Anosmia and parosmia
Transcription
Anosmia and parosmia
How to Treat PULL-OUT SECTION www.australiandoctor.com.au Complete How to Treat quizzes online www.australiandoctor.com.au/cpd to earn CPD or PDP points. INSIDE Anatomy and genetics Pathophysiology Assessment Treatment Prognosis The future the authors Associate Professor Richard Harvey program head and conjoint associate professor, rhinology and skull base surgery, University of NSW and St Vincent’s Hospitals; clinical associate professor, Macquarie University, North Ryde, NSW. Dr Pascal Bou-Haider neuroradiologist, St Vincent’s Hospital, Darlinghurst, NSW. Anosmia and parosmia Introduction SMELL, or chemosensation, is a major function of the nose. Although humans are less reliant on olfaction compared with other mammals it remains a significant evolutionary contribution to our physiology.1 Smell has many functions including the basic surveillance of our environment through both our olfactory and trigeminal nerve systems. The sense of smell plays an intimate role in influencing mood, cognition and behaviour. These behavioural changes modify pleasure, sexuality and even nutrition. Recent evidence suggests that olfaction has a broader role in mother–infant bonding, pheromone detection, recognition of kin and mates and longevity.2-6 Olfactory dysfunction can be categorised by the subjective experience. This may be a difficulty with odour identification (dysosmia, which encompasses hyposmia and anosmia), sensation of an odour different from the typical odour for that substance (parosmia); and perception of an odour where none is present (phantosmia). From a diagnostic perspective, olfactory dysfunction is more commonly classified as conductive (odorant delivery) or receptive (chemosensation). The common risk factors are age, male sex, viral infections, head trauma, metal ion exposure and pes- ticide exposure.7 Exposure to certain occupational hazards, such as paint solvents and hydrogen sulfide, have been well characterised in patients with olfactory disturbances.8,9 Perhaps the best-characterised study, that of 2491 subjects from Wisconsin, showed that current smoking, stroke, epilepsy and sinonasal disease were associated with decreased olfaction.10 Our understanding of the mechanisms of smell has greatly evolved in the past 25 years. However, there are many unanswered questions about how the human brain is able to interpret odorant complexity — from the smell of grass after rain, baking of www.australiandoctor.com.au food, to smoke from a barbecue. Even less well understood is the subsequent invoked emotional response from this primitive sense. Over the past three decades, an enormous contribution has been made by pioneers such as Richard Axel at Columbia University and Linda Buck at the Fred Hutchinson Cancer Research Center in Seattle, who shared the 2004 Nobel Prize in Physiology or Medicine “for their discoveries of odorant receptors and the organisation of the olfactory system”. Their discoveries provide a detailed picture of how odorants are detected by sensory neurons in the olfactory epithelium of the nose. cont’d next page Copyright © 2013 Australian Doctor All rights reserved. No part of this publication may be reproduced, distributed, or transmitted in any form or by any means without the prior written permission of the publisher. For permission requests, email: [email protected] 18 October 2013 | Australian Doctor | 27 How To Treat – Anosmia and parosmia Anatomy and genetics The olfactory apparatus THE human body contains 10-20 million olfactory neurons. These bipolar cells lie in a vast region of mucosa almost 22cm2 in area within the sinonasal cavity. Their distribution is much greater than previously thought with extension beyond the olfactory cleft to include both the septum and middle turbinate. These bipolar cells have a single dendrite with a thickened ending (the olfactory knob) extending to the mucosal surface where olfactory receptors have access to the mucus (figure 1). When odorants are delivered to this area they combine with odorant-binding proteins that facilitate movement through mucus and then subsequent rapid clearing after recognition. Thus mucus rheology plays an important part of odour detection. Odorants gain access to the olfactory epithelium via two important mechanisms. The sniff produces turbulent air flow that distributes odorants away from the usual direct pathway to the posterior choana and throughout the nasal cavity. This is orthonasal smell. The retronasal delivery occurs when we chew and is the main component of the perception of flavour, which is 70% smell and 30% taste. Supporting cells in the olfactory epithelium, including pluri-potential basal cells, are thought to provide neuromodulation as well as regenerative power to the olfactory neurons. The axonal arm of Figure 1: Structure of olfactory apparatus, showing odorants in the mucus layer transmitted through receptor cells in the supporting cells layer to the