The pathophysiology of psychogenic movement disorders (PMD) is very poorly understood. These disorders are common in the population, diagnosis is difficult and treatment typically ineffective. We are studying the mechanisms underlying these disorders using cognitive tasks, neurophysiological testing, psychiatric measures, and functional imaging. One functional imaging study was an fMRI investigation of patients with tremor, and results showed abnormally reduced activation in the temporoparietal junction region. We have initiated similar studies in patients with psychogenic myoclonus. We are also looking for abnormal activations related to tasks that probe functions such as emotional expression and movement inhibition, and have already shown abnormal activation in the amygdala. We have also investigated these patients for their sense of agency during fMRI studies, similar to the way we have studied normal subjects. In a large study, with psychiatric help, we are exploring the biopsychosocial underpinnings of psychogenic movement disorders. The origin of tics is generally unknown, and we have been approaching physiology in several ways. Tourette syndrome patients report "premonitory urge" and other sensory abnormalities associated with the presence of tics. We have been studying tic genesis with functional neuroimaging and EEG, and are pursuing a series of studies looking at the physiology of the sensory urge. We are also seeing if we can detect the urge with real time fMRI. For many years, we have been collecting families with essential tremor looking for possible genetic abnormalities, and in several families found an area suggestive of genetic linkage on chromosome 6 and 11. This work is being pursued with additional sequencing in conjunction with Drs. Lev Goldfarb and David Goldman. While it is known that many patients with essential tremor respond to ethanol, it is not clear how many and what the physiology of the response is. We are investigating this including TMS measures of cortical excitability.

Project Start
Project End
Budget Start
Budget End
Support Year
28
Fiscal Year
2012
Total Cost
$1,261,150
Indirect Cost
City
State
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Hallett, Mark (2016) Functional (psychogenic) movement disorders - Clinical presentations. Parkinsonism Relat Disord 22 Suppl 1:S149-52
Hallett, Mark (2015) Tourette Syndrome: Update. Brain Dev 37:651-5
Leon-Sarmiento, Fidias E; Peckham, Elizabeth; Leon-Ariza, Daniel S et al. (2015) Auditory and Lower Limb Tactile Prepulse Inhibition in Primary Restless Legs Syndrome: Clues to Its Pathophysiology. J Clin Neurophysiol 32:369-74
Bodranghien, Florian; Bastian, Amy; Casali, Carlo et al. (2015) Consensus Paper: Revisiting the Symptoms and Signs of Cerebellar Syndrome. Cerebellum :
Chang, Ki-Eun; Pratt, Drew; Mishra, Bibhuti B et al. (2015) Type II (adult onset) Alexander disease in a paraplegic male with a rare D128N mutation in the GFAP gene. Clin Neuropathol 34:298-302
Maurer, Carine W; LaFaver, Kathrin; Ameli, Rezvan et al. (2015) A biological measure of stress levels in patients with functional movement disorders. Parkinsonism Relat Disord 21:1072-5
Johnson, Brian; Zhang, Kai; Hallett, Mark et al. (2015) Functional neuroimaging of acute oculomotor deficits in concussed athletes. Brain Imaging Behav 9:564-73
Tinaz, Sule; Malone, Patrick; Hallett, Mark et al. (2015) Role of the right dorsal anterior insula in the urge to tic in Tourette syndrome. Mov Disord 30:1190-7
Ramos, Vesper Fe Marie L; Pillai, Ajay S; Lungu, Codrin et al. (2015) Intraoperative neurophysiology in deep brain surgery for psychogenic dystonia. Ann Clin Transl Neurol 2:707-10
Ewen, Joshua B; Lakshmanan, Balaji M; Hallett, Mark et al. (2015) Dynamics of functional and effective connectivity within human cortical motor control networks. Clin Neurophysiol 126:987-96

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