Olfactory dysfunction: a sequela of pediatric blunt head trauma

OBJECTIVE: To evaluate olfactory function in children with blunt head trauma. METHODS: Eligible subjects were consecutive children presenting at San Diego Children's Hospital Emergency Department or Trauma Service with blunt head trauma. Thirty-seven head injured children mean age 10.11+/-2.74 were evaluated; 36 healthy age and gender matched community children, mean age 10.08+/-2.99, served as controls. The medical record was reviewed for clinical measures related to head injury (HI). All children underwent olfactory assessment with the San Diego Children's Odor Identification Test (SDOIT). Olfactory event-related potentials were recorded on a subset of head injured and control children. RESULTS: Three of 37 head injured children had olfactory dysfunction. The head injured hyposmics had signs of more severe head injury represented by lower Glasgow Coma Scores (GCS), 10.33+/-5.51, when compared to their normosmic counterparts with mean GCS of 14.06+/-2.82. When stratifying the head injured children by clinical measures, lower Glasgow Coma Score, and abnormalities on head CT scan were associated with poorer olfactory performance. CONCLUSION: Children with blunt head injury may suffer post-traumatic olfactory impairment. More severe head injuries are more likely to produce olfactory deficits. In cases of significant head injury, cranial nerve I evaluation is imperative.     

Management of chronic sinusitis in cystic fibrosis

Chronic rhinosinusitis is extremely common in patients with cystic fibrosis. It causes numerous problems in these patients and can put them at risk for life-threatening illness. Potential problems include nasal obstruction, congestion, sinus pain and pressure, infection (usually with Pseudomonas organisms), hyposmia or anosmia, and the seeding of bacteria into the lower respiratory tract. Cystic fibrosis patients with chronically infected sinuses are at increased risk for pneumonia following lung transplantation. A prophylactic protocol has been developed for the management of chronic sinusitis in patients with cystic fibrosis. These patients are fully evaluated at the Nasal Dysfunction Clinic of the University of California, San Diego (UCSD), Medical Center. Based on the results of the evaluation, they are treated with endoscopic sinus surgery, partial middle turbinectomy, septoplasty, and a large middle meatal maxillary antrostomy. Surgery is followed by a rigorous regimen of pulsatile hypotonic saline nasal irrigation to wash away tenacious cystic secretions. Tobramycin (Nebcin®) is given once daily in the nasal irrigant to inhibit the growth of Pseudomonas organisms. At the USCD Nasal Dysfunction Clinic, this prepulmonary transplantation protocol is now used in all cystic fibrosis patients with chronic sinusitis.     

Clinical study and literature review of nasal irrigation

OBJECTIVES/HYPOTHESIS: Nasal disease, including chronic rhinosinusitis and allergic rhinitis, is a significant source of morbidity. Nasal irrigation has been used as an adjunctive treatment of sinonasal disease. However, despite an abundance of anecdotal reports, there has been little statistical evidence to support its efficacy. The objective of this study was to determine the efficacy of the use of pulsatile hypertonic saline nasal irrigation in the treatment of sinonasal disease. Study DESIGN: A prospective controlled clinical study. METHODS: Two hundred eleven patients from the University of California, San Diego (San Diego, CA) Nasal Dysfunction Clinic with sinonasal disease (including allergic rhinitis, aging rhinitis, atrophic rhinitis, and postnasal drip) and 20 disease-free control subjects were enrolled. Patients irrigated their nasal cavities using hypertonic saline delivered by a Water Pik device using a commercially available nasal adapter twice daily for 3 to 6 weeks. Patients rated nasal disease-specific symptoms and completed a self-administered quality of well-being questionnaire before intervention and at follow-up. RESULTS: Patients who used nasal irrigation for the treatment of sinonasal disease experienced statistically significant improvements in 23 of the 30 nasal symptoms queried. Improvement was also measured in the global assessment of health status using the Quality of Well-Being scale. CONCLUSIONS: Nasal irrigation is effective in improving symptoms and the health status of patients with sinonasal disease.     

