Delayed decrease in hemispheric cerebral blood flow during Wada test demonstrated by 99mTc-HMPAO single photon emission computer tomography.
We describe how brain regions with a flow (and metabolism) decrease can be visualized after an injection of short-acting barbiturate in one of the internal carotid arteries during a Wada test. An intravenous administration of 99mTc-HMPAO (Ceretec) was used to mark the relative flow distribution. The 99mTc-HMPAO distribution in the brain was recorded three-dimensionally about 1 h later, by means of a single photon emission computer tomograph. We show that the timing of the intravenous 99mTc-HMPAO administration during the Wada test is important for the visualization of the low-flow regions. The administration of the tracer substance should be delayed at least 30 s after the first signs of the barbiturate effect. The rCBF decrease in the barbiturate-injected cerebral hemisphere was associated with a simultaneous decrease in the contralateral, pharmacologically not directly affected, cerebellar hemisphere (crossed cerebellar diaschisis).
Ryding
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E
Department of Clinical Neurophysiology, University Hospital, Lund, Sweden.
Sjöholm
H
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Skeidsvoll
H
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Elmqvist
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D
D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000502:physiology; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory / Q000502:physiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D015609:Organotechnetium Compounds; D010091:Oximes; D011877:Radionuclide Imaging; D013060:Speech / Q000502:physiology*; D019690:Technetium Tc 99m Exametazime
D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime