technetium-tc-99m-exametazime and Brain-Damage--Chronic

Brain imaging has become an integral part of the evaluation of neurological and psychiatric disorders. Functional imaging techniques, SPECT and PET, together with structural modalities, CT and MRI, are widely employed. Functional imaging studies are routinely used in the diagnostic workup of patients with well-characterized neurological disorders, such as epilepsy and brain tumors, and have a growing role in research on psychiatric disorders without known mechanisms such as depression and schizophrenia. Furthermore, many well-defined neurological disorders manifest prominent psychiatric symptomatology which may pose difficulties in differential diagnosis. This review addresses the current knowledge of SPECT findings in patients who present with psychiatric phenomena, associated with disorders at the interface of neurology and psychiatry.

Topics: Alzheimer Disease; Brain; Brain Damage, Chronic; Brain Diseases; Brain Injuries; Brain Neoplasms; Dementia; Diagnosis, Differential; Epilepsy, Temporal Lobe; Humans; Huntington Disease; Neurocognitive Disorders; Organotechnetium Compounds; Oximes; Parkinson Disease; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

To evaluate change in regional cerebral perfusion (rCBF) after median nerve stimulation (MNS) therapy in brain-damaged patients.. Twelve brain-damaged patients received 12 courses of MNS. Technetium-99m-ethyl cysteinate diethylester (99mTc-ECD) SPECT was performed before and 4 weeks after MNS initiation. Clinical response was assessed by Glasglow coma scale or clinical improvement. 12 MNS patients were grouped as good responder (GR) (n = 6) and poor responder (PR) (n = 6) according to therapy response. Scan images were analyzed by Statistical Parametric Mapping 2 (SPM2).. In the GR group, paired Student t test between the pre- and post-MNS images showed 2 activation clusters over the left frontal and parietal lobes, including regions of the precentral gyrus, middle frontal gyrus, superior frontal gyrus, subgyral, inferior parietal lobule, and postcentral gyms (corresponding to Brodmann areas 4, 6, and 40). In the PR group, paired Student t test did not show any activation clusters. Clusters with significant differences between the GR and PR groups shared no mutual voxels with those clusters having significant regional effects after MNS in the GR group.. Median nerve stimulation enhanced the rCBF of the contralateral motor and somatosensory cortex, which is compatible with the few previous studies using other modalities.

Topics: Adolescent; Adult; Aged; Brain Damage, Chronic; Brain Mapping; Cerebrovascular Circulation; Electric Stimulation Therapy; Female; Functional Laterality; Humans; Male; Median Nerve; Middle Aged; Motor Cortex; Radiopharmaceuticals; Somatosensory Cortex; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Cerebral perfusion brain scintigraphy obtained in six unselected patients (age newborn to 14 years) from among 50 children with vein of Galen malformations was used in conjunction with magnetic resonance imaging to determine the basis of the neurological and cognitive abnormalities in patients with vein of Galen malformations (VGMs). Five had a hemiparesis - persistent, transient, or alternating. Four were developmentally delayed. Two had so far been cognitively normal and acquired a neurological deficit, following an embolization procedure. The school age patient had a nonverbal learning disability. Three had epilepsy and/or an abnormal electroencephalogram. Magnetic resonance imaging documented only the VGM, hydrocephalus and atrophy; one child with perinatal asphyxia had periventricular leukomalacia. Perfusion brain scintigraphy was normal in two (a normal infant, and a toddler with a hemiparesis and aphasia). Abnormal findings included: left parietal hypoperfusion, fronto-temporal atrophy, patchy flow; left fronto-temporal hypoperfusion, left hemiatrophy, bilateral medial temporal hypoperfusion, right cerebellar hypoperfusion; right temporal hypoperfusion, patchy flow; right hemiatrophy, occipital hypoperfusion. Perfusion brain scintigraphy findings correlated better with focal neurological and cognitive defects than did magnetic resonance imaging.

Topics: Adolescent; Brain; Brain Damage, Chronic; Cerebral Veins; Child; Child, Preschool; Developmental Disabilities; Dominance, Cerebral; Female; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Infant; Infant, Newborn; Intracranial Arteriovenous Malformations; Magnetic Resonance Imaging; Male; Radionuclide Imaging; Regional Blood Flow; Technetium Tc 99m Exametazime

Regional brain injury in three neonates with hypoglycemic encephalopathy are presented using serial 99mTc-hexamethyl propyleneamine oxime (HMPAO) SPECT and, for comparison, MRI. During the acute stage, both 99mTc-HMPAO SPECT and MRI reveal abnormalities in the posterior cerebrum. Technetium-99m-HMPAO SPECT reveals further areas of insult, for example the frontal lobes. The degree of hypoperfusion correlates with the clinical severity of hypoglycemia during the neonatal period and subsequent neurological sequelae. Follow-up with HMPAO SPECT several months after insult demonstrates persistent hypoperfusion in some areas, mainly in the occipital and posterior parietal regions. MRI can depict morphological changes with superior resolution. Because morphological change generally follows slowly after functional change, MRI is less sensitive than HMPAO SPECT in detecting and predicting the extent of hypoglycemic cerebral injury during the acute phase. HMPAO SPECT during the acute stage is a valuable tool for evaluating the extent and severity of brain injury in neonates with hypoglycemic encephalopathy.

