Objective: To evaluate the immediate effect of acupuncture on cortico spinal tract (CST) activity in patients with chronic disorders of consciousness (DOC) after traumatic brain injury (TBI) by measuring motor-evoked potential (MEP) using transcranial magnetic stimulation (TMS).
Design: Changes in several variables in the acupuncture session were compared with those in the control session without acupuncture in the same patients.
Setting: Chubu Medical Center for Prolonged Traumatic Brain Dysfunction, Gifu, Japan.
Patients: Fourteen patients (mean age ± standard deviation, 39 ± 17 years; 12 men) with chronic DOC (5 in a vegetative state and 9 in a minimally conscious state) following severe TBI.
Intervention: Acupuncture treatment was performed at GV 26, Ex-HN 3, bilateral LI 4, and ST 36 for 10 minutes.
Outcome measures: Main outcome measure was MEP amplitude. MEP amplitude, measured by using TMS on the primary motor cortex, was recorded from the abductor pollicis brevis muscle. MEP recordings were performed before acupuncture (baseline), 10 minutes after needle insertion (phase 1), and 10 minutes after needle removal (phase 2). As a control, the same procedure without acupuncture was performed on another day with the order randomized. MEP amplitude and latency were calculated. Evoked F-wave measurements were also performed to calculate maximum M-wave amplitude (Mmax), M-wave latency, and F-wave latency in the same muscle. Central motor conduction time (CMCT) and MEP/Mmax ratio were also calculated from the MEP and F-wave measurement data.
Results: MEP amplitude and MEP/Mmax were increased significantly in the acupuncture session at phases 1 and 2 compared with the control session (p < 0.001, p < 0.001, p < 0.001, and p = 0.001, respectively). CMCTs were reduced at phases 1 and 2 in the acupuncture session compared with the control session, and the change at phase 1 was statistically significant (P = 0.002).
Conclusions: Acupuncture treatment increased the CST activity of patients with chronic DOC after severe TBI.
Keywords: acupuncture; brain injury; cortico-spinal tract; disorder of consciousness; transcranial magnetic stimulation.