Spinocerebellar ataxia type 2 olfactory impairment shows a pattern similar to other major neurodegenerative diseases

Centro para la Investigación y Rehabilitación de las Ataxias Hereditarias Carlos J. Finlay, Holguín, Cuba.
Journal of Neurology (Impact Factor: 3.38). 10/2006; 253(9):1165-9. DOI: 10.1007/s00415-006-0183-2
Source: PubMed


Olfactory function is affected in different neurodegenerative diseases. Recently, it has been found that some hereditary ataxias are also associated with significant olfactory impairment. However, the initial findings did not examine the nature of the olfactory impairment associated with these ataxias. In the present article the effect of spinocerebellar ataxia type 2 (SCA2) on olfactory function was studied in 53 SCA2 patients and 53 healthy control subjects from Holguín, Cuba. Several tests were applied to evaluate olfactory threshold, description, identification and discrimination. The results show significant impairment in SCA2 patients on all olfactory measurements, and the pattern of olfactory deficits found suggests that they have much in common with those reported for other neurodegenerative diseases such as Parkinson's and Alzheimer's diseases.

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    • "Additionally, SCA2 patients show a significant impairment of olfactory threshold, identification and discrimination capabilities. The score of the University of Pennsylvania smell identification test (UPSIT) is significantly reduced and it correlates positively with ataxia score but it is not influenced by the age, age at onset, disease duration and CAG repeats (Velázquez et al, 2006). "

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    • "Spinocerebellar ataxia type 2 (SCA2) is a genetic-based disorder with primary symptoms of progressive gait ataxia, diminished saccade velocity [1], poor coordination of speech musculature (dysarthria), olfactory deficits [2], [3] and absence of neurological reflexes such as the knee jerk reaction (areflexia) [4]–[6]. This polyglutamine (PolyQ) disorder produces severe degeneration of pontine nuclei, inferior olives, and Purkinje cells in the cerebellum [7], [8]. "
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    • "First, there are reports of olfactory dysfunction in patients with cerebellar diseases (Connelly et al., 2003; Mainland et al., 2005; Tucker, 1911; Velazquez-Perez et al., 2006). Second, the staggerer mouse, which has abnormalities in the olivocerebellar pathway, is hyposmic (Deiss and Baudoin, 1997; Deiss and Baudoin, 1999). "
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