Importance of Distinguishing Between Mitochondrial Encephalomyopathy With Elderly Onset of Stroke-Like Episodes and Cerebral Infarction

Clinical features, pathogenesis, and management of stroke-like episodes due to MELAS

Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) is a disease that should be considered as a differential diagnosis to acute ischemic stroke taking into account its onset pattern and neurological symptoms, which are similar to those of an ischemic stroke. Technological advancements in neuroimaging modalities have greatly facilitated differential diagnosis between stroke and MELAS on diagnostic imaging. Stroke-like episodes in MELAS have the following features: (1) symptoms are neurolocalized according to lesion site; (2) epileptic seizures are often present; (3) lesion distribution is inconsistent with vascular territory; (4) lesions are common in the posterior brain regions; (5) lesions continuously develop in adjacent sites over several weeks or months; (6) neurological symptoms and stroke-like lesions tend to be reversible, as presented on magnetic resonance imaging; (7) the rate of recurrence is high; and; (8) brain dysfunction and atrophy are slowly progressive. The m.3243ANG mutation in the MT-TL1 gene encoding the mitochondrial tRNA^Leu(UUR) is most commonly associated with MELAS. Although the precise pathophysiology is still unclear, one possible hypothesis for these episodes is a neuronal hyperexcitability theory, including neuron-astrocyte uncoupling. Supplementation, such as with L-arginine or taurine, has been proposed as preventive treatments for stroke-like episodes. As this disease is still untreatable and devastating, numerous drugs are being tested, and new gene therapies hold great promise for the future. This article contributes to the understanding of MELAS and its implications for clinical practice, by deepening their insight into the latest pathophysiological hypotheses and therapeutic developments.

Influence of butyphthalide combined with urinary kallikrein in ACI treatment on neuro-cytokines and vascular endothelial function and its clinical effect

Objective: To study the influence of butyphthalide combined with urinary kallikrein in acute cerebral infarction (ACI) treatment on neuro-cytokines and indicators of vascular endothelial function, observe the curative effect and adverse effects, and discuss its safety and feasibility.Method: 110 ACI patients were chosen as the objects, and classified into observation group (55 cases) and control group (55 cases) according to the method of random number table. Butyphthalide injection combined with urinary kallikrein was adopted for the observation group based on conventional treatment, while cinepazide maleate injection combined with alprostadil injection was applied for the control group based on conventional treatment. The following indicators of both groups were compared before and after treatment: neurotrophic factor (NTF), nerve growth factor (NGF), neuron specific enolase (NSE); content of CXC chemotactic factor ligand 16 (CXCL16), soluble CD ligand (CD40L), Fibulin-5 and high mobility group box B1 (HMGB1); the content of indicators of vascular endothelial function including plasma endothelin -1 (ET-1) and no therapeutic effects and adverse effects were recorded.Results: NSE of both groups after treatment decreased obviously, and the content of NTF and NGF increased obviously. NSE content of observation group was lower than that of control group. NTF content and NGF content of observation group were higher than those of control group. The differences had statistical significance (p < 0.05). The levels of CXCL16, CD40L, Fibulin-5 and HMGB1 declined obviously, compared with pre-treatment, and the levels of observation groups were significantly lower than those of control grip. The differences had statistical significance (p < 0.05). ET-1 level rose significantly after treatment, and NO level declined obviously after treatment. ET-1 level of observation group was significantly higher than that of control group, and NO level of observation group was significantly lower than that of control group. The difference had statistical significance (p < 0.05). Clinical effect of observation group was significantly higher than that of control group. The difference had statistical significance (p < 0.05). The comparison difference of both groups in the occurrence rate of adverse effects had no statistical significance (p > 0.05).Conclusion: The application of butyphthalide combined with urinary kallikrein in ACI treatment can effectively inhibit secretion and release of neuro-cytokines, and improve patients' vascular endothelial function, with significant treatment effect and high safety. Therefore, it deserves to be promoted clinically.

Dynamic derangement in amino acid profile during and after a stroke-like episode in adult-onset mitochondrial disease: a case report

Background

Maternally inherited diabetes and deafness, and mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes are examples of mitochondrial diseases that are relatively common in the adult population. Mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes are assumed to be associated with decreases in arginine and citrulline. Biomarkers, such as growth differentiation factor-15, were developed to assist in the diagnosis of mitochondrial diseases.

Case presentation

A 55-year-old Japanese man, an insulin user, presented after a loss of consciousness. A laboratory test showed diabetic ketoacidosis. He and his mother had severe hearing difficulty. Bilateral lesions on magnetic resonance imaging, the presence of seizure, and an elevated ratio of lactate to pyruvate, altogether suggested a diagnosis of mitochondrial disease. Mitochondrial DNA in our patient’s peripheral blood was positive with a 3243A>G mutation, which is the most frequent cause of maternally inherited diabetes and deafness, and mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes. As a result, maternally inherited diabetes and deafness/mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes was diagnosed. We measured growth differentiation factor-15 and multiple amino acids in his blood, longitudinally during and after the stroke-like episode. Growth differentiation factor-15 was increased to an immeasurably high level on the day of the stroke-like episode. Although his diabetes improved with an increased dose of insulin, the growth differentiation factor-15 level gradually increased, suggesting that his mitochondrial insufficiency did not improve. Multiple amino acid species, including arginine, citrulline, and taurine, showed a decreased level on the day of the episode and a sharp increase the next day. In contrast, the level of aspartic acid increased to an extremely high level on the day of the episode, and decreased gradually thereafter.

Conclusions

Growth differentiation factor-15 can be used not only for the diagnosis of mitochondrial disease, but as an indicator of its acute exacerbation. A stroke-like episode of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes reflects a drastic derangement of multiple amino acids. The involvement of aspartic acid in the episodes should be explored in future studies.

Comparison of magnetic resonance spectroscopy (MRS) with arterial spin labeling (ASL) in the differentiation between mitochondrial encephalomyopathy, lactic Acidosis, plus stroke-like episodes (MELAS) and acute ischemic stroke (AIS)

To compare the utility and limitation of magnetic resonance spectroscopy (MRS) and arterial spin labeling (ASL) in the differentiation between mitochondrial encephalomyopathy, lactic acidosis, plus stroke-like episodes (MELAS) and acute ischemic stroke (AIS), a retrospective review of 17 MELAS and 26 AIS patients were performed. In all patients both MRS and ASL scans were performed within 1 week after admission. Demographic, clinical, laboratory and MR imaging data were reviewed and compared between the two groups. Compared with AIS, MELAS patients had a younger age of onset, a longer disease duration, a higher occurrence of epilepsy attack, occipital and parietal lesions, and dilated cerebral arteries (P < 0.05). In all MELAS patients lactate peak and hyperperfusion of the lesion was revealed. However in AIS lactate peak was observed in only 69.2% and hyperperfusion was observed in only 34.6% ischemic lesions (P < 0.05). Choline/Creatine ratios and Lactate/Creatine ratios were higher in AIS, while in MELAS cerebral blood flow and lesion-normal perfusion ratio was much higher (P < 0.05). No correlations was found between metabolite ratios and perfusion parameters in either group (P > 0.05). Area under curve (AUC) of perfusion for the differentiation between MELAS and AIS was 0.958 (P < 0.001). The cut-off value was 2.075, with a sensitivity of 88.2% and a specificity of 96.2%. AUC of Lactate/Creatine ratio was 0.469 (P = 0.737). Utility of MRS is limited in the differentiation between MELAS and AIS, while MR perfusion profiles are much more sensitive and specific.