Peripheric and central olfactory measurements in patients with bipolar disorder.

BACKGROUND: Bipolar disorder (BD) is a mental health disorder. PURPOSE: To investigate the peripheric and central olfactory measurements in patients with BD using magnetic resonance imaging (MRI). MATERIAL AND METHODS: This study was conducted retrospectively. Group 1 consisted of 27 euthymic patients with BD (14 men, 13 women) and Group 2 consisted of 27 healthy controls (14 men, 13 women). Olfactory bulb (OB) volume and olfactory sulcus (OS) depth (peripheric), and corpus amygdala and insular gyrus area (central) measurements were performed using cranial MRI. RESULTS: OB volume and OS depth value of the bipolar group were lower than the control group, but there were no significant differences between the groups (P > 0.05). The corpus amygdala and left insular gyrus area of the bipolar group were significantly lower than those in the control group (P < 0.05). There were positive correlations between OB volumes and OS depths, the insular gyrus areas, and the corpus amygdala areas (P < 0.05). As the number of depressive episodes and duration of illness increased in bipolar patients, the depth of the sulcus decreased (P < 0.05). CONCLUSION: In the present study a correlation was detected between OB volumes and the structures, known as emotional processing (e.g. insular gyrus area, corpus amygdala), and clinical features. Accordingly, new treatment techniques, such as olfactory training, may be considered an option in the treatment of such patients with BD.

Assessment of factors influencing the olfactory bulb volume in patients with post-viral olfactory dysfunction.

PURPOSE: To investigate the factors influencing the volume of the olfactory bulb (OB) in patients with post-viral olfactory dysfunction (PVOD). METHODS: We collected 92 olfactory bulb volumes from patients with PVOD who underwent a sinus computed tomographic and magnetic resonance imaging (MRI) scan of the head and collected clinical information including gender, age, disease course, minimal cross-sectional area, nasal airway resistance, and olfactory function. OB volume was measured in MRI and the scans were evaluated according to the Lund-Mackay (LM) scoring system. RESULTS: Male patients with PVOD had a larger OB volume (ß = 0.284, P < 0.05). OB volume was smaller in patients with a longer course of olfactory dysfunction (ß = - 0.254, P < 0.05). According to the LM scoring system, patients with a higher anterior ethmoidal sinus score had smaller OB volume (ß = - 0.476, P < 0.05). CONCLUSIONS: The study revealed that gender, disease course, and the score of anterior ethmoidal sinusitis can affect the OB volume in patients with PVOD.

Peripheral and central smell regions in COVID-19 positive patients: an MRI evaluation.

BACKGROUND: Coronaviruses may lead to invasion of the central nervous system. PURPOSE: To investigate the effects of COVID-19 infection on smell using cranial magnetic resonance imaging (MRI). MATERIAL AND METHODS: Cranial MRI scans of 23 patients with COVID-19 (patient group [PG]) and 23 healthy controls (HCs) were evaluated. Peripheric (olfactory bulb [OB] volume and olfactory sulcus [OS] depth) and central (insular gyrus and corpus amygdala areas) smell regions were measured. RESULTS: Smell loss was present in nine patients (39.1%) in the PG. The means of the disease duration and antiviral treatment were 3.00 ± 2.35 and 5.65 ± 1.72 days, respectively. OB volumes of the PG were significantly lower than those of the HCs bilaterally. However, no significant differences were observed between the OS depth, insular gyrus, and corpus amygdala areas of both groups. The left corpus amygdala areas were both increased with the increased disease (P = 0.035, r = 0.442) and treatment durations (P = 0.037, r = 0.438). In the PG, longer treatment duration, increase in C-reactive protein (CRP), lymphocyte count decrease, and positive thoracic computed tomography (CT) involvement were related to OS depth decrease. Right corpus amygdala areas increased in patients with COVID-19 with increased D-dimer values, and thoracic CT involvement was detected. CONCLUSION: COVID-19 disease affects the peripheric smell region of OBs and does not affect the central smell regions of the insular gyrus and corpus amygdala areas. The importance of our study is to detect MRI findings in patients with COVID-19 leading to odor disorders. These findings may help in diagnosing the disease at an early stage.

