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PubMed1987

Olfaction and hemodialysis: baseline and acute treatment decrements.

The effect of hemodialysis (HD) on olfactory recognition and memory function was investigated in people receiving chronic HD treatment. Fifteen subjects were given an olfactory recognition task 0.5 h before and 0.5 h after a dialysis session in counterbalanced order. Ten dialysis patients received a verbal recall task twice. Ten age-matched normal subjects received the olfactory task twice. Results were: (1) olfactory scores in the HD group were significantly lower than control subjects scores; (2) within the dialysis sample, olfactory identification scores were significantly lower after treatment than before, and (3) there were no parallel decreases in memory performance of the dialysis group after a HD treatment. We therefore conclude that those subjects receiving HD treatment demonstrate acute and chronic deficits in olfactory recognition which are unlikely to be due to fatigue, cognitive disequilibrium, anticoagulant treatment or high levels of uremic toxins.

Adolescent↗
PubMed1989

Olfaction and psychiatry.

Recent clinical studies have identified significant olfactory deficits in several neuropsychiatric disorders, notably Alzheimer's disease and Parkinson's disease. These have correlated with neurochemical and neuropathological studies of the olfactory system. The presence of a specific sensory deficit may be related to the localisation of pathology within the brain. There is a need for incorporation of olfactory testing into routine clinical examination.

Brain↗
PubMed2004

Olfaction differentiates parkin disease from early-onset parkinsonism and Parkinson disease.

The authors studied whether olfactory dysfunction is present in parkin disease using the University of Pennsylvania Smell Identification Test (UPSIT). The mean UPSIT score in parkin patients was 27.3 (95% CI 24.4 to 30.2). This did not differ from the normal group mean of 29.4 (95% CI 28.0 to 30.7; p = 0.22) but was higher than the Parkinson disease group (mean 14.3; 95% CI 12.2 to 19.5; p < 0.0001) and the parkin-negative group (mean 17.1; 95% CI 14.8 to 16.3; p < 0.0001) values. Parkin disease may be a distinct and separate entity from Parkinson disease.

Age of Onset↗
PubMed1987

Improvement of olfaction in laryngectomized patients with the larynx bypass.

Hyposmia following laryngectomy is an often recognized phenomenon. A larynx bypass device was used to determine whether this olfactory deficit could be reversed simply by restoring nasal airflow. Odorant detection thresholds and confusion matrix identification tests were administered to laryngectomy and normal comparison groups. Data on nasal airflow characteristics with and without the bypass were also analyzed. The results suggested that restoration of nasal airflow completely reversed the hyposmia for trigeminal nerve stimuli. However, the reversal of hyposmia was not complete for those odorants which primarily, if not exclusively, stimulate the olfactory nerve. This suggested that other factors may contribute to laryngectomy-induced hyposmia for olfatory nerve stimuli. Additionally, nasal airflow analysis revealed that confusion matrix identification scores were depedent upon inspiratory sniff flow rates with and without the larynx bypass. It is argued that rehabilitation for the laryngectomee should include efforts to restore and maintain preoperative olfactory acuity.

Adult↗
PubMed1994

The risk to olfaction from nasal surgery.

Implicit in all types of nasal surgery is the potential for worsening of olfactory function. Not only can injury occur to the delicate olfactory neuroepithelium itself, but also more indirect disturbances are engendered by pharmacologic agents, distortions of intranasal anatomy, persistent mucosal edema or crusts, and other processes. This study examined 93 patients undergoing various types of nasal surgery, including ethmoidectomy, polypectomy, Caldwell-Luc procedure, open reduction of nasal fracture, closed reduction of nasal fracture, rhinoplasty, and septoplasty. Factors considered as contributing to loss of olfactory acuity were age, gender, use of general anesthesia, and type of operation. The University of Pennsylvania Smell Identification Test (UPSIT), a 40-item, microencapsulated scratch-and-sniff procedure, was used to ascertain olfactory ability. Sixty-one patients (66%) had either improved or unchanged UPSIT scores after surgery; the remaining 32 patients (34%) had a decline in score. One patient (1%) became anosmic. Statistical treatment of outcome data using analysis of covariance with repeated measures showed no effect of age, gender, type of operation, or anesthetic.

Adolescent↗
PubMed2002

Evaluation of olfaction.

The sense of smell is often taken for granted until it is impaired or lost. Chemosensory disorders involving a decreased, absent, or distorted sense of smell can be devastating to those who suffer them and may have an impact on an individual's health, safety, and quality of life in a number of ways. It is necessary to approach the diagnosis of chemosensory disorders in a systematic manner that may reveal reversible pathology and to provide patients with counseling that can help them accommodate their disability.

