technetium-tc-99m-exametazime and Subarachnoid-Hemorrhage

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

The imaging of regional cerebral blood flow (rCBF) by 99mTc-d, 1 HM-PAO and SPECT is described. Its relevance to clinical syndromes, such as stroke, transient ischemic attacks, various forms of dementia, epilepsy, and subarachnoid hemorrhage, is reported.

Topics: Animals; Brain; Cerebrovascular Circulation; Cerebrovascular Disorders; Chemical Phenomena; Chemistry; Dementia; Epilepsy; Humans; Ischemic Attack, Transient; Organometallic Compounds; Organotechnetium Compounds; Oximes; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed

Cerebral blood flow tests have increasingly been advocated for the confirmation of brain death (BD). Four-vessel angiography has been considered the most reliable investigation in the diagnosis of BD for >30 yrs, but it is invasive. (99m)Tc-HMPAO SPECT provides noninvasive, multiplanar imaging of brain tissue perfusion. The aim of this study was to check the reliability of SPECT compared with contrast angiography.. Prospective, blind study.. Neurointensive care unit of a university hospital.. Consecutive clinically brain dead patients with flat electroencephalogram.. BD was diagnosed according to Italian law. (99m)Tc-HMPAO SPECT and four-vessel angiography were performed in the same session; the rater of each investigation ignored the results of the other. Blood pressure, Sp(O2), and P(ECO2) were monitored throughout the study: any episode of hypoxia or hypotension caused exclusion of the patient from the study.. Twenty brain dead patients were enrolled. The cause of BD was head injury in seven cases (35%), subarachnoid hemorrhage in seven (30%), spontaneous hemorrhage in one (10%), brain tumors in two (10%), stroke in two (10%), and thrombosis of the sagittal sinus in one (5%). Both angiography and SPECT confirmed BD in 19 of 20 patients: angiography showed the absence of filling of intracranial arteries, while SPECT showed a picture of "empty skull." For the remaining patient, angiography showed slight and late filling of left vertebral, basilar, and posterior cerebral arteries, while SPECT showed faint traces of uptake in the posterior fossa on the right side and on the midline. For this patient, the tests were repeated 48 hrs later, and both showed the arrest of intracranial circulation, thus confirming BD.. Our results confirm the reliability of SPECT in the diagnosis of BD; because SPECT is noninvasive, it is a good candidate for the "gold standard" of diagnosis.

Topics: Adult; Aged; Aged, 80 and over; Brain Death; Brain Neoplasms; Cerebral Angiography; Cerebral Hemorrhage; Female; Humans; Intracranial Thrombosis; Male; Middle Aged; Prospective Studies; Radiopharmaceuticals; Stroke; 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

The primary objective of this study was to correlate Tc-99m HMPAO and ethyl cysteine dimer perfusion brain SPECT imaging with angiography and transcranial Doppler (TCD) to identify vasospasm after subarachnoid hemorrhage.. A retrospective analysis of consecutive patients who had cerebral blood flow SPECT imaging for subarachnoid hemorrhage and aneurysm clipping was made. Flow velocity measurements were correlated using TCD and cerebrovascular angiography.. Of the 129 patients were included in this study, 84 were female and 45 were male, with a mean age of 51.9 years and a median age of 51 years (range, 9 to 84 years). Eighty-nine patients had brain SPECT evidence of hypoperfusion. Concordance was found between SPECT and TCD with vasospasm in 57 of 89 (64%) patients and nonconcordance was evident in 32 patients (36%). Eleven patients who had concordance between SPECT and TCD had nonconcordant results of angiography for vasospasm.. These findings suggest that all three methods are complementary to each other in the evaluation of patients with vasospasm after subarachnoid hemorrhage. Concordance of 64% between SPECT and TCD is acceptable and explicable by the differences in technique and measurement of cerebral blood flow compared with vascular narrowing, respectively.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Brain; Cerebral Angiography; Child; Female; Humans; Male; Middle Aged; Radiopharmaceuticals; Retrospective Studies; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Ultrasonography, Doppler, Transcranial; Vasospasm, Intracranial