Sinonasal Disease and Olfactory Impairment in HIV Disease: Endoscopic Sinus Surgery and Outcome Measures

Objectives To investigate the effects of ESS (ESS) on olfactory impairment, disease‐specific symptoms, and general quality of well‐being In HIV+ patients with sinonasal disease. Study Design Study 1: Nasal cytology, rhinomanometry, nasal examination including endoscopy, disease‐specific sinonasal symptoms, olfactory threshold sensitivity, and odor identification testing were performed before and after ESS in HIV+ patients with sinonasal complaints. Study 2: Quality of well‐being was assessed before and after ESS in HIV+ patients with sinonasal complaints and controls. Results Significant olfactory sensitivity loss persisted for patients with chronic sinusitis after ESS, suggesting that the impairment in these patients may be due to viral disease rather than inflammation. Significant improvement in other disease‐specific symptom scores (nasal obstruction, nasal congestion, headache, sinus pain, etc.) and results of the general quality of well‐being assessment showed ESS to be beneficial in the extended health management of HIV illness. Conclusions The current study indicated both olfactory dysfunction and subjective negative symptoms in HIV+ patients with chronic sinusitis. Although olfactory dysfunction remained, ESS was successful in providing marked alleviation of symptomatology in HIV+ patients with chronic sinusitis. The results support ESS as an appropriate treatment option for HIV+ patients with chronic sinusitis.     

Intranasal trigeminal chemosensitivity in patients with postviral and post-traumatic olfactory dysfunction

Abstract Conclusions: The olfactory and intranasal trigeminal systems are closely connected. With regard to intranasal trigeminal event-related potential (ERP), patients with olfactory dysfunction (OD) showed longer latency and lower amplitude, which indicated decreased trigeminal sensitivity. Different age, etiology, and olfactory status also affect trigeminal sensitivity differently. Objective: OD is a common symptom in the rhinology clinic. ERP is considered an important method to evaluate chemosensitivity. The aim of this study was to investigate changes of intranasal trigeminal sense in patients with postviral OD (PVOD) and post-traumatic OD (PTOD). Methods: A total of 96 participants (30 healthy adults and 66 patients with OD) aged 20-65 years were investigated. The T&T olfactometer, the Sniffin' Sticks olfactory test, and trigeminal ERPs (tERPs) were used. We evaluated trigeminal sensitivity influenced by different factors (age, etiology, and olfactory status) in healthy subjects with normal olfactory function and in patients with PVOD and PTOD. Results: Patients with OD showed higher trigeminal thresholds than normal controls. Compared with controls, N1/P2 latencies of tERPs increased and amplitudes decreased in patients with OD. Older subjects showed longer latencies and lower amplitudes than young subjects in both controls and the OD group. Patients with PTOD exhibited worse psychophysical olfactory function and decreased trigeminal sensitivity.     

Fluctuating olfactory sensitivity and distorted odor perception in allergic rhinitis.

OBJECTIVE: To characterize the relationship between allergic rhinitis, the severity and duration of nasal disease, olfactory function, and self-reported olfactory symptoms, including fluctuations or distortions in odor perception. DESIGN: Assessment of olfactory function and symptoms of 90 patients with allergic rhinitis. SETTING: A clinic of a university teaching hospital and research facility. PATIENTS: Sixty patients who presented to the Taste and Smell Clinic who had positive allergy test results and 30 patients who presented to the Allergy-Immunology Clinic. The Taste and Smell Clinic patients were grouped by nasal-sinus disease status (30 without chronic rhinosinusitis or nasal polyps, 14 with chronic rhinosinusitis but without polyps, and 16 with nasal polyps). MAIN OUTCOME MEASURES: Subjective olfactory symptom questionnaire and objective olfactory function tests. RESULTS: The Allergy-Immunology Clinic patients were diagnosed as being normosmic and the Taste and Smell Clinic patients as being hyposmic or anosmic with olfactory loss that increased significantly with nasal-sinus disease severity. Comparisons with normative data confirm that olfactory scores observed in all groups were significantly lower than expected because of the aging process alone. The self-reported duration of olfactory loss increased significantly with nasal-sinus disease severity. The Taste and Smell Clinic patients without chronic rhinosinusitis or nasal polyps reported the greatest incidence of olfactory distortions and olfactory loss associated with upper respiratory tract infections. CONCLUSIONS: There appears to be a continuum of duration and severity of olfactory loss in allergic rhinitis that parallels increasing severity of nasal-sinus disease. As a result of the increased frequency of respiratory infection associated with allergic rhinitis, these patients are at risk for damage to the olfactory epithelium.     

