|An Online Compendium of News & Clinical Science||April 25, 2016|
Disorders of Odor Perception offers links to the latest science and news about olfactory dysfunction. It is updated frequently. Newest items are at the top of each column.
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Anosmia & Hyposmia
Patients with impaired odor perception are more likely to be overweight or obese than controls. Read more.
Age-related macular degeneration is associated with impaired odor perception. Read more.
Volume of olfactory bulbs/tracts based on MRI, combined with olfactory measures, can distinguish Parkinson's disease from related disorders. Read more.
State and trait anxiety (but not smoking) linked to reduced olfactory ability. Read more.
Self-assessment of olfactory loss correlates with actual performance only at the level of total anosmia. Read more.
Parkinson's disease patients who smoke show less olfactory dysfunction than patients who never smoked or who no longer smoke. Read more.
Genome-wide analysis of older adults suggests SNPs at tau protein locus may link olfactory dysfunction to neurodegenerative diseases. Read more.
Mutation in TENMI gene linked to congenital general anosmia. Read more.
Large-scale study in Italy suggests sense of smell does not decrease linearly with age but forms 'juvenile,' 'mature,' and 'elder' phenotypes. Read more.
Olfactory performance scores can help discriminate Alzheimer's disease from dementia with Lewy bodies in patients with mild cognitive impairment. Read more.
Changes in olfactory sensitivity with age may be odor-specific. Read more.
Algorithm predicts extent of post-traumatic olfactory loss based on pattern of brain lesions. Read more.
Olfactory dysfunction in Parkinson's disease is associated with faster disease progression. Read more.
Hormone replacement therapy in postmenopausal women positively influences a limited number of olfactory and cognitive measures. Read more.
Smell dysfunction in first-degree relatives of patients with cleft lip or palate linked to morphology of upper nasal region. Read more.
Olfactory impairment reduces physical but not mental quality of life measures, with combined sensory impairments worsening the effect of a single-sense deficit. Read more.
Only three smells are necessary for an odor identification test with sufficient sensitivity and specificity. Read more.
Neuroticism scores are higher in patients with olfactory dysfunction. Read more.
Lingering post-smell activation in orbitofrontal cortex observed in patients with multiple chemical sensitivity. Read more.
Consultation with ENT physician improves quality of life and olfactory measures in chronic rhinosinusitis patients. Read more.
Reduced olfactory function in obese women linked to higher levels of circulating endocannabinoids. Read more.
Comparison of two smell tests finds performance difference when used with children five to six years of age. Read more.
Radiation treatment for nasopharyngeal cancer associated with impaired smell and taste function. Read more.
Study suggests normosmic Parkinson's disease patients are a unique clinical phenotype with more benign course. Read more.
Olfactory bulb volume in Parkinson's disease not associated with disease severity or smell function. Read more.
Olfactory bulb volume increases and odor sensitivity improves after functional endoscopic sinus surgery for nasal polyps. Read more.
Five-year followup confirms African-Americans more likely than other groups to experience initial decline in olfactory function. Read more.
Atrophy in primary olfactory cortex and hippocampus correlates with smell loss in mild cognitive impairment and Alzheimer's dieseas. Read more.
Manganese exposure in teenagers linked to reduced odor perception and to changes in brain response and morphology. Read more.
New self-administered, computerized olfactory threshold test validated on patients with anosmia and hyposmia. Read more.
New test of odor identification and intensity validated for Taiwanese population. Read more.
Odor identification test shows correlations with age and Alzheimer's disease in Japanese population. Read more.
Plasma oxytocin levels may predict odor identification ability and negativity of odor response in patients with schizophrenia. Read more.
MRI confirms reduced/absent olfactory bulbs and hypoplastic olfactory sulci in congenital anosmics. Read more.
MRI study finds age, laterality, and task-specific effects of smell loss on olfactory bulb volume and olfactory sulcus depth. Read more.
Rapid maxillary expansion improves olfactory sensitivity in children. Read more.
Age-related trends in odor perception confirmed in large, cumulative ad hoc dataset. Read more.
Odor identification scores fail to predict transition from ultra-high risk status to schizophrenia but may predict poor functional outcome. Read more.
Study compares MRI results with chemosensory event-related potentials in patients with post-traumatic anosmia. Read more.
