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

Intracranial aneurysms in the pediatric age group are rare occurrences. They usually present with subarachnoid hemorrhage or mass effect. Their association with epilepsy has rarely been reported; such concurrence may not be a coincidence. We present a 16-year-old girl with a 5-year history of medically intractable complex partial seizures. Preoperative electrophysiological and neuroimaging studies demonstrated an epileptogenic focus and atrophy in the right mesial temporal lobe, and ipsilateral incidental aneurysm at the carotid artery bifurcation. The patient underwent a complete right anterior temporal lobectomy, followed by clipping of the aneurysm. We concluded that the epilepsy management in association with cerebral aneurysms is controversial, but when surgery is indicated, clipping of the aneurysm and resection of the epileptogenic focus may provide the optimal outcome. The relevant literature is reviewed and the possible mechanisms of production of epilepsy by intracranial aneurysms are discussed.

Topics: Adolescent; Atrophy; Cerebral Angiography; Electroencephalography; Epilepsy, Complex Partial; Epilepsy, Temporal Lobe; Female; Humans; Intracranial Aneurysm; Magnetic Resonance Imaging; Psychosurgery; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

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

Test balloon occlusion (TBO) is important in the management of complex cerebrovascular and skull base lesions when permanent occlusion (PO) of a parent artery may be indicated. Several adjuncts may be used to increase the sensitivity of TBO to predict whether PO will be tolerated. This is an observational study to evaluate the utility of internal carotid artery (ICA) TBO using single photon emission computed tomography (SPECT) scan in the management of complex vascular pathology and skull base tumors.. All TBO procedures performed over a 20-year period were analyzed. Clinical assessment and angiographic collateral flow were combined with semi-quantitative cerebral blood flow analysis using. Eighty-three patients underwent TBO without complication. Of 45 patients with satisfactory TBO, 28 proceeded to PO. Three patients developed transient ischemic symptoms thought to be embolic in origin. Thirty-eight patients had unsatisfactory TBO, of whom 15 required PO accompanied by a bypass procedure. Forty patients in the series did not undergo permanent vessel occlusion.. SPECT scan-enhanced TBO is an important component of the management of complex vascular pathology and skull base tumors, permitting safe PO of the parent vessel and definitive treatment of the main pathology.

Topics: Balloon Occlusion; Brain; Carotid Artery, Internal; Cerebral Angiography; Cerebrovascular Circulation; Collateral Circulation; Humans; Intracranial Aneurysm; Ligation; Preoperative Care; Radiopharmaceuticals; Retrospective Studies; Skull Base Neoplasms; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

This study was conducted to show the reliability of fully automated quantification of regional cerebral blood flow (rCBF) in balloon occlusion test (BOT) of the internal carotid artery (ICA). We also shows the usefulness of ratio of rCBF during BOT to rCBF at rest (BOT/rest ratio = rCBF during BOT/rCBF at rest) rather than asymmetry index (AI) during BOT (AI = occluded-side rCBF/contralateral rCBF).. In the last 2 years, we performed the BOT on 10 consecutive patients (4 with intracranial aneurysms and 6 with head and neck tumors). During the BOT, mean stump pressure (MSTP) of the ICA was monitored. We measured cerebral blood flow (CBF) with technetium-99m hexamethylpropylene amine oxime single-photon emission computed tomography at rest and during BOT. rCBF was determined using 3-dimensional stereotaxic region of interest template (3DSRT) which automatically divided CBF into 12 segments. We defined hypoperfusion segment as BOT/rest ratio <0.9 or AI <0.9.. When the BOT/rest ratio was used as a hypoperfusion parameter, the number of hypoperfusion segments was significantly greater in patients with an MSTP ≤50 mm Hg than in patients with an MSTP >50 mm Hg. However, only AI during BOT did not reflect MSTP significantly.. The evaluation of CBF changes in BOT using 3DSRT and the BOT/rest ratio were useful because of objective comparison.