Evaluation of peripheral olfactory pathways in chronic autoimmune thyroiditis.

PURPOSE: In this study, we aimed to radiologically evaluate the olfactory bulb (OB) volume and olfactory sulcus (OS) depth of adult patients diagnosed with chronic autoimmune thyroiditis. METHODS: Sixty-eight patients over 18 years of age with Hashimoto's thyroiditis and 66 healthy controls with normal thyroid function tests were included in the study. OB volume and OS depth measurements were performed using cranial magnetic resonance imaging (MRI) obtained from coronal T2-weighted images. The relationship between thyroid function tests, autoantibodies, and measurements of the OB and OS were evaluated. RESULTS: The right and left OB volumes were significantly lower in the patients with Hashimoto's thyroiditis than in the control group (p < 0.05). No significant difference was found between the patient and control groups in terms of OS depth (p > 0.05). There were significantly negative correlations among TSH, thyroid antibodies, and the bilateral OB volume measurements. In the Bonferroni post hoc analysis, when people with euthyroid Hashimoto's thyroiditis and the control group were compared, there was no statistically significant difference between bilateral OB volumes and thyroid function tests. CONCLUSION: Diminished bilateral OB volumes were found in our patients with chronic autoimmune thyroiditis. Interestingly, the OB volumes were not affected in patients with euthyroid Hashimoto's thyroiditis. When a decrease in OB volume is detected on MRI, it should be kept in mind that odor dysfunction in hypothyroid patients with Hashimoto's thyroiditis may occur and patients should be clinically evaluated.

Olfactory loss is associated with reduced hippocampal activation in response to emotional pictures.

Emotional processing evolved within brain structures that were originally dedicated to olfactory function. Reduced olfactory function, absence of the olfactory bulb and the experimental removal of the olfactory bulb are associated with depressive behavior. Against this background, we hypothesized that olfactory dysfunction modifies the neural processing of non-olfactory emotion information. Using a functional magnetic resonance imaging design, we therefore tested whether people with and without impaired olfactory function differ in emotional perception and processing. Neural activity of 17 patients with acquired olfactory loss and 23 age- and sex-matched control participants were monitored in the MRI scanner, while they were presented with emotional and neutral pictures. Participants rated the valence and arousal for each picture after scanning. Patients showed reduced right hippocampal brain responses to emotional but not neutral pictures independent of their depressive symptoms. In addition, emotion-dependent activation in the hippocampus and insula was positively associated with the olfactory bulb (OB) volumes in healthy participants. Taken together, these findings suggest a disrupted neural processing of emotional pictures among patients with olfactory loss. This indicates a significant role of the neural olfactory trajectories for general emotion processing. Central emotion processing is reduced in olfactory disorders and relates to the OB volume in normosmic individuals.

Olfactory bulbus volume and olfactory sulcus depth in migraine patients: an MRI evaluation.

