title: Diffusion-weighted imaging study of patients with essential tremor.
abstract: The pathophysiology of essential tremor (ET) is unknown. PET and fMRI studies have revealed bilateral activation and (1)H-MRS studies metabolic abnormalities in the cerebellum and other functionally related brain structures in ET. Diffusion-weighted imaging (DWI) was used to search for evidence of tissue integrity abnormalities in these areas in ET patients and 10 matched controls by calculating water apparent diffusion coefficients (ADCs). Regions of interest included the left and right cerebellum, red nucleus, thalamus, caudate, putamen, pallidum, and frontal white matter. Histograms of ADCs were generated for all pixels in the infratentorial compartment and manually segmented areas corresponding to brainstem, vermis, and cerebellar hemispheres. ADC values were similar in all brain areas in patients and controls. Our study did not detect changes affecting the investigated brain regions in ET patients. These findings argue against major structural damage in the ET brain, although more subtle neurodegenerative changes cannot be ruled out.
authors.affiliation: Dipartimento di Scienze Neurologiche, Università di Bologna, Bologna, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Martinelli
authors.forename: Giovanni
authors.initials: G
authors.lastname: Rizzo
authors.forename: David
authors.initials: D
authors.lastname: Manners
authors.forename: Caterina
authors.initials: C
authors.lastname: Tonon
authors.forename: Fabio
authors.initials: F
authors.lastname: Pizza
authors.forename: Claudia
authors.initials: C
authors.lastname: Testa
authors.forename: Cesa
authors.initials: C
authors.lastname: Scaglione
authors.forename: Bruno
authors.initials: B
authors.lastname: Barbiroli
authors.forename: Raffaele
authors.initials: R
authors.lastname: Lodi
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D001921:Brain / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D020329:Essential Tremor / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index