Topics: Brain; Brain Damage, Chronic; Cerebrovascular Circulation; Female; Follow-Up Studies; Humans; Hypoglycemia; Infant, Newborn; Magnetic Resonance Imaging; Male; Radiopharmaceuticals; Technetium Tc 99m Exametazime; Time Factors; Tomography, Emission-Computed, Single-Photon

The purposes of this study were: (1) to determine the prevalence of abnormal 99mTc-HMPAO SPECT scans in patients suffering from persistent post-concussive syndrome (PPCS) after mild closed head injury (CHI); (2) to compare SPECT with structural neuroimaging (MRI and CT) in patients with mild CHI; and (3) to investigate correlations between SPECT and clinical data obtained from the patient sample (neuropsychological testing, demographics, psychiatric diagnoses). Forty-three patients were included. SPECT was read as abnormal in 53% of patients and showed a total of 37 lesions while MRI was read as abnormal in 9% and CT scan in only 4.6% of patients after mild CHI. SPECT appears to be more sensitive in detecting cerebral abnormalities after mild CHI, especially in patients with PPCS symptoms, than either CT or MRI. No statistically significant relationship was found between SPECT scan abnormalities and age, past psychiatric history, history of substance abuse, or history of multiple CHI. Education level did not differ between patients with normal and abnormal SPECT. Current neuropsychiatric symptoms did not seem to have any impact on the results of SPECT scan.

Topics: Adolescent; Adult; Brain Concussion; Brain Damage, Chronic; Cerebral Cortex; Dominance, Cerebral; Energy Metabolism; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Regional Blood Flow; Syndrome; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Single photon emission computed tomography (SPECT) with 99mTc-labeled hexamethylpropylene-amine oxime (HMPAO) was used to evaluate cerebral blood flow in 6 patients with hypoxic brain injury (HBI). The SPECT scans were compared with electroencephalograms (EEGs), magnetic resonance imaging (MRI) scans, or computer tomography (CT) scans. The findings on SPECT scans in all 6 patients supported the clinical impression of HBI. SPECT showed decreased perfusion in regions of the brain including the hippocampus, cerebellum white matter, rostral brain stem, the cortex, and occiput. MRI, CT, and EEG provided information that was often not representative of HBI. It was believed that SPECT provided more useful information in the identification of HBI. SPECT imaging with 99mTc HMPAO appears to be a valuable adjunct for evaluation and clinical diagnosis of HBI patients.

Topics: Adult; Aged; Aged, 80 and over; Brain Damage, Chronic; Cerebrovascular Circulation; Electroencephalography; Female; Humans; Hypoxia, Brain; Magnetic Resonance Angiography; Male; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

Diagnosis of brain death must be certain to allow discontinuation of artificial ventilation and organ transplantation. Brain death is present when all functions of the brain stem have irreversibly ceased. Clinical and electrophysiological criteria may be misinterpreted due to drug intoxication, hypothermia or technical artefacts. Thus, if clinical assessment is suboptimal, reliable early confirmatory tests may be required for demonstrating absence of intracranial blood flow. We have easily carried out and interpreted 99mTc HM-PAO SPECT in a consecutive series of 40 comatose patients with brain damage, without discontinuing therapy. Brain death was diagnosed in 7 patients, by recognising absence of brain perfusion, as shown by no intracranial radionuclide uptake. In patients in whom perfusion was seen on brain scans, HM-PAO SPECT improved assessment of the extent of injury, which in general was larger than suggested by CT.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Brain; Brain Damage, Chronic; Brain Death; Child; Coma; Female; Humans; Life Support Care; Male; Middle Aged; Organotechnetium Compounds; Oximes; Prognosis; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

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

Cortical remote effects of right deep-seated lesions were studied with two cerebral blood flow measurement methods (two-dimensional xenon-133 inhalation and 99mTc HMPAO SPECT) in a population of 13 right-handed stroke patients. A neuropsychological battery of tests suitable for assessment of possible visual neglect was performed. Neglect was present in 7 cases. A regional cortical hypoperfusion was observed in all patients. However, in neglect patients it was more extended and involved the right inferior parietal region suggesting a causal relationship between cortical dysfunction and neuropsychological deficit. This finding supports the model attributing neglect to a unilateral attention-arousal defect in a cortico-limbic-reticular loop.

Topics: Aged; Aged, 80 and over; Arousal; Attention; Brain Damage, Chronic; Brain Mapping; Cerebral Cortex; Cerebrovascular Disorders; Dominance, Cerebral; Female; Humans; Limbic System; Male; Middle Aged; Neural Pathways; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Psychomotor Performance; Regional Blood Flow; Reticular Formation; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon; Xenon Radioisotopes

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

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

The role of the somatosensory cortex in central pain syndromes is widely questioned. Two recent position emission tomography studies detected a strong activation of the parietal and cingular cortices after brief nociceptive stimuli. On the other hand, a recent single photon emission computed tomography study found no cortical activation in five patients affected by central poststroke pain and algodystrophia. In this study, we present the single photon emission computed tomography findings in five patients suffering from central pain syndromes. Two of these, one with facial postrhizotomy anesthesia dolorosa and the other with central poststroke pain, showed a decrease of blood flow in the parietal lobe, further decreasing after stimulation by nonpainful maneuvers. Our results suggest that somatosensory cortical areas might be involved in the generation of anomalous pain states in some cases of central pain syndromes.

