technetium-tc-99m-exametazime and Cerebellar-Diseases

Quantitative assessment of regional cerebral blood flow (rCBF) in the bilateral cerebral and cerebellar cortices was performed in 13 epileptic patients receiving long-term high-dose phenytoin (PHT) therapy, using single photon emission computed tomography (SPECT) with N-isopropyl-(iodine 123) p-iodoamphetamine. In 4 of the 13 patients, both the cerebellar to frontal rCBF ratio and cerebellar to cerebral rCBF ratio showed low values as compared with those in 22 normal subjects matched for sex and age, probably reflecting abnormal relative cerebellar hypoperfusion. None of the 4 patients showed any abnormal findings on X-ray computed tomography or magnetic resonance brain imaging. The patients with a history of acute PHT intoxication tended to show the abnormal relative cerebellar hypoperfusion. These results suggest the utility of SPECT scans for early detection of cerebellar abnormalities known to be often present in epileptic patients, and imply a risk of long-term high-dose PHT therapy.

Topics: Adult; Amphetamines; Cerebellar Diseases; Cerebellum; Epilepsies, Partial; Female; Frontal Lobe; Functional Laterality; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Phenytoin; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

In 53 patients with chronic occlusive cerebrovascular diseases, we evaluated cerebral perfusion reserve. Cerebral perfusion reserve was evaluated by the change in cerebral blood flow (CBF) at rest and the CBF after acetazolamide (Diamox) as measured by the 133Xe gas inhalation SPECT method. Crossed cerebellar diaschisis (CCD) was evaluated semiquantitatively by the count ratio of the cerebellar cortex using 99mTc-HMPAO SPECT. Thirty-two (49%) of the 65 affected lesions in 53 patients had shown a decreased response to Diamox. In the cases of decreased response to Diamox, the response improved significantly after surgery. However, CBF did not improve as much as the response. In the 40 nonaffected sides, 21 (53%) showed decreased CBF at rest but good response to Diamox. At rest, no difference of the CBF ratio (affected/contralateral nonaffected cerebral cortex) was observed between the patients with CCD (6 pts) and those without CCD (8 pts). After Diamox, however, the CBF ratio of the patients with CCD was significantly higher than that without CCD. The change of the CBF ratio before and after Diamox correlated significantly with the degree of CCD (r = -0.794, p < 0.01). Diamox was useful for evaluating the cerebral perfusion reserve to indicate surgery in patients with chronic cerebrovascular diseases. Perhaps CCD could be a useful index in the differentiation of the decreased CBF caused by reduced perfusion pressure from that caused by reduced metabolic demand because CCD had a close relationship with the cerebral perfusion reserve.

Topics: Acetazolamide; Adult; Aged; Brain; Cerebellar Diseases; Cerebrovascular Circulation; Cerebrovascular Disorders; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Xenon Radioisotopes

A 59-year-old man was admitted for further investigation of headache. Neurological examination revealed memory loss, disorientation, and bilateral intention tremor. Legionella pneumophila antigen was detected in the urine. Brain magnetic resonance diffusion-weighted images showed marked hyperintensity in the splenium of the corpus callosum without other abnormalities. Single photon emission CT with Tc-99m hexamethyl-propyleneamine oxime showed multi-focal hypoperfusion in the brain, involving mainly the cerebellum and frontal lobe. This is the first report demonstrating cerebellar and frontal lobe hypoperfusion without corresponding MRI abnormalities in a patient with central nervous system Legionnaires' disease.

Topics: Central Nervous System Bacterial Infections; Cerebellar Diseases; Corpus Callosum; Frontal Lobe; Headache; Humans; Legionnaires' Disease; Male; Middle Aged; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We used Technetium-99m hexamethyl propylene amine oxime single-photon emission computed tomography (HMPAO-SPECT) and magnetic resonance imaging (MRI) to evaluate a 30-year-old woman who developed cerebellar dysfunction after infection with Epstein Barr virus. Although no abnormal findings were evident from a brain MRI, the HMPAO-SPECT revealed increased perfusion in both cerebellar hemispheres. The patient improved without specific treatment. Two sequential HMPAO-SPECTs showed gradually reduced hyperperfusion in the cerebellum, which was correlated with her clinical recovery. We suggest that brain HMPAO-SPECT may thus be useful for identifying acute cerebellitis and predicting its clinical outcome.

Topics: Adult; Cerebellar Diseases; Cerebellum; Cerebral Cortex; Dominance, Cerebral; Encephalitis, Viral; Epstein-Barr Virus Infections; Female; Follow-Up Studies; Gait Ataxia; Humans; Hyperemia; Image Enhancement; Image Processing, Computer-Assisted; Neurologic Examination; Regional Blood Flow; Remission, Spontaneous; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The study investigates the effect of zolpidem (CAS 82626-48-0) on brain injuries and cerebellar diaschisis. Four patients with varied brain injuries, three of them with cerebellar diaschisis, were imaged by 99mTc HMPAO Brain SPECT before and after application of zolpidem. The baseline SPECT before zolpidem showed poor tracer uptake in brain injury areas and cerebellar diaschisis. After zolpidem, cerebral perfusion through brain injury areas improved substantially in three patients and the cerebellar diaschisis was reversed. Observations point to a GABA based phenomenon that occurs in brain injury and diaschisis that is reversible by zolpidem.

Topics: Adult; Brain Injuries; Cerebellar Diseases; Cerebrovascular Circulation; Child, Preschool; Diabetes Mellitus; Humans; Hypnotics and Sedatives; Male; Near Drowning; Persistent Vegetative State; Pyridines; Radiopharmaceuticals; Spinocerebellar Ataxias; Stroke; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Zolpidem

Topics: Adult; Atlanto-Occipital Joint; Brain Infarction; Cerebellar Diseases; Humans; Joint Dislocations; Male; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime

The aim of this study was to evaluate regional and remote diaschisis of inferior brain stem or cerebellar infarcts in 25 patients presenting with relatively limited lesions. Patients presented with medullary, pontine or cerebellar infarction.. Lesions were evaluated on MRI (0.5 T). Regional cerebral blood flow (rCBF) was assessed by means of SPECT, after injection of 9rmTc-hexamethyl propyleneamine oxime (HMPAO) and, when possible, inhalation of 133Xe in the same session. For each method, asymmetry indices (Als), comparing contralateral to ipsilateral rCBF values, were calculated in four areas of each cerebral hemisphere and in the cerebellum and later compared with values obtained in healthy subjects (P = 0.05).. Higher rCBF values were observed in the contralateral cerebellum in 2 of 7 patients with selective lateral medullary lesions, and cerebellar Als were significantly increased. When a cerebellar infarct was associated with a lateral medullary lesion, the cerebellar and contralateral hemispheric asymmetries were more severe. Unilateral paramedian pontine infarcts had more frequent consequences on the cerebellum (2 of 3 cases), with rCBF or tracer uptake being reduced in the ipsilateral or the contralateral lobe. Inverse cerebral hemispheric asymmetry could then be observed. Bilateral pontine lesions were difficult to evaluate. Using 99mTc-HMPAO, discrete cerebellar asymmetry was observed in 3 of 6 cases. Pure cerebellar infarcts in the posterior inferior cerebellar artery territory were always associated with a severe ipsilateral flow drop in the cerebellum, and contralateral hemispheric diaschisis was frequent (3 of 4 patients), predominating in the frontotemporal cortex and subcortical structures. This was also more obvious using 99mTC-HMPAO than 133Xe. Variance analysis showed that hemispheric diaschisis was more severe in mixed brain stem and cerebellar infarcts than in pure cerebellar or brain stem lesions. Furthermore, cerebellar and hemispheric AI values were not correlated with measurements of clinical deficits, disability or handicap.. Unilateral and limited inferior brain stem lesions can have ipsi- or contralateral consequences on the cerebellum and cerebral hemispheres rCBF. These remote effects are related to lesions of the main pathways joining these structures, resulting in deactivation and, in some cases, overactivation. Contrary to what has been suggested, consequences on cerebral hemispheres are more severe in mixed cerebellar and brain stem infarcts than in pure cerebellar lesions.

Topics: Adult; Cerebellar Diseases; Cerebral Infarction; Cerebrovascular Circulation; Female; Humans; Male; Medulla Oblongata; Middle Aged; Pons; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Xenon Radioisotopes

Topics: Brain; Brain Diseases; Carotid Artery Thrombosis; Carotid Artery, Internal; Cerebellar Diseases; Cerebral Infarction; Child; Female; Heart Septal Defects; Humans; Radiopharmaceuticals; Spleen; Syndrome; Technetium Tc 99m Aggregated Albumin; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Whole-Body Counting

We compared Tc-99m HMPAO brain SPECT and MRI with the clinical findings in a case of a 14-year-old boy with post-infectious cerebellitis.. Tc-99m HMPAO brain SPECT scan showed marked reduction in perfusion to the left anterior lobe, left lateral hemisphere, and left posterior lobe of the cerebellum. The MRI showed a limited region of abnormal signal in the mid posterior left cerebellar hemisphere. Since the patient's overall neurological deficit was characterized by ataxia, nystagmus, head and body titubation, dysmetria, dysdiadochokinesia, loss of normal check, and rebound testing attributed to the involvement of the anterior, lateral, and posterior lobes of the left cerebellar hemisphere, the Tc-99m HMPAO brain SPECT finding correlated better with the extent of functional neurological deficits.. Tc-99m HMPAO brain SPECT may better assess cerebellar signs and symptoms in cerebellitis since the blood flow abnormalities correlated with dysfunction of the cerebellum, whereas the MRI abnormalities did not encompass the scope of the neurological deficits.

Topics: Adolescent; Cerebellar Diseases; Cerebellum; Encephalitis; Humans; Magnetic Resonance Imaging; Male; Radiopharmaceuticals; Respiratory Tract Infections; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Virus Diseases

To determine the frequency and patterns of periictal cerebellar hyperperfusion, whether it is associated with increased cerebellar atrophy, and whether cerebellar hyperperfusion and cerebellar atrophy are associated with predisposing clinical factors or with the outcome of epilepsy surgery.. Periictal and interictal SPECT scans and volumetric brain magnetic resonance imaging (MRI) were quantitatively analyzed in 54 consecutive patients with medically refractory partial epilepsy. Their histories were reviewed and their postsurgical outcomes assessed.. Significant periictal cerebellar hyperperfusion was found in 26 (48.1%) patients, of whom 18 had CCH, two had homolateral cerebellar hyperperfusion (HCH), and six had symmetrical bilateral hyperperfusion (BCH). No relation found between the site of the SPECT seizure localization and the presence or type of cerebellar hyperperfusion. CCH was more common when the injected seizure involved unilateral clonic motor activity (p < 0.05). A smaller MRI relative cerebellar volume (cerebellar volume/cerebral volume) was correlated with a greater seizure frequency (Rs = -0.30; p < 0.05) but not with the duration of epilepsy. There was no difference in the cerebellar volumes between the different patterns of cerebellar perfusion (p > 0.05). However, patients without a focal structural MRI lesion had significantly smaller cerebellar volumes (p < 0.05). In patients who underwent epilepsy surgery (n = 31), there was a trend for those without excellent outcomes to have smaller relative cerebellar volumes than did those with excellent outcome (10.6 vs. 11.8%; p = 0.08).. Periictal changes in cerebellar perfusion, particularly CCH, are common in patients with intractable partial epilepsy. However, periictal hyperperfusion does not appear to be a major contributor to the development of cerebellar atrophy.

Topics: Adolescent; Adult; Aged; Atrophy; Cerebellar Diseases; Cerebellum; Child; Child, Preschool; Epilepsies, Partial; Epilepsy, Temporal Lobe; Female; Humans; Infant; Magnetic Resonance Imaging; Male; Middle Aged; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

The sensitivity of single-photon emission computed tomography (SPECT) in evaluating posterior circulation infarcts compared with that of computed tomography (CT) or magnetic resonance imaging (MRI) remains unknown. In a hospital-based population, the authors studied SPECT, CT, and MRI in 35 consecutive patients presenting with acute infarction clinically localized in the thalamus (7), posterior cerebral artery (PCA) territory (15), brainstem (19), and cerebellum (3). Multiple infarcts were noted in 8 patients. Overall, the SPECT sensitivity was lower than that of MRI (21% vs 93%, p = 0.004) and CT (42% vs 65%, p = 0.046). The SPECT and CT sensitivities were not significantly different (67% vs 73%) for PCA infarcts. Performed within 24 hours, SPECT showed a relevant hypoperfusion in all PCA infarcts. For brainstem infarcts, CT (33%, p = 0.074) and MRI (91%, p = 0.004) were more sensitive than SPECT, which showed no hemispheric hypoperfusion. The sensitivity of the three imaging techniques was 100% for large cerebellar infarcts. For the small group of thalamic infarcts, the SPECT, CT, and MRI sensitivities were 14, 71, and 100%, respectively. Thus, SPECT compared to CT and MRI is not helpful in the subacute phase to localize PCA and cerebellar infarcts and is of limited value for thalamic infarcts. In the first hours, the absence of cerebral hypoperfusion in brainstem infarcts may help to differentiate them from hemispheric infarcts usually associated with profound hypoperfusion.

