Khedr EM, Elbeh KAM, Elserogy Y, Khalifa HE, Ahmed MA, Hafez MH, Ali AM, Elfetoh NA. Motor cortical excitability in obsessive-compulsive disorder: Transcranial magnetic stimulation study.
Neurophysiol Clin 2016;
46:135-43. [PMID:
27016878 DOI:
10.1016/j.neucli.2016.02.003]
[Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 01/28/2016] [Accepted: 02/15/2016] [Indexed: 01/17/2023] Open
Abstract
OBJECTIVES
Transcranial magnetic stimulation is a non-invasive method of stimulating the brain that is increasingly being used in neuropsychiatric research. Previous work has suggested that the pathophysiology of obsessive-compulsive disorder (OCD) may involve dysfunction of excitatory and/or inhibitory brain function. This study aimed to extend those findings.
METHODS
The study included 45 OCD patients and 15 age- and sex-matched healthy volunteers. Clinical evaluation was conducted using the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), Hamilton Anxiety Rating Scale (HAM-A), and Clinical Global Impression rating scale (CGI). Physiological measures were resting and active motor thresholds (RMT and AMT), motor evoked potential (MEP) amplitude, cortical silent period (CSP) and transcallosal inhibition (TCI) durations, short-interval intracortical inhibition (SICI), and intracortical facilitation.
RESULTS
RMT and AMT were significantly lower in patients than in the control group. The mean duration of the CSP and TCI were also significantly shorter. Obsessive trait was associated with significant reduction of TCI duration compared to compulsive trait. There was significant reduction in SICI in OCD patients compared to controls. There were no significant correlations between the Y-BOCS, HAM-A and CGI scores and the cortical excitability parameters.
CONCLUSION
These results provide further evidence for inhibitory deficits or increased facilitation in cortical circuits of patients with OCD.
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