Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Olfaction Disorders”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 757 records · Page 42Linked to original sources
PubMed1991

Parental behavior in the mouse: effects of lesions in the entorhinal/piriform cortex.

The effects of bilateral radiofrequency lesions in the region of the entorhinal and piriform cortex (ENT/PIR cortex) on pup-retrieving and ultrasound-elicited pup-searching behavior were investigated in ovariectomized estrogen-treated female mice, which were sensitized to pups by co-caring for a litter for 5 days together with the mother (FoEBex), as well as in primiparous lactating females (Flact). A further group of FoEBex were rendered anosmic by an intranasal treatment with zinc sulfate-solution before the sensitization period and tests for parental motivation. Both pup-retrieving and pup-searching behavior were disturbed to the same extent by ENT/PIR lesions and ZnSO4-induced anosmia in FoEBex. In Flact, however, pup-retrieving was not affected by the lesion, while ultrasound-recognition leading to pup-searching was disrupted. The present data suggest sensitization to pups as a case of olfactory learning and thus, the effects of the ENT/PIR lesions are regarded as anterograde olfactory amnesia. From the present data and results reported in the literature, it is suggested to differentiate between the neural substrates processing stimuli relevant for the appetitive component (pup-searching) of parental behavior (among others, the region of the entorhinal and piriform cortex), and the mechanisms regulating the consummatory component (pup-retrieving).

Animals↗
PubMed1996

Anosmia and chronic sinus disease.

Chronic sinus disease associated with progressive mucosal disease is often a cause for anosmia. Despite aggressive allergic, medical, and surgical intervention, long-term relief of anosmia has been difficult to document. Fifty patients sought treatment for subjective anosmia and symptoms of progressive sinusitis and underwent endoscopic sinus surgery. After surgery 52% maintained significant improvement in smell by subjective measures that correlated with objective olfactory University of Pennsylvania Small Identification test ("UPSIT") results. Of the remaining patients, some had intermittent improvement, but most remained hyposmic or anosmic despite clinically well-healed ethmoid surgical beds. Of the preoperative and postoperative historical, clinical, and radiological data analyzed, severity of the presenting sinus disease (defined as stage II In the Kennedy staging criteria or disease extending beyond the ethmoids on preoperative computed tomography scan) and persistent mucosal disease in the surgical bed are associated with persistent anosmia (p = 0.005).

Adult↗
PubMedDate not supplied

Subjective improvement of olfactory function after endoscopic sinus surgery for chronic rhinosinusitis.

OBJECTIVE: The purpose of this study was to determine the effect of functional endoscopic sinus surgery (FESS) on subjective olfactory dysfunction in patients with chronic rhinosinusitis. Materials and methods Prospective collection of data on consecutive patients undergoing FESS after failing prolonged medical therapy for chronic rhinosinusitis at a tertiary institution. Patients were asked to grade their olfactory dysfunction from 0 to 10, with 0 representing normal function and 10 complete anosmia. In addition, data such as computed tomography scores, presence or absence of nasal polyps, and the presence or absence of asthma were recorded and analyzed. Patients were followed up to 1 year after surgery. RESULTS: Data were collected on 178 patients who had sinus surgery over a 2-year period. The average olfactory dysfunction score before surgery was 4.9. This improved to 0.9 at 1 year after surgery (P =.00). Higher computed tomography scores as per Lund and MacKay correlated with higher olfactory dysfunction scores (r = 0.62, P <.01) and greater improvement after surgery (r = 0.82, P <.01). Asthmatics and patients with polyps had higher subjective olfactory dysfunction scores than nonasthmatics and patients without polyps (6.8 and 7.2 v 4.4 and 4.1, respectively). All groups had subjective improvement at 1 year (2.3 and 1.5 v 0.6 and 0.7, respectively; P =.00). CONCLUSION: Patients with subjective olfactory dysfunction despite appropriate medical management for rhinosinusitis benefit from FESS.

Chronic Disease↗
PubMedDate not supplied

Initial mechanisms basic to olfactory perception.

Animal experimentation has proposed three mechanisms at the olfactory mucosa that may underlie olfactory discrimination. First, the olfactory receptor cells appear selectively tuned to different odorants. Second, in a gas chromatographic-like process, the molecules of different odorants appear to be distributed in different sorption patterns across the mucosal surface. Third, different regions of the mucosa appear to have different selective sensitivities. These three mechanisms could complement each other by together generating a greater number of neural discharge patterns to encode the odorants passing over the mucosal surface. In this interplay, the mucosal distribution patterns could differentially limit the receptor cells and mucosal regions to which different odorants have access. The mucosal distribution pattern could thereby affect the odorant analyses made by these other mechanisms as well as contribute its own analysis. The mucosal distribution patterns appear fairly stable in the face of rather wide variations in the pertinent variables characterizing the nasal airflow (namely, odorant concentration, flow rate, volume, and duration). There are, however, limits to these variables beyond which significant shifts in the molecular distributions and neural discharge patterns can be produced. Thus, in humans any naturally occurring or surgically induced alteration in the nasal airflow which appreciably alters these variables may affect olfactory perception. Olfaction in a laryngectomized patient is discussed as an example.