Diagnosis, Differential↗
PubMedDate not supplied

Recent advances in the neuropsychology of human olfaction and anosmia.

Patients' olfactory functioning is rarely considered by rehabilitation specialists because this capacity is seen as unnecessary for most vocational and academic purposes. However, several recent studies have shown that intermittent exposure to fragrances can help subjects sustain attention more efficiently. As this effect is especially pronounced when subjects report attention-maintenance difficulties, accessory olfactory stimulation may enhance the sustained attention capacities of head-injured subjects. Another study is cited in which subjects who lost their sense of smell following head injuries were found to experience more difficulty in maintaining employment. This effect is probably related to orbital lobe damage, which usually accompanies post-traumatic anosmia. The implications of these studies for rehabilitation professionals are discussed.

Arousal↗
PubMed2002

Maturation and death of adult-born olfactory bulb granule neurons: role of olfaction.

Young neurons born in the subventricular zone (SVZ) of adult mice migrate to the olfactory bulb (OB) where they differentiate into granule cells (GCs) and periglomerular interneurons. Using retroviral labeling of precursors in the SVZ, we describe five stages and the timing for the maturation of newly formed GCs: (1) tangentially migrating neuroblasts (days 2-7); (2) radially migrating young neurons (days 5-7); (3) GCs with a simple unbranched dendrite that does not extend beyond the mitral cell layer (days 9-13); (4) GCs with a nonspiny branched dendrite in the external plexiform layer (days 11-22); and (5) mature GCs (days 15-30). Using [3H]thymidine, we show that the maximum number of labeled GCs is observed around day 15 after injection. Interestingly, between days 15 and 45 after birth, soon after the cells developed spines, the number of [3H]thymidine-labeled GCs declined by 50%. Using anosmic mice, we found that sensory input was critical for the survival of GCs from day 15 to 45 after labeling. However, the number and morphology of 15-d-old cells in the granule cell layer was similar in anosmic and wild-type mice. We infer that the lack of activity did not have an effect on the generation, migration, and early differentiation of granule cells. Soon after young GCs matured, and presumably became synaptically connected, their survival depended on the level of activity that they received. This selection mechanism might allow the construction of specific OB circuits based on olfactory experience and suggests possible functions of OB cell replacement.

Aging↗
PubMedDate not supplied

[Olfaction assessment in daily practice].

A simple examination system for the detection and follow-up of olfactory disorders is described. This model distinguishes levels of detection, variations in the characteristics of smells, recognition of smells, and the number of correct responses. A systematic procedure is described.

Cranial Nerves↗
PubMed1999

Cell and molecular biology of olfaction.

Genetics, experience, environment, and health can all affect the anatomic and physiologic components of the olfactory system and thereby influence olfactory performance. Large individual differences exist among subjects with respect to olfactory sensitivity and identification ability, which may result in both qualitative and quantitative differences in perceptual ability.

Adolescent↗
PubMed2001

[Olfaction disorders: preliminary findings and results in 45 cases].

In this work we present the preliminary results of a retrospective study on 45 cases of disordered sense of smell. Our approach is based on a diagnostic tripod--a thorough history (with a questionnaire for evaluation), clinical examination (nasal endoscopy), and imaging. The mean age of our patients was 42.6 years, and 60% were male. In the aetiological factors there was a predominance of naso-sinus disease (62.2%), especially inflammatory (polyposis of the nose and sinuses), while general causes (metabolic and drug-induced) accounted for 24.4%, and neurological causes a further 13.3% of cases. Treatment resulted in a favourable outcome (with partial or total recovery) in 71.1% of cases, and failed in 26.6%.

Adult↗
PubMed2002

The effects of passive smoking on olfaction in children.

The effect of passive smoking on odor identification was studied in 10 children exposed to passive smoke at home. All had at least one parent who smoked at least one pack of cigarettes a day. The control group consisted of 10 children of nonsmoking parents. Ten odorants were tested: vinegar, ammonia, peppermint, roses, bleach, vanilla, cough drops, turpentine, licorice and mothballs. Each child was presented with five test trays containing all 10 odorants in random order. Of the total of 500 odors presented, the control group correctly identified 396 (79%) and the study group, 356 (71%) (p < 0.005). This work demonstrates that children exposed to passive smoke have difficulty identifying odors in comparison to children raised in relatively smoke-free environments. Since the study group tend to misidentify four of the 10 odorants tested--vanilla, roses, mothballs and cough drops--we suggest that these four odorants should suffice in testing odor identification in children.

Adolescent↗