|An Online Compendium of News & Clinical Science||Updated regularly|
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.
and their Supporters
Anosmia & Hyposmia
June 11, 2019
Subsequent incidence of Parkinson's disease higher following idiopathic loss of both taste and smell, compared to loss of either one alone. Read more.
May 19, 2019
The idea of olfactory implants as a therapeutic option for loss of smell meets with interest from patients. Read more.
May 14, 2019
Community-based prospective study links poor olfaction to higher long-term mortality in older adults. Read more.
May 7, 2019
Ofactory and trigeminal sensitivity is greater when minimum cross-sectional area of the nostril is smaller. Read more.
Evidence of olfactory dysfunction in Wilson's disease. Read more.
April 8, 2019
Impaired wine odor categorization in early-blind individuals. Read more.
Lower odor identification performance in elderly men with elevated blood lead levels. Read more.
Olfactory dysfunction significantly associated with tinnitus in middle-aged and elderly Koreans. Read more.
March 11, 2019
Smell and taste function decrease for six months after breast cancer chemotherapy, and recover for all but patients receiving trastuzumab. Read more.
Gray matter in olfactory brain areas increases after surgical treatment for chronic rhinosinusitis. Read more.
Spondyloarthritis is associated with olfactory dysfunction. Read more.
Researchers from 19 countries validate a new "universal sniff test" for children. Read more.
Significant association found between severe insulin resistance and smell dysfunction in older U.S. adults. Read more.
Negative correlation reported between olfactory threshold and number of drugs taken by older (>64 years) people. Read more.
New odor identification test developed for Chinese population. Read more.
Perception of odor intensity reduced by non-invasive stimulation of median nerve in healthy men. Read more.
Sniffin' Sticks smell test recalibrated for Danish population finds differences with scores from other countries. Read more.
Olfactory deficits in Parkinson's disease less severe than in other causes of smell loss but show no differences between PD subgroups. Read more.
Schizophrenia patients score worse on odor identification than controls but scores in both groups were related to measures of early cognitive and social function. Read more.
Olfactory function is related to course and duration, not severity, of depression. Read more.
Hyposmia indicated by reduced odor identification performance linked to more rapid cognitive decline in early Parkinson's disease. Read more.
Olfactory function in individuals experiencing first-episode psychosis is lower across multiple measures of odor perception. Read more.
Decreased sexual desire in patients with olfactory loss. Read more.
Reduced olfactory function in adults with Tourette syndrome. Read more.
Latent toxoplasmosis is associated with changes in human olfactory function. Read more.
People at high risk for psychosis show olfactory identitication deficits similar to those of schizophrenic patients. Read more.
fMRI reveals upstream changes in odor-induced brain activity following traumatic brain injury. Read more.
Greater olfactory-related brain and airway structural anomalies in young adults at high risk for psychosis. Read more.
Reduced olfactory function in patients with type 2 diabetes, but no difference between diabetic patients with and without peripheral neuropathy. Read more.
Reduced odor perception during pollen season in children with allergic rhinitis. Read more.
Normobaric hypoxia equivalent to 4000m altitude reduces odor sensitivity and perceived intensity of smells. Read more.
Olfactory impairment may be a transient feature of relapse in multiple sclerosis. Read more.
Olfactory dysfunction progresses in tight relation with both motor impairment and non-motor symptoms in Parkinson's disease. Read more.
Patients with acquired olfactory dysfunction also show decreased electrogustametric taste sensitivity. Read more.
Patients with nonsyndromic cleft lip and/or cleft palate as well as their unaffected first degree relatives display reduced olfactory function and reduced volumes in olfactory brain areas. Read more.
Large study in Brazil links low socioeconomic status to poor performance on odor identification test. Read more.
Case series of 37 children with olfactory dysfunction finds rhinologic disease most frequent cause. Read more.
Endoscopic transsphenoidal technique for pituitary surgery without nasal flap has little apparent effect on sense of smell. Read more.
Case series of 52 patients with post-traumatic taste disorder reveals that all had olfactory deficits while only a fraction showed taste deficits. Read more.
Frequent attacks and longer duration of disease are associated with reduced odor perception in patients with multiple sclerosis. Read more.
Olfactory but not gustatory impairment is associated with CSF biomarkers for Alzheimer's disease. Read more.
