Increased basal-ganglia activation performing a non-dystonia-related task in focal dystonia.

BACKGROUND AND PURPOSE: We tried to determine whether altered sensorimotor cortex and basal-ganglia activation in blepharospasm (BSP) and cervical dystonia (CD) are restricted to areas directly responsible for the innervation of dystonic muscles, or whether impairment in focal dystonia reaches beyond these direct associations supporting a more global disturbance of sensory and motor control in focal dystonia. METHODS: Twenty patients with focal dystonia (11 BSP, 9 CD) and 14 healthy controls were investigated with functional magnetic resonance imaging (fMRI) performing a simple grip force forearm contraction task. RESULTS: BSP and CD patients and healthy controls showed similar activation in the pre-motor, primary motor and primary sensory cortex, whilst basal-ganglia activation was increased in BSP and CD with related activation patterns compared with controls. BSP patients had increased activation in the thalamus, caudate nucleus, putamen and lateral globus pallidus, whilst CD patients showed increased activation in the caudate nucleus, putamen and thalamus. No differences in applied grip force were detected between groups. CONCLUSIONS: In both, BSP and CD, increased basal-ganglia activation could be demonstrated in a task not primarily involving the dystonic musculature affected by these disorders. Comparable activation changes may also indicate a common pathway in the pathophysiology in BSP and CD.

Hemispheric dominance in the processing of J.S. Bach fugues: a transcranial Doppler sonography (TCD) study with musicians.

Although the majority of studies on musical processing in musicians observed a left hemisphere dominance which has usually been explained by a proficient analytical strategy used by these subjects, the findings are still inconsistent. Changes in hemispheric activity induced by listening to music (J. S. Bach fugues) and by recognizing the repetitions of the fugue theme were examined, using the technique of bilateral transcranial Doppler sonography (TCD) of the left and right middle cerebral artery (MCA). Subjects were 32 right-handed musicians, half of whom were members of an orchestra or members of a choir. The fugues were presented in two versions: a-cappella and instrumental. During passive listening to the a-cappella version, a weak left-dominant asymmetry of blood flow acceleration was observed, while there was no hemispheric asymmetry during listening to the instrumental version. During the task of fugue theme recognition, a highly significant asymmetry in favour of the right MCA was observed with both versions. It is concluded that when the processing of complex musical material has to be based on the analysis of melodic contour features and calls for working memory capacities a right hemisphere dominance is observed even in musically sophisticated subjects.

Cerebral hemodynamics during electrically induced seizures.

Electroconvulsive therapy (ECT) is an appropriate clinical model to investigate blood flow during seizures. In this study cerebral blood flow velocity (CBFV) was measured during 40 ECTs in 10 patients by means of transcranial Doppler sonography. EEG was recorded continuously. Under general anesthesia, the pre-convulsive blood flow velocity (Vmean) decreased significantly. After ECT, we measured a dramatic increase in Vmean which was significantly greater in the left MCA than in the right MCA. After termination of seizures, flow velocities returned to baseline levels. The striking increase in cerebral blood flow velocity reflects excessive cerebral metabolism during convulsive neuronal activation. The left hemisphere seems to be more sensitive to electrical stimuli as was indicated by its predominant augmentation of CBFVs.

Orthopedic and neurological complications of cervical dystonia--review of the literature.

Cervical dystonia is the most frequent form of focal dystonia. Further, cervical dystonia can occur as a feature of segmental or generalized dystonias and cerebral palsy. Treatment with botulinum toxin to relieve pain and improve functional and psychological outcome is effective, but expensive. However, pharmacoeconomic studies evaluating treatment and disease costs have not taken into consideration the long-term complications of cervical dystonia. Here we present a review of the medical literature on orthopedic and neurological complications arising from cervical dystonia, including cervical spine degeneration, spondylosis, disk herniation, vertebral subluxations and fractures, radiculopathies and myelopathies. In summary, complications are more often reported in generalized dystonia and cerebral palsy than in focal dystonia. The prevalence is not well established, published estimations go from 18 to 41% in selected populations. Awareness of the frequent occurrence of complications and screening for symptoms of radiculomyelopathy in patients with dystonia is essential to avoid irreversible spinal cord damage. Complications of cervical dystonia need to be taken into consideration when weighting risks and calculating costs of the disease and its treatment.

