Neuropathy demyelinative

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. 

Seroconversion neuropathy Inflammatory demyelinating neuropathy Early pre-AIDS Acute Generalized systemic dlness, mononeuropathies Immune dysfunction... 

Acute inflammatory demyelinating polyradiculopathy Early pre-AIDS Acute Motor to sensory signs NCS show demyelinating features Immune dysfunction complement/macrophage-mediated demyelinating neuropathy... 

Opportunistic infection, eg. CMV Progressive polyradiculopathy AIDS Acute, subacute Multiple, asymmetric mononeuropathies, usually painful CMV infection, Schwann cell infection demyelinating neuropathy... 

DIES-associated neuropathy has a variety of chnical presentations, including painful symmetric or asymmetric sensorimotor neuropathy, distal sensory neuropathy, mononeuritis multiplex, and demyelinating polyneuropathy (Gherardi et al. 1998). Cranial neuropathy without evidence of a more generahzed neuropathy may occur, typically as a facial nerve palsy in association with parotidomegaly (Itescu et al. 1990 Brew 2003). The neuropathy develops subacutely over days to weeks. In some cases, muscle weakness may be a result of an inflammatory myositis (Kazi et al. 1996). 

Electrophysiologic studies usually show axonal neuropathy, but in 15%, it is demyelinating (Moulignier et al. 1997). CSF is remarkable for a mild nonspecific lymphocytic pleocytosis, but with markedly raised protein up to 2 g/L (Brew 2003). Nerve biopsy shows marked angiocentric CD8 infiltrates without mural necrosis... 

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... 

Diphtheria causes a demyelinative neuropathy. Coryne-bacterium diphtheriae colonizes the pharynx or open wounds, and secretes a protein exotoxin. The B subunit of this exotoxin binds to plasma membranes and facilitates entry into cytosol of the A subunit, which catalyzes ADP-ribosylation, and inactivation of an elongation factor required for protein synthesis. Cardiac muscle and Schwann cells are particularly susceptible to this toxin, and hence patients with diphtheria develop cardiomyopathy and demyelinative polyneuropathy [20]. While diphtheria is now uncommon because of childhood immunization against C. diphtheriae, the disruption in preventative medicine programs caused by disintegration of the Soviet Union was followed by a substantial incidence of diphtheritic polyneuropathy in Russia. 

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. 

Familial demyelinative/dysmyelinative neuropathies may be caused by impaired peroxisomal lipid metabolism. 

Familial demyelinative/dysmyelinative and axonal neuropathies may also be caused by impaired lysosomal lipid metabolism. Metachromatic leukodystrophy (sulfatide lipidosis) results from mutations of the arylsulfatase A gene, which encodes a lysosomal enzyme required for sulfatide turnover. Myelin is affected in both CNS and PNS, though dysfunction is restricted to the PNS in some patients, and the onset of symptoms can occur at any time between infancy and adulthood. Bone marrow transplantation can slow disease progression and improve nerve conduction velocities [57]. (See in Ch. 41.)... 

Magira, E. E., Papaioakim, M., Nachamkin, I. et al. Differential distribution of HLA-DQP/DRP epitopes in the two forms of Guillain-Barre syndrome, acute motor axonal neuropathy and acute inflammatory demyelinating... 

Griffin, J. W. and Price, D. L. Demyelination in experimental beta, beta -iminodipropionitrile and hexacarbon neuropathies. Evidence for an axonal influence. Lab. Invest. 45 130-141,1981. 

Hattori, N., Yamamoto, M., Yoshihara, T. et al. Study Group for Hereditary Neuropathy in Japan. Demyelinating and axonal features of Charcot-Marie-Tooth disease with mutations of myelin-related proteins (PMP22, MPZ and Cx32) a clinicopathological study of 205 Japanese patients. Brain 126 134-151,2003. 

Some human peripheral neuropathies involving demyelination are immune-mediated 645... 

Once the monoclonal antibodies reacting with complex glycolipids were shown to occur frequently in patients with neuropathy in association with gammopathy, antibodies were demonstrated in some patients with GBS and other forms of inflammatory demyelinating neuropathy [21]. 

Kieseier, B. C., Dalakas, M. C. and Hartung, H. P. Immune mechanisms in chronic inflammatory demyelinating neuropathy. Neurology 59, S7-S12, 2002. 

Glucocorticoids are also used in the treatment of a number of HIV-related disorders, including Pneumocystis carinii pneumonia, demyelinating peripheral neuropathies, tuberculous meningitis, and nephropathy. Glucocorticoids are used as adjunctive therapy in Pneumo cystitis carinii pneumonia to decrease the inflammatory response and allow time for antimicrobial agents to exert their effects. In patients who are immunocompromised because of HIV infection, adjunctive steroids may be less beneficial in promoting survival. 

Nervous system (dementia, stroke, epilepsy, extrapyramidal diseases [Parkinson s], demyelinating diseases [multiple sclerosis], neuropathy, myasthenia gravis, psychosis, schizophrenia)... 

---