a pyridoxine-deficient diet, with some possible axone damage (Figs. 31 and 32). The myelin degeneration is progressive, and the dorsal root fibers and dorsal columns of the spinal cord also become affected (see Fig. 38). The nerve cells in these regions show chromatolysis, atrophy, and eventually necrosis (see also Fig. 38a). 

Unfortunately there is a dearth of pathologiceJ studies of this condition, but neurophysiological studies and nerve biopsies suggest that there is segmental demyelination of peripheral nerves as well as central components [33]. 

Peripheral neuropathy is degeneration of peripheral nerves. Because motor and sensory axons tun in the same nerves, usually both motor and sensory functions are affected in this disease. Neuropathies may be either acute (e.g., Charcot-Marie-Tooth disease) or chronic (e.g., Guillain-Barre syndrome) and are categorized as demyelinating or axonal. 

The appearance of nerve roots is similar to that of peripheral nerves. In addition to partial demyelination there is extensive connective tissue proliferation. Blood vessels of the spinal cord may appear hyaline and the vessel wall shows increased eosinophilia (Reese and Bareta 1950). 

Microscopic examination confirmed the clinical diagnosis of involvement of the posterior, lateral and anterior columns, and of the pyramidal and cerebellar tracts. There was demyelination of the anterior columns, of the spino-cerebellar tracts and of the cerebellum, with loss of anterior horn cells and cerebellar nuclei. Sections of peripheral nerves, too, showed foci of demyelination. Histochemical studies were not performed in this case. 

Segmental demyelination (primarily of peripheral nerves) resulting in ataxia, weakness, hypermetria, irKxx)rdina-tion, paresis, paralysis... 

Alterations of peripheral nerves, interpreted by light microscopy as segmental demyelination [48] and degeneration... 

Guillain-Barre syndrome is a transient neurologic disorder involving inflammatory demyelination of the peripheral nerves. The syndrome is characterized by progressive symmetric weakness of the legs and arms with loss of reflexes. Occasionally sensory abnormalities and paralysis of respiratory muscles will occur.16... 

Peripheral neuropathies maybe widely disseminated or focal. Patients with disseminated polyneuropathy, whether demyelinative or axonal, usually demonstrate distal sensory and/or motor impairment. Multifocal neuropathy, also referred to as mononeuropathy multiplex, is often a consequence of lesions affecting the vasa nervorum, the blood vessels that supply peripheral nerves. The most common diseases to compromise the vasa nervorum and cause infarction of nerve fascicles are diabetes mellitus and periarteritis nodosa. Other frequent causes of mononeuropathy multiplex include infection (e.g. Lyme disease and leprosy) and multiple compression injury (e.g. bilateral carpal tunnel syndrome). When mononeuropathy... 

Diabetes mellitus is the most common cause of peripheral neuropathy in the United States. Approximately half of all diabetics demonstrate evidences of neuropathy. The usual clinical pattern is that of a slowly progressive, mixed sensorimotor and autonomic polyneuropathy. More acute, asymmetrical motor neuropathies are also seen, usually affecting the lumbosacral plexus, particularly in older persons with type 2 (non-insulin-dependent) diabetes mellitus. Patients with diabetes mellitus are also prone to develop isolated palsies of cranial nerve III or VII, and there is a high incidence of asymptomatic focal demyelin-ation in the distal median nerve. 

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