Clinical experience with patients with olfactory complaints, and their quality of life

CONCLUSION. A special consulting team for patients with olfactory disorders would be able to verify, describe, and explain the characteristics of the disorders, also in cases where a patient experiences a disorder, but has a normal sense of smell. OBJECTIVES. The general purpose of this paper was to present our experience with patients seeking medical attention for olfactory disorders, and to describe how quantitative and qualitative olfactory disorders are diagnosed, what the etiologies are, and how quality of life is compromised in patients with olfactory disorders. SUBJECTS AND METHODS. This investigation was performed prospectively over a 10-year period by one physician responsible for the consulting team for patients with olfactory disorders. Based on a standardized clinical examination, a structured interview, and assessment of olfactory function, its aim was to diagnose quantitative and qualitative disorders in 303 consecutive patients. Health-related quality of life was assessed with the Nottingham Health Profile (NHP) in about one-third of patients. RESULTS. In the majority of patients, a reduced sense of smell was found after testing. Often, but not always, this was combined with qualitative disorders. Dominating etiologies were infections, nasal polyposis, head trauma, and aging. Patients complaining of olfactory disorders experience a significantly reduced quality of life regarding the impact of their health problem on paid employment, household work, and social and family life.     

Recovery of olfactory function following closed head injury or infections of the upper respiratory tract

OBJECTIVE: To investigate the outcome of olfactory function in patients with olfactory loss following infections of the upper respiratory tract (post-URTI) or head trauma. DESIGN: Retrospective patient-based study. SETTING: Smell and Taste Outpatient Clinic at a university hospital. PATIENTS: A total of 361 patients (228 women, 133 men) were included. MAIN OUTCOME MEASURES: Olfactory function was assessed using the "Sniffin' Sticks" test battery, which result in a threshold, discrimination, and identification score. The mean interval between first and last visit was 14 months. RESULTS: In comparing the overall threshold, discrimination, and identification scores between the last and first visit, olfactory function improved in 26% of the patients whereas it decreased in 6%. The cause of olfactory impairment had a significant effect on the recovery rate of olfactory function. Within the post-URTI group (n = 262), 32% of the patients improved, but in the posttraumatic group (n = 99) only 10% improved. In patients with post-URTI olfactory loss, a negative correlation was found between age and recovery of olfactory function. In general, the factor "sex" had no significant effect on recovery of smell function. CONCLUSIONS: To our knowledge, the series of patients presented herein is the largest in the literature to date in which standardized testing methods were used to assess the progression of impaired olfaction. It showed that the rate of improvement of olfactory function was significantly higher in patients with post-URTI dysosmia compared with patients with posttraumatic dysosmia. During an observation period of approximately 1 year, more than 30% of patients with post-URTI olfactory loss experienced improvement, whereas only 10% of patients with posttraumatic olfactory loss experienced improvement. Furthermore, age plays a significant role in the recovery of olfactory function.     

