Improvement of language function after Contralateral Seventh Cervical Nerve Transfer in hemiplegic patients combined with post-stroke aphasia: a prospective observational cohort study

Background While the contralateral seventh cervical nerve (CC7) cross transfer was designed to reconstruct paralyzed arm function after stroke, improvement in language function was found in patients combined with aphasia. Objective To evaluate the effect of improvement in language function after CC7 cross transfer in stroke patients with chronic aphasia and explore its potential mechanism. Methods In a prospective observative cohort, patients diagnosed with hemiplegia combined with aphasia were included. The language function was evaluated through the changes of Aphasia Quotient evaluated by Western Aphasia Battery (WAB-AQ) as well as its four subtests from baseline to 1 week and 6 months after the surgery. Patients also received oral agility test by Boston Diagnostic Aphasia Examination (BDAE-OA). Resting-state functional MRI (rs-fMRI) was scanned before and over 6 months after the surgery to explore the potential central mechanism in language improvements. Results The average increase of WAB-AQ was 8.08 points from baseline to 1 week post-operatively (P<0.001, 95%CI: 5.05-11.10), and 9.51 from baseline to 6-month (P<0.001, 95%CI: 6.75-12.27). In 8 patients who participant in BDAE-OA, the average increase was 3.7 points (95%CI: 0.56-6.84; corrected P =0.023) from baseline to 1-week follow-up, and 5.3 points from baseline to 6 months follow-up. Significant higher local activity was detected at right precentral cortex, right gyrus rectus, and right anterior cingulate cortex after the surgery from rs-fMRI. Conclusions Immediate and stable improvement in language function was detected after CC7 cross transfer in hemiplegic patients combined with aphasia, which may be realized through enhanced function of language network in the bilateral hemisphere.