OBJECTIVES: To compare the measurements of olfactory bulb volume and olfactory sulcus depth in patients with migraine and a control group. METHODS: The study included the cranial MRI (1.5 T) images of 200 adults diagnosed with migraine and a control group of 100 subjects without migraine. The control group mainly consisted of the patients with non-migraneous headache. The measurements were obtained from coronal T2-weighted images for standard olfactory bulb (OB) volume and olfactory sulcus (OS) depth. RESULTS: The OB volume and OS depth values were lower in the migraine group than in the control group. In the migraine group, left OB volume of the males was significantly lower than those of the females. In both the migraine and control groups separately, the left-side OB volume values and the right side OS depth values were significantly greater than those of the contralateral side. There were positive correlations between right and left OB volume, and right and left OS depth values. No change was seen in OB volume and OS depth values according to gender. In older patients, a decrease was determined in the right and left OB volume, and the left-side OS depth values. There was a negative correlation between osmophobia and OB volume values. In migraine patients with osmophobia, the OB volume values were significantly decreased. CONCLUSION: OB volume values were lower in migraine patients. When osmophobia was present, the OB volume was lower than that of the non-osmophobia migraine patients. Olfactory function monitoring with olfactory tests and olfactory volume monitoring on MRI can be recommended for all migraine patients to diagnose olfactory dysfunction earlier, especially those with osmophobia. Because their OB volume values were detected as lower than those of the migraine patients without osmophobia, it may be thought that blood flow changes and osmophobia may affect the olfactory bulb volume shrinkage in migraine patients.

Olfactory bulbus volume and olfactory sulcus depth in psychotic patients and patients with anxiety disorder/depression.

OBJECTIVES: In the present study, we investigated olfactory bulb (OB) volume and olfactory sulcus (OS) depth of the psychotic patients (predominantly schizophrenia) and patients with anxiety disorder/depression. METHODS: This study was conducted retrospectively. Group 1 consisted of 30 psychotic patients (predominantly schizophrenia) (19 males and 11 females). Group 2 consisted of 37 patients with anxiety disorder/depression (10 males, 27 females). Group 3 consisted of 30 non-psychotic and non-anxiety disorder/depression subjects (9 males and 21 females). OB volume and OS depth measurements were performed on Cranial MRI. RESULTS: OB volume (right and left) of the psychotic; and anxiety disorder/depression groups were significantly lower than those of the control group (padjusted < 0.0175). OS depth (Left) value of anxiety disorder/depression group was significantly lower than those of the control group (padjusted < 0.0175). In psychotic and anxiety disorder/depression groups, left OS depth values were significantly lower than those of the right side (p < 0.05). In each of the males and females of the anxiety disorder/depression group, left OS depth values were significantly lower than those of the right side (p < 0.05). In psychotic group, OS depth (left) values get lower in older patients (p < 0.05). CONCLUSION: Decreased OB volume in the psychotic patients and decreased OB volume and OS depth in anxiety disorder/depression patients were detected. Lower OB volume and OS depth are related to the olfactory loss/or olfactory impairment. Physicians should be aware of the olfactory deficits in psychotic patients (mainly schizophrenia) and patients with anxiety disorder/depression. When reduced OB volume is detected on MRI, psychosis, schizophrenia or depression should also be kept in mind and the patients should be evaluated in detail for these diseases.

The association between olfactory bulb volume, cognitive dysfunction, physical disability and depression in multiple sclerosis.

BACKGROUND AND PURPOSE: Olfactory bulb atrophy is associated with cognitive dysfunction in Parkinson's and Alzheimer's disease, and with major depression. It has been suggested that olfactory bulb atrophy or dysfunction is therefore a marker of neurodegeneration. Multiple sclerosis (MS) is now also recognized as having a significant neurodegenerative component. Thus, the aim of this study was to investigate associations between physical and cognitive disability, depression and olfactory bulb volume in MS. METHODS: In total, 146 patients with MS (mean age 49.0 ± 10.9 years, disease duration 21.2 ± 9.3 years, median Expanded Disability Status Scale (EDSS) score 3.0 (range 0-7.5), 103 relapsing-remitting, 35 secondary progressive and eight primary progressive MS) underwent a standardized neurological examination, comprehensive neuropsychological testing and magnetic resonance imaging (MRI); data of 27 healthy people served as age- and gender-matched control subjects. The olfactory bulb was semi-automatically segmented on high-resolution three-dimensional T1-weighted MRI. RESULTS: Mean olfactory bulb volume was lower in MS patients than healthy controls (183.9 ± 40.1 vs. 209.2 ± 59.3 µl; P = 0.018 adjusted to intracranial volume). Olfactory bulb volume was similar across clinical disease subtypes and did not correlate with cognitive performance, EDSS scores or total proton density/T2 white matter lesion volume. However, in progressive MS, the mean olfactory bulb volume correlated with depression scores (Spearman's rho = -0.38, P < 0.05) confirmed using a multivariate linear regression analysis including cognitive fatigue scores. This association was not observed in relapsing-remitting MS. CONCLUSION: Olfactory bulb volume was lower in MS than in healthy controls. Olfactory bulb volume does not seem to mirror cognitive impairment in MS; however, it is associated with higher depression scores in progressive MS.

