Neurological complications of Lyme disease.

A tick-bite associated rash with later neurological manifestations, including pa­ ralysis and meningitis, had been docu­ mented in Europe for several years before Lyme arthritis was recognized in the 1970s.-4 The illness was later understood to be part of a multisysrem disease caused by spirochetae and transmitted by Ixodes ticks. . " Borrelia burgdorferi, although initially thought to be a single species, has been found to have several sub-species. These subgroups may be responsible for the variation in clinical symptoms observed in different parts of the world. 7 The pathophysiology of neuro­ borreliosis is difficult to demonstrate, but mimics other spirochetal infections. In­ fection is local with subsequent dissemi­ nation. During this time spirochete num­ bers are high. B. burgdorferi components that induce cytokine production by T and B cells produce immune activation and indirect cell damage. Central ner­ vous system involvement is common and clinical syndromes tend to occur in stages. 7 Lyme disease has been implicated in a variety of peripheral and central ner­ vous system disorders. The neurological syndromes are often accompanied by more general complaints (arthralgias, fa­ tigue, myalgias). Earlier neurological symptoms, or those occurring during dis­ semination within weeks to months, tend to be more clinically obvious and develop in an estimated 15% to 20% of patients. Several late syndromes seem to follow a more insidious course. 8 For purposes of simplification, disorders of the peripheral and central nervous systems will be re­ viewed separately.