Right C7 neurotomy at the intervertebral foramen plus intensive speech and language therapy versus intensive speech and language therapy alone for chronic post-stroke aphasia: multicentre, randomised controlled trial

Abstract

Objective: To evaluate whether right neurotomy of the seventh cervical nerve (C7) at the intervertebral foramen plus intensive speech and language therapy (SLT) improves language function compared intensive SLT alone in patients with chronic aphasia after stroke.

Design: Multicentre, assessor blinded, randomised controlled trial.

Setting: Four centres in mainland China.

Participants: 50 adults aged 40-65 years with aphasia for more than one year after a single left hemispheric stroke.

Interventions: Participants were randomised 1:1 to receive either C7 neurotomy plus three weeks of intensive SLT or three weeks of intensive SLT only, stratified by treatment centre.

Main outcome measures: The primary outcome was change in score on the 60 item Boston naming test (BNT, scores 0-60, with higher scores indicating better naming function) from baseline to one week after C7 neurotomy plus intensive SLT for three weeks or intensive SLT for three weeks after deferral for one week (control group). Secondary outcomes included change in severity of aphasia using the aphasia quotient, calculated using the western aphasia battery, and patient reported outcomes on quality of life and depression after stroke.

Results: From 25 July 2022 to 31 July 2023, 322 out of 1086 patients received a diagnosis of post-stroke aphasia and were screened for eligibility. 50 eligible participants were randomly assigned to treatment groups (25 in each). Mean increase in BNT score was 11.16 points in the neurotomy plus SLT group and 2.72 points in the control group at one month (difference 8.51 points, 95% confidence interval (CI) 5.31 to 11.71, P<0.001). The between group difference in BNT score remained stable at six months (difference 8.26 points, 4.16 to 12.35, P<0.001). In addition, the aphasia quotient improved significantly in the neurotomy plus SLT group versus control group (difference at one month 7.06 points, 4.41 to 9.72, P<0.001), as did patient reported activities of daily living and post-stroke depression. No treatment related severe adverse events were reported.

Conclusions: C7 neurotomy plus three weeks of intensive SLT was associated with a greater improvement in language function compared with three weeks of intensive SLT alone over a period of six months. No severe adverse events or long term troublesome symptoms or functional loss were reported.

Trial registration: Chinese Clinical Trial Register ChiCTR2200057180.

Fig 1

Flow chart of participants through study. C7 neurotomy=right neurotomy of the seventh cervical nerve at the intervertebral foramen; MRI=magnetic resonance imaging; SLT=speech and language therapy

Fig 2

Mean change in BNT score (standard error) from baseline in C7 neurotomy plus intensive SLT group and intensive SLT only group. Data are from baseline to three days after surgery in the neurotomy plus intensive SLT group or three days after start of one week’s deferral of intensive SLT in the control group, one month from surgery or start of deferral, and baseline to six months after start of intensive SLT. BNT=Boston naming test; C7 neurotomy=right neurotomy of the seventh cervical nerve at the intervertebral foramen; SLT=speech and language therapy

Fig 3

Waterfall plot depicting observed change in BNT score for each participant from baseline to one month follow-up in C7 neurotomy plus intensive SLT group and intensive SLT only group. BNT=Boston naming test; C7 neurotomy=right neurotomy of the seventh cervical nerve at the intervertebral foramen; SLT=speech and language therapy

Fig 4

Dynamic changes in correlation map between BNT score and brain activation during overt picture naming in C7 neurotomy plus intensive SLT group. Top images are schematic of proposed bilateral pathway for language processing based on dual stream model by Hickok and Poeppel. The dorsal stream (green) projects from superior temporal gyrus towards supramarginal gyrus, inferior frontal gyrus, and regions in motor pathways, whereas the ventral stream (brown) projects towards anterior middle and inferior temporal gyrus and inferior front gyrus. The BNT score in the neurotomy plus intensive SLT group correlated with brain activation in right supramarginal gyrus and right inferior frontal gyrus at one month, and with right supramarginal gyrus and left inferior temporal gyrus at six months. No significant cluster was observed at baseline in either group. The probability threshold for all images was set at P<0.005 and cluster corrected at P<0.05. BNT=Boston naming test; C7 neurotomy=neurotomy of the seventh cervical nerve at the intervertebral foramen; SLT=speech and language therapy