It could be demonstrated that cervical spinal cord stimulation increases cerebral blood flow. The effects of electrical stimulation of the trigeminal ganglion in the acute phase of SAH in pigs were investigated. The experiments were carried out on 11 domestic pigs divided in two groups (group I: SAH [n = 5]; group II: SAH and trigeminal stimulation [n = 6]). In all animals a native SPECT was performed. The Gasserian ganglion was exposed for inserting the stimulation electrode. SAH was induced by injecting 10 ml autologous blood through a catheter placed in the suprasellar cistern. 30 minutes after SAH-induction electrical stimulation was started for two hours in group II (2.8-4.5 V, 50 Hz, 300 microseconds). 99mTc-HMPAO (400-540 MBq) was injected intravenously 110 minutes later. In group I 99mTc-HMPAO was applied after the same time interval. 80 minutes later SPECT was performed. Data were processed to calculate the uptake of radioactivity (%/kg tissue weight). The mean values were calculated for the different groups: native animal examination (%/kg tissue weight): 0.6343; group I: 0.468; group II: 0.6533. Comparing the mean values a highly significant difference between group I and group II (p < 0.01) and between native examination and group I (p < 0.01) could be found. No statistical significance could be detected on comparing the left/right-ratio in any ROI. The electrical stimulation of the Gasserian ganglion leads to a significantly increased uptake of 99mTc-HMPAO after induced SAH. Maybe the stimulation of the Gasserian ganglion constitutes a new therapeutic modality treating disturbed rCBF after SAH.

Topics: Animals; Blood Flow Velocity; Brain; Cerebrovascular Circulation; Electric Stimulation; Intracranial Pressure; Radiopharmaceuticals; Random Allocation; Spinal Cord; Subarachnoid Hemorrhage; Swine; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Trigeminal Ganglion

Topics: Animals; Cerebrovascular Circulation; Cervical Vertebrae; Electric Stimulation Therapy; Radiopharmaceuticals; Rats; Rats, Wistar; Spinal Cord; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime

Topics: Animals; Blood Pressure; Blood Volume; Cerebrovascular Circulation; Hemodilution; Hemodynamics; Intracranial Pressure; Radiopharmaceuticals; Subarachnoid Hemorrhage; Swine; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Cerebrovascular reactivity (CVR) to acetazolamide was investigated in 41 patients with normal pressure hydrocephalus (NPH). The aetiology was subarachnoid haemorrhage in 20 patients, trauma in nine, brain tumour in three and idiopathic in nine. Mean cerebral blood flow (CBF) of the whole brain was measured by performing first-pass radionuclide angiography using 99Tcm-hexamethylpropylene++ amine oxime. Cerebrovascular reactivity was measured as the percentage change from the baseline mean CBF value after the administration of 500 mg of acetazolamide. Cerebrovascular reactivity was significantly (P < 0.001) reduced in patients with the complete triad of NPH (1.4 +/- 3.1%), regardless of the aetiology, compared with normal controls (14.7 +/- 3.3%). Patients with the incomplete triad also showed significantly (P < 0.05) reduced CVR (9.6 +/- 5.4%). Patients with the complete triad had significantly (P < 0.001) lower CVR than those with the incomplete triad. Post-operative CVR in both groups (20 patients with the complete triad and 9 patients with the incomplete triad) increased significantly, from 1.5 +/- 3.5% to 10.0 +/- 5.5% (P < 0.001) and from 8.7 +/- 4.9% to 14.9 +/- 5.4% (P < 0.05), respectively. Cerebrovascular reactivity is impaired in patients with NPH regardless of the aetiology and improves after shunting.

Topics: Acetazolamide; Adult; Aged; Aged, 80 and over; Brain Injuries; Brain Neoplasms; Cerebrovascular Circulation; Diuretics; Female; Humans; Hydrocephalus, Normal Pressure; Male; Middle Aged; Radionuclide Imaging; Radiopharmaceuticals; Regional Blood Flow; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime

To report the results of the first 50 consecutive patients with vasospasm secondary to subarachnoid hemorrhage treated with balloon angioplasty after failure of medical management.. Retrospective uncontrolled study of 50 consecutive patients treated with balloon angioplasty between February 1988 and July 1992. Forty-six had objective clinical deterioration despite maximal medical therapy, whereas four were treated on the basis of rapidly accelerating transcranial Doppler velocities and decreased regional blood perfusion detected by technetium-99m-exametazime brain single photon emission computed tomography. All patients had evidence of marked vasospasm demonstrated by angiography. Thirty-two (64%) and 46 (92%) patients underwent angioplasty within 12 and 18 hours, respectively.. Of the patients with clinical evidence of vasospasm-induced ischemia, 28 (61%) showed sustained neurological improvement within 72 hours of angioplasty. Three (6%) patients deteriorated within 72 hours after angioplasty, with two (4%) patients dying immediately after angioplasty as a result of vessel rupture and the other patient's Glasgow Coma Scale score decreasing by 2. Two additional patients in poor condition with Hunt and Hess Grade V at the time of angioplasty subsequently died during hospitalization. Two other patients died as a result of unclipped aneurysms that subsequently bled 4 and 12 days after angioplasty, respectively. The improvement demonstrated clinically, angiographically, and by transcranial Doppler after angioplasty was sustained, with only one patient requiring subsequent angioplasty of a previously dilated segment (total, 170 vessel segments dilated). Two patients developed vasospasm in previously undilated segments.. Timely balloon angioplasty can reverse delayed ischemic deficit caused by vasospasm in patients for whom medical therapy has failed.

