Article Text
Statistics from Altmetric.com
Case history
A 70-year-old woman presented to the hospital's general physicians with a 3-week exacerbation of pre-existing migrainous headache, speech and behavioural change. There was a 20-year history of slowly progressive bilateral sensorineural hearing loss, and a 10-year history of diabetes mellitus. On examination, there was marked receptive and expressive dysphasia, but no other abnormalities. She was afebrile. Her leucocyte count and inflammatory markers were normal. Uncontrasted CT scan of the brain showed bilateral temporal lobe low attenuation, more on the right side, with bilateral basal ganglia calcification (figure 1A, B). The lesions could not be characterised further as she could not tolerate MR imaging. Cerebrospinal fluid (CSF) examination was acellular, with normal protein and glucose. EEG showed generalised slowing, consistent with a diffuse disorder of cortical function. An autoimmune screen, including antinuclear antibodies, antithyroid peroxidase antibodies, antivoltage-gated potassium channel antibodies, anti-NMDA receptor antibodies and antineuronal antibodies was negative. Serum protein electrophoresis, carotid Doppler ultrasound and echocardiogram were normal.
CT scan of brain in case of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) presenting with migrainous headache and dysphasia. The encephalopathy in association with bilateral temporal lobe hypointensities (A) was initially interpreted as viral encephalitis. In retrospect, the additional clinical features and the bilateral basal ganglia calcification (B) were more suggestive of MELAS, which was confirmed 3 years later when the patient presented with similar clinical and more extensive imaging features (C, D).
She received intravenous aciclovir for a presumptive diagnosis of herpes simplex virus encephalitis. CSF PCR for herpes simplex virus was negative and aciclovir was stopped after 1 week. The following day she had a single generalised tonic-clonic seizure. Her clinician started phenytoin and reinstated aciclovir for a further week. She was discharged with a mild residual receptive dysphasia and short-term memory impairment, but independent for most activities of …
Footnotes
-
Contributors SA drafted the manuscript. TV, GT, JP and MRT edited the manuscript.
-
Competing interests None.
-
Patient consent Obtained.
-
Provenance and peer review Not commissioned; externally peer reviewed. This paper was reviewed by Patrick Chinnery, Newcastle-upon-Tyne, UK.
Linked Articles
- Editors' choice
Read the full text or download the PDF:
Other content recommended for you
- Clinical mitochondrial genetics
- Mitochondrial disease: mimics and chameleons
- MELAS: a new disease associated mitochondrial DNA mutation and evidence for further genetic heterogeneity
- Clinical features, investigation, and management of patients with defects of mitochondrial DNA
- Could it be mitochondrial? When and how to investigate
- Six-year prospective follow-up study in 151 carriers of the mitochondrial DNA 3243 A>G variant
- The UK MRC Mitochondrial Disease Patient Cohort Study: clinical phenotypes associated with the m.3243A>G mutation—implications for diagnosis and management
- Diagnosis and therapy in neuromuscular disorders: diagnosis and new treatments in mitochondrial diseases
- Mitochondria
- Frequency of mitochondrial transfer RNA mutations and deletions in 225 patients presenting with respiratory chain deficiencies