Transcranial magnetic stimulation as a treatment for functional (psychogenic) upper limb weakness.
There has been a recent resurgence of interest in physical treatments for functional motor disorders (FMD) including Transcranial Magnetic Stimulation (TMS). This pilot study aimed to test the effectiveness of a single session of motor cortex TMS as a treatment for functional upper limb weakness.



Ten subjects with a diagnosis of functional upper limb weakness were randomised to immediate (n=7) or delayed (3months) (n=3) TMS treatment. Median age was 35 (range 23-52) and median symptom duration was 2.3years (range 5months - 20years). 46-70 single pulses were applied to the motor cortex at 120-150% motor threshold. We used a verbal protocol designed to standardized the effects of suggestion. Primary outcome measures were self-reported symptom severity, grip strength and tapping frequency immediately after treatment, and symptom severity and disability (SF-12 and Modified Rankin Scale (MRS)) after 3months.



There was a small significant reduction in symptom severity immediately after treatment, but no improvement in grip strength or tapping frequency and no change in symptom severity, SF-12 or MRS 3months after treatment. Small numbers precluded comparison of immediate treatment with delayed treatment. Four of eight subjects responding to three-month follow-up reported late-onset adverse effects.



This pilot study suggests limited benefits for TMS as a one-off non-neuromodulatory treatment for stable chronic outpatients. TMS may still have a role alongside more intensive multidisciplinary therapy input, or in patients with severe deficits where the possibility of normal movement can be hard to demonstrate.



NCT02102906.
Royal Edinburgh Hospital, Edinburgh, United Kingdom; Department of Clinical Neurosciences, Western General Hospital, Edinburgh, United Kingdom. Electronic address: lauramcw@doctors.org.uk.
Laura
L
McWhirter
University of Hamburg, Germany.
Lea
L
Ludwig
Department of Clinical Neurosciences, Western General Hospital, Edinburgh, United Kingdom; Department of Rehabilitation Medicine, Astley Ainslie Hospital, Edinburgh, United Kingdom.
Alan
A
Carson
Psychology, University of Edinburgh, United Kingdom.
Robert D
RD
McIntosh
Department of Clinical Neurosciences, Western General Hospital, Edinburgh, United Kingdom.
Jon
J
Stone
D000328:Adult; D000368:Aged; D001132:Arm / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology; D009068:Movement / Q000502:physiology; D018908:Muscle Weakness / Q000503:physiopathology / Q000523:psychology* / Q000628:therapy*; D010865:Pilot Projects; D050781:Transcranial Magnetic Stimulation / Q000379:methods* / Q000639:trends; D016896:Treatment Outcome; D055815:Young Adult
Functional neurological disorder; Motor conversion disorder; Movement disorders; Transcranial magnetic stimulation; Treatment