[en] Sixteen patients with stroke, five patients with permanent regressive ischemic neurologic deficit, and three patients with transient ischemic attacks were studied by single photon emission computed tomography performed within the first hour (early scan) and four hours (delayed scan) after injection of N-isopropyl-p-iodoamphetamine-iodine-123 (IMP). These patients were classified into three groups according to their clinical improvement three months later, and results of single photon emission computed tomography were compared with computed tomographic scan results and correlated to the clinical outcome. Regional brain hypoactivity of IMP differed in some cases between early and delayed IMP scans, showing in those cases a ''redistribution'' activity. The amplitude of this redistribution was significantly correlated with the clinical outcome of patients with stroke, whereas the value of hypoactivity on early IMP scan did not show such a correlation. The higher the redistribution amplitude was, the better was the clinical outcome. Comparative regional brain hypoactivity of IMP on early and delayed scans could represent a prognostic index of clinical recovery inasmuch as it gives information concerning viability of ischemic brain tissue

No abstract available

[en] Published in summary form only

[en] The effect of Acetazolamide (Diamox) on cerebral blood perfusion has been studied in ten patients with cerebral ischemia. Previously, the dose and time effects was tested in two independent groups of male Wistar rats. The cerebral blood perfusion was estimated in man by the cerebral distribution of Isopropyliodoamphetamine ¹²³I (IAMP ¹²³I) visualised with conventional emission tomography. The study involved two identical examinations, the second one followed an injection of 1 g of Diamox. The biodistribution of IAMP ¹²³I was studied in rats without or after different doses of Diamox by counting of target organs. In animals, the pulmonary activity curve versus the dose showed a maximum for 100 mg/kg as the cerebral activity curve increased proportional to the dose. The study of time effect indicated that the best conditions for cerebral imaging by IAMP¹²³I seems to take place twenty minutes after the injection of Diamox. In man, the results obtained after Diamox confirmed the known effect of decreasing of vascular resistance, especially in brain. The total cerebral activity in IAMP¹²³I was increased in all the patients. In six patients of the ten, the activity of the ischemic region was lower than expected because of the high uptake of the controlateral hemisphere. This phenomenon may increase the sensitivity of detecting lightly hypoperfused cerebral regions. In some other patients, a high activity of the ischemic zone seems to proove an early regulation of the regional blood flow and may be an element of good pronostic. Making an Acetazolamide injection before a tomoscintigraphic examination of the brain with IAMP¹²³I seems to provide conventional imaging with sensitivity and pronostic value

[en] Short communication

[en] Published in summary form only

[en] Short communication

No abstract available

[en] To compare the merits of ¹²³I-isopropyl-iodoamphetamine (¹²³I-IMP) and ^99mTc-HMPAO in showing abnormal brain uptake distribution during cerebral ischemia, we studied ten patients during the subacute phase of their stroke, a period where metabolism and blood flow are frequently uncoupled. SPECT imaging was performed using both radiopharmaceuticals in the 10 patients from 48 h to 4 weeks after onset of symptoms. Two patients out of the 10 had similar defects with ¹²³I-IMP and ^99mTc-HMPAO SPECT, the location of the defects corresponding to the area of infarction observed on CT. Six patients had normal ^99mTc-HMPAO SPECT and abnormal ¹²³I-IMP SPECT with defects in the area of infarction shown by CT. The remaining 2 patients had hyperactive abnormalities on ^99mTc-HMPAO in areas corresponding to defects on the ¹²³I-IMP images. Two of the patients with SPECT mismatches were studied again more than 1 month after onset. On reexamination, ^99mTc-HMPAO SPECT which was previously normal or hyperactive became hypoactive with a focal area of decreased activity corresponding to the defect on ¹²³I-IMP. Crossed cerebellar diaschisis was found in 7 patients with ^99mTc-HMPAO and was absent for both ¹²³I-IMP and ^99mTc-HMPAO in 3. We suggest that SPECT with ^99mTc-HMPAO could show transient hyperemia not demonstrated by ¹²³I-IMP whereas in some cases cerebral infarction would be more difficult to demonstrate with ^99mTc-HMPAO than with ¹²³I-IMP. SPECT with both tracers is recommended to follow the evolution of strokes in terms of regional cerebral blood flow and tissue metabolism. (orig.)

[en] Focal hyperaemia is a fairly common phenomenon in the subacute phase of an ischaemic stroke. This has rarely been reported with iodine-123 iodoamphetamine (IMP) and has never been identified using technetium-99m bicisate (^99mTc-ECD. In this report, we present the case of a patient suffering from a ledt cerebral posterior stroke. ¹²³I-IMP single-photon emission tomography (SPET) images showed a large area of significantly increased IMP activity located in the left occipital region whereas ^99mTc-bicisate SPET displayed hypoactivity in the same area. (orig.)