Dopaminergic function in Gilles de la Tourette's syndrome, Sydenham's chorea and torsion dystonia

The Dystonias

Dystonia is a difficult problem for both the clinician and the scientist. It is sufficiently common to be seen by almost all physicians, yet uncommon enough to prevent any physician from gaining broad experience in its diagnosis and treatment. Each case represents a difficult challenge even to the specialist. The basic scientist is faced with investigating a disorder that is without relevant animal models and which is so rare that obtaining suitable tissue for study is a major obstacle. Dystonia may be idiopathic, or associated with lesions from many sources, including a variety of rare diseases. If idiopathic, it may be genetically transmitted or sporadic. If genetically transmitted, it may be generalized or focal, with symptoms varying in different members of the same family. It may be refractory to treatment, or it may respond to any one of a number of individual drugs that have very different mechanisms of action. For idiopathic dystonias, no clear method of genetic transmission has been established and no consistent pathology identified.

Blood levels of catecholamine metabolites and brain-derived neurotrophic factor in a case of Sydenham's chorea

We report a case of Sydenham's chorea with neuropsychiatric symptoms who was successfully treated with low-dose risperidone. We also longitudinally investigated serum BDNF levels and plasma levels of catecholamine metabolite in the patient. Serum BDNF levels were increased and plasma levels of HVA and MHPG were decreased according to the recovery from the active phase of the disease. These results suggest that dysfunctions of catecholaminergic neurons and neurotrophic factors might exist in Sydenham's chorea, and the decreasing catecholamine activities in response to risperidone might be associated with the improvement of the disease.

Apomorphine in the evaluation of dopaminergic function in man

1. Apomorphine (Apo), a short acting dopamine (DA) receptor agonist, stimulates growth hormone (GH) secretion, decreases prolactin secretion, induces yawning, penile erections and other physiological effects in man. An effect on behavior, movement disorders and alcoholism has also been described. 2. Apo-mediated responses are used to evaluate DA function in psychiatric and neurological disorders. Many of the studies in schizophrenia using the GH response to Apo as an index of central DA function are difficult to interpret because of failure to control for key variables. 3. The GH response to Apo is a useful system to evaluate the effects of various drugs including peptides which may not cross the blood brain barrier on DA function in man. 4. Apo is a potent sedative. Specific antimanic, antischizophrenic, and anticraving effects in alcoholics have not been convincingly demonstrated. Side effects of Apo and failure to use active placebo make double-blind studies difficult. 5. Apo improves parkinsonian symptoms and certain forms of reflex epilepsy but beneficial effects in other involuntary movement disorders requires further documentation. 6. Apo may be a useful agent to evaluate DA function in impotent patients and predict a therapeutic response to long-acting dopaminergic agents. 7. Impairment of DA function may play a role in diabetic impotence. 8. The development of a simple polygraphic method to monitor the yawning response to Apo may facilitate clinical studies on the basic physiology of yawning in man and the use of the yawning response as a measure of central DA function in schizophrenia and other clinical disorders. 9. The use of Apo with 18F-fluorodeoxyglucose positron emission tomography to examine regional DA function in man opens up a promising area of research. 10. Though long-acting orally active aporphine DA agonists and antagonists have been developed the problem of tolerance may limit their therapeutic potential.

Gilles de la Tourette syndrome in Oriental children

Seventy-four cases of tic syndromes were classified into four groups: chronic multiple tics, subacute multiple tics, chronic simple tics and transient simple tics, and 37 cases of chronic multiple tics (Tourette syndrome) were investigated. Clinical evaluation suggested that a transition existed between the four groups. Posture abnormalities were found in 27% of Tourette syndrome and a relation to dystonia was implied. Clinical evaluation and studies of catecholamine blockers' effectiveness suggested the validity of subtyping Tourette syndrome into four groups whose topographical or biochemical abnormalities differ. It was argued that the neurochemical basis of Tourette syndrome might lie in a multiplicity of biochemical abnormalities including disturbances of dopaminergic and noradrenergic pathways.