Head trauma and olfactory function

Olfactory impairment is a well-established sequela of head injury. The presence and degree of olfactory dysfunction is dependent on severity of head trauma, duration of posttraumatic amnesia, injuries obtained, and as more recently established, age. Deficits in smell can be conductive or neurosensory, contingent on location of injury. The former may be amenable to medical or surgical treatment, whereas the majority of patients with neurosensory deficits will not recover. Many patients will not seek treatment for such deficits until days, weeks, or even months after the traumatic event due to focus on more pressing injuries. Evaluation should start with a comprehensive history and physical exam. Determination of the site of injury can be aided by CT and MRI scanning. Verification of the presence of olfactory deficit, and assessment of its severity requires objective olfactory testing, which can be accomplished with a number of methods. The prognosis of posttraumatic olfactory dysfunction is unfortunate, with approximately only one third improving. Emphasis must be placed on identification of reversible causes, such as nasal bone fractures, septal deviation, or mucosal edema/hematoma. Olfactory loss is often discounted as an annoyance, rather than a major health concern by both patients and many healthcare providers. Patients with olfactory impairment have diminished quality of life, decreased satisfaction with life, and increased risk for personal injury. Paramount to the management of these patients is counseling with regard to adoption of compensatory strategies to avoid safety risks and maximize quality of life. Practicing otolaryngologists should have a thorough understanding of the mechanisms of traumatic olfactory dysfunction in order to effectively diagnose, manage, and counsel affected patients.     

Olfactory function following nasal surgery: a 1-year follow-up

Olfactory dysfunction is a frequent symptom of nasal and sinunasal disease. Many of these patients undergo nasal sinus or nasal septum surgery. In this study, we evaluated the benefit of nasal surgery on olfactory function over a period of 12 months. Patients included in this study underwent either nasal sinus or nasal septum surgery. All patients were tested for olfactory function using the “Sniffin’ sticks” 16 item odor identification test. In addition, patients were asked to rate their nasal patency as well as their olfactory function at each visit. 157 patients were tested 3.5 months after surgery and 52 patients were tested again 12 months after surgery. Olfactory function improved significantly 3.5 months after surgery in patients, who received nasal sinus surgery; no significant increase was found in patients treated with nasal septum surgery. At the 12-month follow-up, the increase in olfactory function over all patients just missed statistical significance. Individually, however, 19% of the patients exhibited improvement after 3.5 months and 17% after 12 months. These numbers increased in patients with rhinosinusitis with nasal polyps, who exhibited improvement of 30% after 3.5 months, and 32% after 12 months. Nasal sinus surgery produced an increase in measured olfactory function, but not nasal septum surgery. This increase appeared to be stable over the examined period of 12 months.     

Screening of olfactory function using the Biolfa olfactory test: investigations in patients with dysosmia

OBJECTIVE: To present a statistical evaluation of a new olfactory test, Biolfa. MATERIAL AND METHODS: The olfactory test was carried out in individuals with normal olfactory function (n=67; 31 males; mean age 27.4 years) and in patients with mild, moderate or severe hyposmia (n=155; 61 males; mean age 54.6 years). The main diagnoses of the hyposmic patients were upper respiratory tract infection (32%), nasal polyposis (24%), head trauma (8%), idiopathic (8%), old age (5%) and chronic rhinitis (5%). In the first part of the test, olfactory thresholds were measured for three different substances (eugenol, aldehyde C14 and phenyl ethyl alcohol). The second part comprised an odor identification test for determining olfactory function for a large panel of common odors of Southern European countries. RESULTS: Mean olfactory thresholds were determined for subjects with normal olfaction and hyposmic patients; there was a statistically significant relationship between olfactory thresholds and degree of olfaction (mild to moderate hyposmia versus severe hyposmia). For the odor identification test, a global score was determined to allow the differentiation of normosmic subjects from patients with mild, moderate or severe hyposmia. The principles of decision theory (i.e. analysis of the receiver operating characteristic curve) were applied to the problem of evaluating the ability of Biolfa to distinguish subnormal subjects from hyposmic subjects. CONCLUSION: This study provides a basis for the routine clinical use of Biolfa.     