olfactory bulb. Neuron Olfactory bulb Axonal arms of olfactory neuronal cells Genetics Receptor cell Odorants the olfactory neuronal cells transmits signals to the brain. These axons group together to form nasal to the cranial cavity (figure 2). From here, the axons synapse in the olfactory bulb, which projects neurons along the olfactory tracts to distribute the cortical centres. The ‘primary olfactory region’ (piriform cortex, olfactory nucleus and tubercle, amygdala, entorhinal cortex) and secondary olfactory areas (hippocampus, hypothalamus, thalamus, orbitofrontal cortex and the cerebellum) have many links in the limbic and primitive cortical areas and may account for the role of olfaction in mood, emotion, pleasure, sexual behaviour and memory. 16-20 olfactory fascicles (olfactory fila) that perforate the cribriform plate of the ethmoid bone. The cribriform plate is known for its appearance because of these fascicles transgressing from the The aetiology of such a wide variability of reception is a fundamentally unanswered question of olfactory biology. Humans have an enormous part of their genome dedicated to the olfactory genes with almost 900 genes identified (half non-functional). These genes represent 3% of the estimated 30,000 genes in the human genome and are underutilised compared with other mammals, such as the mouse that has three times the amount of activated olfactory genes.11 However, only one olfactory receptor gene is expressed in each neuron. The neurons come together in multiple cross-linking connections within the bulb and cortex to produce the enormously diverse olfactory map that represents the smells that we can distinguish. Figure 2: Olfactory area and cribriform plate. A: The superior view of the cribriform plate and olfactory groove in the floor of the anterior cranial fossa. This site is prone to fracture extension as a result of the thin bone. B and C: The endoscopic view of the cribriform plate and olfactory cleft. The position is posterior to the middle turbinate. Pathophysiology OLFACTORY disturbance is usually clinically categorised into conductive (odorant delivery) and receptive (chemosensation) to associate better the presenting complaint with the appropriate investigation and treatment. Common conductive and receptive aetiologies are listed in table 1. Some associations are from low levels of evidence but many have large epidemiological studies and biological plausibility to support the association. Age is a common cause of olfactory decline.10,12 Up to 25% of all patients older than 55 have evidence of olfactory changes and 62.5% of octogenarians have objective impairment, although a lesser proportion will complain of it.13 Additionally, urban living, male sex, smoking, stroke, and epilepsy are more commonly associated with earlier olfactory decline.14 It is unusual, however, for patients younger than 60 to have environmental or age-related decline. 28 | Australian Doctor | 18 October 2013 Sinonasal disease, primarily rhinitis and rhinosinusitis, are common causes of olfactory loss. There is a component of conductive disturbance (ie, affecting the delivery of an odorant) with oedema and sometimes frank nasal polyps. However, it is well recognised that the inflammation associated with these conditions also produces an abnormality of the olfactory neurons and chemosensation. Olfactory decline has been associated with several neurodegenerative diseases, including Alzheimer’s disease and Parkinson’s disease, which is believed to be a result of disordered central or cortical olfactory processing. While it is possible that olfactory decline may precede the more severe manifestations of these diseases, its role as a predictor or marker of disease onset has not been clearly established.7 cont’d page 30 Table 1: Common causes of olfactory disturbance Conductive (odorant delivery) Receptive (chemosensation) Mucosal oedema (figure 3) Postviral Chronic rhinosinusitis with nasal polyps (figure 4) Neurodegenerative disease (figure 6) Sinonasal tumours (figure 5) Age-related decline Local infective conditions (odontogenic sinusitis) producing cacosmia Smoking Sjogren’s disease Occupational exposure (benzene, menthol, sulfur dioxide, carbon disulfide, heavy metals, and dust) Trauma (cribriform fractures) Tumours of the olfactory apparatus (figure 8) Liver disease and alcohol abuse Renal disease Menopause, menstrual cycle, pregnancy Drugs (cancer chemotherapy, antibiotics (aminoglycosides, macrolides, tetracycline), anti-thyroid medication, opiates, sympathomimetics, antacids, and L-dopa) Vitamin A, B and thiamine deficiency Diabetes www.australiandoctor.com.au How To Treat – Anosmia and parosmia from page 28 Figure 3: A: The endoscopic appearance of the right olfactory cleft in a patient with wellcontrolled inflammatory sinus disease, but with oedema and polypoid changes to the olfactory cleft mucosa (arrow). B: This area (*) lies between the septum and middle turbinate and can be challenging