Olfactory identification deficits in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

BACKGROUND/AIMS: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited angiopathy caused by mutations of the Notch 3 gene. Olfactory identification deficits are present in a number of neurodegenerative disorders. However, olfaction has not been investigated in CADASIL. The aim of the present study was to assess olfactory identification in CADASIL and to determine whether there is an association between olfactory identification and the frontotemporal lobe.

METHODS

Twenty-seven patients and 27 control subjects had an olfactory identification test and neuropsychological testing. Brain MRIs were obtained from 25 patients. Involvement of frontal white matter, anterior temporal white matter and the external capsule were measured.

RESULTS

Olfactory identification scores were lower in CADASIL patients than in healthy comparison subjects. The Mini-Mental Status Examination (MMSE) and semantic Controlled Oral Word Association Test (COWAT) were also affected. In CADASIL patients, olfactory identification scores correlated with MMSE, COWAT scores and Scheltens' scores from frontal white matter. The tendency for an association between olfactory identification scores and Scheltens' scores from anterior temporal white matter was also observed.

CONCLUSION

Our findings suggest that olfactory identification deficits may be a sensitive indicator of frontotemporal dysfunction in CADASIL.