Animals↗
PubMedDate not supplied

Clinical evaluation of olfaction.

An odor identification test and an odor threshold test offered satisfactory quantitative information on olfactory function in patients with chemosensory complaints. The threshold test used various concentrations of butanol presented in an ascending sequence. On each trial, the participant had to choose between stimulus and blank (two-alternative forced-choice procedure). The identification test used common odorous items (e.g., baby powder and ground coffee) and pungent items (e.g., ammonia) to test trigeminal function. A list of odor names and use of corrective feedback during testing overcame word-finding difficulty in odor identification. Each test readily distinguished between patients and control subjects. At present, a score that reflects the combined outcome of the tests is used to indicate five categories of functioning: normal osmesis, mild hyposmia, moderate hyposmia, severe hyposmia, and anosmia.

Chemoreceptor Cells↗
PubMedDate not supplied

Olfactory ability as a function of nasal air flow volume in laryngectomees.

This study tested a number of hypotheses concerning the interrelationships between the olfactory abilities and the volume of nasal airflow in laryngectomees. Data were collected from 25 laryngectomees and 25 control subjects and comprised the following: 1) Odor threshold and identification test results. In the threshold test, an 11-step aqueous dilution series of butanol was used. In the odor identification tests, 14 common odorants were used. 2) Measurement of nasal air flow volume in liters per minute. For olfaction and airflow, the laryngectomees' measurements were made under two conditions: 1) using unassisted airflow through the nose, and 2) using a laryngeal bypass that linked the stoma to the mouth and allowed airflow through the nose. The major findings showed that among laryngectomees olfactory abilities depend on nasal airflow. It is concluded that laryngectomees have intact olfactory mechanisms that function normally when adequate airflow volume is provided.

Humans↗
PubMedDate not supplied

Intracranial complications of submucous resection of the nasal septum.

Submucous resection of the nasal septum (SMR) is a relatively simple and frequently performed operation. Yet, its intracranial complications, although rare, can be very serious and include anosmia, visual disturbances, cavernous sinus thrombosis, meningitis, cerebrospinal fluid rhinorrhea, pneumocephalus, subarachnoid hemorrhage, subdural empyema, and brain abscess. This article reviews intracranial complications of SMR, and the pathogenesis and prevention of such complications are discussed.

Adult↗
PubMedDate not supplied

Apolipoprotein E epsilon4 positive individuals demonstrate delayed olfactory event-related potentials.

Apolipoprotein E epsilon4 positive individuals have deficits in the ability to identify and remember odors, as demonstrated by psychophysical measures of olfactory function. The purpose of the present study was to identify olfactory deficits in this population using an objective electrophysiological measure: the olfactory event-related potential (OERP). Olfactory and auditory ERPs were recorded from the Fz, Cz, and Pz electrode sites in 10 epsilon4 positive individuals and 10 age and gender-matched epsilon4 negative individuals in a single-stimulus paradigm. The results indicate: (1) individuals who are positive for the apolipoprotein E epsilon4 allele demonstrated delays (of approximately 100 ms) in the processing of olfactory information compared to those who are epsilon4 negative; (2) OERP latency is more sensitive than psychophysical measures of olfactory function; (3) delays in the cognitive P3 component of the OERP are associated with deficits in the ability to identify an odor; and (4) unlike the moderate ranges found in auditory ERP, OERP latency showed high sensitivity and specificity in classifying epsilon4 positive and negative individuals.

Aged↗
PubMedDate not supplied

Olfactory impairment increases as a function of age in persons with Down syndrome.

Neuropathology similar to that found in the brains of patients with Alzheimer's disease (AD) has consistently been observed in older individuals with Down syndrome (DS) and this neuropathology is particularly prevalent in areas involved in olfaction. The present study investigated the effects of age on the expression of olfactory impairment in Down syndrome to address the hypothesis that older adults with DS show greater deficits in olfactory function compared with younger persons with DS and compared with age and IQ matched control groups. Between group differences showed that persons with DS had significant deficits in olfactory functioning compared to the two control groups. Further, within the DS group, older adults performed more poorly than the young adults or children. Results support the hypothesis that in a group of persons at risk for AD because of DS, olfactory impairment is greater in older individuals, suggesting progressive impairment over time. Deficits in olfactory function may be useful in signalling incipient dementia in DS.

Adolescent↗
PubMed2003

3-Nitrotyrosine immunoreactivity in olfactory receptor neurons of patients with Alzheimer's disease: implications for impaired odor sensitivity.

