title: Olfactory performance in spinocerebellar ataxia type 7 patients.
abstract: A large body of evidence has shown olfactory deficits in many neurodegenerative diseases. However, the nature of the olfactory impairment remains poorly understood partly because the majority of studies have only explored smell identification capabilities. The purpose of the present study was twofold. First we wanted to test if patients with spinocerebellar ataxia type 7 (SCA7), a progressive neurodegenerative disorder characterized by cerebellar ataxia and visual loss, also have olfactory deficits. Secondly, we wanted to test the nature of the olfactory deficits by testing not only the identification level but also olfactory threshold and discrimination. Based on the olfactory dysfunction found in different neurodegenerative diseases and functional neuroimaging data showing cerebellar activation during olfaction, we hypothesized that SCA7 patients would show an olfactory impairment. To test this hypothesis we studied twenty-eight genetically confirmed SCA7 patients and twenty-seven matched controls using the Sniffing Sticks Test and the University of Pennsylvania Smell Identification Test (UPSIT). The results show that SCA7 patients' ability to discriminate and identify odors is significantly impaired, although their odor detection thresholds were at normal levels. These results suggest that SCA7 neurological damage affects olfactory perception but spares the patients' olfactory sensory capabilities.
authors.affiliation: Instituto de Neuroetología, Universidad Veracruzana, Mexico. Electronic address: victorgalvezzuniga@yahoo.com.mx.
authors.forename: Victor
authors.initials: V
authors.lastname: Galvez
authors.affiliation: Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autonoma de México, Mexico.
authors.forename: Rosalinda
authors.initials: R
authors.lastname: Diaz
authors.affiliation: Instituto de Neuroetología, Universidad Veracruzana, Mexico.
authors.forename: Carlos Roberto
authors.initials: CR
authors.lastname: Hernandez-Castillo
authors.affiliation: Unidad periférica de Neurociencias, Facultad de Medicina, Universidad Nacional Autónoma de México, Instituto Nacional de Neurología y Neurocirugía "MVS", Mexico.
authors.forename: Aurelio
authors.initials: A
authors.lastname: Campos-Romo
authors.affiliation: Instituto de Neuroetología, Universidad Veracruzana, Mexico; Departamento de Fisiología, Facultad de Medicina, Universidad Nacional Autonoma de México, Mexico; Facultad de Psicología, Universidad Veracruzana, Mexico. Electronic address: jfr@unam.mx.
authors.forename: Juan
authors.initials: J
authors.lastname: Fernandez-Ruiz
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004192:Discrimination, Psychological / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009812:Odorants; D000857:Olfaction Disorders / Q000209:etiology*; D012903:Smell / Q000502:physiology; D020754:Spinocerebellar Ataxias / Q000150:complications*; D055815:Young Adult
keywords: Olfactory impairment; SCA7; Smell; Spinocerebellar ataxia