Brachial plexus injury and resting-state fMRI: Need for consensus.

Objective: The purpose of the study is to conduct the systematic review of literature available on resting-state functional MRI (fMRI) and brachial plexus injury.

Methods: We reviewed all the literature that are available on PubMed; keywords used were resting state, brachial plexus injury, and functional imaging. The reference papers listed were also reviewed. The research items were restricted to publications in English. Some papers have also incorporated studies such as task-based fMRI and transcranial magnetic stimulation (TMS), but only resting-state studies were included for this review.

Results: A total of 13 papers were identified, and only 10 were reviewed based on the criteria. The reviewed papers were further categorized on the basis of whether or not any surgical intervention was done. Seven papers have surgical management such as contralateral cervical 7 (CC7) neurotisation or intercostal nerve (ICN) musculocutaneous nerve (MCN) neurotisation.

Conclusion: There is conclusive evidence showing that there is cortical reorganisation following brachial plexus injury in both birth and traumatic cases. The changes are restricted to some of the resting-state networks only (default mode network, sensorimotor network, in particular). However, no study till date has focused on a far more longitudinal approach at studying these changes. It will be interesting to see the exact time and effect of these changes.