Objective: To reverse the profile of abnormal intracortical excitability in patients with restless legs syndrome (RLS) by administering the dopaminergic agonist cabergoline.
Methods: The effects of this drug on motor cortex excitability were examined with a range of transcranial magnetic stimulation (TMS) protocols before and after administration of cabergoline over a period of 4 weeks in 14 patients with RLS and in 15 healthy volunteers. Measures of cortical excitability included central motor conduction time; resting and active motor threshold to TMS; duration of the cortical silent period; short latency intracortical inhibition (SICI) and intracortical facilitation using a paired-pulse TMS technique.
Results: Short latency intracortical inhibition was significantly reduced in RLS patients compared with the controls and this abnormal profile was reversed by treatment with cabergoline; the other TMS parameters did not differ significantly from the controls and remained unaffected after treatment with cabergoline. Cabergoline had no effect on cortical excitability of the normal subjects.
Conclusions: As dopaminergic drugs are known to increase SICI, our findings suggest that RLS may be caused by a central nervous system dopaminergic dysfunction. This study demonstrates that the cortical hyperexcitability of RLS is reversed by cabergoline, and provides physiological evidence that this dopamine agonist may be a potentially efficacious option for the treatment of RLS.
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http://dx.doi.org/10.1111/j.1600-0404.2006.00669.x | DOI Listing |
Brain Behav
January 2025
Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada.
Introduction: Patients with bipolar disorder (BD) demonstrate episodic memory deficits, which may be hippocampal-dependent and may be attenuated in lithium responders. Induced pluripotent stem cell-derived CA3 pyramidal cell-like neurons show significant hyperexcitability in lithium-responsive BD patients, while lithium nonresponders show marked variance in hyperexcitability. We hypothesize that this variable excitability will impair episodic memory recall, as assessed by cued retrieval (pattern completion) within a computational model of the hippocampal CA3.
View Article and Find Full Text PDFJ Neuroinflammation
January 2025
Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, 98104, USA.
Traumatic brain injury is a leading cause of chronic neurologic disability and a risk factor for development of neurodegenerative disease. However, little is known regarding the pathophysiology of human traumatic brain injury, especially in the window after acute injury and the later life development of progressive neurodegenerative disease. Given the proposed mechanisms of toxic protein production and neuroinflammation as possible initiators or contributors to progressive pathology, we examined phosphorylated tau accumulation, microgliosis and astrogliosis using immunostaining in the orbitofrontal cortex, a region often vulnerable across traumatic brain injury exposures, in an age and sex-matched cohort of community traumatic brain injury including both mild and severe cases in midlife.
View Article and Find Full Text PDFEpilepsia
January 2025
Department of Medical Sciences, Institute of Neurology, Magna Græcia University, Catanzaro, Italy.
We aim to understand whether tremor may be an intrinsic feature of juvenile myoclonic epilepsy (JME) and whether individuals with JME plus tremor experience a different disease course. Thirty-one individuals with JME plus tremor (17 females, mean age = 33.9 ± 13.
View Article and Find Full Text PDFNPJ Parkinsons Dis
January 2025
Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, MD, 20852, USA.
ΑBSTRACT: In Parkinson's disease (PD), Lewy pathology deposits in the cerebral cortex, but how the pathology disrupts cortical circuit integrity and function remains poorly understood. To begin to address this question, we injected α-synuclein (αSyn) preformed fibrils (PFFs) into the dorsolateral striatum of mice to seed αSyn pathology in the cortical cortex and induce degeneration of midbrain dopaminergic neurons. We reported that αSyn aggregates accumulate in the motor cortex in a layer- and cell-subtype-specific pattern.
View Article and Find Full Text PDFElectroencephalographic (EEG) recordings in individuals with Fragile X Syndrome (FXS) and the mouse model of FXS ( KO) display cortical hyperexcitability at rest, as well as deficits in sensory-driven cortical network synchrony. A form of circuit hyperexcitability is observed in cortical slices of KO mice as prolonged persistent activity, or Up, states. It is unknown if the circuit mechanisms that cause prolonged Up states contribute to FXS-relevant EEG phenotypes.
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