No increased risk of sudden sensorineural hearing loss following recent herpes zoster: a nationwide population-based study

Conclusion. A special consulting team for patients with olfactory disorders would be able to verify, describe, and explain the characteristics of the disorders, also in cases where a patient experiences a disorder, but has a normal sense of smell. Objectives. The general purpose of this paper was to present our experience with patients seeking medical attention for olfactory disorders, and to describe how quantitative and qualitative olfactory disorders are diagnosed, what the etiologies are, and how quality of life is compromised in patients with olfactory disorders. Subjects and methods. This investigation was performed prospectively over a 10-year period by one physician responsible for the consulting team for patients with olfactory disorders. Based on a standardized clinical examination, a structured interview, and assessment of olfactory function, its aim was to diagnose quantitative and qualitative disorders in 303 consecutive patients. Health-related quality of life was assessed with the Nottingham Health Profile (NHP) in about one-third of patients. Results. In the majority of patients, a reduced sense of smell was found after testing. Often, but not always, this was combined with qualitative disorders. Dominating etiologies were infections, nasal polyposis, head trauma, and aging. Patients complaining of olfactory disorders experience a significantly reduced quality of life regarding the impact of their health problem on paid employment, household work, and social and family life.     

The quinoxaline derivative caroverine in the treatment of sensorineural smell disorders: a proof-of-concept study

The treatment of non-conductive olfactory disorders is to a large extent an unsolved problem. This proof-of-concept study focused on possible effects of the N-methyl-D-aspartate (NMDA) antagonist caroverine. Potential mechanisms for the hypothesized effect included reduced feedback inhibition in the olfactory bulb as a consequence of NMDA antagonistic actions and antagonism of an excitotoxic action of glutamate. A total of 77 consecutive patients with non-conductive olfactory disorders were included in the study. Fifty-one patients received caroverine for 4 weeks (120 mg/day); 26 controls matched for age, gender and duration of olfactory loss were treated with zinc sulfate for the same length of time (400 mg/day). Olfactory sensitivity was evaluated before and after treatment. Testing included assessment of n-butanol odor threshold and odor identification. When compared to baseline, treatment with caroverine improved both odor thresholds (p = 0.005) and odor identification (p = 0.042) in anosmic patients. In hyposmic patients it significantly improved odor identification ability (p = 0.041). In contrast, zinc sulfate had no significant effect on olfactory function. These results indicate that caroverine appears to be effective for the treatment of non-conductive smell disorders.     

Subjective changes in nasal patency after chewing a menthol-containing gum in patients with olfactory loss

Conclusion: The subjective increase in nasal patency after oral menthol application depends on olfactory function. In patients with relatively low olfactory sensitivity, this effect is small or absent. It was hypothesized that this may also modulate the sensation of nasal blockage. Objective: Menthol stimulates the nasal trigeminal nerve, resulting in a subjectively increased nasal airflow and patency without objectively measurable changes. Patients suffering from olfactory impairment also express a reduced nasal trigeminal sensitivity. The aim of this investigation was to examine the effect of menthol on nasal patency ratings in a group of patients suffering from olfactory dysfunction. Methods: A group of 92 patients with olfactory impairment was included in this study. Olfactory function was assessed using the ‘Sniffin’ Sticks.’ Patients were instructed to chew a menthol-containing gum for 30 s, after which they rated the change in nasal patency on a categorical scale. Results: Patients who rated the change in nasal patency as pronounced scored higher on the Sniffin’ Sticks olfactory test compared to patients who experienced little or no change in nasal patency after chewing the menthol-containing gum. On average, similar changes could be observed for all etiologies of olfactory impairment included in this study.     