Topics: Adult; Aged; Automation; Balloon Occlusion; Carotid Artery Diseases; Carotid Artery, Internal; Cerebrovascular Circulation; Diagnostic Techniques, Cardiovascular; Female; Hemodynamics; Humans; Image Interpretation, Computer-Assisted; Imaging, Three-Dimensional; Intracranial Aneurysm; Male; Middle Aged; Multimodal Imaging; Neoplasm Invasiveness; Positron-Emission Tomography; Predictive Value of Tests; Radiopharmaceuticals; Reproducibility of Results; Technetium Tc 99m Exametazime; Tomography, X-Ray Computed

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

To determine whether the absolute value for the stump pressure might be a useful index of symmetrical cerebral blood flow (CBF), and to examine correlations with the stump pressure ratio (initial mean stump pressure/preocclusion mean arterial pressure), fifty candidates for ICA injury or permanent occlusion were evaluated preoperatively. Each was continuously monitored for mean stump pressure and arterial pressure before, during (for a total of 20 min), and after balloon test occlusion. During the occlusion, CBF was measured by 99 m Tc-hexamethyl-propyleneamine oxime (99 m Tc-HMPAO) single photon emission computed tomography (SPECT). The stump pressure and the stump pressure ratio were then compared with the results of 99 m Tc-HMPAO SPECT. Patients who failed to tolerate even brief periods of carotid occlusion and showed asymmetric decreases in CBF on SPECT were divided into high and moderate risk groups. Those with no significant changes in CBF on the occluded site formed the minimum risk group. Mean stump pressure was over 50 mmHg in 10 of a total of 25 patients in the high and moderate risk groups, and below 50 mmHg in 5 of the 25 patients in the minimum risk group. The stump pressure ratio did not exceed 56% in any but two patients in the high and moderate risk groups, and values were at least 60% in all patients of the minimum risk group. Decrease of CBF in two moderate risk group cases was localized in the posterior circulation. Difference in symmetrical CBF between the stump pressure ratio vs. the absolute value of mean stump pressure were statistically significant (p < 0.01, Fisher's Exact Test). Maintenance of a stump pressure ratio of 60% or more during test occlusion may be a more useful index for a good collateral circulation than any absolute value for mean stump pressure.

Topics: Blood Pressure; Brain Neoplasms; Carotid Artery, Internal; Carotid Stenosis; Catheterization; Cerebrovascular Circulation; Electroencephalography; Granuloma; Humans; Intracranial Aneurysm; Meningioma; Paraganglioma; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Treatment Outcome; Vascular Surgical Procedures

The purpose of this study is to evaluate the effect of brain retraction 1 year or more after intracranial aneurysm clipping, demonstrated by a regional cerebral blood flow (rCBF) imaging technique.. rCBF and cerebrovascular reserve (CV) were evaluated in 40 patients 12-25 months after operation, using single photon emission computed tomography (SPECT) with Tc-99m-hexamethylpropylene amine oxime (HMPAO) combined with acetazolamide test. The images were analysed semiquantitatively, focusing on regions of interest (ROIs) chosen for places retracted during the operation. The regions of hypoperfusion in the retracted tissue were clearly visible in 26 cases. Assymmetry of measured activity, expressed in the Assymmetry Index, reached 12% (SEM +/- 8). After injection of acetazolamide during hypercapnia, the assymmetry decreased.. The results confirm the negative role of brain retraction. However, these consequences seem to be diminished by good vasoreactivity.

