PET demonstrates reduced dopamine transporter expression in PD with dyskinesias.

OBJECTIVE: Dyskinesias are common in Parkinson disease (PD). Prior investigations suggest that dopamine (DA) terminals compensate for abnormal DA transmission. We verified whether similar adaptations could be related to the development of treatment-related complications. METHODS: Thirty-six patients with PD with motor fluctuations were assessed with PET using [(11)C]-d-threo-methylphenidate (MP) and [(11)C]-(+/-) dihydrotetrabenazine (DTBZ). The expression of DA transporter relative to DA nerve terminal density was estimated by determining the MP/DTBZ ratio. Age, treatment, and disease severity were also taken into account in the evaluation of our data. RESULTS: Twenty-seven of the 36 patients had dyskinesias. Nine individuals had motor fluctuations without dyskinesia. The two patient groups were comparable in terms of age, disease duration and severity, medication, and striatal MP and DTBZ binding potentials. The MP/DTBZ ratio in the caudate was not different between groups (nondyskinesia 1.54 +/- 0.36, dyskinesia 1.39 +/- 0.28; mean +/- SD, p = 0.23). Putaminal MP/DTBZ was decreased in individuals with dyskinesia (1.18 +/- 0.24), compared to those who had motor fluctuations without dyskinesia (1.52 +/- 0.24, p = 0.019). The relationship between putaminal MP/DTBZ ratio and the presence of dyskinesias was not altered after correcting for age, treatment, and measures of disease severity. CONCLUSIONS: This investigation supports the role of presynaptic alterations in the appearance of dyskinesias. Dopamine (DA) transporter downregulation may minimize symptoms by contributing to increased synaptic DA levels in early Parkinson disease, but at the expense of leading to increased extracellular DA catabolism and oscillating levels of DA. Such oscillations might ultimately facilitate the appearance of dyskinesias.

Functional imaging in Tourette's syndrome.

The cause or causes of Tourette's syndrome (TS) remain unknown. Functional imaging studies have evaluated several implicated neurotransmitter systems and focused predominantly on the frequency or severity of tics. The results have been inconclusive and frequently contradictory with little light shed on pathogenetic mechanisms. However, metabolic derangements have been demonstrated within regions of the basal ganglia, limbic system and sensori-motor cortex and are in keeping with the concept of TS as both a motor and behavioral disorder. TS has long been regarded an involuntary movement disorder. However, many patients have stated that without the premonitory sensation, there would be no tics. For this reason, it has been suggested that the premonitory urge may be considered the involuntary component of TS and the performance of the tic merely a voluntary response. Future studies are needed to differentiate functional changes relating to urge from those associated with the performance of tics and tic suppression.

[Hemichorea-hemiballism associated to cryptococcal granuloma in a patient with AIDS: case report]. / Hemicoréia-hemibalismo associado a granuloma criptocócico em paciente com SIDA: relato de caso.

Movement disorders are not common in acquired immunodeficiency syndrome. Hemichorea-hemiballism (HC-HB) is the most common of them all, and it is usually related to oportunistic toxoplasmosis of the basal ganglia. We present a 28-year-old man, HIV positive with HC-HB caused by a right subthalamic granuloma, which did not respond to treatment for toxoplasmosis. Cryptoccococic antigen was positive in the cerebrospinal fluid and antifungic therapy led to clinical and radiologic improvement, thus the diagnosis of a granulomatous lesion by Cryptococcus neoformans was established. Current literature on HC-HB and its relationship with AIDS is subsequently reviewed.

[Interictal personality syndrome in non-dominant temporal lobe epilepsy: case report]. / Síndrome de personalidade interictal na epilepsia do lobo temporal não-dominante: relato de caso.

The syndrome of interictal personality in non-dominant temporal lobe epilepsy consists of hyposexuality, hyperreligiosity, humorlessness and hypergraphia. Its notification, in 1974, was followed by an extensive search for these traits in broad epileptic populations. Nevertheless, these statistical studies failed to match this syndrome in general temporal lobe epileptics, and its existence became then target of doubt. We report the case of a 35 year-old man presenting partial complex epilepsy, whose singularity lies in his sophisticated drawing abilities. The large amount of buildings and houses he paints expresses his hypergraphia. He also presents hyposexuality and hyperreligiosity. MRI shows right mesial temporal sclerosis. Temporal hyperconnection, caused by a basal temporal irritative focus, is the most probable pathophysiological mechanism. Epileptic fits can be controlled in the majority of cases. However, behavioural symptoms usually do not respond to pharmacological approach or psychotherapy.

[Neuroacanthocytosis. A case report]. / Neuroacantocitose. Relato de caso.

We present a 45 years old man with neuroacanthocytosis. This gentleman has complex partial seizures and generalized tonic-clonic seizures, as well as movement disorders characterized by chorea and orofacial diskinesia. Complementary examination shows acanthocytosis of 11% on peripheral blood, irritative focus on right temporal lobe on EEG, serum creatinokinase of 101 U/l and volume reduction and hypersignal on caudate nucleus and putamen bilaterally on MRI.

Phenytoin as the first option in female epileptic patients?

OBJECTIVE: Phenytoin (PHT) is one of the first-choice drugs in several epileptic syndromes, mostly in partial epilepsies, in which case it is effective as carbamazepine and phenobarbital. However, like any other anti-epileptic drug (AED), unpleasant side-effects are not rare. The aim of this study is the evaluation of dermatological troubles related to chronic PHT usage in female patients. METHOD: Between 1990-93, 731 new patients underwent investigation for epilepsy at the Multidisciplinary Clinic for Epilepsy in our State. In this sample 283 were AED users at the time of the first assessment. Sixty one female patients taking PHT were identified. They were taking PHT in a dosage ranging from 100 to 300 mg daily, in mono or polytherapy regimen, during 1-5 previous years. RESULTS: More than 50% of the sample showed coarse facial features made by the combination of several degrees of acne, hirsutism and gingival hyperplasia. CONCLUSION: Except in emergency situations, PHT should not be prescribed as the first option to the treatment of female epileptic patients, because not uncommonly the cosmetic side-effects are more socially handicapping than the epileptic syndrome by itself.