Tc-99m HMPAO Research Articles

Prolonged muscular flaccidity after stroke Morphological and functional brain alterations

Patients with a motor deficit due to ischaemic stroke usually develop muscular spasticity, but in some cases they may remain with a prolonged muscular flaccidity which impairs their recovery. Little is known about the causes of these two different functional outcomes. We correlated CT/MRI and 99mTc HM-PAO SPECT with clinical findings in 42 patients at a mean time interval of 3 months after stroke. The patients were divided into two cohorts with either flaccid (prolonged muscular flaccidity) or spastic (muscular spasticity) hemiparesis. Although patients with prolonged muscular flaccidity had a greater motor deficit, the mean structural volume of the ischaemic lesion was similar to that of the muscular spasticity cohort. There was a significantly higher prevalence of structural involvement of the lentiform nucleus in prolonged muscular flaccidity cases. Relative perfusion in the lentiform nucleus, thalamus and contralateral cerebellar hemisphere was significantly lower in prolonged muscular flaccidity than in muscular spasticity patients. A subgroup with only subcortical structural lesions also showed significantly lower relative perfusion in the ipsilateral frontal association areas. A primary involvement of the lentiform nucleus by the structural lesion seems to be crucial for the persistence of flaccidity after stroke. However, cerebral blood flow (CBF) changes in other structurally intact regions indicate their additional role. It is likely that both subcortical-cortical loops involved in motor control, i.e. cortex-basal ganglia-thalamus-cortex and cortex-pons-cerebellum-thalamus-cortex, are more widely and more severely affected in patients with prolonged muscular flaccidity.

Evaluation of cerebral vasospasm in patients with subarachnoid hemorrhage using single photon emission computed tomography.

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

Direct Comparison of Tc-99m DTP A and Tc-99m HMPAO for Evaluating Brain Death

Portable cerebral perfusion studies provide a quick and accurate alternative to traditional confirmatory examinations (such as four-vessel angiography and electroencephalography) to determine brain death. The authors retrospectively analyzed 26 cerebral perfusion studies using both Tc-99m DTPA and Tc-99m HMPAO. The flow agents gave identical results. Additionally, the delayed-phase Tc-99m HMPAO images gave the same results for brain death (14 positive and 12 negative) as the flow images from either agent. Because the Tc-99m HMPAO delayed images can be used for diagnosis, many technical problems become less crucial. Unlike Tc-99m DTPA, Tc-99m HMPAO normally visualizes the gray matter of the cerebellum, midbrain, and medulla. These areas must be evaluated to ensure that they meet the strict criteria for brain death. These differences and the present study suggest that Tc-99m HMPAO is a superior agent for cerebral perfusion studies to determine brain death.

Incidental Finding of Herpes zoster Infection by Tc-99m HMPAO

Tc-99m HMPAO brain SPECT study incidentally demonstrated a large area of increased accumulation in the soft tissue of the face and fronto-parietal region of the head, corresponding to the distribution of the ophthalmic and maxillary branches of the trigeminal nerve, which had been infected by herpes zoster.

Bilateral Cerebral Mediofrontal Hypoactivity in Tc-99m HMPAO SPECT Imaging

Fifteen patients who had bilateral mediofrontal hypoactivity and 30 control subjects without this SPECT anomaly underwent Tc-99m HMPAO brain SPECT imaging. Bilateral mediofrontal hypoactivity was found in various neurologic disorders, including subcortical arteriosclerotic encephalopathy, lacunar state, chronic alcoholism, progressive nonvascular dementia, carbon monoxide poisoning, and diabetes mellitus. This SPECT abnormality was, however, specifically associated with three clinical signs: motor disabilities predominating in the lower limbs, urinary incontinence, and akinetic mutism.

The predictive value of Tc-99m HMPAO white cell scans in pyrexia of unknown origin

The predictive value of Tc-99m HMPAO white cell scans in pyrexia of unknown origin

Neurophysiology and SPECT cerebral blood flow patterns in dementia

A series of elderly patients with dementia of Alzheimer type (AD), multi-infarct dementia (MID) and functional (non-organic) psychiatric illness (major depressive disorder) were selected by DSM III-R criteria and had the following investigations: a battery of cognitive tests, EEG with power and coherence spectral analyses of T4-T6, T3-T5, P4-O2, P3-O1 channels, visual evoked potential (flash and pattern reversal) and P300 recordings as well as single photon emission tomography (SPECT) using 99mTc HMPAO. Three subsets of patients were chosen on clinical and SPECT criteria. These were as follows: patients with a clinical diagnosis of AD and a SPECT rCBF pattern showing bilateral temporo-parietal perfusion deficits (AD type), patients with a clinical diagnosis of MID and a SPECT rCBF pattern showing single focal perfusion deficits or multiple areas of low perfusion in the cerebral cortex suggestive of ischaemic change (MID type SPECT picture) and functionally ill patients with normal rCBF (controls). The AD type group differed from the MID rCBF group in having significantly less alpha and more delta 2 (2− < 4 Hz) power. The latter had significantly lower alpha power than the controls. The 2 dementia groups with abnormal rCBF patterns did not differ in terms of coherence spectra or P300 latencies, but both had lower within and between hemisphere alpha coherence values and longer P300 latencies than the “controls” with normal rCBF. There were no group differences in the flash VEP P2-pattern reversal P100 latency difference values.

Labelled white blood cells

For imaging inflammation, white cells can be labelled with In-111 tropolonate or Tc-99m HMPAO, both of which are lipophilic complexes capable of penetrating etrating cell membranes. Mixed white cells are satisfactory for routine clinical use although in some circumstances, such as for quantitative studies, pure granulocytes are preferable. The normal distribution of labelled leukocytes includes the spleen, liver, bone marrow and lung. Although the extent of pulmonary uptake reflects labelling injury, it also reflects, with different kinetics, increased intravascular granulocyte transit time, which is encountered in several systemic inflammatory diseases. The clinical applications of labelled white cells include imaging soft tissue sepsis, imaging and quantification of inflammatory bowel disease and diagnosis of osteomyelitis. New agents for imaging inflammation are designed, in general, to target inflammationin vivo without the need for blood cell isolationin vitro. They include non-specific immunoglobulin (HIG) and monoclonal antibodies (mAbs) to granulocytes. mAbs to endothelium are also being developed but have not yet been tested in man.

Depression in Neurologic Disease

Back to table of contents Previous article Next article ArticleNo AccessDepression in Neurologic DiseasePaula T. TrzepaczPaula T. TrzepaczSearch for more papers by this authorPublished Online:1 Apr 2006https://doi.org/10.1176/jnp.6.3.324AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail "Depression in Neurologic Disease." The Journal of Neuropsychiatry and Clinical Neurosciences, 6(3), pp. 324–325 Access content To read the fulltext, please use one of the options below to sign in or purchase access. Personal login Institutional Login Sign in via OpenAthens Purchase Save for later Item saved, go to cart PPV Articles - Journal of Neuropsychiatry and Clinical Neurosciences $35.00 Add to cart PPV Articles - Journal of Neuropsychiatry and Clinical Neurosciences Checkout Please login/register if you wish to pair your device and check access availability. Not a subscriber? Subscribe Now / Learn More PsychiatryOnline subscription options offer access to the DSM-5 library, books, journals, CME, and patient resources. This all-in-one virtual library provides psychiatrists and mental health professionals with key resources for diagnosis, treatment, research, and professional development. Need more help? PsychiatryOnline Customer Service may be reached by emailing [email protected] or by calling 800-368-5777 (in the U.S.) or 703-907-7322 (outside the U.S.). FiguresReferencesCited byDetailsCited byPET and SPECT in Hepatic and Uraemic Encephalopathy11 October 2020PET and SPECT in Hepatic and Uraemic Encephalopathy23 April 2014Case Study of Tc-99m HMPAO Brain SPECT Imaging in a Patient With Hepatic Encephalopathy and Carotid Artery StenosisClinical Nuclear Medicine, Vol. 35, No. 5Nature Clinical Practice Gastroenterology & Hepatology, Vol. 4, No. 12AIDS, Vol. 19, No. Suppl 3Annals of Nuclear Medicine, Vol. 18, No. 2European Journal of Gastroenterology & Hepatology, Vol. 16, No. 9Hepatology, Vol. 35, No. 2Journal of Psychiatric Practice, Vol. 7, No. 5 Volume 6Issue 3 August 1994Pages 324-325 Metrics PDF download History Published online 1 April 2006 Published in print 1 August 1994

TC-99m HMPAO Brain SPECT Findings in Pediatric Viral Encephalitis

Two children were diagnosed with viral encephalitis, due to Epstein-Barr virus infection in one case and to herpes simplex virus infection in the other. Tc-99m HMPAO brain SPECT was arranged to detect changes in regional cerebral blood flow (rCBF) secondary to viral encephalitis. During the acute episode, Tc-99m HMPAO brain SPECT showed that the two cases had increased rCBF. After the acute episode, follow-up brain SPECT was arranged 6 months later. The rCBF in one case was restored to normal on the second brain SPECT, and that in the other case was decreased. The child with normal rCBF in the follow-up brain SPECT had better learning ability and intelligence than the other child with decreased rCBF.