Topics: Brain; Cerebrovascular Circulation; Humans; Intracranial Aneurysm; Postoperative Complications; Surgical Instruments; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

To evaluate stroke risk assessment of balloon test occlusion of the internal carotid artery (ICA) with enlarged haemodynamic monitoring prior to permanent ICA occlusion.. 24 patients with cervical metastasis (n = 18), cavernous meningiomas (n = 3) or inoperable cavernous aneurysms (n = 3) were examined. The test occlusion was monitored by EEG, neurological examinations and transcranial Doppler sonography of the ipsilateral middle cerebral artery with evaluation of the cerebrovascular reserve capacity. Additionally 99mTc-HMPAO-SPECT imaging was added showing the perfusion during test occlusion.. In one (4%) patient the test occlusion had to be interrupted previously due to an acute neurological deficit. This patient and two (8%) patients with highly pathological test results in SPECT and TCD were excluded from permanent carotid occlusion. In 6 (25%) patients quantitative TCD monitoring could improve the stroke risk assessment by differentiating the patients in a low and high risk group. 6 (25%) patients were definitely occluded without haemodynamic complications, but two patients suffered from embolic infarctions which cannot be predicted by this procedure.. The multimodal balloon test occlusion with enlarged haemodynamic monitoring allows haemodynamic stroke risk assessment prior to permanent occlusion of the ICA.

Topics: Adult; Aged; Aged, 80 and over; Brain; Carotid Artery Diseases; Carotid Artery, Internal; Catheterization; Cerebral Infarction; Cerebrovascular Disorders; Contrast Media; Embolization, Therapeutic; Female; Head and Neck Neoplasms; Hemodynamics; Humans; Intracranial Aneurysm; Intracranial Embolism and Thrombosis; Male; Meningeal Neoplasms; Meningioma; Middle Aged; Neurologic Examination; Organotechnetium Compounds; Oximes; Prognosis; Regional Blood Flow; Risk Factors; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The main objective of this study was to assess whether 99mTc-HMPAO brain SPECT imaging can identify patients at high risk of developing an infarct following permanent carotid occlusion in the course of brain surgery.. Test balloon occlusion of the internal carotid artery was performed in 44 patients with a variety of head and neck tumors or aneurysms. Technetium-99m-HMPAO was injected intravenously while the balloon was initiated and a SPECT study was obtained 30 min later. Follow-up CT scans were obtained routinely for all patients at 2 wk and 1 mo following surgery, or earlier when necessary. Thirty patients and five normal volunteers had semiquantitative analysis of cerebral perfusion.. Twenty-six patients demonstrated ipsilateral perfusion abnormalities during trial occlusion. Eight patients in this group underwent bypass grafting prior to sacrifice of the artery: two resulting in infarcts. Eighteen patients had symmetric cerebral perfusion during occlusion and four of these patients underwent permanent therapeutic carotid occlusion; three patients had subsequent infarcts and the fourth patient had an impending stroke.. Patients with symmetric cerebral perfusion measured by 99mTc-HMPAO SPECT may still have a high long-term complication rate following carotid sacrifice. The scan findings in these patients were not predictive of the outcome. Patients with asymmetric cerebral perfusion had alternative therapeutic approach to carotid sacrifice and most of them had good surgical outcomes.

Topics: Brain; Brain Neoplasms; Carotid Artery, Internal; Catheterization; Cerebral Infarction; Cerebrovascular Circulation; Female; Follow-Up Studies; Head and Neck Neoplasms; Humans; Intracranial Aneurysm; Male; Middle Aged; Organotechnetium Compounds; Oximes; Postoperative Complications; Predictive Value of Tests; Risk Factors; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon

Does the absolute value of the stump pressure (post-occlusion back pressure) become a useful index of a good collateral circulation? The authors continuously monitored the mean arterial pressure before, during and after 20-minute balloon test occlusion in 24 patients. The stump pressure was then compared with the results of 99mTc-hexa-methyl propyleneamine (99mTc-HMPAO) single photon emission computed tomography (SPECT) performed after 20 minutes of test occlusion. Patients who failed to tolerate even brief periods of carotid occlusion and showed asymmetric decreases in cerebral blood flow (CBF) on SPECT were divided into high and moderate risk groups. Those with no significant change in CBF on the occluded side formed the minimum risk group. Mean stump pressure was over 50 mmHg in three of a total of 13 patients in the high and moderate risk groups, and below 50 mmHg in two of the 11 patients in the minimum risk group. The ratios of the initial mean stump pressure to the pre-occlusion mean arterial pressure (%) and of the final mean stump pressure at the end of occlusion to the post-opening mean arterial pressure (%) did not exceed 58% in any patient in the high and moderate risk groups, and were at least 60% in all patients of the minimum risk group. Maintenance of a mean stump pressure of 60% or more of the mean systemic pressure during test occlusion may be a more useful index of a good collateral circulation than the absolute value of mean stump pressure.