to examine. Figure 5: Olfactory neuroblastoma is a classic tumour that presents with smell loss (A) seen here between the left middle turbinate (*) and septum (#). The MRI demonstrates the left olfactory cleft mass and relationship to the olfactory bulbs, which appear normal in this study (B). Figure 4: Endoscopic view of chronic rhinosinusitis with nasal polyps on the right (A) and left (B). The polyps (*) are clearly different from normal mucosa of the septum (#) or turbinate. Figure 6: Degenerative brain disease can account for central olfactory loss. The subcortical high signal changes (arrow) seen in Alzheimer’s disease is one example of central pathology that is investigated with this axial MRI scan. Assessment History IDENTIFYING patients who progress to hyposmia or anosmia outside of normal olfactory decline is the main focus of clinical history and examination. The majority (75% of patients) will complain of both loss of smell and diminished flavour of food. This is due to the loss of both orthonasal and retronasal mechanisms of odorant delivery to the olfactory apparatus. It is less common to have orthonasal-only olfactory dysfunction, where the flavour of foods is intact but smell is reduced. This occurs in 24% of patients. Only 1% of patients have retronasal loss, where there is loss of flavour but retention of smell via sniffing.15 Both of these groups that only have either orthonasal or retronasal loss should be investigated early for local sinonasal pathology. Urban living and a history of smoking, stroke and epilepsy are all potential risk factors that should all be sought on history. There is also an increased risk with age and being male. Early symptoms and signs of Parkinson’s disease, Alzheimer’s, other dementias and diabetesassociated polyneuropathy should be sought. Another clue may be recent changes to the patient’s drug regimen. While the presence of sinonasal symptoms of nasal obstruction, discharge and pressure is important, it is the loss of smell during exacerbations of these symptoms and the concomitant improvement with treatment that is most telling. A response to treatment may highlight the pathophysiology of the olfactory loss. Anterior rhinoscopy and endoscopy Figure 7: Smell identification testing is the simplest form of objective assessment. The Smell Identification Test is a collection of 40 ‘scratch and sniff’ panels that is easy to selfadminister. oxymetazoline will greatly assist the examination. Objective smell tests Smell tests are divided into odour identification tests, odour threshold assessment and odour discrimination tests. The most commonly used is the odour identification test, which assesses how well patients can identify specific odours. We use the Smell Identification Test, which is a commercial version of the University of Pennsylvania Smell Identification Test, a 40-item scratch-and-sniff smell test that has been validated in cross-cultural populations with age and sex norms provided. It has a high test–retest reliability, is easy to administer and is inexpensive (figure 7).16 Many other smell tests have been developed over the past three decades but the Smell Identification Test and the ‘Sniffin’ Sticks’ tests are the most widely accepted.17 The ‘Sniffin’ Sticks’ tests are a group of 12 pens with a volatile odour that is released from the nib when the Figure 8: Olfactory groove meningioma (arrow) is an example of ‘peripheral’ olfactory loss due to involvement of the olfactory bulbs and tracts seen on this coronal MRI scan. Simple assessment of the nose is critical, even when performed with the simple otoscope. The presence of polyps (figure 4) or an intranasal mass (figure 5) are easy diagnoses to exclude. Subtle mucosal oedema (figure 3) will require a formal endoscopy. Spraying the nose with a decongestant such as 30 | Australian Doctor | 18 October 2013 www.australiandoctor.com.au cap is removed. They are widely used in Europe but have also been validated in the Australian population.12,18 Both tests force the user to choose a response. There are no options to leave responses blank or empty and thus these tests have mechanisms to detect malingering when intentional avoidance or the correct response occurs. Radiological assessment If there is clinical suspicion of sinonasal disease, then a non-contrast CT scan may be warranted. CT imaging is performed merely to define mucosal inflammatory changes and adding IV contrast does not enhance diagnostic ability. CT should be considered when defining the extent of mucosal changes, confirming the diagnosis of chronic rhinosinusitis when in doubt and when surgery is being considered. However, in all other circumstances, MRI is the mainstay of imaging. MRI has greatly improved the value of medical imaging in olfactory disorders by allowing precise depiction of the olfactory bulb, olfactory tract and even very early damage to the CNS. It excludes intracranial pathology of the olfactory apparatus (figure 8) and highlights