Sequential Positron Emission Tomographic Evaluations of Brain Metabolism in Acute Herpes Encephalitis

Abstract

This first known positron emission tomography report on metabolic changes in acute herpes simplex virus (HSV-1) encephalitis demonstrates focal hypermetabolism in areas of cerebral cortex adjacent to actively inflamed hippocampus acutely infected with HSV-1. When neuropsychiatric symptoms recurred in a previously healthy 61-year-old patient 1 month after recovering from acute HSV-1 encephalitis, repeat positron emission tomography with fluorodeoxyglucose was helpful in ruling out recurrent active infection by showing marked hypometabolism throughout the previously infected temporal lobe.

Uncommon 18F-FDG-PET/CT findings in patients affected by limbic encephalitis: hyper-hypometabolic pattern with double antibody positivity and migrating foci of hypermetabolism

“…FDG hypermetabolism converting to hypometabolism on a followup examination has already been described, but in a case of herpetic encephalitis [9]. Anyway, this possibility has been excluded in our patient by HSV serology, and a possible epileptic activity was excluded as well.…”

Multitracer study with positron emission tomography in Creutzfeldt-Jakob disease

“…Suspicion of the disease may emerge in patients with rapidly progressive dementia and multifocal signs. It is of utmost importance to obtain a diagnosis as early as possible since some types of rapidly progressive dementia may be associated with treatable diseases (autoimmune, paraneoplastic or viral encephalitis) [1,2,3,4]. The diagnosis of definite CJD is at present only possible through neuropathological examination of brain tissue according to international (WHO and EU) consensus.…”

Cerebral blood flow changes in general paresis following penicillin treatment: A longitudinal single photon emission computed tomography study

“…The mean CBF counts significantly decreased. Previous SPECT and PET studies in cases of herpes and influenza encephalitis showed similar findings; that is, a decrease of CBF or cerebral glucose metabolism following disappearance of clinical symptoms and CSF findings of inflammation 17–20 17–20 …”

“…Previous SPECT and PET studies in cases of herpes and influenza encephalitis showed similar findings; that is, a decrease of CBF or cerebral glucose metabolism following disappearance of clinical symptoms and CSF findings of inflammation. [17][18][19][20] These reports speculated that functional neuroimaging techniques could detect the inflammation-related hyperactivity of the brain. [17][18][19][20] These findings suggest that in cases of general paresis, the decrease of quantitative CBF counts following the penicillin treatment reflects the disappearance of encephalitis caused by the infection with Treponema pallidum.…”

“…[17][18][19][20] These reports speculated that functional neuroimaging techniques could detect the inflammation-related hyperactivity of the brain. [17][18][19][20] These findings suggest that in cases of general paresis, the decrease of quantitative CBF counts following the penicillin treatment reflects the disappearance of encephalitis caused by the infection with Treponema pallidum. After the acute phase, the CSF protein concentration continued to decrease and IQ and overall level of functioning improved gradually over 1 year, and all cases had found work by 1 year of treatment.…”