Case Report
A34- year old right-handed man was brought to the emergency department with left upper extremity weakness and severe encephalopathy. In his past medical history, multiple hospitalizations were found due to similar symptoms. The patient’s first admission dates back to 7 years ago when he was admitted with bilateral visual loss, which had gradually become worsen during 20 days. He also gave history of new onset seizure and was admitted to rule out cerebral venous thrombosis (CVT).
Physical Examination revealed left homonymous hemianopia. Brain Magnetic Resonance Imaging (MRI), Magnetic Resonance Venography (MRV), and Magnetic Resonance Angiography (MRA) were done and although MRV and MRA study were normal, Brain compound tomography (CT) and MRI findings were suggestive of right temporal lobe ischemia. (Figure1) Laboratory tests which were conducted for the patient were all within normal ranges, including screening for vasculitis. Echocardiography was performed and showed Patent Foramen Ovale (PFO).
Visual field was improved, but his seizure like movements persisted and were misdiagnosed as pseudo-seizures.
6 years ago, he was admitted again because of sudden onset visual loss, which was accompanied with nausea and vomiting. Neuro-ophthalmological examinations disclosed homonymous hemianopia of right side. His vision was gradually enhanced during the one month. Other neurological examinations were unremarkable. Complete paraclinical and laboratory studies were performed including cerebrospinal fluid analysis, electrocardiogram (ECG), brain CT scan and brain MRI. All came back negative except brain MRI which demonstrated signal changes in occipital lobe. (Figure1)
Complete laboratory tests including autoimmune encephalopathy panel was done which was negative in the patient. CSF analysis revealed high lactate levels, which along with the high serum lactate level suggested the diagnosis of mitochondrial encephalopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome. Other laboratory tests were normal which are summarized in Table 1.
In his last admission, the neurological physical examination revealed left side hemiplegia, significant cognitive decline (mini mental status examination: 17).
Echocardiography was performed and showed that left atrial appendage (LAA) was filled with clot, ejection fraction (EF) of 60 percent and PFO, and he received warfarin.
To confirm the diagnosis of mitochondrial disorders muscle biopsy was performed and it revealed ragged red fibers (RRF). (Figure2)