Relationship between cognitive impairment and olfactory function among older adults with olfactory impairment

ObjectiveUnderstanding the relationships among aging, cognitive function, and olfaction may be useful for diagnosing olfactory decline in older adults. Olfactory function declines in the early stage of neurodegenerative diseases, including Alzheimer's and Parkinson's diseases. Aging and cognitive impairment are associated with olfactory decline. Moreover, the assessment of hyposmia and anosmia is paramount to the diagnosis of neurodegenerative diseases. We aimed to assess the relationships among aging, cognitive function, and olfaction in patients with olfactory impairment.MethodsThis observational study included 141 patients with olfactory deterioration who presented with dementia, mild cognitive impairment (MCI), age-related hyposmia, or postviral olfactory dysfunction (PVOD). The patients underwent T&T olfactometry, a self-administered odor questionnaire (SAOQ), a visual analog scale (VAS), and a Mini-Mental State Examination.ResultsT&T odor recognition thresholds decreased with aging (p < 0.01) and cognitive impairment (p < 0.08). The average T&T recognition thresholds were 5.1,4.6,4.2, and 3.7 in dementia, MCI, age-related hyposmia, and PVOD, respectively. Moreover, the average differences between the detection and recognition thresholds were 3.7, 2.8, 2.3, and 2.0 in dementia, MCI, age-related hyposmia, and PVOD, respectively. Hyposmia with dementia presented the highest recognition thresholds (p < 0.05) and the largest differences between the T&T detection and recognition thresholds, compared with age-related hyposmia and PVOD (p < 0.05). Hyposmia with dementia had the highest SAOQ and VAS scores compared with the other groups (p < 0.05).ConclusionThe possibility of dementia should be investigated in patients with hyposmia, including those with high T&T recognition thresholds, a large difference between the T&T detection and recognition thresholds, and high SAOQ and VAS scores.     

Olfactory dysfunction

Otolaryngologists, neurologists and other medical practitioners are often not well equipped for assessing olfactory (dys)function. They either use no or inadequate olfactory tests. This problem of inadequate olfactory testing was systematically attacked by American psychologists in the early 80's and led to the construction of odour identification tests which are easy to administer. Combining the advantages of two of these American tests we developed a Dutch odour identification test (GITU), consisting of two subsets of 18 natural odourants and applicable in two ways: one for use in the ENT clinic, the other for industrial purposes. The first results of this test indicate that the incidence of serious olfactory disorder among adults in the Netherlands may be conservatively estimated at about 1%. The GITU readily discriminates between patients and controls and is sensitive to variables known to affect olfaction (gender, age). The recognition of olfactory dysfunction as a major problem has led in the U.S.A. to the establishment of clinical research centers for the study of human chemoreception. Evaluation results of four of those clinics together with data of three more case series--with a total number of patients of 4000--show that two thirds of all patients fall into three etiological categories: 1. Nasal disease and/or paranasal sinus disease. 2. Viral infection of the upper respiratory pathway. 3. Head trauma. For each of the three categories the literature is reviewed in order to arrive at a clearer picture of the olfactory patient with respect to age, gender, degree of olfactory deficit, spontaneous recovery, effectiveness of therapy and localization of the defect along the olfactory pathway. Finally an appeal is made to clinicians with interest in the subject to exchange more information with research scientists in olfaction. Such exchange is considered essential to making progress in this field.     

Auditory electrophysiology and retrolabyrinthine non-tumorous diseases]

The authors present 55 cases of non-tumoral retrocochlear impairment, studied over the period between 1984 and 1988 in the ENT University Clinic of Bordeaux. Deafness was the most frequent symptom leading patients to come for consultation (89%). The stapedial reflex was pathological in 70% of the cases. No conclusion could be drawn from electro-occulography. Only the early auditory evoked responses made it possible to reach the diagnosis of retrocochlear impairment in 35% of the cases. Electrocochleography was required in 65% of the cases to establish the topographic diagnosis. The neuro-radiological examination proved to be negative in 48 cases, and positive in 7 cases (6 atrophic symptoms, 1 left vertebral dolichoartery). Among the other etiologies, we noted 14 cases of auditory trauma, 12 vascular pathologies, 9 neurological pathologies, 7 cases of Ménière's disease, and 7 sudden onsets of deafness. The incidence of vasculo-nervous conflict reported by other authors appears very low in this series (with only 1 case).     