subtle changes not seen on endoscopy (figure 9). It may also detect grey and white matter features of neurodegenerative disease that may account for ‘cortical’ olfactory loss (figure 6). The normal volume of the olfactory bulb depends on age and is 40-60mm3 when measured on high-resolution MRI.19,20 In cases of congenital anosmia, MRI examination usually demonstrates severely hypoplastic or absent olfactory bulbs along with flattening or even absence of the olfaccont’d page 32 Figure 9. Subtle inflammatory changes within the olfactory cleft bilaterally on patient with previously treated inflammatory airway disease. Residual smell loss was the only outstanding symptom after initial treatment. How To Treat – Anosmia and parosmia from page 30 tory sulci (figure 10). Trauma is a leading cause of olfactory dysfunction. In cases where the usual work-up fails to reveal gross cerebral damage or fractures, reduced olfactory bulb volume may be the only sign. This is likely to be due to a tearing or shearing of the olfactory fila on their way through the cribriform plate of the ethmoid bone. Finally, the assessment of the state of the olfactory bulb has prognostic implications. The size of the Figure 10: Olfactory bulb and tract agenesis (A) and atrophy (B) are important findings to identify that allow for accurate diagnosis of anosmia or prognosis for olfactory return. Compare with anatomy in figure 5. olfactory bulb closely correlates to function, and its measurements have demonstrated high diagnostic and even prognostic value in the evaluation of olfactory disturbances (figure 10).19,21,22 Smell loss can be an early sign of a neurodegenerative disorders such as Alzheimer’s (figure 6). In patients who have Alzheimer’s disease, a correlation has been demonstrated between olfactory bulb volume and the severity of cognitive decline as evaluated by the Mini-Mental State Examination score.23 Treatment AN enormous variety of therapies have been trialled for the loss of smell, including steroids, zinc, theophylline, lipoic acid, caroverine, strychnine, vitamin B and various topical agents. When an obvious cause exists, then this should be addressed. However, when no obvious cause exists (ie, idiopathic), or the loss of smell is suspected to be postviral, from environmental exposure, post trauma or from minor rhinitis or rhinosinusitis, it is still possible to be systematic and sensible in the approach. General advice to patients should always include a caution on their reduced ability to identify spoiled food, smoke and gas. Steroid therapy Initial therapy should include systemic corticosteroids.24 Intranasal steroid sprays are not effective in olfactory loss in chronic rhinosinusitis patients and are not delivered effectively to the olfactory epithelium.25,26 A three-week course of systemic corticosteroid (prednisone) is used with a weaning regime starting at a dose of 25mg for seven days, then 12.5mg for seven days, then 5mg for seven days, based on a 70kg male. This dosing regime is practical, represents the equivalent potency dose from studies performed using betamethasone and is recommended for 14-21 days as this best equates to the lifespan of a tissue eosinophil.15,27 A cumulative dose of less than 300-1000mg is recommended, with a maximum of 30-40mg daily, as this is the range in which significant complications and medicolegal complaints occurred.28 Twenty-five percent of patients will improve on systemic steroids during the treatment period. A further 12% will improve on 12 weeks of direct topical steroid (with drops as opposed to simple sprays) delivered in a ‘supine head-back’ or ‘head to floor’ position. The remaining 63% will not recover and will need further assessment and consideration for alternative treatments discussed below (see figure 11). Topical delivery is less effective in cases of loss of smell due to trauma and chronic rhinosinusitis.15 Fluticasone 400µg nasule drops are available in Australia and come in 28-capsule packets for this purpose. Other forms of local steroid delivery are creams, irrigations or injections prescribed off-label. It is important to emphasise that only oral corticosteroid is effective and the addition of simple nasal sprays (as opposed to nasal drops) does not offer any further benefit.29 However, direct appli- 32 | Australian Doctor | 18 October 2013 Figure 11: Management algorithm for anosmia and parosmia. Step 1 Screen for metabolic disorders, EUC, LFT, zinc, vitamin B (serum pyridoxal phosphate), vitamin A (serum retinol), HbA1c, BSL CT if sinonasal disease Prednisone (three weeks) Minocycline 100mg/d (three weeks for acute losses) Vitamin A, B and zinc replacement Step 2 Hormonal/inflammatory screen – TFT, FSH, LH, beta hCG, FBC, ESR, CRP, ANCA, rheumatoid factor, anti-dsDNA, anti-SSA/SSB MRI Topical budesonide/fluticasone (12 weeks) Step 3 Novel topical agents Olfactory stimulants (theoyphylline) neurodegenerative conditions. The neuroprotective potential of this drug has