Abstract | PURPOSE: The aim of this study was to apply positron emission tomography (PET) with C-8-dicyclopropylmethyl-1-methyl-3-propylxanthine (MPDX), a radioligand for adenosine A1 receptor (A1R), to patients with hemianopia caused by brain injury to study neurorepair mechanisms in the brain. PATIENTS AND METHODS: Four patients with homonymous hemianopia and 15 healthy subjects were examined using PET to measure cerebral glucose metabolism, C- flumazenil (FMZ) binding to the central benzodiazepine receptor, and MPDX binding to A1R. Left and right regions of interest (ROIs) were selected, and semiquantitative data on the 3 kinds of PET examinations were obtained. The ROIs were referenced using the data for homologous regions in the contralateral hemisphere [ipsilateral/contralateral (I/C) ratio]. RESULTS: The I/C ratios for cerebral glucose metabolism and FMZ binding were low in the primary visual cortex ( PVC) and visual association cortex in all the patients, whereas MPDX binding increased in the PVC in patients 1 and 2. Patients 1 and 2 experienced improvement in their visual field after 1 year. However, the other 2 patients showed no changes. We observed an increase in MPDX binding to A1R in the injured portion of the PVC in the patients who recovered. CONCLUSIONS: Evaluation of A1R by MPDX-PET may be useful for predicting prognosis and understanding the compensatory and reorganization processes in hemianopia caused by organic brain damage.
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Authors | Yukihisa Suzuki, Tadashi Nariai, Motohiro Kiyosawa, Manabu Mochizuki, Yuichi Kimura, Keiichi Oda, Kenji Ishii, Kiich Ishiwata |
Journal | Clinical nuclear medicine
(Clin Nucl Med)
Vol. 37
Issue 12
Pg. 1146-51
(Dec 2012)
ISSN: 1536-0229 [Electronic] United States |
PMID | 23154471
(Publication Type: Case Reports, Journal Article)
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Chemical References |
- 1-methyl-8-dicyclopropylmethyl-1-methyl-3-propylxanthine
- Receptor, Adenosine A1
- Xanthines
- Flumazenil
- Glucose
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Topics |
- Adult
- Aged
- Brain Injuries
(complications)
- Female
- Flumazenil
(metabolism)
- Glucose
(metabolism)
- Hemianopsia
(complications, diagnostic imaging, metabolism)
- Humans
- Male
- Middle Aged
- Positron-Emission Tomography
- Prognosis
- Receptor, Adenosine A1
(metabolism)
- Xanthines
(metabolism)
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