title: The status of olfactory function and the striatal dopaminergic system in drug-induced parkinsonism.
abstract: Olfactory impairment has been reported in drug-induced parkinsonism (DIP), but the relationship between dopaminergic dysfunction and smell deficits in DIP patients has not been characterized. To this end, we studied 16 DIP patients and 13 patients affected by Parkinson's disease (PD) using the "Sniffin' Sticks" test and [(123)I] FP-CIT SPECT (single-photon emission computed tomography). DIP patients were divided based on normal (n = 9) and abnormal (n = 7) putamen dopamine transporter binding. Nineteen healthy age- and sex-matched subjects served as controls of smell function. Patients with DIP and pathological putamen uptake had abnormal olfactory function. In this group of patients, olfactory TDI scores (odor threshold, discrimination and identification) correlated significantly with putamen uptake values, as observed in PD patients. By contrast, DIP patients with normal putamen uptake showed odor functions-with the exception of the threshold subtest-similar to control subjects. In this group of patients, no significant correlation was observed between olfactory TDI scores and putamen uptake values. The results of our study suggest that the presence of smell deficits in DIP patients might be more associated with dopaminergic loss rather than with a drug-mediated dopamine receptor blockade. These preliminary results might have prognostic and therapeutic implications, as abnormalities in these individuals may be suggestive of an underlying PD-like neurodegenerative process.
authors.affiliation: Dipartimento di Scienze Neurologiche e della Visione, Università di Verona, Verona, Italy. doctorbox@hotmail.it
authors.forename: Tommaso
authors.initials: T
authors.lastname: Bovi
authors.forename: Angelo
authors.initials: A
authors.lastname: Antonini
authors.forename: Sarah
authors.initials: S
authors.lastname: Ottaviani
authors.forename: Angela
authors.initials: A
authors.lastname: Antonioli
authors.forename: Maria Paola
authors.initials: MP
authors.lastname: Cecchini
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Di Francesco
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Bassetto
authors.forename: Mauro
authors.initials: M
authors.lastname: Zamboni
authors.forename: Antonio
authors.initials: A
authors.lastname: Fiaschi
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Moretto
authors.forename: Andrea
authors.initials: A
authors.lastname: Sbarbati
authors.forename: Francesco
authors.initials: F
authors.lastname: Osculati
authors.forename: Michele
authors.initials: M
authors.lastname: Tinazzi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000978:Antiparkinson Agents / Q000009:adverse effects; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000857:Olfaction Disorders / Q000000981:diagnostic imaging / Q000209:etiology / Q000378:metabolism*; D010300:Parkinson Disease / Q000150:complications / Q000378:metabolism / Q000503:physiopathology; D010302:Parkinson Disease, Secondary / Q000150:complications / Q000378:metabolism* / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D000978:Antiparkinson Agents; D004298:Dopamine