Olfactory sensory function is impaired in patients with the diagnosis of probable Alzheimer's disease (AD) compared to elderly controls, and the olfactory epithelium (OE) of AD patients exhibits several pathological changes characteristic of the AD brain. To confirm that the populations from whom our postmortem tissues are obtained exhibit similar decrements in sensory function, threshold testing was performed; probable AD patients had significantly higher olfactory thresholds than controls. To determine if oxidative stress contributes to decreased olfactory function in AD, we localized 3-nitrotyrosine (3-NT) immunoreactivity in OE obtained postmortem from patients with neuropathologically confirmed AD and age-matched controls with brains free of significant neurodegenerative pathology. In AD patients, immunoreactivity was localized in olfactory receptor neurons (ORNs), including dendritic knobs where ion channels that participate in sensory transduction are located, suggesting a direct mechanism for olfactory impairment. In controls, immunoreactivity occurred in blood vessel endothelium, suggesting age-related vascular dysfunction. Immunohistochemistry for CD68, a macrophage scavenger receptor, demonstrated activated macrophages, a source of free radicals contributing to 3-NT formation, in the OE of AD patients but not controls. These results demonstrate increased oxidative stress and modification of ORN proteins that may contribute directly to olfactory impairment in AD patients.

Aged↗
PubMed1998

Evaluation of the results of delayed rhinoplasty in cleft lip and palate patients. Functional and aesthetic implications and factors that affect successful nasal repair.

Patients born with cleft lip and palate (CLP) present with a variety of nasal deformities. These are either congenital or iatrogenic. Our aim was to establish a correlation between aesthetic and functional nasal impairments in patients with CLP whose nasal reconstruction had been delayed. Fifty-four randomly selected patients with CLP deformities, all of whom had delayed nasal repairs were evaluated objectively, aesthetically in three planes, and functionally for symptoms of nasal obstruction, chronic maxillary sinusitis, and olfactory disturbances. Aesthetically the patients were analysed from 1:1 life-size full face, profile, and submental-vertex photographs, and full skull cephalograms. Nasal patency was assessed by rhinomanometry. The presence of chronic maxillary sinusitis and olfactory disturbances were deduced from the history. The degree of nasal dismorphism correlated with the severity of nasal functional impairments. Delayed nasal repairs in patients with CLP did not produce satisfactory aesthetic or functional results, probably because growth was retarded and midfacial development was disturbed at the time of delayed rhinoplasty and resulted in asymmetry. In CLP the nose should be repaired during the early primary cheilorhinoplasty, as this is essential for the restoration of a normally functioning and aesthetically pleasing nose.

Adolescent↗
PubMed1997

Chloroform-induced olfactory mucosal degeneration and osseous ethmoid hyperplasia are not associated with olfactory deficits in Fischer 344 rats.

Adult female F-344 rats were trained (avoidance rate > 70%) over four days with a coupled tone- (n = 10 rats/dose) or 2 ppm acetaldehyde-cued (n = 6 rats/dose) foot shock paradigm. Rats were gavaged with chloroform dissolved in corn oil for 5 days/week for 3 week at 0 or 400 (tone-cued) or 0, 34, 100, or 400 (odor-cued) mg/kg body weight/day. Tone-cued response was reevaluated 6, 16, and 38 days after the first chloroform dose (day 1). Olfaction was assessed on days 6-7, 20-21, and 41-42 using 2 or 0.0002 ppm acetaldehyde. Nasal histopathology (n = 4-5 rats/dose) was assessed on days 6, 20, and 42. Significantly decreased body weights were observed following a single 100 or 400 mg/kg chloroform dose. Body weights in the 400 mg/kg/day chloroform group remained depressed for 17 days. Histopathology revealed degenerative changes in olfactory mucosa and underlying ethmoid turbinate bones that were essentially identical in nature and severity, including dose-response and progression, to those reported previously for chloroform gavage (Larson et al., Food Chem. Toxicol., 1995;33:443 456). At all dose level and sacrifice timepoints, however, regions of morphologically normal olfactory mucosa were present, especially in dorsal medial and ventral lateral regions of the nose. Neither odor- nor tone-cued avoidance behaviors were affected, indicating that even fairly severe and extensive chloroform-induced olfactory mucosal degeneration is not associated with a detectable olfactory deficit in rats.

Animals↗
PubMed2001

Persistent c-fos expression and NADPH-d reactivity in the medulla and the lumbar spinal cord in rat with short-term peripheral anosmia.

Here we examine hypothesis that short-term peripheral ZnSO(4)-induced anosmia can produce effects on c-fos expression within spinal cord and caudal medulla in male Wistar rats (n=4). Fos-like-immunoreactive cells revealed by avidin-biotin-peroxidase method show a significant bilateral increase in the nucleus proprius (layers 3 and 4) and medial part of layers 5 and 6. In substantia gelatinosa (layer 2(i)) and area 10 Fos-positive neurons were intermixed together with nicotin-amide adenine dineucleotide phosphate-diaphorase (NADPH-d)-reactive cells. Short-term anosmia enhanced c-fos expression in ventral horn (layers 7 and 8), ventrolateral segment and dorsal part of the spinal trigeminal nuclei. In anosmic rats varicose fibres and numerous NADPH-d-stained neurons were present in the gelatinous layer of the spinal trigeminal nucleus caudalis, and a separate population of Fos-positive cells was detected within this layer. Nucleus tractus solitaris also contained a few NADPH-d-reactive, medium sized neurons intermixed with Fos-immunoreactive cells.

Animals↗