SPECT as a diagnostic test in the investigation of dementia (original) (raw)
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Psychiatry Research: Neuroimaging, 1997
Ten patients with probable Alzheimer's disease were assessed at baseline and a mean 2 years later using a battery of neuropsychological tests, CT scans and Tc99m-HMPAO SPECT scans. The subjects had declined significantly in their functional indices. Cerebral perfusion measures declined in the parietal lobes, left hemisphere and whole brain, but the overall decline did not reach statistical significance. The decline in brain perfusion did not correlate significantly with the decline in various indices of neuropsychological function, either globally or for specific brain regions. The index of cerebral perfusion correlated significantly with global indices of neuropsychological function at baseline but not at follow-up. No single perfusion index was a significant predictor of clinical progression of dementia.
Journal of Neurology Neurosurgery and Psychiatry - J NEUROL NEUROSURG PSYCHIAT, 1994
Regional cerebral blood flow (rCBF) was measured with high resolution brain dedicated single photon emission computer tomography (SPECT) and [99mTc]-d,l-hexamethyl-propylene-amine-oxime (HMPAO) in 25 patients with probable Alzheimer's disease and in 25 control subjects, selected according to rigorous inclusion and exclusion criteria. The aim was to analyse the topography of rCBF deficits in individual patients. In the group of patients with Alzheimer's disease as a whole, global CBF was reduced, but a factorial analysis of variance did not show disproportionate reduction of rCBF in any brain region. A parametric analysis of the rCBF data in individual patients was carried out with reference to normal values for internal rCBF ratios and to 13 different abnormal rCBF patterns. These theoretical patterns were predefined by showing significant hypoperfusion in at least one, or in any relevant combination of two, three, or four, of four major brain regions (a left and right fro...
Computerized Medical Imaging and Graphics, 2013
To demonstrate the utility of semi-quantitative circumferential-profile analysis of regional cerebral blood flow (rCBF) SPECT in Alzheimer's disease (AD) versus white matter vascular dementia (WM-VaD). Methods: Subjects underwent dementia evaluation, MRI and Tc-99m HMPAO SPECT. rCBF patterns from 11 AD and 20 WM-VaD patients were compared to 17 controls using semi-quantitative circumferentialprofile analysis. Results: AD patients showed more significant semi-quantitative circumferential-profile reductions in the posterior temporo-parietal regions, whereas WM-VaD patients demonstrated greater reductions involving the frontal regions of the brain. Conclusion: Semi-quantitative circumferential-profile analysis provides a practical semi-quantitative method to evaluate brain SPECT scans in AD versus WM-VaD patients.
Corrected Cerebral Flow Reserve from Brain SPECT as a Marker of Dementia Risk
Alzheimer S and Dementia, 2011
Background: Mixed Dementia (including Alzheimer's) risk may be increased by hypertension (BP), diabetes mellitus (DM), waist-height ratio (WH), traumatic brain injury (TI), thyroid (Td), renal (Rd), pituitary (Pd) disease and depression (De). To study dementia pathogenesis we developed a brain SPECT measure of cerebral flow reserve (CFi) with correction factors due to decreased tracer clearance in Rd. Methods: Outpatients age 22 to 93 yrs had mainly mild cognitive impairment by MMSE or Test Your Memory tests. Brain SPECT included basal, perfusion-stimulated (e.g. 500 mg acetazolamide IV) and post therapy (e.g. 1.2 mg liraglutie sq) with Tc-99m-HMPAO or Tc-99m-ECD.. Cortical metabolic and perfusion indices (CMi, CPi) were calculated from basal and perfusion-stimulated SPECT. CFi = CPi-CMi was corrected by a flat 3% decrease, or from multicompartment analysis, for GFR < 60 ml/min (MDRD formula). De was defined by clinical exam. Hypertensive was untreated BP > 140/90, but treated before brain SPECT as was Td. Pd were treated if post hypophysectomy or post drug therapy. Results: CFi = CPi-CMi was (5+-2)% for patients with low likelihood of disease, and CFi < 1% was the lower limit of normal. Ages were similar among the groups. CFi was low in 90% of Pd (47/52), 59% (80/135) of BP, 57% (43/75) of DM, 67% of De (35/52), 66% of Td (71/107) and 61% (56/92) of Rd, but only 30% in Rd (28/92) if FRi uncorrected. Most, 87% of Pd (55/63) had hypothalamic defects; 68% of Pd (43/63) had orbitofrontal defects, of whom 42% or (18/43) had De. Stroke or TIA occurred in 31% of PD (19/62), 30% of Rd (22/74) and 28% of DM (21/75). Most successful results were 68% of Pd (13/22) with normal CFi post-therapy. Conclusion: Particularly low CFi in Pd suggests a fundamental role of an intact neuroendocrine system to maintain CFi and prevent dementia. Moreover, effective endocrine therapy to improve CFi or prevent its age-related decline could be part of a more comprehensive set of specific therapies to decrease dementia risk. Clinical depression with such a multimodality approach will likely be significant and a key issue in quality of care.
