Neuropathies au cours de la lèpre

Clinical aspects of leprosy

Leprosy is a chronic, infectious disease caused by Mycobacterium leprae. It mainly affects the peripheral nervous system, skin, and certain other tissues such as the reticulo-endothelial system, bones and joints, mucous membranes, eyes, testes, muscles, and adrenals. Leprosy clinical presentation varies from few to widespread lesions. In most patients, early leprosy presents as macular and hypopigmented lesions. This initial clinical presentation is known as indeterminate leprosy and occurs in individuals who have not developed cell-mediated immunity against M. leprae yet. The number of lesions depends on the genetically determined cellular immunity of the patient. Individuals presenting a vigorous cellular immune response and limited humoral immune responses to M. leprae, usually present few skin lesions. Without treatment, those patients tend to evolve into the polar tuberculoid or borderline tuberculoid form of leprosy. Due to the inability to mount an effective cellular-mediated response to M. leprae and the consequent hematogenous spread of the bacilli, some patients may present with numerous and symmetrically distributed hypochromic lesions. Without treatment these patients evolve to a nonresistant form of leprosy, polar lepromatous.

Infectious neuropathies

PURPOSE OF REVIEW

Infectious neuropathies are heterogeneous neuropathies with multiple causes. They still represent an important world health burden and some of them have no current available therapy.

RECENT FINDINGS

Leprosy incidence has decreased by 50% during the last years, but leprosy-related neuropathies still cause severe disability. The pure neuritic leprosy is a diagnostic challenge that may require nerve biopsy or nerve aspiration cytology. The treatment itself may lead to a 'reversal reaction', which further causes injuries to the nerve. HCV-related neuropathies may be related or not to the presence of cryoglobulins. The absence of vasculitis, the most frequent form is a peripheral sensory neuropathy involving small nerve fibers, and more accurately diagnosed by pain-related evoked potentials. HIV-related neuropathy has become the major neurological complication of HIV infection. Both HIV-induced neuropathy and antiretroviral toxic neuropathy are clinically indistinguishable. The existence of an isolated chronic polyneuropathy due to Borrelia burgdorferi remains highly controversial. Lastly, an active infectious ganglioneuritis caused by varicella zoster virus, producing shingles, is the most frequent infectious neuropathy in the world and may cause various neurological complications. Zoster sine herpete remains frequently undiagnosed.

SUMMARY

Recent data have improved our knowledge and diagnostic tools of infectious neuropathies. Treatment of the injured nerves is not yet available, and prevention and rapid diagnosis remain the main priorities for the clinician.