Olfactory identification ability lower among patients with Alzheimer's disease and those with amnestic mild cognitive impairment. Read more.
Olfactory cleft evaluation predicts smell function in patients with a variety of smell disorders. Read more.
Physical, but not emotional, closeness mediates the link between olfactory dysfunction and mortality in older women. Read more.
Smell training increases electrophysiological activity recorded on the olfactory epithelium in response to odor. Read more.
Increased blood lead level linked to impaired odor identification in elderly men. Read more.
Change in olfactory event-related potentials is related to disability progression in multiple sclerosis. Read more.
Five months of olfactory training result in improved smell function in people aged 50 to 84 years. Read more.
Hyposmia diagnosed in patients with ß-thalassemia major undergoing treatment with iron-chelating agents. Read more.
Diffusion tensor imaging may track recovery of function in post-traumatic anosmia better than standard MRI. Read more.
Nasal steroids superior to montelukast in improving olfactory function in allergic rhinitis. Read more.
Auditory stimulation triggers higher responsiveness than olfactory stimulation in patients with unresponsive wakefulness syndrome or minimally conscious state. Read more.
Response to gasoline odor differs in people who frequently experience motion sickness. Read more.
Subthalamic deep brain stimulation improves odor perception in a subset of patients with Parkinson's disease. Read more.
Smell function and quality of life are reduced in patients with transfusion-dependent thalassemia. Read more.
Possible linkage of smell loss with gastrointestinal symptoms in Parkinson's disease. Read more.
Sleep duration, quality and architecture in women linked to differences in sweet taste perception but not in odor perception. Read more.
Olfactory bulb volume is reduced in patients with major depression. Read more.
fMRI study finds decreased functional amygdalar connectivity in Parkinson's disease with severe hyposmia. Read more.
Long-term study in patients with systemic lupus erythematosus and systemic sclerosis finds reduced performance on multiple measure of odor perception. Read more.
Idiopathic Parkinson's disease associated with increased odor thresholds while trigeminal perception may be less affected. Read more.
Negative impact of chronic renal failure on olfactory function in non-diabetic patients. Read more.
Odor sensitivity positively associated with more pleasant sexual experience and (in women) higher frequency of orgasm. Read more.
Helicobacter pylori infection is associated with descreased scores on a test of odor identification. Read more.
Patients with neuro-Behçet disease show marked olfactory dysfunction. Read more.
Background odors during smell testing can impair odor threshold scores, with congruent odors having the greatest impact. Read more.
Poor sleep quality based on actigraph measures linked to reduced odor identification ability. Read more.
Patients with post-traumatic anosmia show improvement in detection of PEA after 3 months olfactory training with PEA. Read more.
Case report of loss of smell and taste following general anesthesia with propofol. Read more.
Comparison of MRI data from patients and controls finds disconnectivity in olfactory-related brain regions in schizophrenia. Read more.
Pilot study of a new format olfactory threshold test reports validity and test-retest correlations for normosmics and patients. Read more.
Prospective longitudinal study finds no strong evidence that acute olfactory function predicts executive function in children with traumatic brain injury. Read more.
A 12-item odor identification test optimized for Japanese subjects shows performance deficits in Parkinson's Disease patients. Read more.
Three-item smell test suggests improvement in odor perception six months after laparoscopic gastric bypass. Read more.
Significant correlation between self-reported severity ratings and objective measures of smell loss. Read more.
Parosmia, Dysosmia, Cacosmia & Phantosmia
June 11, 2019
Patients with psychosis far more likely to experience olfactory and other multisensory hallucinations along with visual hallucinations than are patients with Lewy body dementia, eye disease, or Parkinson's disease. Read more.
May 14, 2019
Clinically significant Olfactory Reference Syndrome symptoms found in 2.4% of Chinese university students. Read more.
May 7, 2019
Prevalence of olfactory and other non-visual hallucinations in people with psychosis who experience visual hallucinations. Read more.
March 11, 2019
A case report of olfactory hallucinations in catatonia related to epilepsy. Read more.
Olfactory Reference Syndrome treated with psychotherapy: A patient's perspective. Read more.
Olfactory hallucinations as initial presenting symptom in acute psychosis. Read more.
Successful treatment of a case of geriatric-onset olfactory reference syndrome. Read more.