Journal of the Neurological Sciences, 2002
Background and objectives: Subcortical vascular dementia (VaD) is a relatively homogeneous subtype of VaD, but the mechanisms of cognitive dysfunction of subcortical VaD are not fully understood. This study investigates the changes of cerebral blood flow (CBF) in patients with subcortical VaD and the contribution of the white matter hyperintensity (WMHI) and clinical severity to CBF changes. Methods: 99mTc-ethyl cysteinate dimer single photon emission computed tomography (SPECT) was performed to measure the regional CBF and statistical parametric mapping SPM99 software was applied to automated and objective analysis of the SPECT image data. Twenty-three patients (12 male, 11 female) with mild to moderate dementia who met both the criteria of the DSM-IV and probable and possible NINDS-AIREN for VaD and had subcortical white matter changes and lacunar infarctions in brain MRI were evaluated against 17 normal control subjects (7 male, 10 female). The severity of the WMHI was measured by the semi-quantitative scale method proposed by Mäntyla. The Clinical Dementia Rating scale measured the severity of dementia. Results: SPM analysis of the SPECT image reveals significantly reduced regional CBF in the right thalamus, left caudate nucleus, cingulate, bilateral superior temporal, and left ventral subcallosal gyri in subcortical VaD patients compared to the normal controls (corrected P < 0.001). Of four WMHIs, only the deep WMHI was associated with the small CBF reduction in the left superior temporal gyrus (uncorrected P < 0.01). The reduction of the CBF according to the severity of dementia was noted in the anterior and posterior association areas (uncorrected P < 0.01). Conclusions: Our study suggests that cognitive dysfunction of subcortical VaD may be related to the reduction of the CBF in the brain areas mentioned, which are probably not associated with the severity of periventricular WMHI and dementia.
Frontiers in Systems Neuroscience, 2015
Alzheimer's disease (AD) and vascular dementia (VaD) are the most common cause of dementia. Cerebral ischemia is a major risk factor for development of dementia. 123 I-FP-CIT SPECT (DaTScan) is a complementary tool in the differential diagnoses of patients with incomplete or uncertain Parkinsonism. Additional application of DaTScan enables the categorization of Parkinsonian disease with dementia (PDD), and its differentiation from pure AD, and may further contribute to change the therapeutic decision. The aim of this study was to analyze the vascular contribution towards dementia and mild cognitive impairment (MCI). We evaluated the utility of DaTScan for the early diagnosis of dementia in patients with and without a clinical vascular component, and the association between neuropsychological function, vascular component and dopaminergic function on DaTScan. One-hundred and five patients with MCI or the initial phases of dementia were studied prospectively. We developed an initial assessment using neurologic examination, blood tests, cognitive function tests, structural neuroimaging and DaTScan. The vascular component was later quantified in two ways: clinically, according to the Framingham Risk Score (FRS) and by structural neuroimaging using Wahlund Scale Total Score (WSTS). Early diagnosis of dementia was associated with an abnormal DaTScan. A significant association was found between a high WSTS and an abnormal DaTScan (p < 0.01). Mixed AD was the group with the highest vascular component, followed by the VaD group, while MCI and pure AD showed similar WSTS. No significant associations were found between neuropsychological impairment and DaTScan independently of associated vascular component. DaTScan seems to be a good tool to discriminate, in a first clinical assessment, patients with MCI from those with established dementia. There was bigger general vascular affectation observable in MRI or CT in patients with abnormal dopaminergic uptake seen on DaTScan.
The investigation of Alzheimer's disease with single photon emission tomography
Journal of Neurology, Neurosurgery & Psychiatry, 1989
Twenty patients satisfying standard clinical criteria for Alzheimer's disease (AD) and six age-matched normal controls were studied using 9'Tc hexamethyl-propyleneamine oxime and single photon emission tomography. The AD patients had lower regional cerebral blood flow (rCBF) in the temporal and posterior parietal lobes compared to controls. AD patients with apraxia and aphasia had lower rCBF in the lateral temporal and posterior parietal lobes than AD patients without these features. Within the AD group, correlations were found between neuropsychological tests and rCBF: praxis correlated with posterior parietal activity, memory with left temporal lobe activity and language with activity throughout the left hemisphere.
Technetium99m HM-PAO-SPECT study of regional cerebral perfusion in early Alzheimer's disease
1988
completely cleared from the blood in a single passage through the cerebral circulation. Thus, its regional dis tribution can be considered proportional to regional blood flow (9). Due to the easy availability of @mTc, the [@Tc]HM-PAO/SPECT technique can be pro posed as a routine method for the assessment of regional perfusion. Aim of the present investigation has been to evaluate the usefulness of this method for the clinical assessment and management of AD.
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2000
To determine the relationship between cerebral cortical blood flow loss and the temporal development of the dementia in Alzheimer's disease (AD), SPECT was studied in a cross section of AD patients with a broad range of impairment. Thirty patients with a diagnosis of probable AD had their mini-mental state examination scores transformed into time-index values to give an estimation of dementia severity relative to the developmental time course. SPECT images were obtained using 99mTc-ethyl cysteinate dimer and a 3-head camera. Cortical surface perfusion was analyzed, including modified Talairach standardization, to obtain cortical elements from the convexity (each representing about 0.25 cm2 at the surface, 6.6-mm cortical depth) referenced to the mean perfusion of the full greater cerebellar hemisphere. These element ratios were analyzed (individually and by averages of estimated Brodmann's areas and brain regions) using linear regression with the time-index value. For indivi...