2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane and Syndrome

Pure akinesia with gait freezing (PAGF) is a clinical syndrome characterized by freezing of gait, handwriting, and speech without abnormal eye movement or cognitive impairment. Several studies have suggested that PAGF may be a variant of progressive supranuclear palsy (PSP). However, the characteristics of striatal dopamine transporter loss in PAGF are unknown.. To investigate the subregional pattern of striatal dopamine transporter loss in patients with PAGF in comparison with patients with PSP and those with Parkinson disease (PD).. This retrospective case-control study included 15 patients with PAGF, 27 with PD, 20 with PSP, and 11 healthy controls who underwent F-18-fluorinated-N-3-fluoropropyl-2β-carboxymethoxy-3β-(4-iodophenyl)-nortropane (18F FP-CIT) positron emission tomography between September 1, 2008, and July 31, 2014. The positron emission tomographic images were analyzed with 12 striatal subregional and 1 occipital volume-of-interest templates. The specific to nonspecific binding ratio (SNBR) and intersubregional ratio (ISR) in patients with PAGF were compared with those in patients with PD and those with PSP.. Comparisons of SNBRs of striatal subregions and ISR among patients with PAGF, PD, and PSP and healthy controls.. The mean (SD) SNBRs (1.4 [0.7]) of the whole striatum in the 15 patients with PAGF (mean [SD] age, 71.4 [6.6] years; 7 men and 8 women) were similar to those in the 20 patients (mean [SD] age, 70.6 [4.5] years; 11 men and 9 women) with PSP (1.5 [0.5]) but significantly lower than those in the 27 patients (mean [SD] age, 67.7 [5.3] years; 10 men and 17 women) with PD (3.0 [1.3]). The mean (SD) SNBRs of the caudate nuclei in patients with PAGF (1.3 [0.9]) were significantly lower than those in patients with PD (3.5 [1.5]; P < .001) but slightly higher than those in patients with PSP (1.2 [0.5]). The mean [SD] anterior caudate to ventral striatum ISRs in patients with PAGF (0.5 [0.3]) were similar to those in patients with PSP (0.4 [0.2]) but not in patients with PD (1.0 [0.2]). The mean (SD) posterior to anterior putamen ISRs in patients with PAGF (0.4 [0.2]) were similar to those in patients with PD (0.5 [0.2]) and those with PSP (0.4 [0.2]).. On 18F FP-CIT positron emission tomography, patients with PAGF show a pattern of preferential dopaminergic loss similar to that seen in patients with PSP. These results suggest a similar distribution of regional neuronal loss in the substantia nigra pars compacta between PAGF and PSP. This finding may be one of the pathophysiological results suggesting that PAGF is a phenotypic variant of PSP.

Topics: Aged; Case-Control Studies; Corpus Striatum; Dopamine Plasma Membrane Transport Proteins; Female; Gait Disorders, Neurologic; Humans; Male; Middle Aged; Movement Disorders; Parkinson Disease; Pars Compacta; Positron-Emission Tomography; Supranuclear Palsy, Progressive; Syndrome; Tropanes

In the semi-quantitative assessment of DaTSCAN images, it has been suggested that the ratio of tracer accumulation in the putamen to that in the caudate nucleus may be helpful and could allow parkinsonian syndromes progression to be assessed. Separation of ratio values has been reported when early Parkinson's disease is compared with essential tremor. The separation is lost, however, when the Parkinson's disease is not early stage.. To evaluate whether a two-stage analysis can differentiate between parkinsonian syndromes, of various stages, and essential tremor, and whether such a two-stage analysis can be undertaken in a single step using artificial neural networks (ANNs).. Data from 18 patients were analysed. Quantification was undertaken by manually drawing irregular regions of interest (ROIs): over each caudate nucleus and putamen and over an occipital cortex area near the posterior edge of the brain. A two-stage analysis was undertaken and was repeated, in a single step, using an ANN.. The first stage, of the two-stage analysis, identified 12 patients with non-early parkinsonian syndromes. The remaining six patients were then successfully classified into early parkinsonian syndromes and essential tremor. The ANN analysis successfully discriminated parkinsonian syndromes from essential tremor, in all patients, in a single step.. The two-stage process provides a method for classifying early disease without being compromised by the noise from non-early disease. The results of the single stage ANN analysis were very definite and it may be considered to have potential in the quantification of DaTSCAN images for clinical use.

Topics: Adult; Aged; Aged, 80 and over; Cluster Analysis; Diagnosis, Differential; Essential Tremor; Female; Humans; Image Enhancement; Image Interpretation, Computer-Assisted; Male; Middle Aged; Neural Networks, Computer; Parkinson Disease; Pattern Recognition, Automated; Radiopharmaceuticals; Reproducibility of Results; Sensitivity and Specificity; Syndrome; Tomography, Emission-Computed, Single-Photon; Tropanes

The authors studied four patients with parkinsonism carrying the fragile X premutation using SPECT with ([23)I]FP-CIT. They found evidence of preserved presynaptic nigrostriatal function, suggesting that parkinsonism in the X fragile premutation might be related to postsynaptic dopaminergic changes or different neurotransmitter alterations.

Topics: Aged; Atrophy; Biomarkers; Brain; Brain Mapping; Corpus Striatum; Dopamine; Dopamine Plasma Membrane Transport Proteins; Female; Fragile X Syndrome; Genetic Predisposition to Disease; Heterozygote; Humans; Male; Middle Aged; Mutation; Neural Pathways; Parkinson Disease; Substantia Nigra; Synaptic Transmission; Syndrome; Tomography, Emission-Computed, Single-Photon; Tropanes