Topics: Adult; Aged; Aged, 80 and over; Brain Damage, Chronic; Cerebral Cortex; Female; Humans; Male; Middle Aged; Neural Inhibition; Neuralgia; Organotechnetium Compounds; Oximes; Pain Measurement; Somatosensory Cortex; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Single Photon Emission Computed Tomography (SPECT) after intravenous administration of Technetium-99m hexamethylpropylene-amine oxime (Tc-99m HM-PAO) makes possible the evaluation of cerebral perfusion. We have been assessing the diagnostic accuracy of SPECT in some groups of head trauma patients: the preliminary results of this study are presented. Fourteen patients have been selected, all of them showing some kind of focal neurological deficit; the Computed Tomography (CT) and Nuclear Magnetic Resonance (NMR) were normal, or showed lesions that could not be responsible for the neurological deficits. In all of the patients Tc-99m HM-PAO SPECT has been performed, showing changes in cerebral perfusion in areas correlated with the abnormalities elicited on clinical examination. These results show that Tc-99m HM-PAO SPECT is a better technique than CT or NMR in demonstrating the organic basis of some neurological deficits observed after head trauma.

Topics: Adolescent; Adult; Blood-Brain Barrier; Brain; Brain Damage, Chronic; Brain Injuries; Dominance, Cerebral; Female; Glasgow Coma Scale; Head Injuries, Closed; Hemiplegia; Humans; Male; Middle Aged; Neurologic Examination; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Focal post traumatic mass lesions such as contusions and intracerebral haematomas are common, and often difficult for neurosurgeons to manage, because little is known of their pathophysiology. We have mapped cerebral blood flow, and studied small vessel ultrastructure at different time points within the first three weeks of head injury, in patients with these lesions. A zone of ischaemic brain is always present around these lesions, and persists for weeks or months. This accords with astrocyte swelling and microvascular compression seen on electron microscopy. Focal zones of hyperaemia were also present in 42% of patients, within the first two weeks of injury, and this appeared only within apparently normal tissue as judged by late MRI or CT.

Topics: Astrocytes; Biopsy; Blood-Brain Barrier; Brain; Brain Concussion; Brain Damage, Chronic; Brain Injuries; Capillaries; Cerebral Hemorrhage; Endothelium, Vascular; Follow-Up Studies; Humans; Hyperemia; Microscopy, Electron, Scanning; Muscle, Smooth, Vascular; Neurologic Examination; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon

Thirty six patients in the chronic stage after severe closed head injury were examined with tests of executive function, memory, intelligence, and functional capacities in daily living. Correlations were sought between test results and Tc-99m-HMPAO uptake of frontal, temporal, and thalamic regions assessed by SPECT. Neither the number of significant correlation coefficients between memory tests and regional uptake nor that between temporal uptake and tests exceeded chance. For the remaining tests, correlations to thalamic regions were stronger than those to the frontal regions, and those to right brain regions stronger than those to homologous left brain regions. Relationships of thalamic isotope uptake to neuropsychological performance may reflect the impact of diffuse brain damage and particularly of diffuse axonal injury on mental capacities.

Topics: Adult; Amnesia; Brain; Brain Damage, Chronic; Female; Follow-Up Studies; Frontal Lobe; Glasgow Coma Scale; Head Injuries, Closed; Humans; Male; Mental Processes; Mental Recall; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Regional Blood Flow; Technetium Tc 99m Exametazime; Temporal Lobe; Tomography, Emission-Computed, Single-Photon

Seventeen patients with relapsing remitting multiple sclerosis (MS) and mild physical disability had neuropsychological testing, magnetic resonance imaging (MRI) and single photon emission computerised tomography (SPECT) using technetium 99m (99mTc) hexamethyl-propyleneamine oxime (HMPAO). Performance in verbal fluency, naming and memory testing appeared to be impaired in MS patients compared with 17 age-sex and education matched normal controls. Weighted periventricular and confluent lesion scores and the width of the third ventricle, proved to be the most sensitive MRI measures in differentiating more cognitively impaired patients from those who were relatively unimpaired. Ratios of regional to whole brain activity, measured by SPECT, showed significant reduction in the frontal lobes and in the left temporal lobe of MS patients. A relationship was found between left temporal abnormality in 99mTc-HMPAO uptake and deficit in verbal fluency and verbal memory. Finally, asymmetrical lobar activity indicated a predominant left rather than right temporo-parietal involvement.

Topics: Brain; Brain Damage, Chronic; Humans; Magnetic Resonance Imaging; Multiple Sclerosis; Neurocognitive Disorders; Neuropsychological Tests; Organotechnetium Compounds; Oximes; Technetium Tc 99m Exametazime; Tomography, Emission-Computed, Single-Photon