Case report of phantosmic rotten egg smell associated with duloxetine that resolved after cessation of medication. Read more.
20-year followup study finds olfactory hallucinations in a minority of schizophrenia patients and very few schizoaffective and bipolar patients. Read more.
Lifetime prevalence of olfactory hallucination in schizophrenia-spectrum disorders is 6 to 10%. Read more.
A follow-up to a previous report of olfactory craving (desiderosmia) in iron deficiency anemia. Read more.
Report of olfactory craving (desiderosmia) linked to iron deficiency anemia. Read more.
Ictal fear associated with olfactory auras in patients with focal epilepsy. Read more.
Phantosmia and somatosensory disturbances in patient with long history of migrainous headaches. Read more.
Olfactory hallucinations occur in almost half of patients with transient epileptic amnesia. Read more.
Two case reports of phantosmia in migraine with and without headache. Read more.
Case study of dysosmia and dysgeusia associated with midodrine taken for orthostatic hypotension. Read more.
Case study of olfactory hallucination in Parkinson's disease successfully treated with donepezil. Read more.
Hypnotic suggestion induces altered odor perception in highly hypnotizable individuals. Read more.
Olfactory changes confirmed as frequent feature of aura preceding migraine. Read more.
ICD-11 working group explains grouping of olfactory reference disorder with obsessive-complusive and related disorders on basis of repetitive unwanted thoughts. Read more.
Internet-based study outlines clinical features of olfactory reference syndrome. Read more.
Olfactory cortex gray matter volume reduced in combat veterans with post traumatic stress disorder and negatively correlated with odor-related trauma memories. Read more.
Central versus peripheral phantosmia and the efficacy of surgical intervention reviewed in five cases. Read more.
Case study from Massachusetts General Hospital of a 32-year-old man with olfactory hallucinations and paresthesias. Read more.
Case report of delayed dysosmia and dysguesia after thalamic infarction. Read more.
Case report suggests usefulness of cognitive-behavioral therapy for psychosis in treatment of olfactory hallucinations. Read more.
Olfactory hallucinations as warning sign in patient with bipolar disorder. Read more.
Case study: olfactory hallucinations as primary symptom for ischemic stroke in the right posterior insula. Read more.
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
June 11, 2019
Review of 106 studies find that sinus surgery for chronic rhinosinusitis frequently results in improved olfaction, particularly in cases with nasal polyposis. Read more.
Meta-analysis of 12 studies finds that Alzheimer's disease has a moderate to large effect size on olfactory function compared to mild cognitive impairment. Read more.
May 19, 2019
An update on olfactory dysfunction in neurological disease. Read more.
April 8, 2019
A review of 38 data sets finds strong evidence for a negative correlation between body weight (obesity) and olfactory function. Read more.
A review of how best to approach the assessment of olfaction in children with autism spectrum disorder. Read more.
March 11, 2019
Review of neural plasticity follwing loss and regain of olfactory function finds widespread structural changes beyond the olfactory bulb. Read more.
Meta-analysis of sex differences in human olfaction finds that women generally outperform men, althought the differences are small. Read more.
Literature review of patients with chronic sinusitis with nasal polyps confirms temporary improvement with treatment, and identifies chronic eosinophilic inflammation as a promising therapeutic target for longer-term improvement. Read more.
Clinical olfaction pioneer Richard Doty reviews the causes and time course of age-related deficits in smell and taste. Read more.
Analysis of 20 studies using olfactory testing to diagnose Parkinson's disease finds sensitivities ranging from 61% to 95%, and specificities ranging from 66% to 99%, indicating a valuable ancillary role for smell testing. Read more.
Meta-analysis of 10 studies that used olfaction to diagnose preclinical Alzheimer's disease finds larger effect sizes when comparing normals to AD patients than when comparing them to patients with mild cognitive impairment. Read more.
A new paper reviews the close link between neuroimmunological diseases and olfactory dysfunction, including animal models and the possible role of inflammation in the olfactory bulb. Read more.
A re-examination of epidemiological investigations and animal experiments concludes that there is an olfactotoxic effect of exposure to cadmium, chromium, nickel, and formaldehyde. Read more.
Review contrasts the benefits of anti-inflammatory treatment with possible impairment of neuronal regeneration in the olfactory epithelium. Read more.