been suggested by several studies on various neurological disorders, including neurodegenerative conditions, cerebral ischemia, trauma and the degeneration of retinal cells.30-34 We currently recommend that newonset olfactory loss patients use minocycline 100mg a day for three weeks during their corticosteroid therapy although we acknowledge that its benefit is theoretical rather than clinically proven. There is evidence that its use in all patients with olfactory loss is not warranted.35 However, like sensorineural hearing loss or Bell’s facial palsy, the potential to reverse the decline early in the process outweighs the risk of the medication in most cases. Vitamins and trace elements Olfactory training is a valid tool to stimulate patients who are keen on being involved in their recovery when there is no steroid response in the initial treatment. cation with nasal drops will benefit a further 12%.15 Neuroprotection The basis of neuronal decline is thought to be increased apoptosis in a system that has been exposed to a significant insult or ongoing inflammation ensuring apoptosis occurs faster than regeneration from the basal cells. Minocycline exerts a neuroprotective effect by reducing apoptosis in neurons and may be used to treat olfactory disturbance associated with www.australiandoctor.com.au A trial of vitamins and zinc has a low risk for causing harm and may be considered. Vitamin A has been shown to improve olfaction and there are plausible mechanisms for its effects as it is involved in olfaction.36,37 However, a randomised controlled trial on olfactory loss due to many varied causes did not show a benefit.38 When trauma and chronic rhinosinusitis are not present, the use of vitamin A 10,000 IU daily (maximum dose during pregnancy is 2500 IU/day) may be considered for three weeks. Vitamin B and pyridoxal phosphatedependent enzymes play a role in the biosynthesis of five important neurotransmitters: serotonin, dopamine, adrenaline, noradrenaline and gamma-aminobutyric acid (GABA). Vitamin B therapy in olfactory loss showed a benefit in a multi-arm randomised controlled trial.39 A vitamin A, B and zinc supplement would need to be taken at the rate of four tablets a day in order to reach investigated doses. Olfactory training Olfactory training is a valid tool to stimulate patients who are keen on being involved in their recovery when there is no steroid response in the initial treatment. Patients can purchase four intense odours in the form of essential oils: phenylethyl alcohol (rose), eucalyptol (eucalyptus), citronella (lemon), and eugenol (cloves). A twice-daily exposure has been shown to improve objective olfactory testing in patients compared with controls over a 12-week period.40 Methylxanthines Finally, when there is no steroid response, topical therapy has failed, secondary causes excluded and patient is between three months and 12 months post olfactory loss, methylxanthines in the form of oral theophylline have both laboratory and clinical data to support use as a stimulant of hyposmia.41,42 Anti-epileptics When phantosmia or dysosmia persist in the absence of other aetiologies, they are treated as inappropriate local neural activity, as seen in epilepsy, and medications such as gabapentin may be useful. Surgery Surgery is beneficial when chronic rhinosinusitis is present.43 Removal of polyps and other factors that influence the conduction of odorants is likely to account for the benefit seen with sinus surgery.44 However, control of the inflammatory process in chronic rhinosinusitis is the goal and poorly controlled mucosal inflammation on endoscopy is highly correlated with poor olfaction postsurgery.45,46 Prognosis SPONTANEOUS recovery occurs in a large proportion of patients — 20-35% of patients have improvement in the first 12 months.12,35,47 Recovery is best in postviral cases, females, non-smokers and parosmia. Low anosmic scores on smell identification correspond to a lower chance for complete recovery but do not take into account the rate of improvement. Duration of olfactory loss is negatively correlated with recovery.48 Traumatic causes are most likely to lead to complete and permanent anosmia. Recovery of some olfactory function within one year of traumatic or postviral loss is a positive prog- The future VERY active research is ongoing in the area of olfactory disturbance, with much of it funded by the flavour and fragrance industry. Commercial interests exist not just in food and perfume but in medicines that can alter obesity, diabetes and the delivery of agents to the CNS via the olfactory system. Some of the early reports on vitamin A therapy involved very high doses and future topical therapy with high local concentrations is being investigated. Nonhuman applications include the insect repellent industry looking to develop pest controls with odorant molecules such as carbon dioxide to mimic substances that insects avoid. Very active research is ongoing in the area of olfactory