No specific histomorphological changes found in peripheral olfactory epithelium of schizophrenic patients relative to controls. Read more.
Olfactory event-related potentials are absent or reduced in young patients with multiple sclerosis. Read more.
Extended 32-item version of a commercial odor identification test shows high validity and test-retest reliability. Read more.
Anosmia, facial pain, and nasal obstruction in a 27-year-old woman with a large rhinolith. Read more.
Simultaneous anosmia and ageusia in a case of head trauma with frontobasal brain damage. Read more.
Sniffing four odors twice daily for twelve weeks improves sensitivity to these odors in healthy children. Read more.
SNPs in smell-related loci linked to expression of microtubule-associated protein tau in older adults. Read more.
Odor identification deficits linked to increased mortality risk even after controlling for multiple other factors. Read more.
Hunger enhances detection thresholds to food odors but not in a sensory-specific way. Read more.
No difference between saline and saline + budesonide in post-op treatment following sinus surgery. Read more.
After adjusting for confounding variables, no effect of nutritional status on olfaction in the elderly. Read more.
Clinical study finds preoperative corticosteroids improve olfactory outcome in nasal polyposis surgery. Read more.
Level of independent living determines chemosensory ability in the elderly separately from age. Read more.
Adults over 60 years old with highest consumption of fish and nuts have reduced odds of olfactory impairment. Read more.
Large prospective study finds endoscopic sinus surgery more effective than medical managment in resolving major symptoms of chronic rhinosinusitis. Read more.
CT scans and butanol threshold test may be useful in predicting postoperative smell recovery in chronic rhinosinusitis patients. Read more.
Mixed results in olfactory testing of blind and sighted subjects. Read more.
Patients at clinical high risk for schizophrenia did not differ from healthy controls on odor identification. Read more.
Laser surgery for nasolacrimal duct obstruction results in temporary reduction of olfactory function. Read more.
Longer olfactory training and changing odorants during training enhances success rate in patients with postinfectious olfactory loss. Read more.
Quality of life impact measured in patients with chronic sinusitis with nasal polyps. Read more.
Olfactory loss impairs perceived change in nasal patency from chewing menthol-containing gum. Read more.
Repeated sinus surgeries for nasal polyps reduce the likelihood of recovery of olfactory function. Read more.
Crenotherapy (treatment with hyperthermal water rich in mineral salts) improves smell in young and old subjects with hyposmia and chronic rhinosinusitus. Read more.
Possible altered sensory cell function in patients with schizophrenia. Read more.
Smell test results from Taiwanese population show differences from American norms. Read more.
Age-related increase in olfactory threshold tracks those in other sensory modalities. Read more.
Sublingual immunotherapy improves olfactory function and quality of life in allergic rhinitus patients. Read more.
Relative utility of sensory testing, MRI, and olfactory event-related potentials in evaluation of post-traumatic olfactory loss. Read more.
Variable effects of middle ear surgery on smell and taste function. Read more.
Compared to patients with right temporal lobe epilepsy, those with left side focus find odors less pleasant and harder to identify via left nostril. Read more.
Pain and anxiety during migraine is higher in patients with ictal osmophobia. Read more.
Orthonasal olfaction unaffected in adults with enlarged tonsils, but retronasal olfaction impaired in those with extreme hypertrophy. Read more.
Olfactory dysfunction associated with incidental Lewy body disease. Read more.
Panic disorder patients have higher olfactory sensitivity and greater odor awareness than healthy controls. Read more.
People with chronic halitosis show lower odor sensitivity and more frequent hyposmia than controls. Read more.
Subclinical atherosclerotic plaques associated with decline in odor identification ability. Read more.
Reduced nasal volume and cross-sectional area linked to poor olfactory function in patients with obstructive sleep apnea. Read more.
Olfactory bulb volume in Parkinson's disease patients not closely linked with olfactory function and clinical status. Read more.
Intranasal insulin produces immediate improvement in odor perception in patients with post-infectious hyposmia. Read more.
In patients with deviated septum, odor sensitivity, discrimination, and identification are lower on the narrower side. Read more.
Following gastric bypass surgery, 42% of patients experience changes in smell. Read more.
Migraine patients find odors more bothersome than controls; but show no change in olfactory acuity between baseline and active migraine. Read more.