The olfactory bulb volume in patients with idiopathic Parkinson's disease.

BACKGROUND AND PURPOSE: This study addresses the question of whether the neuropathological findings on the olfactory bulb (OB) in idiopathic Parkinson's disease (IPD) correspond to a detectable change in volume of the OB. Additionally, the relationship between OB volume and residual olfactory function, clinical disease characteristics and age are investigated. METHODS: Fifty-two IPD patients were investigated and compared to 31 healthy age-matched controls. All participants were scanned using a 3 T magnetic resonance imaging MRI scanner including a T2 DRIVE sequence in coronal slices through the OB. The OB volumes were measured via manual segmentation of the OB. Olfactory testing was carried out using the Sniffin' Sticks test battery. RESULTS: The OB volume in the IPD group was 42.1 mm³ (SD ± 11.6) for the right and 41.5 mm³ (SD ± 11.7) for the left OB and showed no difference from the controls. Additionally, there were no significant correlations between OB volume and disease characteristics such as disease duration or Unified Parkinson's Disease Rating Scale motor score. Likewise, patients' residual smell function did not correlate with their OB volume. In contrast, controls indicated a correlation between smell function and OB volume. CONCLUSION: The study shows that high resolution MRI does not show a detectable volume loss of the OB in PD patients. It is concluded that OB measurement using in vivo high resolution MRI at 3 T is not helpful to identify IPD.

Effects of Endoscopic Sinus Surgery on Olfactory Bulb Volume among Patients with Chronic Rhinosinusitis: A Systematic Review and Meta-Analysis.

BACKGROUND: Endoscopic sinus surgery (ESS) could significantly improve olfactory function among patients with chronic rhinosinusitis (CRS). This study aimed to perform a meta-analysis to evaluate the effect of ESS on the olfactory bulb volume (OBV) among patients with CRS. METHODS: A systemic search of PubMed, Medline, Embase, Web of Science, and other databases was conducted to identify studies assessing OBV changes in patients with CRS after ESS utilizing magnetic resonance imaging. RESULTS: A total of four studies with 168 participants were included. Comparing the changes in OBV of patients with CRS before and after surgery within 3-6 months, the ESS significantly improved the overall OBV (P = 0.005, I2 = 66%), with the left OBV increased by 5.57mm3 (P = 0.84, I2 = 0%), and the right OBV increased by 8.63mm3 (P = 0.09, I2 = 53%). A difference in OBV persists between healthy controls and patients with CRS 3-6 months after ESS. The overall OBV of patients with CRS after ESS was significantly smaller than controls (mean difference = -3.84, P = 0.04), with a mean difference of 4.13mm3 on the left side (P = 0.72, I2 = 0%), and a mean difference of 3.22mm3 on the right side (P = 0.0001, I2 = 89%). CONCLUSIONS: ESS significantly increases the OBV among patients with CRS.

Olfactory bulb volume in cochlear implant candidates as compared to age-matched control subjects: A potential marker of cognitive function for auditory information processing.

