technetium-tc-99m-exametazime and Aneurysm--Ruptured

Twenty one cases of proven subarachnoid hemorrhage (S.A.H.) have been analysed in a protocol especially including transcranial doppler (T.C.D.) and 88mTc-H.M.P.A.O. single photon emission tomography (H.M.P.A.O.-S.P.E.C.T.). Seventeen patients were intraoperatively studied. All data were compared with clinical grading, computerized tomography (C.T.) and angiography. S.P.E.C.T. is a quite recent method of measuring and three-dimensional imaging of brain perfusion. It provides important information for the diagnosis of ischemic syndromes in S.A.H. Sixty-two S.P.E.C.T.-scans were performed in twenty one patients. Fifty-eight were abnormal and showed significant abnormalities of brain perfusion varying in extent and severity. In this preliminary study, we set out to validate the clinical use of H.M.P.A.O.-S.P.E.C.T. for the diagnosis of "vapospasm" comparing S.P.E.C.T. data with classical criteria. We propose a classification which allowed us to quantify the ischemic risk in an attempt to adapt the global therapeutic management to hemodynamic data. This method appears to be very sensitive and reliable in this field. It will introduce, if these first results are confirmed, important criteria for the evaluation of patients presenting with S.A.H. as far as prognosis and treatment are concerned, especially in regard to timing of surgery and institution of medical hemodynamic therapy.

Topics: Aneurysm, Ruptured; Cerebrovascular Circulation; Echoencephalography; Female; Humans; Intracranial Aneurysm; Intraoperative Period; Ischemic Attack, Transient; Male; Middle Aged; Organotechnetium Compounds; Oximes; Postoperative Period; Preoperative Care; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Our purpose was to assess the usefulness of diffusion- and perfusion-weighted MRI for the detection of ischaemic brain damage in patients with suspected vasospasm after subarachnoid haemorrhage (SAH). We studied 11 patients admitted with a ruptured aneurysm of the anterior circulation and suspected of intracranial vasospasm on clinical examination and transcranial Doppler sonography (TCD). All were investigated by technetium-hexamethyl-propylene amine oxime (Tc-HMPAO) single photon emission computed tomography (SPECT) and diffusion and perfusion-weighted MRI (DWI, PWI) within 2 weeks of their SAH. Trace images and TTP maps were interpreted by two examiners and compared with clinical and imaging follow-up. PWI revealed an area of slowed flow in seven patients, including four with major and three with minor hypoperfusion on SPECT. In two patients, PWI did not demonstrate any abnormality, while SPECT revealed major hypoperfusion in one and a minor deficit hypoperfusion in the other. Two patients with high signal on DWI had a permanent neurological deficit.

Topics: Adult; Aneurysm, Ruptured; Blood Flow Velocity; Brain; Cerebrovascular Circulation; Female; Humans; Intracranial Aneurysm; Magnetic Resonance Imaging; Male; Middle Aged; Radiopharmaceuticals; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Ultrasonography, Doppler, Transcranial; Vasospasm, Intracranial

Arterial vasospasm after subarachnoid hemorrhage may cause cerebral ischemia. Treatment with hemodilution, reducing blood viscosity, and hypervolemia, increasing cardiac performance and distending the vasospastic artery, are clinically established methods to improve blood flow through the vasospastic arterial bed.. Eight patients with transcranial Doppler verified vasospasm after subarachnoid hemorrhage were investigated with global (two-dimensional (133)Xenon) and regional (three-dimensional (99 m)Tc-HMPAO) cerebral blood flow (CBF) measurements, before and after 1/iso- and 2/hypervolemic hemodilution. Hematocrit was reduced to 0.28 from 0.36. Hypervolemia was achieved by increasing blood volume by 1100 ml.. Isovolemic hemodilution increased global cerebral blood flow from 52.25+/-10.12 to 58.56+/-11.73 ml * 100 g(-1) * min(-1) (p<0.05), but after hypervolemic hemodilution CBF returned to 51.38+/-11.34 ml * 100 g(-1) * min(-1). Global cerebral delivery rate of oxygen (CDRO(2)) decreased from 7.94+/-1.92 to 6.98+/-1.66 ml * 100 g(-1) * min(-1) (p<0.001) during isovolemic hemodilution and remained reduced, 6.77+/-1.60 ml * 100 g(-1) * min(-1) (p<0.001), after the hypervolemic hemodilution. As a test of the hemodilution effect on regional CDRO(2) an ischemic threshold was defined as the maximal amount of oxygen transported by a CBF of 10 ml * 100 g(-1) * min(-1) at a Hb 140 g/l which corresponds to a CDRO(2) of 1.83 ml * 100 g(-1) * min(-1). The brain volume with a CDRO(2) exceeding the ichemic threshold was 1300+/-236 ml before intervention. After isovolemic hemodilution the non-ischemic brain volume was reduced to 1206+/-341 (p<0,003). After hypervolemic hemodilution the non-ischemic brain volume remained reduced at 1228+/-347 ml (p<0.05).. The present study of controlled isovolemic hemodilution demonstrated increased global CBF, but there was a pronounced reduction in oxygen delivery capacity. Both CBF and CDRO(2) remained decreased during further hypervolemic hemodilution. We conclude that hemodilution to hematocrit 0.28 is not beneficial for patients with cerebral vasospasm after SAH.

Topics: Adult; Aneurysm, Ruptured; Blood Volume; Brain; Female; Hemodilution; Humans; Intracranial Aneurysm; Male; Middle Aged; Oxygen Consumption; Postoperative Complications; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Ultrasonography, Doppler, Transcranial; Vasospasm, Intracranial

Fifteen patients with a good neurological outcome after aneurysmal SAH and surgery were collected prospectively. Six months after surgery neurological examination and a SPECT study for evaluation of the three dimensional CBF distribution as well as an extensive neuropsychological test were performed. In all patients with pathological SPECT findings the location of the reduced regional CBF correlated with the location of the ruptured aneurysm and/or side of surgical approach. The volume of the brain tissue with reduced rCBF showed a great variety, from 9-112 cm(3) (mean: 33 cm(3)). Similarly, the maximum flow reduction in the affected areas also varied considerably from 17-95% (mean: 39%). In general, the neuropsychological functioning of the patients post SAH was favourable. Seven individuals had a presumably normal neuropsychological appearance with respect to estimates of premorbid levels of functioning. Another four patients were slightly impaired and the remaining four were moderately affected. Only in five cases did the location of SPECT pathology and the site of neuropsychological impairment appear to coincide, whereas this was not the case in the remaining 10 patients. In general, the extent of SPECT pathology did not differ in the three neuropsychological outcome groups (normal, slight and moderate disability).

Topics: Adult; Analysis of Variance; Aneurysm, Ruptured; Cerebrovascular Circulation; Cognition; Female; Glasgow Coma Scale; Humans; Intracranial Aneurysm; Male; Middle Aged; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Postoperative Period; Prospective Studies; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon