technetium-tc-99m-exametazime and Carbon-Monoxide-Poisoning

To investigate whether topographic analysis of EEG mapping and technetium-99m (99mTc) hexamethylpropylenamine oxide (HMPAO) brain single-photon emission computed tomography (SPECT) can detect cerebral anomalies in the acute phase of carbon monoxide poisoning.. Twelve patients aged 18 to 55 years with severe carbon monoxide poisoning and no history of neurologic disorder were evaluated. Either nasal (5 patients) or hyperbaric (7 patients) oxygen therapy was administered. Criteria for hyperbaric oxygen therapy were blood CO of more than 20%, loss of consciousness, pregnancy, or signs of cardiac injury. After oxygen treatment, all patients had a blood CO value of 0% and no patient had persistent acute signs of toxicity. Patients then were investigated by confentional EEG, EEG mapping, and 99mTc HMPAO brain SPECT. These procedures were performed on the day of admission.. After nasal (5 patients) or hyperbaric (7 patients) oxygen therapy was administered, 12 adults with severe carbon monoxide poisoning were evaluated. All studies were performed on the day of admission.. Conventional EEG, EEG mapping, and 99mTc HMPAO brain SPECT.. While classic EEG was normal in 9 of 12 patients and showed diffuse anomalies in 3, EEG mapping and 99mTc HMPAO brain SPECT demonstrated unilateral or bilateral regional anomalies in 8 of 12 patients. Anomalies were localized in temporo-parieto-occipital areas, the watershed areas of the major cerebral arteries, or in temporal cortex.. These preliminary results suggest that EEG mapping and 99mTc HMPAO brain SPECT can be complementary tools to diagnose early regional cerebral anomalies in carbon monoxide-poisoned patients.

Topics: Acute Disease; Adolescent; Adult; Brain Diseases; Brain Mapping; Carbon Monoxide; Carbon Monoxide Poisoning; Electroencephalography; Female; Humans; Hyperbaric Oxygenation; Male; Middle Aged; Organotechnetium Compounds; Oximes; Oxygen Inhalation Therapy; Sensitivity and Specificity; Severity of Illness Index; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Early detection of regional cerebral anomalies in acute carbon monoxide (CO) poisoning by (99m)Tc-hexamethylprophylene amine oxime (HMPAO) brain single photon emission computed tomography (SPECT) imaging has been reported previously. However, SPECT findings varied in these studies because of their small population sizes. In this study, we included 96 patients with acute CO intoxication and analyzed the regional perfusion changes in these patients by means of HMPAO brain SPECT.. Ninety-six patients, aged 4-80 years (mean age 32 years) with acute CO intoxication diagnosed by our emergency department were included in this study. Exclusion criteria included previous cerebrovascular diseases, brain injury, brain surgery and any known neurological and psychological disorders. All patients underwent a brain scan using a dual-head camera and fan-beam collimator 90-120 min after injection of (99m)Tc-HMPAO. Brain SPECT images were obtained for interpretation.. Our data suggested that 79 of the 96 patients (82.3 %) had abnormal HMPAO brain images. The predominant site of disease was basal ganglia (52/96 = 54.2 %), followed by temporal lobe (48/96 = 50.0 %), parietal lobe (44/96 = 45.8 %), frontal lobe (30/96 = 31.2 %), occipital lobe (21/96 = 21.9 %) and thalamus (8/96 = 8.3 %). No patients with acute CO intoxication had perfusion abnormalities in the cerebellum. In addition, there was no significant difference in serum COHb levels between patients with abnormal and normal HMPAO brain images.. (99m)Tc-HMPAO SPECT imaging is a useful tool to detect functional brain injury in acute CO intoxication.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Brain; Carbon Monoxide Poisoning; Cerebrovascular Circulation; Child; Child, Preschool; Female; Humans; Male; Middle Aged; Radionuclide Imaging; Regional Blood Flow; Technetium Tc 99m Exametazime; Young Adult

Abnormal regional cerebral blood flow in patients with acute carbon monoxide (CO) and organophosphate (OP) poisoning was examined using (99m)Tc-hexamethylpropylene amine oxime (HMPAO) brain single photon emission computed tomography (SPECT) in fourteen patients. We evaluated the predictive significance of acute phase brain SPECT findings for long-term neuropsychological sequelae. Changes were found in the frontal, temporal, parietal lobes within the first week after both types of poisoning. The distribution of the hypoperfused cerebral areas as demonstrated by (99m)Tc-HMPAO imaging was similar in the two groups during the acute phase. Neuropsychological sequelae developed in five patients poisoned with OP and six with CO. Patients who had SPECT findings heterogeneously or in the temporal or frontal lobes displayed disorientation. Those with fronto-parietal and frontal lobe changes displayed mental confusion. Parkinsonism also was observed in patients with parieto-occipital, parietal and frontal lobe lesions. The distribution of these lesions appears to predict the long term sequelae of these poisonings, though additional studies with larger numbers of patients are needed to confirm the role of SPECT imaging in both OP and CO poisonings.

Topics: Adult; Brain; Carbon Monoxide Poisoning; Carboxyhemoglobin; Female; Humans; Male; Neuropsychological Tests; Organophosphate Poisoning; Poisoning; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

There were 10 acutely CO poisoned study patients without CNS history (head traumas, epilepsy, dementia, migraine or alcoholic diseases) in whom (99m)Tc-HmPAO SPET, HMRS and neuropsychological testing were performed. 99mTc-HmPAO SPET and neuropsychological testing were performed twice: in acute phase and at six months post CO exposure. HMRS was carried out at 8 months post CO exposure. A multidimensional analysis of variance (MANOVA) was used to statistical analysis. Regional CBF disturbances in acute phase of CO poisoning were observed in frontal cortex, basal ganglia and parietal cortex respectively. The most reversible, as seen in control (99m)Tc-HmPAO SPET examination, were the changes observed in parietal cortex. Diffuse generalized cortex hypoperfusion, both in acute phase and at 6 months post exposure, was seen only in one the patient. In all of the examined patients different elevation in mobile lipid or/and lactate concentration in frontal lobe or/and basal ganglia was revealed by HMRS evaluation at eight months post acute CO exposure. Results of neuropsychological testing at baseline and at 6 months partially correlated with neuro-imagine techniques applied.

Topics: Acute Disease; Adolescent; Adult; Analysis of Variance; Brain Diseases; Carbon Monoxide Poisoning; Cerebrovascular Circulation; Evaluation Studies as Topic; Female; Follow-Up Studies; Humans; Magnetic Resonance Spectroscopy; Male; Neuropsychological Tests; Radiopharmaceuticals; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon

Carbon monoxide (CO) is a common cause of poisoning, and its sequelae include a progressive (25%) and a delayed relapsing form (75%). We report the diffusion-weighted MRI (DWI) findings in the delayed relapsing form of CO poisoning and characterize the types of edema.. From November 1, 2000 to June 1, 2003, 5 consecutive patients (2 men, 3 women, range of age: 54-67 years), who had the delayed relapsing type of CO poisoning, underwent DWI, conventional MRI, MR angiography and SPECT. CO poisoning was diagnosed by the presence of a typical clinical history, an abnormally increased level of serum carboxyhemoglobin and MRI findings. Apparent diffusion coefficient (ADC) values were measured in all of the abnormal lesions with visual inspection of DWI and T(2)-weighted echo-planar imaging.. DWI showed high signal intensities in bilateral periventricular white matter, in the splenium of the corpus callosum, in internal capsules, and brainstem showing moderately decreased ADC values. In the globus pallidus, the ADC values were rather increased with low signal intensities on DWI. Brain SPECT showed decreased perfusion in bilateral white matter and some parts of the cerebral cortex, which correlated well with the DWI findings.. We suggest that prominent, symmetric restricted diffusion can occur in periventricular white matter, brainstem, and corpus callosum after the delayed relapsing type of CO poisoning. Delayed cytotoxic edema can occur in this setting, which provides a new guidance for the pathogenesis of CO poisoning and the differential diagnosis of white matter diseases.

Topics: Aged; Brain Edema; Brain Mapping; Carbon Monoxide; Carbon Monoxide Poisoning; Diffusion Magnetic Resonance Imaging; Female; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Carbon monoxide (CO) poisoning continues to be a significant health problem. An early assessment of organs injury due to carbon monoxide poisoning is even more difficult than confirming the diagnosis of CO poisoning. Numerous neuroimaging techniques have been used to evaluate CO intoxication. The aim of this pilot study was to estimate the regional cerebral perfusion in CO acutely poisoned patients using 99mTc-HmPAO SPET. Disturbances in cerebral perfusion mainly in frontal, parietal cortex and basal ganglia were observed in 17 (85%) of 20 examined CO poisoned patients. 99mTc-HmPAO scintigraphy seems be useful in demonstration of early CNS dysfunction and estimation to what extent perfusion abnormalities influence the brain injury. A further study to evaluate the rCBF in relation to poisoning severity scoring are needed.

Topics: Acute Disease; Adolescent; Adult; Brain Diseases; Carbon Monoxide Poisoning; Cerebrovascular Circulation; Female; Humans; Male; Pilot Projects; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

The purpose of this retrospective study was to assess regional cerebral blood flow in patients after carbon monoxide intoxication by using brain single photon emission computed tomography and statistical parametric mapping. Eight patients with delayed neuropsychiatric sequelae and ten patients with no neuropsychiatric symptoms after carbon monoxide intoxication were studied with brain single photon emission tomography imaging with 99mTc-hexamethyl-propyleneamine oxime. Forty-four control subjects were also studied. We used the adjusted regional cerebral blood flow images in relative flow distribution (normalization of global cerebral blood flow for each subject to 50 ml x 100 g(-1) x min(-1) with proportional scaling) to compare these groups with statistical parametric mapping. Using this technique, significantly decreased regional cerebral blood flow was noted extensively in the bilateral frontal lobes as well as the bilateral insula and a part of the right temporal lobe in the patients with delayed neuropsychiatric sequelae as compared with normal volunteers (P< 0.005). In the patients with no neuropsychiatric symptoms, significantly decreased regional blood flow in the bilateral frontal lobes particularly on the left side was detected. There was a significantly decreased regional cerebral blood flow in the right frontal lobe and insula in the patients with delayed neuropsychiatric sequelae as compared to those with no neuropsychiatric sequelae. It is concluded that statistical parametric mapping is a useful technique for highlighting differences in regional cerebral blood flow in patients following carbon monoxide intoxication as compared with normal volunteers. The selectively reduced blood flow noted in this investigation supports the contention that the decrease following carbon monoxide intoxication may be prolonged and further worsen in the frontal lobe. In addition, the present study may help to clarify the characteristics of the pathophysiological alteration underlying delayed neuropsychiatric sequelae.

Topics: Adult; Aged; Brain; Carbon Monoxide Poisoning; Case-Control Studies; Cerebrovascular Circulation; Female; Humans; Image Processing, Computer-Assisted; Male; Mental Disorders; Middle Aged; Organotechnetium Compounds; Oximes; Radiopharmaceuticals; Retrospective Studies; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Technetium-99m-hexamethylpropylene amine oxime (HMPAO) brain images with fanbeam SPECT, in combination with surface three-dimensional display, were used to detect basal ganglion and cerebral cortex anomalies in the acute phase of carbon monoxide (CO) poisoning.. Ten patients, aged 16-29 yr, with acute CO poisoning and no past history of neurologic disorders were enrolled in this study. After oxygen treatment, all 10 patients were investigated using 99mTc-HMPAO brain images with fanbeam SPECT and surface three-dimensional display. Meanwhile, 6 of 10 patients also received a brain CT scan.. CT scan findings were negative in all 6 patients. Fanbeam SPECT demonstrated unilateral or bilateral hypoactivity of basal ganglia in 6 patients. Local hypoactivity anomalies were found in the brain cortex of 7 patients, using surface three-dimensional display of the brain. Only 2 of 10 patients had normal 99mTc-HMPAO brain images.. This study suggests that, in comparison with traditional brain imaging techniques, 99mTc-HMPAO brain imaging with fanbeam SPECT in combination with surface three-dimensional display is a better tool for early detection of regional cerebral anomalies in acute CO poisoning.

Topics: Acute Disease; Adolescent; Adult; Brain; Carbon Monoxide Poisoning; Female; Humans; Male; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Topics: Adult; Brain; Carbon Monoxide Poisoning; Humans; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Tc-HMPAO isotope brain scans were performed in three patients who received hyperbaric oxygen treatment following carbon monoxide poisoning. Cerebral perfusion imaging provides an index of severity of the initial cerebral damage which correlated with outcome.

Topics: Adult; Brain; Carbon Monoxide Poisoning; Cerebral Hemorrhage; Cerebral Infarction; Cerebrovascular Circulation; Fatal Outcome; Female; Forecasting; Humans; Hyperbaric Oxygenation; Male; Organotechnetium Compounds; Oximes; Purpura; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Treatment Outcome

Using brain computed tomography (CT) and single photon emission computed tomography (SPECT) with technetium-99m hexamethylpropylene amine oxime (99mTc HM-PAO) in 13 patients with delayed neurologic sequelae after carbon monoxide poisoning, we tried to evaluate the clinical outcome of delayed CO sequelae. Among the 13 initial brain CTs, seven showed low density in the cerebral white matter and one revealed hypodensity in both globi pallidi. Of the 7 follow-up CT scans, 3 have remained unchanged, but in 4 cases more aggravating patterns with cortical atrophy without the clinical correlation were observed. There was no correlation between the CT findings and the outcome of delayed CO sequelae. All initial SPECTs in 13 patients with delayed CO sequelae showed diffuse patchy hypoperfusion throughout the cerebral cortex. Among the follow-up SPECTs in 7 patients, 6 patients showed increased cerebral perfusion with the concomitant clinical improvement, but the SPECT of a patient in bedridden state had remained unchanged, compared with the initial SPECT. There seemed to be good correlation between the findings of SPECT and the outcome of delayed CO sequelae. In conclusion, 99mTc HM-PAO brain SPECT is more sensitive than CT, and may be a useful test in evaluating the clinical outcome of delayed neurologic sequelae after CO poisoning.

Topics: Adult; Aged; Atrophy; Brain; Brain Damage, Chronic; Brain Mapping; Carbon Monoxide Poisoning; Carboxyhemoglobin; Cerebral Cortex; Disability Evaluation; Female; Follow-Up Studies; Globus Pallidus; Humans; Hypoxia, Brain; Male; Middle Aged; Neurologic Examination; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Single photon emission computed tomography (SPECT) with technetium-99m (99mTc) hexamethylprophylene amine oxime (HM-PAO) were repeatedly performed in a 55-year-old woman with carbon monoxide (CO) poisoning. The initial brain SPECT 10 days after anoxic insult showed focal hypoperfusion which appeared 20 days prior to the onset of delayed neurologic sequelae, and the findings of follow-up SPECTs correlated with the clinical course of CO poisoning. The possibilities of early hypoperfusion on SPECT of acute CO poisoning were discussed.

Topics: Basal Ganglia; Brain; Brain Damage, Chronic; Carbon Monoxide Poisoning; Cerebral Cortex; Female; Humans; Hypoxia, Brain; Middle Aged; Neurologic Examination; Organotechnetium Compounds; Oximes; Prognosis; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

We used single photon emission computed tomography (SPECT) with technetium-99m hexamethylpropylene amine oxime (99mTc-HM-PAO) in 14 studies on 6 patients with delayed neurologic sequelae from carbon monoxide (CO) poisoning to determine whether any changes in cerebral blood flow could be correlated with clinical or computed tomographic evidence of delayed deficits. Among the six initial CT brain scans, two showed low density of both basal ganglia and two showed decreased density of the cerebral white matter. There was no correlation between the clinical outcome and the findings of the follow-up CT brain scans. Of the two SPECTS with 99mTc-HM-PAO performed during acute anoxic insult, one showed focal hypoperfusion which appeared 20 days prior to the onset of delayed neurologic sequelae after CO poisoning. Seven SPECTs in the six patients performing the delayed phase showed diffuse patched patterns of hypoperfusion which improved on follow-up images. There was good correlation between the clinical outcome and the findings of the 99mTc-HM-PAO SPECT. In preliminary conclusion, 9Tc-HM-PAO brain SPECT can be used for predicting or evaluating the outcome of delayed neurologic sequelae after CO poisoning. Cerebral vascular changes may be the possible cause of hypoperfusion in patients with CO poisoning.

Topics: Adult; Aged; Brain Diseases; Carbon Monoxide Poisoning; Female; Humans; Middle Aged; Organotechnetium Compounds; Oximes; Predictive Value of Tests; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon

A 32-year old woman presented with serious memory impairment and a mental syndrome named loss of psychic auto-activation or psychic akinesia following carbon monoxide poisoning. The MRI findings were bilateral pallidal lesions probably associated with thalamic lesions. The evolution was favourable.

Topics: Adult; Brain; Carbon Monoxide Poisoning; Electroencephalography; Female; Humans; Magnetic Resonance Imaging; Memory Disorders; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Substance-Related Disorders; Technetium Tc 99m Exametazime; Tomography, Emission-Computed