4G versus 3G-enabled telemedicine in prehospital acute stroke care

Background Time to reperfusion treatment is closely related to outcome in ischemic stroke. Prehospital stroke work-up in CT-equipped mobile stroke units is effective in reducing time to thrombolytic treatment. Current evidence predominantly comes from mobile stroke units staffed with neurologists but telemedicine-guided management may be acceptable for providing neurological expertise in ambulances. With unsatisfactory experiences in third-generation (3G)-based approaches, fourth-generation (4G) networks may provide adequate audio-visual quality but systematic comparisons of technological parameters and decision-making are lacking. Methods Trained actors presented stroke symptoms and paramedics assisted the remotely guided extended National Institutes of Health Stroke Scale (eNIHSS) assessment on the mobile stroke unit in Berlin, Germany. We compared technical parameters of 4G and 3G connections, assessed audio-visual quality of examination, and analyzed reliability of neurological assessment and treatment decisions made by the remote neurologist versus the mobile stroke unit neurologist. Results 4G and 3G connections were evaluated in 40 scenarios each. Connectivity was not available in 17% of 4G- and 15% of 3G-attempts with 6% simultaneous unavailability of both networks. The remote examiners graded audio and video quality in 4G better than in 3G with slightly shorter assessment duration in 4G (mean: 9 (SD:5) vs. mean 11 (SD:3) min, p = 0.10). Reliability of the eNIHSS sum scores was high with intraclass correlation coefficients of 0.99 (95% CI: 0.987-1.00) for 4G and 0.98 (95% CI: 0.96-0.99) for 3G. None of the remote treatment decisions differed from onsite decisions. Conclusions 4G mobile communications provided higher quality of video-examination and allowed reliable remote assessment of stroke symptoms but coverage was still incomplete in both networks.