title: Effects of citalopram on the excitability of the human motor cortex: a paired magnetic stimulation study.
abstract: Several recent reports suggest the possibility of monitoring pharmacological effects on brain excitability through transcranial magnetic stimulation (TMS). Different drugs have been studied using paired magnetic stimulation in normal subjects and patients. In particular, it has been suggested that antidepressant drugs may have an appreciable effect on motor excitability. The aim of the present study was to investigate motor area excitability in normal subjects after oral administration of a single dose of citalopram, a selective serotonin reuptake inhibitor (SSRI) antidepressant. Motor cortex excitability was studied by single and paired transcranial magnetic stimulation before and 2.5 and 36 (t1/2=36 h) h after oral administration of 30 mg of citalopram. Cortical excitability was measured using different transcranial magnetic stimulation parameters: motor threshold (MT), motor-evoked potential (MEP) amplitude and latency, motor recruitment, duration of cortical silent period (CSP), intracortical inhibition and intracortical facilitation. Spinal excitability and peripheral nerve conduction were measured by F response and M wave. Temporary but significant increases in motor threshold, motor-evoked potentials, silent period and intracortical inhibition were observed 2.5 h after drug administration, without any significant changes in motor-evoked potential amplitude and latency and spinal excitability parameters. Our findings suggest that a single oral dose of citalopram can induce significant but transitory suppression of motor cortex excitability in normal subjects.
authors.affiliation: Dipartimento di Scienze Neurologiche e della Visione, Sezione Neurologia Riabilitativa, Policlinico Giambattista Rossi, Università di Verona, Via delle Menegone, 10-Verona 37134, Italy. elisarobol@interfree.it
authors.forename: Elisa
authors.initials: E
authors.lastname: Robol
authors.forename: Antonio
authors.initials: A
authors.lastname: Fiaschi
authors.forename: Paolo
authors.initials: P
authors.lastname: Manganotti
mesh_terms: D000284:Administration, Oral; D000328:Adult; D015283:Citalopram / Q000008:administration & dosage / Q000494:pharmacology*; D019054:Evoked Potentials, Motor / Q000187:drug effects; D005260:Female; D006801:Humans; D008280:Magnetics; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009044:Motor Cortex / Q000187:drug effects / Q000502:physiology*; D012680:Sensitivity and Specificity; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D015283:Citalopram; D017367:Selective Serotonin Reuptake Inhibitors