Review examines the links between diabetes mellitus and olfactory dysfunction. Read more.
Researchers suggest using smell testing to track recovery from traumatic head injury in sports. Read more.
Twenty studies on smell and taste function indicate that alterations in chemosensation may be markers for bipolar disorder. Read more.
A review considers smell and taste function in preterm infants, a group in which enteral nutrition and metabolism are major issues. Read more.
An international group of more than three dozen researchers and clinicians has published a position paper on olfactory dysfunction in an effort to adopt a common language with the goal of increasing methodological quality, consistency, and generalizatibilty in the field. Read more.
A review of 14 papers published between 1970 and 2015 on taste and smell in autism spectrum disorders finds differences on measures of identification but not detection threshold, pleasantness or intensity. Read more.
After examining studies published between 2000 and 2015 on olfactory disorders in the elderly, a review concludes that despite promise as a means of early diagnosis of Alzheimer's disease, lack of consensus regarding which test to use is preventing integration of smell assessment into clinical settings. Read more.
A systematic literature review of olfaction in autism spectrum disorders suggests smell dysfunction may be present in these disorders, and that smell testing might have a role in their clinical assessment. Read more.
A review of 50 articles published in the past 20 years about sinonasal status in aging populations finds that immunosenescence, frequency of rhinorrhea, and perception of nasal obstruction all increase with age, a condition the authors call presbynasalis. Read more.
A systematic review and meta-analysis of published studies on chronic rhinosinusitis finds that a significant percentage of patients experiences olfactory dysfunction, with test scores that fall into the dysosmic range. Read more.
Case series review confirms recovery from olfactory dysfunction more likely in patients with respiratory tract infection etiology than those with head trauma, and that systemic steroid treatment may be superior to topical applications. Read more.
Researchers theorize that depression could lead via inattention to reduced olfactory bulb size and activity, and that the bulb may be a useful marker for enhanced vulnerability to depression. Read more.
Researcher suggests that smell dysfunction in neurodegenerative diseases such as Alzheimer's and Parkinson's may have in common damage to forebrain neurotransmitter and neuromodulator circuits involving cholinergic transmission. Read more.
An extended version of the clincal update presented at the 2016 AChemS meeting reviews anosmia from the perspective of patients, diagnosticians, and scientific researchers. Read more.
Review of smell and taste in autism spectrum disorders finds 14 studies showing some differences in odor identification but not detection threshold or pleasantness and intensity perception. Read more.
A paper in the American Journal of Rhinology and Allergy reviews differential diagnosis, workup, and current treatment strategies for anosmia and smell disorders. Read more.
A review of 229 studies on olfactory dysfunction associated with radiotherapy for head and neck cancer confirms that odor detection, identification and discrimination are impaired following treatment. Read more.
The current state of the art in olfactory exploration is reviewed from the point of view of ENT specialists. Read more.
A scoping review of the literature on smell function in multiple sclerosis suggests that impairment is significant and may range from 20% to 45% in the MS population while mechanisms and clinical relevance remain poorly understood. Read more.
Review of papers from 1950 to 2015 on ambient air pollution and human olfaction finds that exposure to polluted air may impact the sense of smell and that future studies should use direct measures of exposure rather than proxy variables. Read more.
Review finds need for better awareness and measurement of olfactory function by physicians when undertaking endoscopic skull base surgery. Read more.
Statistical analysis of smell test results from 10,714 people reveals distinct subpathologies and suggests hyposmia may be a separate diagnostic entity from anosmia and normosmia. Read more.
British academic and anosmic John Sutherland's new book Orwell’s Nose: A Pathological Biography highlights the importance of smell as depicted in the literary works of George Orwell, James Joyce, Jonathan Franzen and others. Read more.
A mini-review examines the causes, prevalence, and consequences of olfactory impairment in aging. Read more.
Comprehensive overview of olfactory neuropathology in incipient Alzheimer's disease with suggested strategies for enhancing olfactory function and ameliorating cognitive decline. Read more.
Odor sensitivity predicts size of a person's social network. Read more.
Literature review examines fifteen patient-reported outcome measures for chronic rhinosinusitis, identifies best measures. Read more.
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.
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 2019 by Synesthetics, Inc.