Reversed robin hood syndrome in acute ischemic stroke patients

Background and Purpose - Recurrent hemodynamic and neurological changes with persisting arterial occlusions may be attributable to cerebral blood flow steal from ischemic to nonaffected brain. Methods - Transcranial Doppler monitoring with voluntary breath- holding and serial NIH Stroke Scale ( NIHSS) scores were obtained in patients with acute middle cerebral artery or internal carotid artery occlusions. The steal phenomenon was detected as transient, spontaneous, or vasodilatory stimuli- induced velocity reductions in affected arteries at the time of velocity increase in normal vessels. The steal magnitude (%) was calculated as [( MFVm - MFVb)/MFVb] X 100, where m = minimum and b = baseline mean flow velocities ( MFV) during the 15- to 30- second period of a total 30 second of breath- holding. Results - Six patients had steal phenomenon on transcranial Doppler ( 53 to 73 years, NIHSS 4 to 15 points). Steal magnitude ranged from - 15.0% to - 43.2%. All patients also had recurrent neurological worsening ( > 2 points increase in NIHSS scores) at stable blood pressure. In 3 of 5 patients receiving noninvasive ventilatory correction for snoring/ sleep apnea, no further velocity or NIHSS score changes were noted. Conclusions - Our descriptive study suggests possibility to detect and quantify the cerebral steal phenomenon in real- time. If the steal is confirmed as the cause of neurological worsening, reversed Robin Hood syndrome may identify a target group for testing blood pressure augmentation and noninvasive ventilatory correction in stroke patients.