Raising Clinical Suspicion for Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-like Episodes (MELAS): Recurrent Seizures, Stroke-like Episodes, and Cortical Atrophy in Young Patients
Srikar Tallavajhala1, Krzysztof Bochenek2, Aanini Dwivedi1, Alexa Caffio-Learner1, Suha Suliman1, Sairah Bashir3, Mohankumar Kurukumbi3
1University of Virginia School of Medicine, 2Department of Radiology, 3Department of Neurology, Inova Fairfax Hospital
Objective:
Phenotypic variability and lack of familiarity with criteria can make diagnosis of MELAS challenging. Clinicians should be cognizant and consider early MR spectroscopy with genetic screening.
Background:
MELAS is a rare, progressive mitochondrial disorder that can be missed if clinical suspicion is low.
Design/Methods:
A thorough chart review was conducted.
Results:

Case 1: A 33-year-old female presented with recurrent right-sided visual scotomas. MRI showed focal DWI changes to the occipital lobe. Continuous video-EEG showed subclinical occipital lobe seizures. The patient had a recurrent episode of right-sided vision changes, speech difficulty and poor comprehension. MRI showed cortical atrophy and DWI abnormalities without ADC mismatch in the left occipital and left posterior temporal lobes. Stroke and infectious workup was unrevealing. Another episode of numbness, hearing loss, and word-finding difficulty prompted MR spectroscopy, screening lactate level, and genetic analysis. The diagnosis of MELAS was established based on the patient’s recurrent seizures, cortical visual loss, acute lesions on MRI, high plasma lactate, and a confirmed, possibly pathogenic mutation in MT-TL1. She suffered from neurological deterioration and passed away 6 months later. 

 

Case 2: Patient is a 26-year-old male with a long history of migraines with visual disturbances. MRI showed edema in the left occipital lobe. Subsequently, he presented with an intractable headache associated with left-sided peripheral vision loss and left leg weakness. MRI was notable for hyperintense flair signal in the right occipital lobe and marked atrophy. EEG showed frequent seizures and workup for stroke and encephalitis was unrevealing. Lactate levels were elevated and genetic screening was notable for MT-TL1 mutation. 

Conclusions:
Patients younger than 40 with stroke-like symptoms, brain atrophy disproportionate to age, and negative infectious and vascular workup should be evaluated for MELAS. MR Spectroscopy, lactate levels, and genetic testing are important non-invasive screening measures. 
10.1212/WNL.0000000000203380