OBJECTIVE: To evaluate magnetic resonance imaging (MRI)-based olfactory bulb (OB) volumes in cochlear implant (CI) candidates with sensorineural hearing loss as compared to age-matched control subjects with normal hearing. METHODS: A total of 31 pediatric CI candidates (mean ± SD age: 7.0 ± 2.5 years, 51.6% were boys) with sensorineural hearing loss and 35 age-matched control subjects (mean ± SD age: 7.1 ± 2.5 years, 54.3% were boys) with normal hearing were included in this study. Data on demographic characteristics (age, gender) and right and left OB volume (mm3) on MRI using planimetric contouring method were recorded in patients and control groups. RESULTS: Median (min-max) values for right OB volume (80(50-120) vs. 90(50-160) mm3, p = 0.006) and left OB volume (70(50-120) vs. 90(50-170) mm3, p = 0.007) were significantly lower in CI candidates vs. controls, regardless of the gender and age. No significant difference was noted between right and left OB volume in CI candidate and control groups. Hearing loss subgroups of CI candidates including hereditary familial (n = 8), hereditary non-familial (n = 14) and mixed syndromic (9) subgroups were also similar in terms of patient demographics and OB volumes. There was a tendency for having lower left OB volume (60(50-120) vs. 80(60-110) mm3) in girls vs. boys in the CI candidate group, along with a tendency for lower left and right OB volume in candidates vs. controls, particularly at age 11 (median 120 vs. 80 mm3 and 120 vs. 60 mm3, respectively). No significant correlation of age was noted with right and left OB volume overall and in the study groups. CONCLUSION: In conclusion, our findings revealed lower left and right OB volumes in CI candidates compared to control subjects, regardless of age and gender, indicating the presence of baseline olfactory dysfunction in patients with hearing loss planned to undergo CI. Accordingly, MRI-based measurement of OB volume in the pre-surgical workup of CI candidates may serve as a marker of cognitive function enabling auditory information processing that may also correlate with post-operative CI outcomes.

The potential for clinical application of automatic quantification of olfactory bulb volume in MRI scans using convolutional neural networks.

The olfactory bulbs (OBs) play a key role in olfactory processing; their volume is important for diagnosis, prognosis and treatment of patients with olfactory loss. Until now, measurements of OB volumes have been limited to quantification of manually segmented OBs, which is a cumbersome task and makes evaluation of OB volumes in large scale clinical studies infeasible. Hence, the aim of this study was to evaluate the potential of our previously developed automatic OB segmentation method for application in clinical practice and to relate the results to clinical outcome measures. To evaluate utilization potential of the automatic segmentation method, three data sets containing MR scans of patients with olfactory loss were included. Dataset 1 (N = 66) and 3 (N = 181) were collected at the Smell and Taste Center in Ede (NL) on a 3 T scanner; dataset 2 (N = 42) was collected at the Smell and Taste Clinic in Dresden (DE) on a 1.5 T scanner. To define the reference standard, manual annotation of the OBs was performed in Dataset 1 and 2. OBs were segmented with a method that employs two consecutive convolutional neural networks (CNNs) that the first localize the OBs in an MRI scan and subsequently segment them. In Dataset 1 and 2, the method accurately segmented the OBs, resulting in a Dice coefficient above 0.7 and average symmetrical surface distance below 0.3 mm. Volumes determined from manual and automatic segmentations showed a strong correlation (Dataset 1: r = 0.79, p < 0.001; Dataset 2: r = 0.72, p = 0.004). In addition, the method was able to recognize the absence of an OB. In Dataset 3, OB volumes computed from automatic segmentations obtained with our method were related to clinical outcome measures, i.e. duration and etiology of olfactory loss, and olfactory ability. We found that OB volume was significantly related to age of the patient, duration and etiology of olfactory loss, and olfactory ability (F(5, 172) = 11.348, p < 0.001, R2 = 0.248). In conclusion, the results demonstrate that automatic segmentation of the OBs and subsequent computation of their volumes in MRI scans can be performed accurately and can be applied in clinical and research population studies. Automatic evaluation may lead to more insight in the role of OB volume in diagnosis, prognosis and treatment of olfactory loss.

