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)