Topics: Angioplasty, Balloon; Cerebral Angiography; Equipment Design; Humans; Ischemic Attack, Transient; Radiopharmaceuticals; Retreatment; Retrospective Studies; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Ultrasonography

Cerebral vasospasm is a frequent complication after subarachnoid hemorrhage and contributes to overall morbidity and mortality. Arteriography is the standard test for determining the presence of vasospasm. A retrospective review of 16 patients with cerebral aneurysm was undertaken to assess the sensitivity and specificity of SPECT for diagnosis of vasospasm. Fourteen patients were hospitalized after subarachnoid hemorrhage and 2 patients were hospitalized for elective aneurysmal clipping. The patients' condition on discharge was correlated to clinical and SPECT evidence of vasospasm.. Vasospasm was defined as the new onset of neurological signs and symptoms not explained by rebleed or hydrocephalus. A total of 20 SPECT studies were performed for 16 patients during their admission and 14 of 16 patients had a single angiographic study.. Thirteen of 16 patients had 14 episodes of clinical evidence of vasospasm and 14 SPECT studies were performed in these 13 patients. The sensitivity and specificity of SPECT in this retrospective study were 89% (8/9) and 71% (5/7), respectively. Our small sample of arteriograms yielded in comparison a sensitivity of 67% (2/3) and specificity of 100% (9/9). The one false-negative SPECT study occurred in conjunction with the one false-negative arteriogram in the presence of clinical findings consistent with vasospasm. Three false-positive SPECT studies occurred in 2 patients who had perfusion abnormalities in areas of normal CT findings without clinical or arteriographic evidence of vasospasm. Five of 5 patients who died became unresponsive as a result of clinically presumed vasospasm and 4 of 5 of these patients had diffuse or hemispheric SPECT perfusion defects. Of the 11 patients who survived, none became unresponsive; 1 of 11 had positive diffuse or hemispheric perfusion defects.. SPECT is a sensitive and fairly specific test for corroboration of clinical findings of vasospasm. A negative SPECT study may obviate the need for arteriography. Unresponsiveness is the best predictor of poor outcome; however, hemispheric SPECT perfusion deficits are also associated with poor outcome.

Topics: Cerebral Angiography; Female; Humans; Ischemic Attack, Transient; Male; Middle Aged; Radiopharmaceuticals; Retrospective Studies; Sensitivity and Specificity; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Cerebral vasospasm after subarachnoid hemorrhage is very common, but it is not universally detectable by transcranial Doppler. SPECT imaging of regional cerebral blood flow with Tc-99m exametazime serves as a complementary test to transcranial Doppler in the evaluation of patients at high risk for vasospasm. The significance of vasospasm, which may be underestimated by TCD, is readily identified with SPECT cerebral perfusion imaging.

Topics: Brain; Female; Humans; Ischemic Attack, Transient; Middle Aged; Organotechnetium Compounds; Oximes; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon; Ultrasonography, Doppler, Transcranial

Cerebral vasospasm (CVS) occurs as a result of the breakdown in cerebral autoregulation mechanisms. Because cerebral vasospasm can occur after subarachnoid hemorrhage (SAH), it is important to evaluate borderline perfusion. Evaluation of borderline vascular insufficiency is important to reduce ischemic complications. In this study 25 patients with SAH were investigated by somatosensory evoked potentials (SEP), computed tomography (CT), digital subtraction angiography (DSA) and single photon emission computed tomography (SPECT) in order to predict borderline ischemic areas. Clinical grades were also correlated with these investigations. Thirteen patients had symptomatic vasospasm and 15 patients had angiographic vasospasm. SPECT showed hypoperfusion in 22 out of 25 patients. CT predicted CVS in 8 of these 22 patients. Our study shows that brain perfusion SPECT is a non-traumatic, non-invasive, non-allergic, inexpensive method for the prediction of cerebral vasospasm. We conclude that brain SPECT with Tc-99m HM-PAO is an accessible technique that can demonstrate varying degrees of regional tissue hypoperfusion in patients with delayed ischemic deficits due to CVS following SAH.