Topics: Adult; Aged; Blood Pressure; Brain; Brain Ischemia; Carotid Artery Diseases; Carotid Artery, Internal; Catheterization; Cerebral Revascularization; Collateral Circulation; Dominance, Cerebral; Female; Humans; Intracranial Aneurysm; Male; Meningeal Neoplasms; Meningioma; Middle Aged; Monitoring, Physiologic; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

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

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

Topics: Brain; Brain Death; Female; Humans; Intracranial Aneurysm; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

The authors describe a patient with a large intracavernous aneurysm of the right internal carotid artery and a marked decrease in focal brain blood flow induced by temporary carotid balloon occlusion. The patient subsequently underwent a superficial temporal to middle cerebral artery bypass followed by successful carotid occlusion using detachable balloons placed proximal to the aneurysm. Postoperative rCBF demonstrated normal perfusion in the region of the right internal carotid artery distribution as well as normalization of perfusion to a previous area of baseline perfusion abnormality. Cerebral brain blood flow imaging was useful in the initial evaluation as well as the management of this patient.

Topics: Aged; Amphetamines; Brain; Carotid Artery Diseases; Carotid Artery, Internal; Catheterization; Cerebral Revascularization; Cerebrovascular Circulation; Collateral Circulation; Female; Humans; Intracranial Aneurysm; Iodine Radioisotopes; Iofetamine; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A 48-year-old lady suffered a transient loss of consciousness. CT and MRI revealed a large vascular lesion compressing the left lower pons. Angiography revealed a large aneurysm at vertebro-basilar junction, dome of which projected anteriorly and left to midline. Her previous vertebral angiogram taken 10 years ago when she suffered a subarachnoid hemorrhage from the left MCA aneurysm, had showed a fenestration of lower basilar artery without apparent aneurysm. Bilateral super-selective vertebral angiograms revealed that the aneurysm arose at the proximal end of the fenestration, and vertebrobasilar junction was incorporated into the aneurysm indicating broad neck aneurysm. The left posterior communicating artery was well developed. Balloon test occlusion (BTO) of bilateral vertebral artery was performed under normotension and induced hypotension. 99mHM-PAO SPECT was used to examine cerebral blood flow (CBF) during hypotensive BTO. The patient tolerated the test and CBF imaging showed insignificant sight decrease in bilateral cerebellar hemispheres. Exploration of the aneurysm was carried out by the right far lateral suboccipital approach. Bilateral vertebral arteries and the right segment of the basilar artery fenestration were identified. Neck clipping of the aneurysm with reconstruction of the parent vessels were tried with fenestrate clip. However, narrow operative field and large dome of the aneurysm made it hard to identify the left segment of the fenestration. Neck clipping was given up and clipping of bilateral vertebral arteries were performed distal to posterior inferior cerebellar artery with three body clippings. The patient showed moderate postoperative left lower nerve palsy, which was gradually improved in several weeks. Follow-up angiography revealed no opacification of the aneurysm.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Basilar Artery; Catheterization; Embolization, Therapeutic; Female; Humans; Hypotension, Controlled; Intracranial Aneurysm; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Vertebrobasilar Insufficiency