Botulinum toxin A in the prophylactic treatment of migraine--a randomized, double-blind, placebo-controlled study.

Botulinum toxin A has been suggested to be effective in the prophylactic treatment of migraine. However, only very few randomized, double-blind, placebo-controlled studies are available. We designed such a study with a specific focus on different injection sites. Sixty patients with a migraine according to the criteria of the International Headache Society were randomly assigned to receive either placebo in the frontal and neck muscles, or to receive 16 U botulinum toxin A in the frontal muscles and placebo in the neck muscles, or to receive in total 100 U botulinum toxin A in the frontal and neck muscles. The observation period was 3 months. In both treatment groups, 30% of patients showed a reduction of migraine frequency in month 3 by at least 50% compared with baseline, in the placebo group 25% of the patients showed such a reduction (P = 0.921). There were no significant differences between the three study groups with respect to reduction of migraine frequency, number of days with migraine, and the number of total single doses to treat a migraine attack. In the post hoc analysis, the reduction of all accompanying symptoms was significantly higher in the 16 U treatment group compared with the placebo group. In the 100 U treatment group significantly more adverse events occurred compared with the placebo group. All adverse events were mild and transient. Our study did not show any efficacy of botulinum toxin A in the prophylactic treatment of migraine. Only accompanying symptoms were significantly reduced in the 16 U but not in the 100 U treatment group. Future studies should focus on the efficacy of botulinum toxin A in specific subgroups of patients, on the efficacy of repetitive injections, and on other injection sites.

Treatment of headache with botulinum toxin A--a review according to evidence-based medicine criteria.

The aim of this review is to evaluate the studies available from reference systems and published congress contributions on the prophylactic treatment of idiopathic and cervicogenic headache with botulinum toxin A, and to classify these studies according to evidence-based medicine (EBM) criteria. The studies were analysed with respect to the study design, the number of patients enrolled, the efficacy parameters, and the significance of results. We used the following classification of EBM. I: randomized, controlled study with sufficient number of patients; II: well-designed, controlled study (or randomized, controlled study with insufficient number of patients, no exact diagnosis, missing data of botulinum toxin A dose); III: well-designed, descriptive study; IV: case reports, opinions of experts. For tension-type headache, two studies were found with negative evidence of I with respect to the primary endpoint. There are about as many positive as negative studies with evidence of II or III. For the therapy of migraine, one study with both negative and positive evidence of I, one in part positive study of II, and three positive studies classified as III are available. Two studies on cervicogenic headache with evidence of II and III are contradictory. In addition, we found several positive case reports. For patients with cluster headache, there are positive and negative case reports. We found one positive case report for the treatment of chronic paroxysmal hemicrania. As a result of this analysis, we consider no sufficient positive evidence for a general treatment of idiopathic and cervicogenic headaches with botulinum toxin A to date. Further studies are needed for a definite evaluation of subgroups with benefit from such treatment.

Localized proton NMR spectroscopy in the striatum of patients with idiopathic spasmodic torticollis.

Single voxel proton spectroscopy was used to study brain metabolism in idiopathic spasmodic torticollis. Peak metabolite ratios in long echo time (135 ms) spectra were evaluated in the basal ganglia of 16 patients (29-65 years). Eight of them were untreated; the other eight were examined 4-6 weeks after administration of botulinum toxin type A. As compared with 60 control spectra, patients showed a significant, therapy-resistant decrease in N-acetyl-L-aspartate (NAA)/choline (Cho). NAA/creatine (Cr) and Cho/Cr were close to normal in the post-treatment group but significantly reduced in untreated patients. This result is consistent with the hypothesis that striatal Cr is reversibly elevated in chronic muscle stimulation. The right and left striatum were affected to the same extent.