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Sensory disturbances such as olfactory or visual dysfunctions are common in Parkinson’s disease (PD). A possible relationship between distorted colour discrimination and the nigrostriatal dopamine deficit is still a matter of debate. We examined 31 de novo Parkinsonian patients with [123I]β-CIT single photon emission tomography (SPECT). We used a single-head γ-camera and calculated the binding ratio striatum/cerebellum (specific/nonspecific binding) of [123I]β-CIT uptake. On the same day, we performed the Farnsworth-Munsell 100 Hue Test (FMT) in these patients and estimated the total error score, in order to investigate abnormalities of colour vision. Parkinsonian patients’ total error score was higher compared with an age- and sex-matched control group ( P = < 0.0001), whereas disability scores of the Hoehn and Yahr scale ( P = 0.019, Spearman r = 0.419) and the Unified Parkinson’s Disease Rating Scale ( P = 0.039, Spearman r = 0.373) correlated with total error score. No significant association appeared between total error score (Spearman r = –0.119, P = 0.525) and [123I]β-CIT-SPECT ratio. Thus both total error scores of the FMT and [123I]β-CIT-SPECT binding ratios have been found to reflect the severity of PD. However, only [123I]β-CIT SPECT reflects degeneration of dopaminergic neurons of the basal ganglia, but does not reflect alterations of the visual system and/or extranigral lesions in PD. From our results, we speculate that FMT may be a valuable clinical method to measure extranigral lesions of the visual system in PD. [ABSTRACT FROM AUTHOR]

We used single photon emission tomography to study regional cerebral perfusion in patients with different forms of spinocerebellar degeneration: 6 patients with Friedreich’s ataxia (FA), 6 with early-onset cerebellar ataxia with retained tendon reflexes (EOCA), 5 with autosomal dominant cerebellar ataxia type 1 (ADCA I) and 11 with idiopathic late-onset cerebellar ataxia (ILOCA). The results were related to clinical and magnetic resonance imaging (MRI) findings. Cerebellar hypoperfusion was constant in ADCA I and frequent in patients with other spinocerebellar degenerations. Brain stem hypoperfusion was constant in ADCA I, frequent in ILOCA patients with pontocerebellar atrophy and absent in FA and EOCA. FA and EOCA often showed a reduction in the parietotemporal cortex blood flow, which was not related to cortical atrophy. ILOCA patients had an asymmetric pattern in the temporal areas with decreased blood flow in the right side only. Caudate hypoperfusion was found in ADCA I patients. Cerebral atrophy did not account for changes in regional blood flow, which probably indicate early involvement of cerebral structures. [ABSTRACT FROM AUTHOR]

The accurate clinical diagnosis of degenerative cortical brain disorders is a necessary prerequisite for patient management and the critical evaluation of new treatments. This study has evaluated the ability of single photon emission tomography (SPET) to differentiate between Alzheimer's disease (AD) and different forms of non-Alzheimer lobar atrophy (LA), using a multi-purpose system in widespread routine clinical use.Tc-HMPAO SPET was carried out in patients with AD and three clinical syndromes associated with LA: frontotemporal dementia (FTD), progressive non-fluent aphasia (PA) and semantic dementia (SD). Principal component (PC) analysis was performed on regional cerebral blood flow (rCBF) data and inter-group comparisons were performed for PC scores using multiple t-tests. Three PCs explained 86.5% of the variation in rCBF values between individual patients and normal controls. The first PC reflected the average rCBF value and separated patient groups from normal controls but failed to distinguish between patient groups. The second PC reflected anterior-posterior asymmetry and separated AD from all three forms of LA. This PC also separated FTD and SD from controls but failed to distinguish between FTD, PA and SD. The third PC reflected left-right asymmetry and separated PA from all other groups.Tc-HMPAO SPET is able to differentiate between degenerative cortical brain disorders in a simple and physiological meaningful way, thereby showing considerable potential as a routine tool in the clinical evaluation and differentiation of AD and LA. [ABSTRACT FROM AUTHOR]

Conventional imaging with computed tomography (CT) and magnetic resonance imaging (MRI) may show abnormalities in central nervous system Behcet's syndrome but is normal in some cases. Recently in two cases positron emission tomography has shown abnormalities in blood flow and glucose metabolism far more extensive than the abnormalities seen on CT and MRI scans in the same patients. We report a patient with neuro-Behcet's syndrome presenting with headache and personality change in whom CT and MRI brain imaging was normal, but regional cerebral blood flow imaging using single photon emission tomography with the tracer HMPAO showed extensive perfusion deficits which partially reversed after 3 months of prednisolone therapy. This technique may aid the diagnosis of cerebral involvement in Behcet's syndrome, although the cause and incidence of the perfusion deficits need further evaluation. [ABSTRACT FROM AUTHOR]

Cerebral perfusion patterns in 18 cases with vascular dementia of Binswanger type (VDBT) (8 moderate and 10 severe cases) were compared with 25 cases with senile dementia of Alzheimer type (SDAT) (16 moderate and 9 severe cases) and 14 controls by single photon emission computed tomography using N-isopropyl- p-I iodoamphetamine (IMP) as a tracer. The cerebral: cerebellar IMP uptake ratio (%) (CCR) was used as a measure of relative cerebral perfusion. The CCRs were about 85-90% in all areas in controls. Moderate VDBT patients showed a remarkable decrease of CCRs in the basal grey region (thalamus and basal ganglia) (right 79%, left 77%) and in the frontal area (right 79%, left 80%) ( P<0.01). In severe VDBT patients a significant decrease of the CCR was noted in all regions ( P<0.01). The decrease of mean CCRs in the hemispheres was significantly correlated with the severity of disease determined by psychometric testing. Patients with SDAT showed a significant decrease of the CCR in the parietal (right 71%, left 74%) and right temporal (78%) areas in the moderate stage ( P<0.01), and further progression of dementia was associated with low perfusion areas extending to the frontal areas (78%, P<0.01). These differences in the perfusion patterns and their changes with progression of the illnesses may be reflected in characteristic clinical features. [ABSTRACT FROM AUTHOR]