Decreased thalamic metabolism without thalamic magnetic resonance imaging abnormalities following shearing injury to the substantia nigra.
A 36-year-old man had fallen about 8 metres. Radiographs showed a mandibular fracture, indicating rotatory force applied to the head. Fluid-attenuated inversion recovery (FLAIR) imaging showed hyperintensity in both medial temporal lobes, left medial midbrain, right midbrain including cerebral peduncle, left pulvinar, left external capsule, fornix, splenium of corpus callosum, and deep white matter of both frontal lobes. Quantitative [(18)F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) indicated markedly suppressed glucose metabolism in the left thalamus but not markedly in the striatum. At that time the neurologic examination demonstrated complete left hemiparesis, severe rigidity of the right upper extremity, and inability to move the right hand and fingers. Levodopa at 300-600 mg/day improved movement of the fingers, decreased the rigidity in the extremity, and lessened the metabolic abnormality. Diminished metabolism in the left thalamus may have contributed to symptoms. The case illustrates the usefulness of PET in disclosing symptom causing abnormalities not detected by magnetic resonance imaging.
Nakamizo
Akira
A
Department of Neurosurgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. nakamizo@ns.med.kyushu-u.ac.jp
Inamura
Takanori
T
Amano
Toshiyuki
T
Inoha
Satoshi
S
Tokuda
Kentaro
K
Yasuda
Osamu
O
Ikezaki
Kiyonobu
K
Fukui
Masashi
M
D000058:Accidental Falls; D000328:Adult; D001930:Brain Injuries / Q000000981:diagnostic imaging* / Q000378:metabolism; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008337:Mandibular Fractures / Q000000981:diagnostic imaging; D013378:Substantia Nigra / Q000000981:diagnostic imaging* / Q000293:injuries*; D013788:Thalamus / Q000000981:diagnostic imaging / Q000378:metabolism*; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed
D019788:Fluorodeoxyglucose F18