Findings of Diffuse Lymphadenitis Secondary to Rheumatoid Arthritis and Synovitis on Tc-99m Labeled Leukocyte Scan

Diffuse lymph node activity was observed within the axillary and inguinal regions in a patient with a biopsyproven synovitis and rheumatoid arthritis on a Tc-99m HMPAO labeled leukocyte scan

Determination of radiochemical purity of technetium-99m-labelled complexes by TLC

Simple TLC systems capable of separating the most important fractions of the radiopharmaceuticals 99mTcMAG3, 99mTcMDP, 99mTcDPD and 99mTcHM-PAO were developed for measurements of radiochemical purity. Silica gel or cellulose layers were used for chromatography and the radioactivity distribution in the developed radiochromatograms was obtained with a TLC linear analyser. The chromatographic procedures proposed are suitable also for studies of kinetic instability.

Imaging of Disseminated Infection by a Rare Fungal Pathogen, Fusarium

Imaging findings from a single case of disseminated infection with Fusarium are presented. This common fungus has been reported as a rare pathogen to the immunocompromised. Disseminated foci were identified on a Tc-99m HMPAO labeled WBC study. Two foci were localized to the proximal tibia using MRI. In this case, imaging was more sensitive to the extent of disease than physical examination, and it also provided a more precise estimate of disease progression than clinical evaluation alone. Imaging offers potential to track regression and to identify early recurrence. This is especially valuable because infection with Fusarium tends to be indolent.

Acute Organophosphate Poisoning??? Tc-99m HMPAO SPECT Imaging of the Brain

Two cases of organophosphate poisoning are presented along with Tc-99m HMPAO brain SPECT findings in the acute and delayed phases. Perfusion defects were more prominent at the onset of poisoning in both cases.

The relationship among the quantitative perfusion-defect indices in Tc-99m HMPAO brain SPECT, IQ test, and involved extremities in children with cerebral palsy due to perinatal asphyxia.

Brain SPECT imaging was performed in 13 children with cerebral palsy (6 girls, 7 boys; age, 7-17 years) due to perinatal asphyxia with mental retardation and involved limbs were studied. The involved coronal slices were summated to a picture for the calculation of the perfusion defect indices as the quantitative and objective estimation of the perfusion defects in each brain. The records of IQ tests were scored from severe to mild mental retardation. Two experienced nuclear medicine physicians analyzed the results of the Tc-99m HMPAO brain SPECTs by visual interpretation. The involved limbs were judged by two pediatricians to be either the right or left side. The relationship among the Tc-99m HMPAO brain SPECTs, IQ test, and physical examinations of the extremities were established. The results showed that two cases of mild mental retardation had the smaller perfusion defect indices (< 0.1), six cases of severe mental retardation had the larger perfusion defect indices (> 0.30), and the other group was between the first two groups. Two cases of mild mental retardation did not have significant perfusion defects in the brain and involved limbs, and two cases with decreased visual acuity had definite perfusion defects in the occipital regions. The other cases had the matched perfusion defects of the brain with the involved limbs. The authors encourage the potential use of Tc-99m HMPAO brain SPECTs to predict the outcome of mental development and limb involvement.

Gastric Crohnʼs Disease Detected by Tc-99m HMPAO Mixed Leukocyte Scan

Gastric involvement in Crohn's disease, though uncommon, is being increasingly recognized and occurs in 1-4 of patients. Upper abdominal pain, weight loss, nausea, and vomiting are the prediminant clinical symptoms. In most cases, the gastric involvement consists of mild changes seen by endoscopy and is established only by means of histologic examination of biopsy material. Radiologic findings are therefore frequently absent or minimal. Tc-99m HMPAO labeled leukocyte scan can be useful in the simultaneous demonstration of gastric and intestinal affectation in Crohn's disease

Basilar Artery Migraine

The authors present a case of basilar artery migraine in a 33-year-old woman who was initially misdiagnosed as having a cerebrovascular or mental disorder and subjected to MRI and cerebral angiography, which, however, did not show any pathologic findings. During admission to the university hospital, she lost consciousness. An emergency Tc-99m HMPAO brain SPECT showed a significant decrease of regional cerebral blood flow in the right temporal and occipital cortices, and right cerebellar hemisphere, where regional cerebral blood flow was decreased by 10-24% as compared to the left side. The second brain SPECT during a symptom-free phase showed the reversion of regional cerebral blood flow to normal in these areas. Basilar artery migraine was diagnosed by the finding of reversible ischemia in the territory of the right basilar artery on brain SPECT images and the clinical picture.

