BrainBlog

Odor identification deficits identify Parkinson's disease patients with poor cognitive performance Movement Disorders. 2011 Sep;26(11):2045-50 Damholdt MF, Borghammer P, Larsen L, Ostergaard K Abstract Olfactory dysfunction is a prodromal and prevalent nonmotor symptom of Parkinson's disease. Unlike olfactory dysfunction in Alzheimer's disease, it is believed to be unrelated to cognitive impairment. However, recent research has implicated cholinergic denervation in Parkinson's disease hyposmia and linked it to verbal memory. This research hypothesized that severe odor identification deficits may identify patients with Parkinson's disease at risk for cognitive impairment. The current study tested this hypothesis by comparing 24 functionally anosmic, nondemented patients with Parkinson's disease and 39 nonanosmic, nondemented patients with Parkinson's disease with 29 healthy control participants on composite scores of memory, processing speed, executive functi...

A new study has been funded to examine the use of olfactory testing in the earlier detection of Alzheimer's disease, one of my interests in neuropsychological assessment. The study is being funded and run is Australia. Here is a news report, from The Australian : Research funding boost for Alzheimer's SUE DUNLEVY October 17, 2011 12:00AM [snippet] "We are interested in developing a test that picks up Alzheimer's disease in the earliest stages, even before problems with cognition appear," he told The Australian. Adapting the strategy of the cardiac stress test that picks up heart disease in its early stages, Professor Schofield wants to see whether a smell test can identify people who later go on to develop Alzheimer's. Participants in the trial would be asked to scratch, sniff and identify 20 smells embedded in a piece of paper, then they would be given a chemical in their left nostril that interfered with the part of the olfactory system affected by Alzheimer...

From The Independent : The smelling test: The genetics of olfaction Why are some people more sensitive to odours than others? And why do no two people experience a scent in the same way? The answer lies in our genes, explains Laura Spinney 24 January 2011 read the article

Landis BN & Burkhard PR. Phantosmias and Parkinson disease. Archives of Neurology . 2008 Sep; 65(9): 1237-1239. BACKGROUND: Impaired olfaction is a common, nonmotor manifestation of Parkinson disease (PD). However, to our knowledge, qualitative olfactory disturbances, such as odor distortions, have not been extensively reported in this condition. OBJECTIVE: To describe 2 patients who reported positive olfactory symptoms preceding typical PD, which were consistent with olfactory hallucinations (phantosmias) in the absence of major smell deficit. DESIGN: Case series. SETTING: University hospital. Patients We describe 2 patients, both seen in 2007, who reported pleasant olfactory hallucinations for several years. MAIN OUTCOME MEASURES: Iodine I 123-labeled ioflupane single-photon emission computed tomography and olfactometric testing results. RESULTS: The (123)I-labeled ioflupane single-photon emission computed tomography showed reduced radiotracer uptake in both striatum more marked...