Topics: Adolescent; Adult; Brain Ischemia; Child; Female; Homeostasis; Humans; Ischemic Attack, Transient; Male; Middle Aged; Organotechnetium Compounds; Oximes; Regional Blood Flow; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Serial brain SPECT imaging was performed on patients after subarachnoid hemorrhage and surgical clipping of intracranial aneurysms. A total of 20 HMPAO scans were performed on 9 patients in whom clinical vasospasm did not develop. Areas of diminished regional cerebral blood flow (rCBF) were found near the operative site in 17 of 20 studies, which did not correlate with the patients' neurologic condition and were suggestive of postoperative edema. Brain SPECT imaging has a potentially valuable role to play in the evaluation of postoperative patients susceptible to vasospasm; however, it is important to be aware of postoperative changes in rCBF that are not related to vasospasm.

Topics: Brain; Brain Edema; Cerebrovascular Circulation; Female; Humans; Intracranial Aneurysm; Ischemic Attack, Transient; Male; Middle Aged; Organotechnetium Compounds; Oximes; Postoperative Complications; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon

Regional hypoperfusion is a very frequent complication of subarachnoid haemorrhage (SAH), being related to vasospasm in the majority of cases. Twenty-six patients who were admitted for SAH underwent follow-up with technetium-99m hexamethylpropylene amine oxime single photon emission tomography (SPECT) 3 and 8 days after surgery. Fifteen patients of these had one more examination 15 days after surgery. The degree of hypoperfusion was quantified using an index of asymmetry which allow the comparison of two symmetrical regions of interest (ROIs) on the transaxial slice which presented the greatest perfusion defect. Comparison of CT data, transcranial Doppler data and clinical signs with the perfusion as quantified by 99mTc-HMPAO SPECT indicates that a difference in counts of less than 10% between the two symmetrical ROIs is of no diagnostic value. Follow-up of the brain perfusion clearly shows that the most pronounced hypoperfusion was observed just after surgery, with progressive normalization at 8 and 15 days after surgery. 99mTc-HMPAO SPECT performed 8 days after surgery allows prediction of the clinical outcome. For these reasons, 99mTc-HMPAO SPECT, which is the only method for follow-up of cerebral perfusion in routine clinical practice, should be the first examination to be performed after surgery in patients with SAH.

Topics: Brain; Cerebrovascular Circulation; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Postoperative Period; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Cerebral vasospasm is a major determinant of outcome after subarachnoid hemorrhage (SAH). Brain SPECT with 99mTc-HMPAO was obtained before and after cerebral angioplasty in 10 patients with delayed ischemia due to vasospasm. Eight patients had clinically evident neurologic improvement after the procedure. Visual interpretation and an internal-reference (cerebellum), manual, semi-quantitative region of interest (ROI) analysis revealed improvement of regional cerebral blood flow (rCBF) in 9 out of 10. There were disagreements between the visual and ROI analysis in the two that did not improve clinically. For all 10, the average increase per anterior circulation vessel dilated (n = 17) was 8.8% by comparison of the corticocerebellar ratios. For the eight that improved, the average increase was 10.5%. Brain SPECT is valuable for evaluating delayed cerebral ischemia caused by vasospasm after SAH and is useful to document the changes in rCBF induced by angioplasty. It is possible that SPECT may be useful to detect critical reductions in perfusion before clinical deficits develop, thereby offering the potential to identify candidates for early treatment with angioplasty.

Topics: Adult; Angioplasty, Balloon; Brain; Cerebrovascular Circulation; Humans; Ischemic Attack, Transient; Middle Aged; Neurologic Examination; Organotechnetium Compounds; Oximes; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon

Using single photon emission computed tomography (SPECT), cerebral blood flow was studied in eight patients with gradual deterioration in the level of consciousness after subarachnoid haemorrhage. Four had cerebral ischaemia and four had acute hydrocephalus. In patients with cerebral ischaemia, single photon emission computed tomography scanning showed multiple regions with decreased uptake of technetium-99M labelled d,l-hexamethyl-propylene amine oxime (99mTcHM-PAO) mainly in watershed areas. In patients with acute hydrocephalus, decreased uptake was seen mainly in the basal parts of the brain: around the third ventricle, around the temporal horns of the lateral ventricles, and in the basal part of the frontal lobe. After serial lumbar puncture, there was improvement of the uptake of 99mTc HM-PAO in these basal areas in three (convincingly in two and slightly in the other) of the four patients accompanied by clinical improvement in these three patients. These results suggest that patients with acute hydrocephalus and impaired consciousness after SAH, in contrast to patients with cerebral ischaemia, have decreased cerebral blood flow predominantly in the basal parts of the brain.