Large-scale NSHAP study finds odor identification failure increases with age and the decline is more rapid among African-Americans. Read more.
Odor identification significantly lower in first trimester of pregnancy; 2nd and 3rd trimesters not different from non-pregnant controls. Read more.
In a sample of cognitively healthy people, 79% of those with measurable olfactory dysfunction self-reported normal sense of smell. Read more.
Olfaction is impaired in patients with idiopathic inflammatory myopathies. Read more.
Patients with fibromyalgia syndrome and systemic sclerosis show impaired olfaction. Read more.
Odor identification deficits linked to neurodegeneration and markers of Alzheimer's disease in the clinically normal elderly. Read more.
Smell recovery after surgery for nasal polyposis predicted by olfactory cleft opacity on CT scan. Read more.
Male patients with newly diagnosed Parkinson disease have greater olfactory deficits than do female patients. Read more.
Orally delivered THC raises olfactory thresholds and reduces odor discrimination performance in healthy volunteers. Read more.
Most effective pairwise test odorants identified in Japanese screening test for smell impairment. Read more.
The osmophobia and photophobia associated with migraine headaches may be related to different gene polymorphisms. Read more.
Structural MRI study links olfactory dysfunction in Bardet-Biedl syndrome to reduced gray matter volume. Read more.
Rasagiline improves olfactory function in early stage but not long-term Parksinson's disease. Read more.
Smell loss is less frequent in LRRK2 G2019S-associated form of Parkinson's disease. Read more.
Study finds recovery of odor perception following traumatic anosmia is improved by treatment with zinc gluconate. Read more.
Unilateral nasal obstruction is associated with significant reduction in size of ipsilateral olfactory bulb. Read more.
Olfactory impairment and cardiac sympathetic denervation are strongly associated in Parkinson's disease. Read more.
Odor identification impairment appears to be common to a variety of frontotemporal lobar degeneration subtypes. Read more.
Analysis of the 2011-2012 NHANES data suggests 10.6% of Americans experienced self-reported smell disturbance in the past year. Read more.
A bioinformatics approach identifies 152 substances with potential olfactory effects. Read more.
Olfactory dysfunction associated with cognitive impairment in eldery patients with type 2 diabetes. Read more.
Some migraineurs experience reduced ability to name odors during an attack. Read more.
Differences in odor memory performance by patients with unipolar major depression and those with Alzheimer's disease. Read more.
Rare case of primary nasal tuberculosis: 46-year-old woman presents with anosmia and nasal obstruction. Read more.
MRI shows gray matter loss in olfactory cortices of patients with idiopathic olfactory loss. Read more.
Olfactory impairment associated with frontal lobe injury in blast-injured combat troops. Read more.
Centripetal endoscopic sinus surgery produces sustained improvements in a series of 114 patients with chronic rhinosinusitis. Read more.
Subjective improvement found in post-viral olfactory loss at long-term follow-up (~33 months). Read more.
Olfactory dysfunction in first-degree relatives of patients with cleft lip and/or palate may be due to smaller upper nasal region. Read more.
Neurodegeneration in Anderson-Fabry disease is not accompanied by hyposmia. Read more.
Taste and smell alterations in lung cancer patients show gender differences and impact appetite and food enjoyment. Read more.
No effects of subthalamic deep brain stimulation on odor identification ability in patients with Parkinson's disease. Read more.
Nasal airflow-inducing manoeuvre in laryngectomy patients improves smell without respect to nasal endoscopy findings. Read more.
Reduced olfactory function associated with brain lesions in patients with multiple sclerosis. Read more.
Pilot study links flu vaccination to lower rate of olfactory dysfunction. Read more.
Smell sensitivity depends on molecular weight of the odor molecule for older but not for younger adults. Read more.
Endoscopic, CT scan, and sensory measures are correlated in pre- and post-surgical chronic rhinosinusitis patients. Read more.
Olfactory training restores smell loss and alters neural connectivity in olfactory-related brain areas. Read more.
Endoscopic sinus surgery and medical treatment produce comparable improvements in olfaction in chronic rhinosinusitus. Read more.
Olfactory dysfunction predicts early transition from idiopatic REM sleep behavior disorder to Lewy body disease. Read more.
Odor identification better than verbal memory performance in predicting cognitive decline in an urban population. Read more.
