Evaluation of vascular autoregulation in mitochondrial myopathy, encephalopathy, lactic acidosis,and stroke-like episodes patients / 中华神经科杂志

ABSTRACT

Objective To investigate the cerebral vascular autoregulation in patients with mitochondrial encephalomyopathy with lactic acidosis and strokc-like episodes (MELAS) during the remission of stroke-like episodes,including cerebrovascular CO2 reactivity and vascular endothelial function.Methods Twenty-nine MELAS patients confirmed by genetic analysis were recruited in this study. They underwent the examination at least 2 weeks after the onset of last stroke-like episode.Twenty-eight healthy people were collcctcd as healthy controls. Carotid ultrasound and brain magnetic resonance angiogram (MRA) were done to evaluate the cervical and intracranial appearance of large arteries. Evaluation of vascular autoregulation included (1) the cerebrovascular CO2 reactivity with breath-holding test by transcranial Doppler and calculating breath holding index (BHI),and ( 2 ) flow-mediatcd dilation ( FMD )and nitroglycerin-mediated dilation with ultrasound assessment of humeral artery.Independent-samples t test was done between the results of two groups.Results Carotid ultrasound and cranial MRA revealed no abnormalities in both MELAS patients and healthy controls.The BHI of MELAS patients was significantly decreased than that of normal controls ( 1.36 ± 0.52 vs 1.81 ±0.26,t =- 3.693,P ＜ 0.01 ),and the FMD of MELAS patients was also significantly lower than that of normal controls (11.0％ ±4.8％ vs 15.8％ ±5.8％,t =-3.390,P ＜0.01).Conclusion The function of vascular autoregulation,including cerebrovascular CO2 reactivity and FMD,is impaired in MELAS patients.