HMPAO SPECT in Parkinson's disease before and after levodopa: correlation with dopaminergic responsiveness.

Regional cerebral perfusion was evaluated by SPECT with technetium 99m hexamethylpropyleneamine oxime (99mTc HMPAO) as a tracer in 21 patients presenting with Parkinson's disease and in 11 normal controls. In the parkinsonian patients, scans were performed both off treatment, and after levodopa, and clinical dopaminergic responsiveness was evaluated. Uptake of HMPAO by the basal ganglia was significantly decreased in the parkinsonian subjects, compared with normal controls. This reduction was seen in both responders (n = 14) and non-responders (n = 7) to dopaminergic treatment. Uptake of HMPAO by the basal ganglia rose after treatment with levodopa, but the change was similar in both responders and non-responders. By contrast a striking difference in cortical HMPAO uptake was found between responders and non-responders, with significantly lower uptake in the medial temporal and posterior parietal cortex in the non-responders. This reduction was symmetrical. Basal ganglia perfusion assessed by this technique is unlikely to be of use in the diagnosis of Parkinson's disease that is responsive to dopaminergic treatment. The presence of extensive cortical involvement on a baseline scan correlates with a lack of dopaminergic responsiveness, however, and this may be useful diagnostically.

Evidence of “regional hyperemia” in patients with severe closed head injury using single-photon emission computed tomography

Regional cerebral blood flow (rCBF) was assessed in 32 patients with acute/subacute (n = 18) or chronic (n = 14) head injury using single-photon emission computed tomography (SPECT) and (99m)Tc-hexamethylpropylenenamine oxime (HMPAO) (n = 20) or (123)I-IMP (n = 12). Twelve of the 18 patients with acute/subacute head injury were studied with a high-resolution three-head camera and (99m)Tc-HMPAO. Twenty-eight SPECT studies showed regional abnormalities of tracer uptake. In all cases in which computed tomography (CT) and/or magnetic resonance imaging (MRI) (n = 30) were available for comparison, SPECT showed similar or more extensive abnormalities with high agreement on the laterality of the lesions. Particularly in the 18 patients with acute/subacute head injury, SPECT revealed more and larger lesions than the anatomical scans. In 9 of the 12 patients, at least one region with increase in HMPAO uptake reflecting "hyperemia" was detected (mean study time after injury, 6.3 ± 2.7 days). Follow-up SPECT scans in two patients showed decreased tracer uptake in the previous hyperemic regions and encephalomalacia in the anatomical scan. Thus, hyperemia may reflect "luxury perfusion" in early phases of head injury. In three patients with diffuse axonal injury, a generalized reduction in cortical tracer activity, especially in occipital/parietal regions, was observed. The typical finding in chronic head injury was observation of lesions of similar sizes and high agreement in focal abnormalities between SPECT and CT and/or MRI. However, in nine patients with behavioral disturbances, a decrease in the cortical/basal ganglia was detected. Thus, our study confirms the presence of hyperemia in acute/subacute head injury and demonstrates the value of SPECT for assessing functional impairment in these patients.

Cerebral perfusion studies during maturation using single photon emission computed tomography in the neonatal period.

In this study, we used single photon emission computed tomography (SPECT) radiolabelled 99mTc HMPAO to assess cerebral perfusion during maturation in the neonatal period. Results of SPECT examinations in 18 newborn infants, in whom gestational age ranged form 30 to 41 weeks, and who were found to be neurologically normal in retrospect, were reviewed. The developmental changes in cerebral perfusion during the neonatal period shown by SPECT parallel findings of other methods on maturational changes of the central nervous system (neuropathological studies, positron emission tomography scan, magnetic resonance imaging). Cerebral perfusion progresses from the central part of the brain to the cerebellum, sensorimotor and then visual cortex. A close relation seems to exist between cerebral perfusion, metabolism and behavior under normal conditions in the neonatal period.