Screening of Olfactory function Using the Biolfa® Olfactory Test: Investigations in Patients with Dysosmia

Objective —To present a statistical evaluation of a new olfactory test, Biolfa^®.

Material and Methods —The olfactory test was carried out in individuals with normal olfactory function (n=67; 31 males; mean age 27.4 years) and in patients with mild, moderate or severe hyposmia (n=155; 61 males; mean age 54.6 years). The main diagnoses of the hyposmic patients were upper respiratory tract infection (32%), nasal polyposis (24%), head trauma (8%), idiopathic (8%), old age (5%) and chronic rhinitis (5%). In the first part of the test, olfactory thresholds were measured for three different substances (eugenol, aldehyde C14 and phenyl ethyl alcohol). The second part comprised an odor identification test for determining olfactory function for a large panel of common odors of Southern European countries.

Results —Mean olfactory thresholds were determined for subjects with normal olfaction and hyposmic patients; there was a statistically significant relationship between olfactory thresholds and degree of olfaction (mild to moderate hyposmia versus severe hyposmia). For the odor identification test, a global score was determined to allow the differentiation of normosmic subjects from patients with mild, moderate or severe hyposmia. The principles of decision theory (i.e. analysis of the receiver operating characteristic curve) were applied to the problem of evaluating the ability of Biolfa to distinguish subnormal subjects from hyposmic subjects.

Conclusion —This study provides a basis for the routine clinical use of Biolfa.     

Suitability of the odor stick identification test for the Japanese in patients suffering from olfactory disturbance

We studied the suitability of the Odor Stick Identification Test for the Japanese (OSIT-J) in patients suffering from olfactory disturbance. In 120 patients with olfactory disturbance (age range 12-85 years) there were statistically significant correlations between the odor identification rate on the OSIT-J, the results of the Japanese standardized olfactory test (T&T olfactometry) and subjective symptom scores. In every patient treated for olfactory disturbance, the OSIT-J reflected the grade of recovery from the olfactory disturbance as determined by means of T&T olfactometry. The odor identification rate on the OSIT-J also correlated significantly with the results of the i.v. Alinamin test. Regarding the rate of correct recognition of odors on the OSIT-J, menthol and curry odors were recognized with a high rate and orange and wood odors with a low rate. Although the OSIT-J includes 13 kinds of odorants, the number of odorants used can be reduced to a minimum of 5 as the results obtained with this reduced form of the OSIT-J also correlated with the results of T&T olfactometry and the subjective symptom scores as well as with the results obtained with the 13-odorant OSIT-J. We conclude that the OSIT-J is suitable not only as a screening test for olfactory disturbance but also for practical use in clinical otorhinolaryngology.     

The impact and prospect of traumatic brain injury on olfactory function: a cross-sectional and prospective study

Traumatic brain injury (TBI) can cause olfactory loss. The aim of this cross-sectional and prospective study was to determine the prevalence of olfactory loss among 110 patients with TBI within 3 months after the trauma. In 81 patients (“cross-sectional”-group), olfactory function could be measured using the validated “Sniffin’ Sticks” test for odor threshold and odor identification. In addition, the prospective change of olfactory function was studied in 36 patients (“follow-up”-group) by means of a validated odor threshold, discrimination and identification test. Olfactory function was significantly better in patients with TBI I° compared to individuals with TBI II° and III°. Clinically significant improvement of olfactory function was found in 36 % of the patients, most frequently during the first 6 months after the injury, in a median follow-up interval of 21 months. TBI I° has in general no major effect on olfaction. In contrast, patients with TBI II° and III° exhibit smell loss in 57 %. Chances for olfactory recovery were highest within the first 6 months after the trauma.