Mild taste and smell alterations common in patients investigated for lung cancer but at same rate for those with and without disease. Read more.
Perception of suprathreshold odor intensity is reduced in early-stage Parkinson's disease. Read more.
Primary and secondary olfactory cortical atrophy in Parkinson's disease correlates with smell dysfunction. Read more.
Poorer olfactory performance in patients with pemphigus vulgaris correlates with number of lesions. Read more.
Self-reported olfactory impairment is a significant predictor of dementia. Read more.
A history of smoking is associated with better olfaction among Parkinson's disease patients. Read more.
Olfactory ability discriminates Parkinson's disease from other tremor disorders. Read more.
Smell testing may differentiate frontotemporal dementia from major depressive disorder. Read more.
Impaired olfaction is associated with higher risk of delirium following cardic surgery. Read more.
A six-item, five-minute long, n-butanol olfactory threshold test has been developed for use with home-dwelling older adults. Read more.
Smell and taste disturbances linked to brain irradiation treatment for glioma. Read more.
Patients with idiopathic environmental intolerance show no fMRI difference to smell in olfactory brain areas. Read more.
Failure to find a link between smell function and nutritional status in the old and very old. Read more.
Food preference and intake of obese and normal weight women do not differ in response to odors of no-, low-, and high-energy foods. Read more.
Risk of hazardous events increases with degree of olfactory impairment; age, sex and race also significant factors. Read more.
Smell test modification validated for use with children 6 to 17 years of age. Read more.
Only 0.19% of patients with chemosensory dysfunction attribute it to flu vaccination; no association found between sense of smell and lifetime flu vaccinations. Read more.
Economic model suggests that routine brain MRI is not cost-effective in patients with idiopathic olfactory loss. Read more.
Adenotonsillectomy improves ortho- and retronasal olfaction in children with infectious and/or obstructive adenotonsillar disease. Read more.
Crohn's disease may be associated with abnormal odor perception. Read more.
Questionnaire study suggests that Lyme disease is associated with hyperosmia. Read more.
Parosmia, Dysosmia, Cacosmia & Phantosmia
High prevalence of osmophobia in migraine patients makes it a useful tool in primary care diagnosis of migraine. Read more.
Osmophobia more often associated with cutaneous allodynia in chronic rather than episodic migraine. Read more.
Case study of PTSD patient with olfactory hallucinations finds enhanced connectivity in olfactory cortex. Read more.
Olfactory hallucinations found in 3.9% of young migraineurs; typically follow shortly on onset of headache and last 15 to 50 minutes. Read more.
Osmophobia is a significant risk factor for suicidality in migraine patients. Read more.
Case study of patient with abdominal pain, arterial hypertension, and smell disturbances due to adrenocortical adenoma. Read more.
Survey of 269 patients with chemosensory disorders finds dysosmia more frequent in patients taking more than four medications daily. Read more.
Case report of 37-year-old woman with delusions of bad breath discussed with respect to differential diagnoses. Read more.
"Bad smell", nausea and dizziness as symptoms of cerebral aneurysm in a 54-year-old woman. Read more.
Epilepsy Phenome/Genome Project finds no sex difference in olfactory symptoms related to epileptic seizures. Read more.
The use of valproate to manage idiopathic olfactory hallucinations. Read more.
Case study of olfactory hallucinations in a 53-year-old woman with post-traumatic stress disorder. Read more.
Case study finds parosmia in a middle-aged woman associated with vitamin B12 deficiency. Read more.
Self-selected sample of 496 Britains suffering olfactory dysfunction finds parosmia experienced by 19% and phantosmia by 24%. Read more.
Two case studies suggest that olfactory reference syndrome responds to treatment with antipsychotic and SSRI medications. Read more.
Case study of olfactory hallucinations serving as early warning sign in patient with bipolar disorder. Read more.
Report of Charles Bonnet syndrome with olfactory hallucinations. Read more.
Parosmia and phantosmia are enhanced in patients with severe depression. Read more.
Significant prevalence of olfactory hallucinations in Parkinson's disease. Read more.
No long-term benefit to topical cocainization as a treatment for phantosmia. Read more.
Patient complaining of bad body odor suffering from olfactory delusional syndrome rather than phantosmia. Read more.
