Detection of preclinically latent hyperperfusion due to stroke-like episodes by arterial spin-labeling perfusion MRI in MELAS patients

Increased cerebral blood flow as a predictor of episodes in MELAS using multimodal MRI

“…Here, focal hyperperfusion was detected in the recovery state of three MELAS patients, and ultimately progressed into stroke‐like lesions. This is consistent with a previous report indicating that subclinical lesions appearing hyperperfused on ASL occurred more than 3 months before clinical onset …”

Review: Central nervous system involvement in mitochondrial disease

“…Recently there have been a number of radiological studies to determine the mechanisms contributing to the onset of a stroke‐like episode and also to monitor its progression as they can migrate to other regions of the brain. There is evidence that during preclinical or acute onset of a stroke‐like episode, focal hyperperfusion can be detected by either arterial spin labelling or SPECT and can manifest before any structural abnormalities might be seen on MRI . In addition to this, there are reports of vasodilation following magnetic resonance angiogram and impaired cerebrovascular reactivity .…”

Arterial Spin–Labeled Perfusion Imaging in Acute Ischemic Stroke

“…Particularly interesting is the possibility that ASL might be sensitive to pre-clinical ischemic episodes in children with mitochondrial disease. Ikawa et al 24 showed abnormally high ASL signal in a patient with myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome several months before the clinical appearance of a diffusion-positive stroke-like episode, suggesting it could be used for management. More recently, small studies have also been performed in peri-natal stroke, 25, 26 a challenging group of patients, due to their small size, motion, and longer arterial arrival times.…”