[Prognostic value of olfactory bulb volume in patients with post-viral olfactory dysfunction].

Objective:The purpose of this study was to compare the olfactory function examination results of patients with post-viral olfactory dysfunction（PVOD） in different prognostic groups and analyze prognostic factors, especially the influence of olfactory bulb volume（OBV） on prognosis, so as to provide objective basis for clinical diagnosis and treatment. Methods:After approval by the hospital ethics committee, the patients with PVOD admitted to Beijing Anzhen Hospital's outpatient department from January 2019 to December 2019 were followed up for at least 1 year. These patients completed the Sniffin' Sticks test and MRI examination of the olfactory pathway before treatment. According to the results of the Sniffin' Sticks test after 1 year follow-up（threshold-discrimination-identification（TDI） score of the patients was increased at least 6 points）, the patients were divided into two groups as the improvement group and the non-improvement group. The prognostic factors of PVOD patients were preliminarily determined by comparing the differences of various factors and the results of olfactory function examination between the two groups. Results:In this study, 47 patients with PVOD were included, with the smell improvement rate was 53.2%. Compared with the improvement group, the patients in the non-improvement group had longer duration, poorer initial olfactory function, higher olfactory threshold, and poorer olfactory discrimination and recognition ability（All P<0.01）. There was no statistical difference in terms of gender, age, allergic rhinitis and smoking between the two groups（All P>0.05）.The OBV of the non-improvement group was （59.48±23.92） mm³, which was significantly lower than that in the improvement group（[92.77±14.35]mm³, P<0.001）. Multiple logistic regression analysis showed that prognostic factors included course of disease（OR 0.677, 95%CI 0.461-0.993, P=0.046）, initial T value（OR 263.806, 95%CI 1.028-67 675.884, P=0.049） and OBV（OR 1.160, 95%CI 1.002-1.343, P=0.047）. The area under the receiver operating characteristic curve（ROC curve） of OBV was 0.888（0.797-0.979, P<0.001）. The correct diagnostic index of OBV≥78.50 mm³was used to determine the prognosis of olfactory function, with a specificity of 0.818 and a sensitivity of 0.840. The ROC curve analysis showed that the area under the ROC curve of duration was 0.822（0.703-0.940, P<0.001）. The correct diagnostic index of the duration ≤6 months was used to determine the prognosis of olfactory function, with a specificity of 0.727 and a sensitivity of 0.800. The area of T score was 0.793（0.662-0.924, P=0.001）. T score ≥1.25 was used as the correct diagnostic index to determine the prognosis of olfactory function. The specificity and sensitivity were 0.818 and 0.680, respectively. Conclusion:The prognosis of olfactory function in PVOD patients is related to the course of disease, the degree of olfactory loss and OBV. Those with no improvement in olfactory function have a longer disease course, aggravated olfactory damage and reduced OBV than those with improved olfactory function. The factors of Duration ≤6 months, T value ≥1.25 and OBV≥78.50 mm³suggested better prognosis, and the results of objective olfactory examination have greater value in evaluating the prognosis of olfactory function.

Peripheral and central smell regions in children with epilepsy: An MRI evaluation.

OBJECTIVES: We investigated the peripheral and central olfactory regions in children with epilepsy using cranial MRI. METHODS: In this retrospective study, cranial MRI images were obtained from 23 children with epilepsy and 23 healthy controls. Olfactory bulb (OB) volume and olfactory sulcus (OS) depth in the peripheral olfactory region and insular cortex and corpus amygdala areas in the central olfactory region were measured. RESULTS: There was no significant difference in the OB volume and OS depth in the peripheral olfactory regions in the two groups (p > 0.05). In the central olfactory region, the insular cortex and corpus amygdala areas in the epilepsy group were significantly smaller than those in the control group (p < 0.05). In both groups, the OS depth on the right side was significantly higher than that on the left side (p < 0.05). In the epilepsy group, there were positive correlations between each of the OB volumes, OS depths, insular cortex areas, and corpus amygdala areas bilaterally (p < 0.05). In both groups, there were positive correlations between the OB volume and OS depth, OS depth and insular cortex area and insular cortex area and corpus amygdala areas (p < 0.05). CONCLUSION: A change in the central olfactory region in epileptic patients may be related to central tissue damage due to epilepsy. This finding has important implications for epilepsy patients, with early diagnosis and treatment potentially preventing a reduction in the volumes/depths of components of the central olfactory region in the pediatric population.

