Evidence for deficiencies in perceptual and semantic olfactory processes in Parkinson's disease.
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Olfactory deficits have been reported in Parkinson's disease (PD) and are thought to represent a sensitive marker of the disease. The aim of the present study was to examine the differential contribution in olfactory dysfunction of perceptual and semantic processes of odours in PD patients. Twenty-four PD patients (12 males and 12 females) and 24 control subjects (12 males and 12 females) were tested. The experiment included two sessions. Initially, 12 odorants were delivered, one per minute. For each odour, subjects were asked to rate intensity, pleasantness, familiarity and edibility using linear rating scales. The odorants were again presented and the subjects were asked to identify them. The four olfactory judgements and odour identification were severely disturbed in PD patients when compared to control subjects. These findings demonstrate major deficits for all cognitive tasks of olfactory judgement in PD, and suggest that PD is associated with disruption of olfactory areas situated in the temporal lobes and also in the prefrontal cortex. (+info)
Wegener's granulomatosis in a patient with a rheumatoid arthritis.
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A 38-year-old woman with rheumatoid arthritis who developed Wegener's granulomatosis is described. Wegener's granulomatosis appeared with saddle nose, perforation in her nasal septum, and granuloma in the nasal cavity. Laboratory evaluation showed a positive rheumatoid factor and circulating immune complex. Radiographic examination revealed ankylotic changes in both wrist and elbow joints. Bilateral anosmia and other disease manifestations completely responded to treatment with oral cyclophosphamide and prednisolone. (+info)
Olfactory dysfunction in degenerative ataxias.
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Several lines of evidence suggest that the cerebellum may play a role in higher-order olfactory processing. In this study, we administered the University of Pennsylvania Smell Identification Test (UPSIT), a standardised test of olfactory function, to patients with ataxias primarily due to cerebellar pathology (spinocerebellar ataxias and related disorders) and to patients with Friedreich ataxia, an ataxia associated mainly with loss of afferent cerebellar pathways. UPSIT scores were slightly lower in both patient groups than in the control subjects, but no differences were noted between the scores of the Friedreich and the other ataxia patients. Within the Friedreich ataxia group, the smell test scores did not correlate with the number of pathologic GAA repeats (a marker of genetic severity), disease duration, or categorical ambulatory ability. UPSIT scores did not correlate with disease duration, although they correlated marginally with ambulatory status in the patients with cerebellar pathology. This study suggests that olfactory dysfunction may be a subtle clinical component of degenerative ataxias, in concordance with the hypothesis that the cerebellum or its afferents plays some role in central olfactory processing. (+info)
Calcification of the olfactory bulbs in three patients with hyposmia.
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An estimated two million Americans suffer from chemosensory disorders. We present the clinical and imaging findings in three hyposmic patients with bilateral olfactory bulb calcification detected by CT. To our knowledge, these are the first cases of olfactory bulb calcification reported in the literature. A review of the literature concerning calcification of cranial nerves, olfactory neuritis, and the potential etiology and clinical significance of olfactory bulb calcification in our patients is presented. (+info)
Does intranasal application of zinc sulfate produce anosmia in the mouse? An olfactometric and anatomical study.
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Mice pre-trained in an olfactometer were tested daily on odor detection and discrimination tasks after irrigation of their olfactory epithelium in each naris with 50 microl of 5% zinc sulfate or saline. Anterograde transport of a wheatgerm agglutinin-horseradish peroxidase (WGA-HRP) conjugate from the epithelium to the olfactory bulb was used to assess anatomical connectivity in these and in mice that were used only for histological analyses. One day after treatment, saline controls performed at high levels of accuracy in detecting vapor from solutions of 5-0.01% ethyl acetate and in an odor discrimination task but most ZnSO4-treated mice performed at chance for 5-30 days before showing recovery. Although dense WGA-HRP reaction product was found in the accessory olfactory bulb, there was little or no evidence for axonal transport to glomeruli of the main olfactory bulb in the first 4-8 days after treatment. These results demonstrate that intranasal application of ZnSO4 to mice produces a brief but essentially total disruption of functional connections from the olfactory epithelium to the main olfactory bulb and a corresponding transient anosmia. (+info)
Anosmia treated with acupuncture.
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This is a report detailing the successful treatment of a case of anosmia with acupuncture. The patient was managed conventionally for two years with no sign of improvement. She regained the sense of smell following one session of acupuncture. Such patients should be investigated for any detectable organic cause prior to treatment with acupuncture. (+info)
Chemosensory additivity in trigeminal chemoreception as reflected by detection of mixtures.
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A series of experiments probed into the degree of chemosensory detection additivity exhibited by mixtures of ethyl propanoate and heptanoate in terms of their trigeminal detectability via nasal pungency (i.e., irritation) and eye irritation. Nasal pungency was tested in subjects lacking a functional sense of smell (i.e., anosmics) to avoid olfactory biases. First, we built concentration-detection functions for each chemical and sensory endpoint. Second, we used the data from the functions to prepare mixtures of the two compounds in complementary proportions, and suitable single-chemical standards, all of which should be equally detectable under a rule of complete additivity, i.e., independence of detection. Third, we compared the experimentally obtained detectability with that expected under such rule. The outcome revealed that, at a low detectability level (but still above chance), the mixtures showed complete additivity for both trigeminal endpoints. At a high detectability level (but below perfect detection), the mixtures showed complete additivity for nasal pungency but less than complete additivity for eye irritation. In the context of previous studies, the results consolidate a picture of higher degree of detection additivity at perithreshold levels in trigeminal than in olfactory chemoreception. The outcome presents another line of evidence suggesting broader chemical tuning in chemesthesis compared to olfaction. (+info)
A simple and reliable method for clinical assessment of odor thresholds.
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We investigated whether presenting of dilutions of phenyl ethyl alcohol at random succession according to the method of constant stimuli can replace the standard procedure of presenting a various number of dilutions in a staircase paradigm. Forty-six men and 44 women, aged 19-76 years, participated in this study. Phenyl ethyl alcohol was diluted in a ratio of 1:2, starting from 4%. Presentation of the odorant followed a three-alternative, temporal forced-choice paradigm with two blanks in addition to the odorant. Twenty dilutions were administered in a randomized order. Odor threshold was obtained by logistic regression of the correct and incorrect identifications of the probe containing the odorant. Thresholds were also calculated on the basis of the first 16 dilution steps only. Results from these procedures were compared with 'gold-standard' threshold assessment employing a three-alternative, temporal forced-choice staircase paradigm with seven reversals using 16 dilutions of phenyl ethyl alcohol. The method of constant stimuli took a shorter and less variable testing time than the staircase technique. The use of 20 dilution steps provided no better results than the use of 16 steps. The method of constant stimuli exhibited a good test-retest reliability (r = 0.7; P < 0.001) comparable to that of the staircase method and provided unbiased results highly correlated (r = 0.8; P < 0.001) with those of the staircase technique with similar inter-test variability. Applying 16 dilutions (1:2 steps) of phenyl ethyl alcohol at random succession in a three-alternative, temporal forced-choice paradigm is thus a simple and reliable procedure for the reproducible assessment of odor thresholds that may be contemplated as an alternative to the 'gold-standard' staircase method of clinical odor threshold assessment. (+info)