Challenges in Recruitment for the Study of Noninvasive Brain Stimulation in Stroke: Lessons from Deep Brain Stimulation.
OBJECTIVE
Noninvasive brain stimulation (NIBS) can augment functional recovery following stroke; however, the technique lacks regulatory approval. Low enrollment in NIBS clinical trials is a key roadblock. Here, we pursued evidence to support the prevailing opinion that enrollment in trials of NIBS is even lower than enrollment in trials of invasive, deep brain stimulation (DBS).


METHODS
We compared 2 clinical trials in stroke conducted within a single urban hospital system, one employing NIBS and the other using DBS, (1) to identify specific criteria that generate low enrollment rates for NIBS and (2) to devise strategies to increase recruitment with guidance from DBS.


RESULTS
Notably, we found that enrollment in the NIBS case study was 5 times lower (2.8%) than the DBS trial (14.5%) (χ(2) = 20.815, P < .0001). Although the number of candidates who met the inclusion criteria was not different (χ(2) = .04, P < .841), exclusion rates differed significantly between the 2 studies (χ(2) = 21.354, P < .0001). Beyond lack of interest, higher exclusion rates in the NIBS study were largely due to exclusion criteria that were not present in the DBS study, including restrictions for recurrent strokes, seizures, and medications.


CONCLUSIONS
Based on our findings, we conclude and suggest that by (1) establishing criteria specific to each NIBS modality, (2) adjusting exclusion criteria based on guidance from DBS, and (3) including patients with common contraindications based on a probability of risk, we may increase enrollment and hence significantly impact the feasibility and generalizability of NIBS paradigms, particularly in stroke.
['Potter-Baker|Kelsey A|KA|', 'Bonnett|Corin E|CE|', 'Chabra|Patrick|P|', 'Roelle|Sarah|S|', 'Varnerin|Nicole|N|', 'Cunningham|David A|DA|', 'Sankarasubramanian|Vishwanath|V|', 'Pundik|Svetlana|S|', 'Conforto|Adriana B|AB|', 'Machado|Andre G|AG|', 'Plow|Ela B|EB|']
D000328:Adult D000368:Aged D001921:Brain D002986:Clinical Trials as Topic D046690:Deep Brain Stimulation D005260:Female D006801:Humans D008297:Male D008875:Middle Aged D010146:Pain D059408:Pain Management D020127:Recovery of Function D020521:Stroke D050781:Transcranial Magnetic Stimulation D016896:Treatment Outcome D055815:Young Adult
clinical trial DBS TMS patient recruitment rehabilitation tDCS