Single photon emission computed tomography with technetium-99m-d, l-hexamethylpropyleneamineoxime was used to assess variations in regional cerebral blood flow during temporary clipping in the course of intracranial aneurysm surgery and during the postoperative period in 20 patients, 14 of whom underwent temporary clipping. Of these 14 patients (Group A), 9 had aneurysms of the anterior communicating artery, 2 had aneurysms of the middle cerebral artery, and 3 had aneurysms of the carotid siphon. Temporary clips were applied, according to the site of the lesion, on A1, on the trunk of the middle cerebral artery, or on the trunk of the internal carotid artery. The occlusion time ranged from 2 to 31 minutes. The six patients who did not undergo temporary clipping served as controls (Group B), as follows: three had aneurysms of the posterior communicating artery, one of the anterior communicating artery, one of the middle cerebral artery, and one of the internal carotid artery. All patients were investigated with cerebral single photon emission computed tomography preoperatively, perioperatively, and postoperatively. In all the patients of Group A, the preliminary results of the study show a sharp fall in the perfusion of the territories of the temporarily clipped parent vessel and practically a complete recovery within 2 to 7 days of surgery, with no significant neurological symptoms. No similar disturbance of perfusion was found in the patients of Group B.

Topics: Adult; Aged; Brain; Brain Damage, Chronic; Brain Ischemia; Carotid Artery Diseases; Carotid Artery, Internal; Female; Humans; Intracranial Aneurysm; Intraoperative Complications; Male; Middle Aged; Monitoring, Intraoperative; Organotechnetium Compounds; Oximes; Postoperative Complications; Regional Blood Flow; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon

Three patients with large carotid aneurysms were treated by parent artery occlusion with detachable balloons. Of these, 2 had intracavernous carotid artery aneurysms and one had a carotid-ophthalmic aneurysm. All patients underwent a formal balloon occlusion test and tolerated it well. One patient with a carotid-ophthalmic aneurysm, however, developed postoperative ischemic effects. This case was that of a 55 year-old female with right visual disturbance. Her middle cerebral artery flow had been compromised during test occlusion under induced hypotension. Although initially intact after balloon occlusion, she was found to be hemiplegic 24 hours later. She subsequently developed multiple small infarcts which were shown on MRI and which corresponded exactly to the previously demonstrated region of decreased flow during testing. This ischemic complication is possibly due to hypoperfusion, but embolism from the thrombosed aneurysm can not be denied. To prevent these complications, an extracranial-intracranial artery anastomosis prior to parent artery occlusion should be considered if the preoperative 99mTc-HMPAO SPECT shows a compromised cerebral blood flow. In addition to this, postoperative anticoagulant therapy should be given even if test occlusion was well tolerated clinically.

Topics: Brain Ischemia; Carotid Artery Diseases; Carotid Artery, Internal; Catheterization; Cerebrovascular Circulation; Female; Humans; Intracranial Aneurysm; Middle Aged; Organotechnetium Compounds; Oximes; Radionuclide Imaging; Technetium Tc 99m Exametazime

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

The authors presented clinical material on cerebral hemodynamics in patients with neurological pathology in suspected tumor vascular cerebral diseases and craniocerebral traumas. Investigation of cerebral microcirculation was performed using a multidetector single-photon emission tomograph "Testoscan" (USSR) after iv administration of 99mTc-hexamethylpropilene-amyloxine. This radiopharmaceutical is good for the evaluation of cerebral perfusion and gives a clinician rich information on cerebral microcirculation.

Topics: Adult; Aged; Cerebrovascular Circulation; Cerebrovascular Disorders; Drug Evaluation; Head; Humans; Intracranial Aneurysm; Ischemic Attack, Transient; Microcirculation; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Three cases with cerebral ischemic symptoms and an intracranial aneurysm are presented. Using [99mTc]hexamethyl-propyleneamine oxime (HM-PAO) single photon emission computed tomography imaging before and during the Matas test, a quantitative measurement method was developed for evaluating brain collateral circulation. The evaluation correlated well with findings of contrast carotid angiography. This noninvasive method seems to be useful for selection of patients for appropriate surgical treatment.

Topics: Aged; Brain; Brain Ischemia; Carotid Arteries; Cerebrovascular Circulation; Collateral Circulation; Constriction; Female; Humans; Intracranial Aneurysm; Male; Organometallic Compounds; Oximes; Technetium; Technetium Tc 99m Exametazime; Tomography, Emission-Computed