Odor source localization less accurate in schizophrenic patients with olfactory hallucinations. Read more.
Case study of cacosmia associated with fungal dacryocystitis. Read more.
Halitosis-like phantosmia experienced by two young patients undergoing radiation therapy for brain tumors. Read more.
Case report of unilateral cacosmia associated with maxillary sinus fungal infection. Read more.
Case report of complex olfactory hallucinations during a migraine attack in a 17-year-old patient. Read more.
Despite expense, MRI imaging is cost-effective in the workup of idiopathic dysosmia. Read more.
Schizophrenic patients have altered hedonic responses to the smell of amyl acetate. Read more.
Changes in odor perception during major depressive episode persist after clinical improvement of depression. Read more.
Osmophobia is common in Taiwanese migaineurs and linked to higher anxiety and depression scores. Read more.
Olfactory reference syndrome in a patient with Parkinson's disease. Read more.
A study links olfactory hallucinations in schizophrenia to specific neuropsychological impairments. Read more.
A case report of Olfactory Reference Syndrome discusses proposed changes to the DSM-V classification. Read more.
Olfactory hallucinations may be a significant non-motor symptom in Parkinson's disease. Read more.
Schizophrenic patients with olfactory hallucinations more likely to have olfactory habituation deficits and past episodes of brief unconsciousness. Read more.
Case report of subacute combined degeneration of the spinal cord and a novel dysosmia. Read more.
An unusual case of migraine headache associated with olfactory hallucinations in a patient with post-traumatic anosmia. Read more.
Activation of subdural electrodes implanted near the olfactory bulb in epileptic children produce olfactory hallucinations. Read more.
A case report of long lasting phantosmia that disappeared under anti-depressive treatment with venlafaxine. Read more.
Case report of headaches in a migraine patient induced by a Valsalva manoeuvre she used to relieve persistent cacosmia. Read more.
Large Chinese study characterizes olfactory and trigeminal event-related potentials in hyposmic and anosmic patients. Read more.
Olfactory hallucinations in headache typically last 5 to 60 minutes, occur shortly before or with the onset of head pain, and consist of a highly specific unpleasant odor. Read more.
A review of the current clinical understanding of olfactory distortions and how to evaluate them. Read more.
A case report from Ceylon of a soldier in his early thirties diagnosed with Olfactory Reference Syndrome, on the basis of an imagined smell of urine in the absence of actual urinary incontinence. Read more.
Australian psychologist R.J. Stevenson examines the evidence for olfactory illusions and the reasons they may escape awareness. Read more.
The body locations that most frequently preoccupy patients with Olfactory Reference Syndrome are mouth (75%), armpits (60%) and genitals (35%). Read more.
A review of all 84 case studies of Olfactory Reference Syndrome published since 1891 reveals that a majority of patients are male with an age of onset <20 years. Read more.
Brain areas involved in odor quality discrimination and odor memory are reduced in size in parosmic patients. Read more.
News & Reviews
A meta review of 20 years worth of studies on prevention and management of taste and smell alterations in cancer patients concludes that no intervention has proven effective. Read more.
Bringing the link between Alzheimer's disease and smell into sharper focus: a review of AD pathology in olfactory system interneurons. Read more.
A chapter by Richard Doty in the new Handbook of Clinical Neurology covers the neurotoxic consequences on smell of exposure to solvents, metals, and particulate matter. Read more.
In nine studies of endoscopic sinus surgery, some show improvement in olfactory performance with resection (versus preservation) of middle turbinate. Read more.
A review of 36 studies on smell in allergic rhinitis finds likelihood of olfactory dysfunction increases with duration of disorder, reaching frequencies of 20% to 40%, and only limited evidence that treatments improve function. Read more.
In an essay at Mosaic Science, Emma Young describes how life has changed for Nick Johnson following a traumatic brain injury that left him anosmic. Read more.
Meta-analysis of controlled clinical trials of chronic rhinosinusitis with nasal polyposis finds treatment with oral steroids significantly improves objective and subjective measures of olfaction. Read more.
Neuromodulation of olfactory and gustatory processing is produced by a variety of neurotransmitters and neuropeptides, as described in a new review. Read more.
A literature review finds high prevalence of smell and taste alterations in patients undergoing palliative care. Read more.