disturbance, with much of it funded by the flavour and fragrance industry. Change in diet nostic sign.49 An olfactory bulb volume of 40mm3 or less on MRI has been associated with no recovery regardless of the duration of anosmia.50 tary regimes are more frequent.51 Many patients have a change in their usual diet — 30% eat less, almost half eat or drink less sweet foods and fluids, 47% eat out less and most favour savoury, more spicy and salty foods.51 Weight gain is harder to predict as congenital anosmics tend to be more likely to have a healthy weight compared with the average population. However, younger, overweight patients (BMI >30kg/ m2) with acquired olfactory loss and a long duration of gradually developing anosmia tend to gain weight. Nutritional deficiency is potential sequelae in patients with acquired olfactory loss as poor die- Psychosocial impact Depression is a frequent association in anosmia and lower quality of life has been recorded.52 Particular attention should be paid to patients with dual sensory loss (olfactory loss with either hearing or visual loss that may be more common with age) as this is a proven risk for depression.53 Adjustment does occur for the majority of patients with anosmia. It is thought to take up to 12 months for patients to abandon behaviour meaningful only to normosmics although 13% continue to have adjustment issues beyond 12 months.54 Case studies RACHEL is a 45-year-old female who presents with a 20-year history of worsening nasal congestion with cycling blockage between sides. The nasal obstruction is worse at night when she is lying flat. She has little in the form of nasal itch, sneeze or discharge. Rachel says that smell loss or “poor” smell has been a significant feature. There are no accompanying conjunctival, asthma or dermatitis symptoms or signs. Her nasal peak inspiratory flow is 90L/minute. Endoscopy demonstrates severe turbinate hypertrophy and a deviation of her septum (figure 12A, B). There are no inflammatory changes (polyps, oedema, and secretions) in her nose. CT scan demonstrates normal sinus mucosa. Allergy screening is negative for inhalant antigens. Initial treatment was with a trial of steroid drops/irrigation to better target the olfactory cleft and with vitamin A, B and zinc replacement. There was no response to the corticosteroid. These findings are out of keeping with olfactory disturbance from rhinitis alone. Objective testing demonstrates total anosmia (figure 13). A diagnosis of non-allergic rhinitis and potentially unrelated anosmia is made. She proceeds with surgery to correct her nasal airway but the cause of the olfactory loss requires further investigation as it is unlikely to be conductive or related to persistent rhinitis alone. An excellent airway result is obtained at three months (figure 12C, D — the changes reflect remodelling the nasal airway anatomy to allow nasal function despite the condition, rather than a treatment for the condition). However, smell remains unchanged. An MRI is organised and demonstrates dysgenesis of the olfactory apparatus (figure 10). Rachel’s loss of smell has been present for many years and she has adapted well. She does not perceive herself as anosmic, although testing suggests total anosmia. Her other senses, including taste, have adapted accordingly. A discussion of longterm awareness of difficulty with smoke and gas detection and the need to ensure good alarm systems at home is made. Improvements in smell are not anticipated and the patient stops attempting to treat the condition. cont’d next page Figure 12: The endoscopic appearance of the nasal airway of the patient with persistent nonallergic rhinitis on the right (A) and left (B). The postoperative view of the right (C) and left (D) show the changes to the nasal airway with a midline septum and uniformly reduced inferior turbinates. NOSE LAB 354 Victoria Street, Darlinghurst NS tel: 02 9360 4811 • fax: 02 936 web: http://sydneyentclin @ Sydney Ear Nose and Throat Clinic NOSE LAB NOSE @ Sydney EarLAB Nose and Throat Clinic 354 Victoria Street, Darlinghurst NSW 2010 tel: 02 Street, 9360 4811 • fax: 02 NSW 9360 2010 9919 354 Victoria Darlinghurst http://sydneyentclinic.com tel:web: 02 9360 4811 • fax: 02 9360 9919 web: http://sydneyentclinic.com @ Sydney Ear Nose and Throat Clinic Date: 13/09/2013 Date: UPSIT 40 Date: UPSIT 40 UPSIT 40 Test Score 13/09/2013 Score13/09/2013 18 Score Score 18 18 Males Olfactory Diagnosis 00-05 Test Score 06-18 Males malingering Probable Olfactory Diagnosis Males Total anosmia 00-05 Test Score 19-25 06-18 00-05 26-29 19-25 06-18 30-33 26-29 19-25 34-40 Probable malingering Olfactory Diagnosis Severe microsmia Total anosmia Probable malingering Moderate microsmia Severe microsmia Total anosmia Mild microsmia Moderate microsmia Severe microsmia Normosmia 30-33 26-29 34-40 30-33 34-40 Mild microsmia Moderate microsmia Normosmia Mild microsmia Normosmia Diagnosis (see below for definitions) anosmia Diagnosis (seeTotal below