Cluster headache-like disorder in childhood.
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This paper reviews the diagnostic features of cluster headache-like disorder and describes its presentation in childhood. Case note summaries of patients with this condition are presented in the context of a brief summary of the literature. Four patients (two girls; aged 12 to 15 years) with cluster headache-like disorder were seen over a period of four years in the paediatric neurology department of Birmingham Children's Hospital. Their histories and clinical courses are described. All had a history of "thrashing around" or bizarre behaviour during attacks, which had distracted attention from the headache and seemed to contribute to delay in diagnosis. It appears that cluster headache-like disorder does occur in childhood but is not common and can be mistaken for other conditions. A history of thrashing around accompanied by headache is very suggestive. Recognition of the symptoms in the general paediatric clinic would allow rapid diagnosis. (+info)
Motor disorder in Huntington's disease begins as a dysfunction in error feedback control.
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A steady progression of motor dysfunction takes place in Huntington's disease (HD). The origin of this disturbance with relation to the motor control process is not understood. Here we studied reaching movements in asymptomatic HD gene-carriers (AGCs) and subjects with manifest HD. We found that movement jerkiness, which characterizes the smoothness and efficiency of motion, was a sensitive indicator of presymptomatic HD progression. A large fraction of AGCs displayed elevated jerk even when more than seven years remained until predicted disease onset. Movement termination was disturbed much more than initiation and was highly variable from trial to trial. Analysis of this variability revealed that the sensitivity of end-movement jerk to subtle, self-generated early-movement errors was greater in HD subjects than in controls. Additionally, we found that HD corrective responses to externally-generated force pulses were greatly disturbed, indicating that HD subjects display aberrant responses to both external and self-generated errors. Because feedback corrections are driven by error and are delayed such that they predominantly affect movement termination, these findings suggest that a dysfunction in error correction characterizes the motor control deficit in early HD. This dysfunction may be observed years before clinical disease onset and grows worse as the disease progresses. (+info)
Long-term follow-up of unilateral pallidotomy in advanced Parkinson's disease.
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BACKGROUND: Although the short-term benefits of posteroventral pallidotomy for patients with advanced Parkinson's disease have been well documented, little is known about the long-term outcome of the procedure. METHODS: We conducted a long-term follow-up study of a cohort of 40 patients who had undergone unilateral posteroventral medial pallidotomy between 1993 and 1996. Twenty patients were not evaluated because they had undergone a second surgical procedure (11 patients) or had died (2) or because they had dementia or another debilitating illness (4), lived too far away (1), or had been lost to follow-up (2). We conducted serial postoperative assessments of parkinsonism in the remaining 20 patients while they were taking medications ("on" period) and after overnight withdrawal of the drugs ("off" period). The mean follow-up time was 52 months (range, 41 to 64). RESULTS: The combined off-period score for activities of daily living and motor function on the Unified Parkinson's Disease Rating Scale was 18.0 percent better at the last evaluation than at base line (95 percent confidence interval, 4.9 to 31.0 percent; P=0.01). Significant improvements were also evident in the off-period scores for contralateral tremor (65.4 percent improvement, P=0.007), rigidity (43.2 percent, P=0.03), and bradykinesia (18.2 percent, P=0.04) and in the on-period score for contralateral dyskinesia (70.6 percent, P<0.001). Changes in medication did not contribute to the sustained improvement. The 20 patients who could not be included in the long-term analysis had similar base-line characteristics but a worse response to surgery at six months. CONCLUSIONS: In the group of patients with advanced Parkinson's disease who could be enrolled in our long-term follow-up study of unilateral posteroventral medial pallidotomy (20 patients from the original cohort of 40), significant early improvements in off-period contralateral signs of parkinsonism were sustained for up to five and a half years. There was a sustained significant improvement in on-period contralateral dyskinesia but not in other on-period signs of parkinsonism. (+info)
Functional anatomy of movement disorders.
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Models of basal ganglia function are described which encapsulate the principal pathophysiological mechanisms underlying parkinsonian akinesia on the one hand and abnormal involuntary movement disorders (dyskinesias) on the other. In Parkinson's disease, degeneration of the nigrostriatal dopamine system leads to overactivity of the 'indirect' striatopallidal projection to the lateral (external) segment of the globus pallidus. This causes inhibition of lateral pallidal neurons, which in turn project to the subthalamic nucleus. Disinhibition of the subthalamic nucleus leads to abnormal subthalamic overactivity and, as a consequence, overactivity of medial (internal) pallidal output neurons. Dyskinesias, such as are observed in Huntington's disease, levodopa-induced dyskinesia and ballism, share mechanistic features in common and are associated with decreased neuronal activity in both the subthalamic nucleus and the medial globus pallidus. (+info)
Long term outcome of unilateral pallidotomy: follow up of 15 patients for 3 years.
