Investigators at University of Bologna zero in on Parkinson disease
December 8th, 2008
2008 DEC 8 -- "Corticobasal degeneration (CBD) and progressive supranuclear palsy (PSP) are two neurodegenerative disorders within the category of tauopathies, which must be considered in differential diagnosis of Parkinsons disease. Although specific clinical and neuroradiological features help to guide the clinician to a likely diagnosis of Parkinsons disease, CBD or PSP, differential diagnosis remains difficult," scientists in Bologna, Italy report.
"The aim of our study was to analyse apparent diffusion coefficient (ADC(ave)) maps from patients with clinical diagnosis of CBD (corticobasal syndrome, CBS), classical phenotype of PSP (Richardsons syndrome, RS) and Parkinsons disease (PD) in order to identify objective markers to discriminate between these groups. Thirteen Parkinsons disease patients, 10 RS patients, 7 CBS patients and 9 healthy volunteers were recruited and studied in a 1.5 T MR scanner. Axial diffusion-weighted images were obtained and the ADC(ave) map was generated. Regions of interest (ROIs) included mesencephalon, corpus callosum and left and right superior cerebellar peduncle (SCP), thalamus, caudate, putamen, pallidus, posterior limb of internal capsule, frontal and parietal white matter. Histograms of ADC(ave) were generated for all voxels in left and right cerebral hemispheres and in left and right deep grey matter regions separately, and the 50th percentile values (medians) were determined. The ratio of the smaller to the larger median value (symmetry ratio) was calculated for left and right hemispheres and for left and right deep grey matter regions (1 perfect symmetry). Putaminal ADC(ave) values in CBS and RS were significantly greater than those in Parkinsons disease and healthy volunteers, but could not distinguish CBS from RS patients. In CBS patients, the values of the medians of cerebral hemispheres histograms were significantly higher than those in RS, Parkinsons disease and healthy volunteers, while the hemispheric symmetry ratio in CBS (0.968, range 0.952-0.976) was markedly reduced compared with RS (0.993, range 0.992-0.994), Parkinsons disease (0.991, range 0.988-0.993) and healthy controls (0.990, range 0.988-0.993). The hemispheric symmetry ratio differentiated CBS patients from RS and Parkinsons disease patients with a sensitivity and specificity of 100%. In RS patients, the ADC(ave) values of the SCPs were significantly greater than those in Parkinsons disease and healthy volunteers. Our findings confirm that putaminal ADC(ave) values evaluation provides a good discrimination between Parkinsons disease and atypical parkinsonisms, including RS and CBS," wrote G. Rizzo and colleagues, University of Bologna.
The researchers concluded: "Furthermore, diffusion-weighted imaging, by detecting the brain microstructural correlates of the typical asymmetric signs and symptoms in CBS and the SCP involvement in RS, was shown to aid characterization and differentiation of atypical parkinsonism."
Rizzo and colleagues published their study in Brain (Diffusion-weighted brain imaging study of patients with clinical diagnosis of corticobasal degeneration, progressive supranuclear palsy and Parkinson's disease. Brain, 2008;131(Part 10):2690-2700).
For additional information, contact R. Lodi, University of Bologna, Policinico S Orsola, Dipartimento Med Clinic & Biotecnol Applicata, Via Massarenti 9, I-40138 Bologna, Italy.
The publisher's contact information for the journal Brain is: Oxford University Press, Great Clarendon St., Oxford OX2 6DP, England.
Keywords: Italy, Bologna, Central Nervous System Disease, Corticobasal Degeneration, Corticobasal Syndrome, Differential Diagnosis, Mental Health, Neurodegenerative, Neurology, Parkinson Disease, Progressive Supranuclear Palsy, Supranuclear Palsy, Tauopathies, University of Bologna.
This article was prepared by Pain & Central Nervous System Week editors from staff and other reports. Copyright 2008, Pain & Central Nervous System Week via NewsRx.com.