Topics: Aged; Aged, 80 and over; Brain Stem; Cerebellar Diseases; Cerebellum; Cerebral Arteries; Cerebral Infarction; Cerebrovascular Circulation; Cohort Studies; Female; Follow-Up Studies; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Oximes; Prospective Studies; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Thalamus; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Topics: Aged; Amphetamines; Brain; Cerebellar Diseases; Cerebral Hemorrhage; Cerebrovascular Circulation; Humans; Iodine Radioisotopes; Iofetamine; Male; Organotechnetium Compounds; Oximes; Putamen; Seizures; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

99Tcm-hexamethylpropyleneamine oxime (99Tcm-HMPAO) single photon emission computed tomographic (SPECT) brain imaging performed in conjunction with balloon test occlusion of the carotid artery has been used to assess risk of neurologic sequelae that might follow permanent surgical ligation of the artery. The predictive value of cortical hypoperfusion during temporary carotid occlusion for adverse neurologic events has been debated in previous publications. We believe that the risk of an adverse event is greater when a reduction in cortical perfusion during balloon test occlusion is associated with crossed cerebellar diaschisis (CCD). To test our hypothesis we evaluated the results of 27 99Tcm-HMPAO SPECT brain studies obtained in association with balloon test occlusions of the carotid artery. In each case we correlated clinical outcome with the presence or absence of regional decreases in cerebral perfusion and CCD. All of the 27 patients were free of neurologic symptoms during the balloon test occlusion. Seventeen of the 27 scintigraphic studies were felt to be abnormal, showing cortical perfusion defects all on the side of the occlusion. Among these 17 patients, five demonstrated CCD. Four of these five CCD patients showed evidence for cerebral cortical ischaemia on the side of the temporary carotid occlusion either shortly after the procedure or following carotid artery sacrifice. Of the remaining 12 patients with regionally reduced cerebral perfusion and no CCD, none showed evidence for cortical ischaemia in association with balloon test occlusion, and five of these 12 patients had carotid ligation without subsequent neurologic sequelae.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Aged; Aged, 80 and over; Brain; Carotid Artery, Common; Carotid Artery, Internal; Catheterization; Cerebellar Diseases; Cerebral Infarction; Cerebrovascular Circulation; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Postoperative Complications; Predictive Value of Tests; Risk Factors; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We studied the effect of acetazolamine (DIAMOXR) on vascular response in areas with crossed cerebellar diaschisis (CCD) using consecutive 99mTc-hexamethyl-propyleneamine oxime (HMPAO) SPECT studies before and after DIAMOX administration with a subtraction method. Regions of interest were drawn over the bilateral cerebellar cortices and interhemispheric asymmetry indices (IAI) were obtained. Eleven of 14 patients with CCD at baseline showed decrease of IAI after DIAMOX administration. Although there is a possibility of underestimation of increase in perfusion in unaffected cerebellar hemisphere, this result suggests a greater increase in perfusion in the affected cerebellar hemisphere as compared with in the contralateral unaffected one and suggests more dilatation of the arterioles in areas with CCD post-DIAMOX than in areas without CCD. However nonsignificant correlation between IAI at baseline and difference of IAI from baseline to post-DIAMOX did not support the hypothesis of more dilatation post-DIAMOX of more constricted arterioles.