Smell Regions in Patients with Vitamin D Deficiency: An MRI Evaluation.

Objective We investigated the effects of vitamin D deficiency in the peripheral and central smell regions by magnetic resonance imaging (MRI). Methods This retrospective study included 29 patients (12 males, 17 females) with 25-dihydroxy vitamin D3 [25(OH) 2 D 3 ] deficiency (group 1) and 34 subjects without 25(OH) 2 D 3 deficiency (14 males, 20 females) (group 2). Using cranial MRIs, the peripheral (olfactory bulb [OB] volume and olfactory sulcus [OS] depth) and central (insular gyrus and corpus amygdala) smell regions were evaluated. Results The OB volume and OS depth values of the 25(OH) 2 D3 deficiency group were significantly lower than those of the control group ( p < 0.05). For the central smell regions, the insular gyrus and corpus amygdala areas of the 25(OH) 2 D3 deficiency group were nonsignificantly lower than those in the control group ( p > 0.05). There were positive correlations between OB volumes, OS depths, and insular gyrus and corpus amygdala areas bilaterally in the 25(OH) 2 D3 deficiency group separately and in all subjects (groups 1 and 2) ( p < 0.05). In the 25(OH) 2 D3 deficiency group, as the 25(OH) 2 D3 values became lower, the insular gyrus area values decreased bilaterally ( p < 0.05). In females, the corpus amygdala area values were lower than in males ( p < 0.05). Conclusion Since vitamin D3 deficiency affected the peripheral and central smell regions negatively, we recommend evaluating patients' vitamin D levels as a health policy to prevent vitamin D3 deficiency-related cranial smell region problems. Moreover, sunlight exposure is very important to increase vitamin D levels, and the public should be informed about this topic.

Quantitative analysis of healthy olfactory sulcus depth, olfactory tract length and olfactory bulb volume in the paediatric population: a magnetic resonance study.

BACKGROUND: The aim of this study was to determine the normal reference values for olfactory sulcus depth, olfactory tract length and olfactory bulb volume in the paediatric population with routine magnetic resonance imaging (MRI) and determine the relationship, if any, between these values and patient sex and age. MATERIALS AND METHODS: Ninety patients with a median age of 8 years (age range: 3-17 years), consisting of 45 males and 45 females with normal brain MRI scans were evaluated. The patients were divided into three subgroups based on age range, with n = 30 per subgroup; group 1: young children (3-6 years), group 2: children (7-11 years) and group 3: adolescents (12-17 years). In the cranial MRI examination of all groups, the right, left and total olfactory bulb volume values were measured in mm3, the right and left olfactory tract length values and the right and left olfactory sulcus depth values were calculated manually in mm. Demographic data including sex and age were recorded. RESULTS: There was no significant difference between the age groups in terms of sex. Right-left olfactory sulcus depth; right-left olfactory tract length and right-left total olfactory bulb volume values increased significantly when they are compared in terms of age groups (p < 0.0001, = 0.028; < 0.0001, < 0.0001; < 0.0001, < 0.0001; < 0.0001, respectively). There was no significant difference between right and left olfactory tract length and olfactory bulb volumes in all groups (p = 0.792 and p = 0.478), but the right olfactory sulcus depth was significantly larger than the left (p = 0.003). CONCLUSIONS: Especially as the age progresses, olfactory tract length and olfactory bulb volume dimensions of olfactory nerve and olfactory sulcus depth should be checked during diagnosis of respective illnesses in paediatric population.