for definitions) Diagnosis (see below for definitions) Total anosmia Total Females anosmia Test Score 00-05 Test06-18 Score 00-05 Test Score 19-25 06-18 00-05 26-30 19-25 06-18 31-34 26-30 19-25 35-40 31-34 26-30 35-40 31-34 35-40 Olfactory Diagnosis Females Probable malingering Olfactory Diagnosis Females Total anosmia Probable malingering Olfactory Diagnosis Severe microsmia Total anosmia Probable malingering Moderate microsmia Severe microsmia Total anosmia Mild microsmia Moderate microsmia Severe microsmia Normosmia Mild microsmia Moderate microsmia Normosmia Mild microsmia Normosmia Interpretation of scores Interpretation of scores In general, the following In general, the following has hasInterpretation been developed of scores for establi been developed for Interpretation establishing In general, the followingolfactory has ofpatient's scores an adult an In adult patient’s been developed forclassification established general, the following has diagnosis. This an adult patient's for olfactory been developed established olfactory diagnosis. scheme is based on a diagnosis. This classification an adult patient's olfactory This classification characterisation of the test scheme is This based diagnosis. classification scheme is based onon a that is independent of subje characterisation scheme is based of onthe a test scores a characterisation of age. It does apply that is independent ofnot subject characterisation of the test scoresin thethat test scores that is case of individuals less than age.is independent It does not apply in the of subject of . less independent of age subject caseyears of individuals than age. It does not apply in 15 the years of individuals age case of age. It does not. applyless in than 15 age . Inof this classification scheme, theyears case of individuals In this classification scheme, anosmia defined as total younger than 15isyears anosmia is defined as totalqualitat In thisinability classification scheme, to perceive of age. inability to qualitative anosmia is perceive defined as total odour sensations, whereas odour sensations, inability to perceive qualitative microsmia is whereas defined as In this classification microsmia is defined asability. odour sensations, whereas decreased smell scheme, anosmia isability. decreased microsmia issmell defined as decreased smell ability. defined as total inability to perceive qualitative odour sensations, whereas microsmia is defined as decreased smell ability. Figure 13: Rachel’s olfactory identification test results. The score of 18 places her in the anosmic range for her age group. www.australiandoctor.com.au 18 October 2013 | Australian Doctor | 33 How To Treat – Anosmia and parosmia Conclusion Summary Olfactory dysfunction should not be overlooked as a health issue as it has a significant impact on quality of life, mental health and may flag a more significant condition. OLFACTORY loss can be devastating to patients especially when it occurs suddenly and in young patients. It has a significant impact on nutrition, wellbeing and mental health. A comprehensive approach should be taken to exclude underlying causes followed by the early and aggressive implementation of a structured stepwise plan. Recovery of the sense of smell at 12 months is a positive sign. However, those patients with evidence of olfactory bulb atrophy should not pursue active treatments that may carry both expense and risk. Corticosteroids given orally are the mainstay of treatment when inflammatory aetiology is suspect and should be given early in postviral anosmia MRI scan is essential in patients who do not respond to corticosteroids and have otherwise normal examinations. References Available on request from [email protected] Instructions How to Treat Quiz Complete this quiz online and fill in the GP evaluation form to earn 2 CPD or PDP points. We no longer accept quizzes by post or fax. The mark required to obtain points is 80%. Please note that some questions have more than one correct answer. Anosmia and parosmia — 18 October 2013 1. Which TWO statements are correct regarding the anatomy and genetics of the olfactory apparatus? a) There are 10-20 million olfactory neurons b) The distribution of the olfactory neurons are restricted to the cribriform plate c) The olfactory axons form fascicles that synapse in the olfactory bulb and then distribute to the cortical centres d) Only a small percentage (<0.1%) of the human genome is associated with olfaction 2. Which TWO statements are correct regarding the pathophysiology of olfactory disturbance? a) Olfactory decline has been associated with several neurodegenerative diseases, including Alzheimer’s disease and Parkinson’s disease b) Studies have shown an association between epilepsy and decreased olfaction c) Age is usually not a factor in the loss of smell d) Sinonasal disease causes loss of smell only through conductive disturbance 3. Which THREE of the following pathoaetiologies may cause conductive olfactory