Abstract
Background Mitochondrial disorders can manifest in stroke-like episodes which can pose several diagnostic and management challenges in the acute setting.
Presentation We present the case of a 45-year-old female, presenting with bilateral cerebral infarcts on a background of cerebral atrophy, cognitive decline, ataxia, sensorineural hearing loss, peripheral neuropathy, Type 1 Diabetes mellitus, and androgen insensitivity syndrome with investigations revealing a new diagnosis of Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-like episodes (MELAS).
Management and Outcomes Initial diagnostic investigations revealed an elevated serum and cerebrospinal fluid lactate, and MRI Brain revealed bilateral cerebral infarcts. Genetic testing on blood confirmed the presence of the m.3243A>G pathogenic variant in the mitochondrial gene MT-TL1, one of the common genetic mutations causing MELAS in the caucasian population. The heteroplasmy level on the sample was 24.6%. Further cascade testing identified several other affected family members. Ultimately, the patient was managed with oral arginine and subsequently oral taurine for secondary stroke prevention.
Discussion This case demonstrates the importance of recognising mitochondrial disorders in atypical stroke presentations as the acute and long-term treatments can vary from standard stroke care. While treatment with arginine therapy acutely is established in management of stroke-like presentations in MELAS, taurine therapy has also demonstrated potential reduction in stroke-like events in this patient group.1 2 Making an accurate diagnosis is important in guiding long term management, family counselling and identifying relatives at risk who would benefit from early arginine treatment when presenting with stroke-like episodes, and screening for associated co-morbidities.
References
Rikimaru M, Ohsawa Y, Wolf AM, Nishimaki K, Ichimiya H, Kamimura N, Nishimatsu S, Ohta S, Sunada Y. Taurine ameliorates impaired the mitochondrial function and prevents stroke-like episodes in patients with MELAS. Intern Med. 2012;51(24):3351–7. doi: 10.2169/internalmedicine.51.7529. Epub 2012 Dec 15. PMID: 23257519.
Ohsawa Y, Hagiwara H, Nishimatsu SI, Hirakawa A, Kamimura N, Ohtsubo H, Fukai Y, Murakami T, Koga Y, Goto YI, Ohta S, Sunada Y; KN01 Study Group. Taurine supplementation for prevention of stroke-like episodes in MELAS: a multicentre, open-label, 52-week phase III trial. J Neurol Neurosurg Psychiatry. 2019 May;90(5):529–536. doi: 10.1136/jnnp-2018-317964. Epub 2018 Apr 17. PMID: 29666206; PMCID: PMC6581075.