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OBJECTIVES: With the advent of new antiparkinsonian drug therapy and promising results from subthalamic and pallidal stimulation, this study evaluated the long term efficacy of unilateral pallidotomy, a technique which has gained popularity over the past decade for the management of advanced Parkinson's disease. METHODS: The 15 patients reported here are part of the original cohort of 24 patients who underwent posteroventral pallidotomy for motor fluctuations and disabling dyskinesias 3 years ago as part of a prospective study. Evaluation scales included the unified Parkinson's disease rating scale, the Goetz dyskinesia scale, and the Purdue pegboard test. RESULTS: When compared with the prepallidotomy scores, the reduction in the limb dyskinesias and off state tremor scores persisted on the side contralateral to pallidotomy at the end of 3 years (dyskinesias were reduced by 64% (p<0.01) and tremor by 63% (p<0.05). Other measures tended to deteriorate. The dosage of antiparkinsonian medications did not change significantly from 3 months prepallidotomy to 3 years postpallidotomy. CONCLUSIONS: Although unilateral pallidotomy is useful in controlling the contralateral dyskinesias and tremor 3 years after surgery, all other early benefits disappear and activities of daily living continue to worsen. (+info)
Firing patterns and correlations of spontaneous discharge of pallidal neurons in the normal and the tremulous 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine vervet model of parkinsonism.
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To investigate the role of the basal ganglia in parkinsonian tremor, we recorded hand tremor and simultaneous activity of several neurons in the external and internal segments of the globus pallidus (GPe and GPi) in two vervet monkeys, before and after systemic treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and development of parkinsonism with tremor of 5 and 11 Hz. In healthy monkeys, only 11% (20/174) of the GPe cells and 3% (1/29) of the GPi cells displayed significant 3-19 Hz oscillations. After MPTP treatment, 39% (107/271) of the GPe cells and 43% (26/61) of the GPi cells developed significant oscillations. Oscillation frequencies of single cells after MPTP treatment were bimodally distributed around 7 and 13 Hz. For 10% of the oscillatory cells that were recorded during tremor periods, there was a significant tendency for the tremor and neuronal oscillations to appear simultaneously. Cross-correlation analysis revealed a very low level of correlated activity between pallidal neurons in the normal state; 95.6% (477/499) of the pairs were not correlated, and oscillatory cross-correlograms were found in only 1% (5/499) of the pairs. After MPTP treatment, the correlations increased dramatically, and 40% (432/1080) of the cross-correlograms had significant oscillations, centered around 13-14 Hz. Phase shifts of the cross-correlograms of GPe pairs, but not of GPi, were clustered around 0 degrees. The results illustrate that MPTP treatment changes the pattern of activity and synchronization in the GPe and GPi. These changes are related to the symptoms of Parkinson's disease and especially to the parkinsonian tremor. (+info)
The subthalamic nucleus, hemiballismus and Parkinson's disease: reappraisal of a neurosurgical dogma.
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The subthalamic nucleus (STN) currently is considered to play a key role in the pathophysiological origin of the parkinsonian state and is therefore the main target for surgical treatment of Parkinson's disease. The authors review the incidence of hemichorea/ballism (HCB) as a complication of thalamotomy, pallidotomy or campotomy procedures before the introduction of levodopa therapy, including the few reported cases accompanied by a neuropathological study. The literature shows that only a small number of parkinsonian patients with HCB had a lesion of the STN. Preliminary data in Parkinson's disease patients submitted to a subthalamotomy with current functional stereotaxy also indicate that HCB is a very rare complication. To explain this observation, we suggest that the parkinsonian state is characterized by an increased threshold for the induction of dyskinesia following STN lesioning. This arises as a consequence of reduced activity in the 'direct' GABA projection to the globus pallidus medialis (GPm) which accompanies dopamine depletion. Lesioning of the STN reduces excitation of the GPm, and theoretically this should induce dyskinesias. However, an STN lesion also, simultaneously, further reduces the hypoactivity in the globus pallidus lateralis (GPl) that is a feature of Parkinson's disease, and hence may compensate for GPm hypoactivity, thus self-stabilizing basal ganglia output activity and reducing the risk of HCB. We conclude that lesioning of the STN in Parkinson's disease is a feasible approach in some circumstances. (+info)
Involuntary movements after anterior cerebral artery territory infarction.
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BACKGROUND AND PURPOSE: Patients with anterior cerebral artery territory infarction presenting with involuntary movements have rarely been described in the literature. CASE DESCRIPTIONS: The author reports 9 such patients: 3 with asterixis, 5 with hemiparkinsonism (tremor, rigidity, hypokinesia), and 1 with both. Asterixis developed in the acute stage in patients with minimal arm weakness, whereas parkinsonism was usually observed after the motor dysfunction improved in patients with initially severe limb weakness. Asterixis correlated with small lesions preferentially involving the prefrontal area; parkinsonism is related to relatively large lesions involving the supplementary motor area. CONCLUSIONS: Anterior cerebral artery territory infarction should be included in the differential diagnosis of asterixis and hemiparkinsonism. (+info)