Leigh syndrome is a progressive neurodegenerative disorder of childhood. The symmetrical necrotic lesions in the basal ganglia and/or brainstem which appear as hyperintense lesions on T2-weighted MRI is characteristic and one of the essential diagnostic criteria. Recognising this MR imaging pattern in a child with neurological problems should prompt the clinician to investigate for Leigh syndrome. We present here two cases of Leigh syndrome due to different biochemical/genetic defects, and discuss the subtle differences in their MR neuroimaging features.
Neurosyphilis is a broad term used to describe an infection caused by Treponema pallidum in the central nervous system. While this was a common cause of stroke in the 19th century, it saw a decline after the introduction of penicillin. However, in the recent past, there has been an increase in the incidence of syphilis, especially with HIV coinfection. Neurosyphilis results from an untreated primary syphilis. Neuropsychiatric disorder appears to be the commonest manifestation followed cerebrovascular accident, myelopathy, ocular disease and seizure. Known as the 'great imitator', this entity, however, may be easily missed if not for a high index of suspicion. This is especially so because of its similar presentation to other more common clinical conditions. We describe the case of a 39-year-old man displaying acute global aphasia and right-sided facial weakness in keeping with a left middle cerebral artery infarct. This was confirmed with computed tomography of the brain, and subsequently, further investigations revealed a diagnosis of neurosyphilis. The patient was treated with intravenous benzylpenicillin and recovered well with treatment.