OBJECTIVES Manganese exposure leads to diffuse cerebral metal deposition with the highest concentration in the globus pallidus associated with increased T1-weighted MRI signal. T1 signal intensity in extra-pallidal basal ganglia (caudate and putamen) has not been studied in occupationally exposed workers. Diffusion weighted imaging is a non-invasive measure of neuronal damage and may provide a ...

In 1942, it was thought that basal ganglia surgery would cause permanent unconsciousness and significant impairment of motor control. By 1947, when human stereotactic surgery was introduced, the first target was the globus pallidus in a patient with chorea. What happened during those 5 years to set the stage for stereotactic surgery? During the last half of the 19th century, it was first noted ...

The basal ganglia and cerebellum are major subcortical structures that influence not only movement, but putatively also cognition and affect. Both structures receive input from and send output to the cerebral cortex. Thus, the basal ganglia and cerebellum form multisynaptic loops with the cerebral cortex. Basal ganglia and cerebellar loops have been assumed to be anatomically separate and to pe...

deep brain stimulation (dbs) is a neurosurgical procedure that enables brain structures to be stimulated electrically by a pacemaker implanted under the skin. in the 1980s, over a decade after its first use in pain, implantable dbs of the thalamus was performed to suppress tremor in parkinson’s disease (pd) refractory to drug treatments. primate-based research soon afterwards identified the sub...

Dear Editor, A 35-year-old man presented with severe headache and left sided hemiparesis since one day prior to admission. He reported frequent bouts of oral and genital aphthous ulcers, an attack of deep venous thrombosis of left lower extremity, one episode of right knee arthritis, and several attacks of headache, neck rigidity, and fever. He had been a victim of mustard-gas poisoning at the ...

Basal ganglia disorders are common clinical conditions characterised by specific motor dysfunction and associated behavioral problems. The underlying pathophysiology primarily consists in alterations of the cortico-striato-thalamo-cortical pathways, which can be related to both neurodegenerative pathology (e.g. Parkinson disease, Huntington disease) and neurodevelopmental processes (e.g. Touret...

Parallel, largely segregated, closed-loop projections are an important component of cortical-basal ganglia-cortical connectional architecture. Here, we present the hypothesis that such loops involving the neocortex are neither novel nor the first evolutionary example of closed-loop architecture involving the basal ganglia. Specifically, we propose that a phylogenetically older, closed-loop seri...

Our understanding of the organization of the basal ganglia has advanced markedly over the last 10 years, mainly due to increased knowledge of their anatomical, neurochemical and physiological organization. These developments have led to a unifying model of the functional organization of the basal ganglia in both health and disease. The hypothesis is based on the so-called "direct" and "indirect...

Population activity in cortico-basal ganglia circuits is synchronized at different frequencies according to brain state. However, the structures that are likely to drive the synchronization of activity in these circuits remain unclear. Furthermore, it is not known whether the direction of transmission of activity is fixed or dependent on brain state. We have used the directed transfer function ...