From 1986 to 1999, 2460 HIV-positive inpatients were seen in our Hospital. Neurological abnormalities were detected in 1053 (42.8%) patients. In this group, 28 (2.7%) had involuntary movements, 14 (50%) with secondary parkinsonism, six (21.4%) with hemichorea/hemiballismus, four (14.2%) with myoclonus, two (7.2%) with painful legs and moving toes, one (3.6%) with hemidystonia and one (3.6%) with Holmes' tremor. The HIV itself (12 patients), toxoplasmosis of the midbrain (1) and metoclopramide-related symptoms (1) were the most probable causes for the parkinsonism. All patients with hemichorea/hemiballismus were men and in all of them toxoplasmosis of the basal ganglia, mostly on the right side, was the cause of the involuntary movements. Generalized myoclonus was seen in two patients and they were due to toxoplasmosis and HIV-encephalopathy respectively; two others presented with spinal myoclonus. The two patients with painful legs and moving toes had an axonal neuropathy. The patient with hemidystonia suffered from toxoplasmosis in the basal ganglia and the patient with Holmes' tremor had co-infection with tuberculosis and toxoplasmosis affecting the midbrain and cerebellum. We conclude that HIV-infected patients can present almost any movement disorder. They can be related to opportunistic infections, medications, mass lesions and possibly to a direct or indirect effect of the HIV itself.

Paroxysmal dyskinesias (PD) are thought to be rare movement disorders. The overwhelming majority of reported cases are primary. Secondary PD has seen reported to occur in some conditions, mainly in multiple sclerosis and head trauma. The anatomic origin of the lesion is also rarely seen at the spinal cord. Our objective was to describe four patients with paroxysmal dystonia secondary to spinal lesions during the recovering phase of a neuromyelitis optica (NMO) bout. In the reviewed literature, we do not find any report of PD related to NMO.

Extramedullary hematopoiesis is a common accompaniment of a variety of hematologic diseases such as hereditary spherocytosis, thalassemia and myelofibrosis. The association of extramedullary hematopoiesis with polycythemia vera in the proliferative phase is much less usual. We report a patient who presented with paraplegia due to spinal cord compression; clinical investigation revealed a paravertebral hematopoietic tumor, and the diagnosis of polycythemia vera was then established.

We studied 1086 AIDS patients in the last six years. Of these 389 (35.82%) had neurological manifestation and 7 (1.8%) male patients had abnormal involuntary movements (parkinsonism in 3, hemichorea-hemiballism in 2, spinal myoclonus in 1 and rubral tremor in another). All patients were men, 5 white and 2 black. Four were homosexual, 2 drug-users and 1 bisexual. The mean age was 33.14 years. The time between AIDS diagnosis and the onset of movement disorders was 23.8 months in 5 patients and in 2 it was the first symptom. The parkinsonian patients did not show any opportunistic infection in connection with the neurological symptoms but in the remaining four cases this relationship was suggested. The data showed that not only the opportunistic infection but also the AIDS virus may play an important role on the development of involuntary movements.

RESUMO-Após breve revisão dos dados históricos, do conceito, do quadro clínico e dos critérios para o diagnóstico, analisamos os principais aspectos genéticos e neuroquímicos atuais dos tiques e da síndrome de Gilles de La Tourette. Dados epidemiológicos sugerem que todo tique seja de natureza orgânica, a maioria de origem genética, e que obedecem a transmissão autossômica dominante com penetrância aproximada de 100%. Ressaltamos, ainda, os recentes estudos imuno-histoquímicos, particularmente os que se referem aos sistemas dopaminérgico, noradrenérgico e serotoninérgico, que modulam a atividade dos circuitos córtico-estriato-talâmico-cortical, envolvidos na gênese dos tiques e dos transtornos obsessivos-compulsivos.PALAVRAS-CHAVE: tiques, síndrome de Gilles de La Tourette, genética, atividade dopaminérgica. Genetic and neurochemical factors in tic disordersABSTRACT -We review historical, conceptual, clinical and diagnostic criteria as well as present genetic and neurochemical factors of tic disorders. Epidemiologic data sugest that tic is an organic disease with autosomal dominant transmission. We emphasize imunohistochemical studies particularly related to the dopaminergic, noradrenergic and serotonergic systems. These modulate the activity of the cortico-striato-thalamocortical circuits implicated in both Tourette's syndrome and obsessive-compulsive disorder.KEY WORDS: tics,Gilles de la Tourette syndrome, genetics,dopaminergic activity.Georges Albert Edouard Brutus Gilles de La Tourette viveu somente 46 anos, tendo sido um dos alunos prediletos de Charcot e, posteriormente, seu chefe de clínicas. Quando contava apenas 28 anos, deixou seu nome na história da Neurologia ao publicar seu mais importante trabalho entitulado " Étude sur une affection nerveuse caractérisée par l'incoordenation motrice accompagnée d'echolalie et de coprolalie". Em nenhum momento utilizou o termo tique, preferindo incoordenação motora, convulsões, contorções e descargas musculares [1][2][3][4] . Os tiques são definidos como movimentos anormais, clônicos, breves, rápidos, súbitos, sem propósitos e irresistíveis. São exacerbados por situações de ansiedade e tensão emocional; atenuados pelo repouso e por situações que exigem concentração. Podem ser suprimidos pela vontade (por segundos ou horas), logo seguidos por exacerbações secundárias 3,5 .A síndrome de Gilles de La Tourette é definida como um distúrbio neurológico caracterizado por frequentes tiques motores e vocais (fônicos) que costumam começar na infância. Outras manifestações, tais como, ecolalia, ecopraxia, coprolalia e copropraxia podem, também, estar presentes. A associação de hiperatividade com déficit de atenção (HDA) e transtorno obsessivo compulsivo (TOC) é relativamente comum 6,7 . O quadro clínico pode ser dividido em três categorias: tiques motores, tiques fônicos e sinais acessórios. Os tiques motores ocorrem em 100% dos pacientes, tornando adequada a expressão "doença dos tiques". Podem ser simples ou complexos. Simples, quando ocorrem em um grupo muscular; complexos...