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...

Just noticeable difference in olfaction: A discriminative tool between healthy elderly and patients with cognitive disorders associated with dementia Rhinology. 2011 15 1; 49(5): 513-518. Chopard G, Galmiche J, Jacquot L, Brand G Abstract Olfactory dysfunction appears to be one of the earliest signs of several age-related neurodegenerative disorders, including Alzheimer`s disease (AD) or Parkinson`s disease (PD). To rate performance and olfactory deficits in patients with cognitive disorders, various olfactory tasks have been used such as odor detection, discrimination, recognition memory, identification and naming but no study has been focused on just noticeable difference (JND), a sensitive tool of detection. The aim of this study was to investigate and compare variations in JNDs in healthy elderly and in patients with cognitive disorders associated with dementia. The results showed significantly higher olfactory JNDs in a population with cognitive disorders associated with dementia...

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

Jiang RS, Su MC, Liang KL, Shiao JY, Wu SH, & Hsin CH. A pilot study of a traditional Chinese version of the University of Pennsylvania Smell Identification Test for application in Taiwan. American Journal of Rhinol Allergy. 2010 Jan-Feb;24(1):45-50. BACKGROUND: The 40-item University of Pennsylvania Smell Identification Test (UPSIT) is the most widely used smell test in the world. Presently, culturally modified versions of this test are available in 12 languages. This study describes the first assessment of a prototype traditional Chinese version of the UPSIT (UPSIT-TC) for administration in Taiwan. The goals were to determine the efficacy of specific items for testing Taiwanese subjects and to establish normative adjustments to allow for the use of North American norms. METHODS: The American version of the UPSIT and the UPSIT-TC were administered to 40 healthy Taiwanese subjects on two test occasions separated from one another by 2 weeks. One subject was excluded because of in...

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...

Kranick SM, & Duda JE. Olfactory dysfunction in Parkinson's disease. Neurosignals. 2008; 16(1): 35-40. Department of Neurology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA. Prior to the onset of the cardinal motor features of idiopathic Parkinson's disease (PD), other manifestations of neurodegeneration such as olfactory dysfunction are often apparent. Characterizing these potential biomarkers of preclinical PD is particularly important in identifying individuals who will go on to develop disabling symptoms, and thus be good candidates for new neuroprotective strategies. As shown by the Braak neuropathologic staging of PD, the olfactory system is among the first neuronal populations to display Lewy body pathology. Clinically, loss of smell can be easily tested in the office using several validated techniques and is often helpful to the physician in distinguishing idiopathic PD from other forms of parkinsonism. Recent findings have indicated that a...

From today's New York Times : Sniff Test May Signal Disorders’ Early Stages By ELIZABETH SVOBODA Published: August 14, 2007 [snip] The Sniff Magnitude Test, developed with the aid of a $1.3 million grant from the National Institutes of Health, consists of a nasal tube called a cannula attached to a plastic container about the size and shape of a coffee thermos. Chemical vapors inside the canister are released through the tube, exposing subjects to a series of smells, some more objectionable than others. “People describe some of the smells as skunky or sewerlike,” said Jason Bailie, a University of Cincinnati graduate student working on the test. “There’s also one that smells like banana.” As patients take whiffs of each new fragrance, sensors in the thermos unit measure the negative pressure the inhalations produce. The size and intensity of these sniffs turn out to be important gauges of olfactory ability. After detecting a strong or disagreeable odor, people with a normal sense o...

Hubbard PS, Esiri MM, Reading M, McShane R, & Nagy Z. Alpha-synuclein pathology in the olfactory pathways of dementia patients. Journal of Anatomy. 2007 Jun 6; [Epub ahead of print] Division of Neuroscience, The Medical School, University of Birmingham, UK. Lewy-type pathology is a characteristic of a number of neurodegenerative disorders, including Parkinson's disease and dementia with Lewy bodies. Thus far, the definitive diagnosis of these dementias can only be confirmed at post-mortem. However, it is known that the loss of smell (anosmia) is an early symptom in patients who develop dementia, and the use of the smell test has been proposed as an early diagnostic procedure. The aim of this study was to understand further the extent of Lewy pathology in the olfactory system of patients with neurodegenerative disorders. Post-mortem tissue from 250 subjects was obtained from the OPTIMA brain bank. Five areas of the olfactory pathway were examined by immunolabelling for alpha-s...