Case reportEpilepsy Surgery in a Case of Encephalitis: Use of 11C-PK11195 Positron Emission Tomography
Introduction
Refractory seizures in patients with encephalitis can be very difficult to manage, and probably contribute to further brain injury. Given that some of these children manifest focal features in seizure semiology and on their electroencephalograms, their seizures may be emanating from focal brain regions of inflammation or ischemic injury. Activated microglia in areas of inflammation express many types of receptors, including peripheral-type benzodiazepine receptors [1], [2]. The positron emission tomography radiotracer 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)-3-isoquinoline carboxamide (PK11195) labeled with 11C specifically binds to the peripheral-type benzodiazepine receptor and has been used to image areas of neuroinflammation in various conditions [1], [3], [4].
In the present case, 11C-PK11195 positron emission tomography was used in the evaluation and surgical treatment of a 5-year-old boy with refractory seizures associated with encephalitis of unknown etiology—a novel use of 11C-PK11195 positron emission tomography.
Section snippets
Case Report
The patient was a previously normal 5-year-old right-handed boy who developed intermittent high-grade fever associated with cough of 1-week duration. He was found to have an ear infection with viral pneumonia and was started on azithromycin. Despite this antibiotic, however, he remained febrile and was irritable. On the day of admission, he had a generalized convulsion lasting 5 to 7 minutes, followed by postictal lethargy. He was subsequently taken to the emergency department, where he
Discussion
In patients with intractable epilepsy not responding to treatment, underlying brain inflammation should be considered. The inflammation may be very subtle or undetectable, without any disruption of the blood-brain barrier, as in the present case, in which all investigations—imaging (including computed tomography, magnetic resonance imaging with contrast, magnetic resonance spectroscopy, and [18F]fluorodeoxyglucose positron emission tomography), biochemical, serological, and immunological—were
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