disturbance? a) Sinusitis caused by an upper dental abscess b) Sjogren’s disease c) Sinonasal tumours d) Fracture of the cribriform plate 4. Which TWO statements are correct GO ONLINE TO COMPLETE THE QUIZ www.australiandoctor.com.au/education/how-to-treat regarding history and examination of olfactory disturbance? a) The Smell Identification Test has not been validated in the Australian population b) History-taking should include asking about smoking, stroke and epilepsy c) Otoscopes are not useful in assessing the nose d) Nasal examination may be aided by a decongestant spray such as oxymetazoline 5. Which TWO statements are correct regarding imaging in olfactory disturbance? a) The addition of IV contrast improves the diagnostic accuracy of CT in sinonasal disease b) The normal volume of the olfactory bulb is 40-60mm3 on high-resolution MRI c) Trauma causing shearing of the olfactory fila can be detected as a swelling in the volume of the olfactory bulb d) The severity of associated Alzheimer’s disease correlates with the volume of the olfactory bulb 6. W hich TWO statements are correct regarding steroid treatment for olfactory disturbance? a) The recommended duration of steroid treatment is 14-21 days b) The improvement from topical steroid sprays is greater in cases of traumatic and chronic rhinosinusitis than in other patho-aetiologies c) A cumulative dose of less than 300-1000mg is recommended, with a maximum of 3040mg daily d) T he addition of simple nasal sprays improves the effectiveness of the oral steroid treatment of chronic rhinosinusitis 7. W hich TWO statements are correct regarding other potential treatments of olfactory disturbance? a) Minocycline may theoretically be useful in treating olfactory disturbance associated with neurodegenerative conditions b) P oorly controlled mucosal inflammation on endoscopy will have a poor olfactory outcome with surgery c) Randomised trials have shown clear benefit with vitamin A but not with vitamin B supplementation d) O lfactory training involves stimulating the nose daily with garlic, onion and other strong provoking agents 8. W hich TWO statements are correct regarding prognosis in olfactory disturbance? a) Recovery from olfactory disturbance is best in postviral causes, females, non-smokers and parosmia b) L ow anosmic scores on smell identification signify a poor rate of improvement c) Spontaneous recovery occurs in a very small proportion of patients (<0.1%) in the first 12 months d) N utritional deficiency may accompany acquired olfactory loss as poor dietary regimes are more frequent 9. Norman is an 87-year-old man who had a recent fall causing head trauma and anosmia. Which TWO statements are correct regarding his anosmia and acute management? a) Anosmia at his age has been clearly shown to be a marker for the onset of a neurodegenerative disease such as Parkinson’s b) Norman should be cautioned about his reduced ability to identify spoiled food, smoke and gas c) Traumatic causes of anosmia have the best chance for subsequent recovery d) An olfactory bulb volume of 40mm or less on MRI has been associated with minimal recovery regardless of the duration of anosmia 10. Norman returns for follow-up after discharge from acute care for traumatic anosmia. Which TWO statements are correct regarding holistic management and prognosis of his condition? a) Depression is a rare association in anosmia b) Patients who have signs of recovery from traumatic anosmia at one year have a good prognosis c) It may take up to 12 months for patients to abandon behaviour meaningful only to normosmics d) Duration of olfactory loss is not a prognostic marker CPD QUIZ UPDATE The RACGP requires that a brief GP evaluation form be completed with every quiz to obtain category 2 CPD or PDP points for the 2011-13 triennium. You can complete this online along with the quiz at www.australiandoctor.com.au. Because this is a requirement, we are no longer able to accept the quiz by post or fax. However, we have included the quiz questions here for those who like to prepare the answers before completing the quiz online. how to treat Editor: Dr Steve Liang Email: [email protected] Next week Tumour screening aims to decrease the morbidity and mortality of cancer by detecting cancers at an earlier stage. The next How to Treat examines the role of tumour markers in the context of cancer screening, assessing their usefulness in the monitoring and surveillance of diagnosed cancers. The authors are Associate Professor Gavin Marx, associate professor, Sydney Medical School, University of Sydney, and oncologist, Sydney Adventist Hospital, Wahroonga, and Cancer Institute, Frenchs Forest, NSW; and Dr David Chan, advanced trainee in oncology, Royal North Shore Hospital, St Leonards, NSW; and Dr Adrian Lee, medical oncology advanced trainee, Royal North Shore Hospital, St Leonards, and clinical lecturer, Sydney Medical School, University of Sydney. 34 | Australian Doctor | 18 October 2013 www.australiandoctor.com.au