Topics: Acute Disease; Brain Ischemia; Cerebrovascular Circulation; Follow-Up Studies; Humans; Hydrocephalus; Intracranial Aneurysm; Organotechnetium Compounds; Oximes; Spinal Puncture; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

We used single-photon emission computed tomography with technetium-99m hexamethylpropylene amine oxime in 18 studies on 13 patients with subarachnoid hemorrhage to determine whether any changes in cerebral blood flow could be correlated with clinical or computed tomographic evidence of delayed ischemia. Among the seven patients without focal neurologic deficits, regional cerebral hypoperfusion was demonstrated in only one who died. Among the 10 patients with aneurysmal subarachnoid hemorrhage, one died before surgery, and six developed postoperative delayed ischemic deficits, of whom two died. Among the patients with angiographically documented aneurysms, regional hypoperfusion correlated with the presence and severity of delayed neurologic deficits, whereas correlative computed tomographic scans showed either early infarction or no relevant abnormality. This technique facilitates early diagnosis of cerebral tissue hypoperfusion due to vasospasm after subarachnoid hemorrhage.

Topics: Cerebral Angiography; Cerebrovascular Circulation; Female; Humans; Image Processing, Computer-Assisted; Intracranial Aneurysm; Ischemic Attack, Transient; Male; Middle Aged; Organotechnetium Compounds; Oximes; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime; Tomography, Emission-Computed; Tomography, X-Ray Computed

Vasospasm of intracranial vessels is difficult to diagnose on clinical ground alone. Still, a clear diagnosis is important because it can impact on surgical timing; and also because it can help evaluate new treatments. Fifteen patients with sub-arachnoid hemorrhage secondary to aneurysm rupture were submitted to a total of 26 tomographic technetium-99m-hexamethyl-propyleneamine oxime (99mTc-HM-PAO) brain examinations that were correlated with temporally close (generally less than 24 hr) angiography or transmission computed tomography (TCT). Nine of 10 angiographically confirmed episodes of spasm and 6 of 6 infarcts seen on angiography or TCT were correctly diagnosed with 99mTc-HM-PAO. One normal scintigraphic exam was angiographically doubtful, one positive 99mTc-HM-PAO study was normal on angiography (sub-radiologic spasm?), one technically poor scintigraphy was positive for spasm on angiograms, and eight exams were normal for spasm with all modalities. We had agreement between tests in 23 of 26 series of exams (88%) obtained in 15 patients. We think that 99mTc-HM-PAO tomography should be useful for the evaluation of patients with suspected vasospasm.

Topics: Adult; Aged; Cerebral Angiography; Female; Humans; Intracranial Aneurysm; Ischemic Attack, Transient; Male; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Rupture, Spontaneous; Subarachnoid Hemorrhage; Technetium Tc 99m Exametazime

Technetium 99m hexamethylpropylene amine oxime (HMPAO) is an agent which, when injected intravenously, gives images which reflect cerebral blood flow. Seven patients who had suffered subarachnoid haemorrhage were examined by cerebral angiography and by 99Tcm HMPAO scanning. The two studies were compared and in six cases there was evidence of decreased cerebral perfusion in relation to the ruptured aneurysm causing the subarachnoid haemorrhage. In one case no cause for the haemorrhage was demonstrated angiographically, and the HMPAO study was normal. In two of the six cases, spasm of the cerebral artery distal to the ruptured aneurysm was seen angiographically and it appears that 99Tcm HMPAO scanning does not correlate with gross arterial spasm but reflects smaller degrees of cerebral underperfusion not demonstrable by angiography. The results demonstrate a relationship between local decreased cerebral perfusion and ruptured cerebral aneurysm and may be of use in determining which aneurysm has bled in patients who have more than one aneurysm demonstrated angiographically.

Topics: Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organometallic Compounds; Oximes; Radionuclide Imaging; Subarachnoid Hemorrhage; Technetium; Technetium Tc 99m Exametazime; Tomography, X-Ray Computed