A German review article for ENTs describes the state of the art in the diagnosis of olfactory disorders. Read more.
A selective review of the literature recommends further research into the utility of smell testing in routine clinical practice as a diagnostic tool for Alzheimer's disease. Read more.
Case review of 100 consecutive patients finds MRI imaging adds little value to patient history and clinical examination findings. Read more.
Human clinical data and animal models suggest a link between olfactory dysfunction and depression. Read more.
Olfaction is among the sensory modalities that display altered processing in migraine. Read more.
Review of the literature suggests that olfactory dysfunction may be useful in differential diagnosis of two common conditions in the elderly: Alzheimer's disease and depression. Read more.
A literature review considers how to use olfactory tests that detect incipient Alzheimer's dementia in clinical trials and screening programs. Read more.
A new review highlights the functional significance of social chemosignals in human reproduction and survival. Read more.
Impaired olfaction is a characteristic feature of Parkinson's disease. A new review summarizes this aspect of PD and the use of smell tests for early and differential diagnosis. Read more.
A cross-cultural comparison of Europeans, Cook Islanders and the Tsimane' of Bolivia finds higher olfactory acuity in the second group, a modern society living amid less air pollution. Read more.
Review of legal cases in the Westlaw database suggests that median settlements and awards for olfactory dysfunction resulting from physician negligence are $300,000 and $412,500 respectively. Read more.
A review of olfactory dysfunction in dementia examines current research and compilation of olfactory assessment tools. Read more.
Systematic literature review finds lack of standardization in quantitative assessment of children's sense of smell. Read more.
Differences in cannabinoid receptor expression in olfactory bulb may account for different sensory effects of cannabis in mice and humans. Read more.
Transient receptor potential (TRP) channels could play a important functional roles in mammalian olfaction. Read more.
A review of olfactory bulb involvement in neurodegenerative diseases, with analysis of large autopsy study of olfactory tract and bulb pathology. Read more.
Literature review finds clear and consistent correlation between general olfactory function and olfactory bulb volume. Read more.
Anatomical features of the anthropoid nose are vestiges of previously functional structures; the vomeronasal organ is absent in adult humans but has a role in olfactory neurogenesis. Read more.
Olfactory event-related potentials now have been recorded successfully from infants between 23 and 41 days old. Read more.
The role of anti-inflammatory therapy and controlled odor exposure in the management of gradual onset smell loss. Read more.
Meta-analysis suggests that olfactory deficits are a useful marker for schizophrenia risk status. Read more.
A review of the anatomy and cellular constituents of the human olfactory mucosa. Read more.
The few studies available suggest that anosmia and olfactory dysfunction are dose-response outcomes of pediatric traumatic brain injury. Read more.
A review of the literature considers how smell impairment impacts quality of life. Read more.
A review of hyposmia in Parkinson's disease and its role as a potential biomarker. Read more.
French review of surgical treatment for nasal polyposis finds improvement in olfactory function. Read more.
How variation in olfactory receptor genes contributes to individual differences in odor perception. Read more.
A review of olfactory deficits and other features of different hypogonadotropic hypogonadal syndromes. Read more.
A review of olfactory neuropathology in Alzheimer's disease. Read more.
Interdisciplinary team speculates about olfactory measures to diagnose and treat infant malnutrition. Read more.
A smell and taste clinic reviews findings from 5,183 patients examined over a 40-year span. Read more.
A review of Machado-Joseph disease notes olfactory dysfunction as one of its nonmotor, extracerebellar features. Read more.
A first-person account of congenital anosmia by a philosopher is included in a special smell issue of The Anatomical Record. Read more.
Humans can discriminate as many as one trillion odors, far more than previously thought. Read more.
A comprehensive review suggests links between smell function and autoimmune disease. Read more.
A systematic review of chemosensation in myasthenia gravis recommends olfactory testing in this disorder. Read more.
A literature review places olfactory dysfunction among the non-cognitive symptoms of Alzheimer's disease. Read more.
Disorders of Odor Perception is updated frequently. Items are entered chronologically with newest items at the top of each column.
Disorders of Odor Perception offers links to the latest science and news about olfactory dysfunction. It does not endorse the material on the linked sites, nor does it offer medical advice. For medical advice about disorders of smell, consult your physician.
Copyright 2016 by Synesthetics, Inc.