Journal of neurology, neurosurgery, and psychiatry
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J. Neurol. Neurosurg. Psychiatr. · May 2008
Comparative Study Clinical TrialInduction of parkinsonian resting tremor by stimulation of the caudal zona incerta nucleus: a clinical study.
We hypothesise that parkinsonian tremor arises when the caudal zona incerta (cZI) and subthalamic nucleus (STN) are deprived of dopamine and become increasingly responsive to motor cortical alpha and beta frequency oscillations. These oscillations are synchronised and amplified through the basal ganglia thalamocortical loop and entrained into the cerebello-thalamocortical loop via the cZI. On receiving potent gamma-aminobutyric acid (GABA)-ergic alpha and beta frequency oscillations in cZI afferents, ventrolateral (VL) thalamocortical neurons become hyperpolarised and rebound burst fire, generating 4-6 Hz tremor oscillations. We test this hypothesis by stimulating the cZI at alpha and beta frequencies using deep brain stimulation (DBS) in non-tremulous parkinsonian patients to see whether a 4-6 Hz tremor can be induced. ⋯ We discuss the implications of these findings and argue that resting tremor in PD is generated in the cortico-ZI-VL-thalamocortical loop rather than in the cortico-basal-ganglia-thalamocortical loop.
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J. Neurol. Neurosurg. Psychiatr. · May 2008
Variability in language recovery after first-time stroke.
Predicting aphasia recovery after stroke has been difficult due to substantial variability in outcomes. Few studies have characterised the nature and extent of recovery, beginning with baselines at 24-72 hours after stroke onset. ⋯ There was significant variability in language recovery after first-time stroke, even in more severe, initial syndromes. Traditional predictors of post-stroke language outcomes did not reliably predict function at 90 days. These data suggest that other factors that account for functional stroke recovery have not yet been identified.
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J. Neurol. Neurosurg. Psychiatr. · May 2008
Bilateral stimulation of the caudal zona incerta nucleus for tremor control.
The ventrolateral (VL) nucleus of the thalamus is the commonly chosen target for deep brain stimulation (DBS) to alleviate tremor. However, it has a poor efficacy in alleviating proximal tremor and patients may develop tolerance to the action component of tremor. We performed bilateral stimulation of the caudal or motor part of the zona incerta nucleus (cZI) to determine its safety and efficacy in alleviating tremor. ⋯ This prospective study shows that the cZI may be an alternative target for the treatment of tremor with DBS. In contrast to bilateral DBS of the VL nucleus, it improves all components of tremor affecting both the distal and proximal limbs as well as the axial musculature.
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J. Neurol. Neurosurg. Psychiatr. · May 2008
Early predictors of unfavourable outcome in subjects with moderate head injury in the emergency department.
Subjects with moderate head injury are a particular challenge for the emergency physician. They represent a heterogeneous population of subjects with large variability in injury severity, clinical course and outcome. We aimed to determine the early predictors of outcome of subjects with moderate head injury admitted to an Emergency Department (ED) of a general hospital linked via telemedicine to the Regional Neurosurgical Centre. ⋯ A group of selected variables proves highly accurate in the prediction of unfavourable outcome at 6 months, when applied to subjects admitted to an ED of a General Hospital with moderate head injury.
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J. Neurol. Neurosurg. Psychiatr. · May 2008
Effects of subthalamic deep brain stimulation on dysarthrophonia in Parkinson's disease.
Motor deficits in Parkinson's disease (PD) are reduced by deep brain stimulation (DBS) of the subthalamic nucleus (STN), but the impact of this therapy on dysarthrophonic problems in PD remains controversial. We therefore aimed to disentangle the effects of STN DBS on the speech skills of long-term treated patients. ⋯ In parallel to the beneficial effects on the motor symptoms of PD, STN DBS reduces designated disease-inherent dysarthrophonic symptoms, such as glottic tremor. However, these actions on speech are predominantly outweighed by the general dysarthrogenic effects of STN DBS, probably based on a decline of complex (eg, prosodic) functions. Thus, stimulation-induced speech impairment should be considered a likely problem in the course of this treatment.