Late resolution of diffusion-weighted MRI changes in a patient with prolonged reversible ischemic neurological deficit after thrombolytic therapy

Background-Reduced apparent diffusion coefficients (ADCs) correlate with ce rebral ischemia. The combination of ADC with techniques to measure cerebral perfusion may help to assess the effect of treatment. Case Description-The authors describe a patient who experienced an acute st roke with hemianopia, consequently treated with intravenous recombinant tis sue plasminogen activator. Positron emission tomographic imaging and MRI, i ncluding diffusion-weighted MRI, were performed during and shortly after tr eatment with recombinant tissue plasminogen activator and 34 to 35 hours la ter. Cerebral perfusion of the left occipital region was reduced to 74%. Di ffusion-weighted MRI detected a territory of restricted water movement in t he corresponding area. Further magnetic resonance sequences did not show an y pathologies. In follow-up, positron emission tomography demonstrated repe rfusion. The volume of diffusion and ADC abnormalities detected by MRI decr eased markedly. A few hours later, the patient recovered completely. A thir d MRI examination 10 days later showed normal findings. Conclusions-In a patient with prolonged reversible ischemic neurological de ficit, resolution of early diffusion changes corresponded to cerebral reper fusion and to the recovery of clinical symptoms.