Topics: Acetazolamide; Adult; Cerebellar Diseases; Cerebrovascular Circulation; Female; Humans; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Brain; Cerebellar Diseases; Cerebral Infarction; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Four patients with clinical signs of cerebellar stroke were studied twice by SPECT using 99mTc-HMPAO as a tracer for cerebral blood flow (CBF). When first scanned 6 to 22 days after onset, all had a region of very low CBF in the symptomatic cerebellar hemisphere, and a mild to moderate CBF reduction (average 10%) in contralateral hemispheric cortex. In all four cases clinical signs of unilateral cerebellar dysfunction were still present when rescanned 1 to 4 months later and the relative CBF decrease in the contralateral cortex of the forebrain also remained. The basal ganglia contralateral to the cerebellar lesion CBF showed variable alterations. A relative CBF decrease was seen in upper part of basal ganglia in all four cases, but it was not a constant phenomenon. A relative CBF increase in both early and late SPECT scans was seen at low levels of neostriatum in two cases. The remote CBF changes in cerebellar stroke seen in the forebrain are probably caused by reduced or abolished cerebellar output. The term "Crossed Cerebral Diaschisis" may be used to describe these CBF changes that would appear to reflect both decreased and increased neuronal activity.

Topics: Aged; Basal Ganglia Diseases; Cerebellar Diseases; Cerebellum; Cerebral Infarction; Cerebrovascular Circulation; Functional Laterality; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Tc-99m HMPAO brain SPECT was performed in a patient who had partial complex seizures for 1 year after successful acyclovir treatment of biopsy-proven herpes simplex encephalitis 2 years earlier. In spite of antiepileptic medications, her seizures were intractable and occurred daily. Tc-99m HMPAO was administered intravenously while she was having subclinical seizures, and brain SPECT demonstrated an area of hyperperfusion in the right temporal lobe medially and in the contralateral cerebellum. This reverse of the crossed cerebellar diaschisis phenomenon in epileptic disorders has not previously been documented.

Topics: Adult; Brain; Cerebellar Diseases; Encephalitis; Epilepsy, Complex Partial; Female; Herpes Simplex; Humans; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

A scintigraphic single photon emission computed tomographic (SPECT) evaluation of frontal perfusion alteration was performed in five patients with known cerebellar lesions but with normal supratentorial computed tomographic (CT) or magnetic resonance (MR) scans. A clearly evident asymmetry was found in prefrontal areas in the four subjects with acquired cerebellar damage. The fifth subject, who had congenital left cerebellar hypoplasia, did not show any frontal flow asymmetry. The data support the growing clinical evidence that the cerebellum contributes to the cognitive processes of the frontal lobes and suggest a possible role for SPECT examination in the assessment of functional cognitive impairment in patients with acquired cerebellar lesions.

Topics: Adolescent; Adult; Cerebellar Diseases; Cerebral Cortex; Child; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

The effects of acetazolamide (Diamox) on vascular response were investigated in areas with intrahemispheric thalamic diaschisis and crossed cerebellar diaschisis using consecutive Tc-99m HMPAO brain SPECT studies before and after Diamox administration. All six patients with thalamic diaschisis and five of eight patients with crossed cerebellar diaschisis at baseline showed significantly augmented perfusion after Diamox administration in the affected thalamus and cerebellum compared with that in the contralateral unaffected areas. These results suggest more dilatation of the arterioles in areas with diaschisis after Diamox administration than in areas without diaschisis. Diamox may produce relative luxury perfusion in areas with diaschisis.

Topics: Acetazolamide; Adult; Aged; Cerebellar Diseases; Cerebrovascular Disorders; Female; Humans; Male; Middle Aged; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Thalamic Diseases; Tomography, Emission-Computed, Single-Photon

Eight patients with drug-resistant complex-partial seizures were subjected to left- and right-sided intracarotid sodium amytal (ISA) procedures during preoperative investigations for surgical treatment. Regional changes of cerebral and cerebellar blood flow during barbiturization were measured by [99mTc]-HMPAO-SPECT. Crossed cerebellar diaschisis (CCD) was observed in 13 out of 16 tests (81%) as well as ipsilateral cerebral hypoperfusion (87%). Thus CCD occurred more frequently in ISA procedures than in previously studied patients with cerebral infarctions and tumors. Since intracarotid injections of sodium amytal lead to hypoperfusion mainly in those areas of the brain that are supplied by the middle cerebral artery, functional suppression of these regions is supposed to be one of the main preconditions of CCD. Our findings suggest that CCD as demonstrated by the SPECT-technique is a common phenomenon in ISA procedures.

Topics: Adolescent; Adult; Amobarbital; Carotid Artery, Internal; Cerebellar Diseases; Cerebrovascular Circulation; Epilepsy, Temporal Lobe; Female; Humans; Injections, Intra-Arterial; Male; Organotechnetium Compounds; Oximes; Speech; Technetium Tc 99m Exametazime; Tomography, Emission-Computed