Radiological evidence to changes in the olfactory bulb volume depending on body mass index in the childhood.

OBJECTIVE: Energy balance is preserved through the exchange between body weight and adipose tissue across the multi-faceted complex network that is composed of the sensorial, metabolic, and neuro-endocrine circuits. The olfactory control of energy homeostasis is maintained through the interplay between the olfactory bulb (OB) and adipose tissue. While extremely studied, most researches still report controversial results and sensorial regulation of obesity is not fully understood. This study aims to investigate the interplay between olfactory bulb volume (OBV) as a radiological clue of sensorial control and obesity in children. SUBJECTS AND METHOD: Children (n = 195) were classified into four groups based on body mass index (BMI) percentiles: normal weight (n = 89), overweight (n = 31), obese (n = 32) and morbidly obese (n = 43). OBV were calculated using MRI. RESULTS: Mean OBV was higher in children with obesity than in those of normal weights. The means of OBV are found higher in the overweight and obese children (43.76 ± 9.50-49.29 ± 8.61 mm3) than in those of morbidly obese (38.23 ± 11.52 mm3) (p < 0.001). In overweight and obese children, a positive correlation were found between the BMI and OBV (roverweigh = 0.275-robese = 0.377), while in the morbidly obese group, there was a negative correlation (rseverelyobese = -0.445). CONCLUSION: This study reveals that OBV is higher in obese children. Also, it shows that there is a positive correlation between OBV and BMI in overweight and obese children and a negative correlation in the morbidly obese group. These radiological bimodal changes in OBV indicate that olfactory control acts to provide energy balance, mediated by positive in the overweight and obese children, negative feedback in the morbidly obese group.

Olfactory bulb surroundings can help to distinguish Parkinson's disease from non-parkinsonian olfactory dysfunction.

BACKGROUND: The olfactory bulb is one of the first regions of insult in Parkinson's disease (PD), consistent with the early onset of olfactory dysfunction. Investigations of the olfactory bulb may, therefore, help early pre-motor diagnosis. We aimed to investigate olfactory bulb and its surrounding regions in PD-related olfactory dysfunction when specifically compared to other forms of non-parkinsonian olfactory dysfunction (NPOD) and healthy controls. METHODS: We carried out MRI-based olfactory bulb volume measurements from T2-weighted imaging in scans from 15 patients diagnosed with PD, 15 patients with either post-viral or sinonasal NPOD and 15 control participants. Further, we applied a deep learning model (convolutional neural network; CNN) to scans of the olfactory bulb and its surrounding area to classify PD-related scans from NPOD-related scans. RESULTS: Compared to controls, both PD and NPOD patients had smaller olfactory bulbs, when measured manually (both p < .001) whereas no difference was found between PD and NPOD patients. In contrast, when a CNN was used to differentiate between PD patients and NPOD patients, an accuracy of 88.3% was achieved. The cortical area above the olfactory bulb which stretches around and into the olfactory sulcus appears to be a region of interest in the differentiation between PD and NPOD patients. CONCLUSION: Measures from and around the olfactory bulb in combination with the use of a deep learning model may help differentiate PD patients from patients with NPOD, which may be used to develop early diagnostic tools based on olfactory dysfunction.

The relationship between the olfactory bulb and precocious puberty: from the nose to the pituitary.

Background/objective The olfactory bulb (OB) and pubertal development have a close relationship as they share a common ontogenetic origin. The aim of this study was to analyze the potential relationship between precocious puberty (PP) in girls as a sign of early pubertal timing and their OB volume as an indicator of its functional activity. Design In the study group (n = 125), OB volume, pituitary height (PH), body mass index (BMI) and body surface (S) variables were retrospectively investigated in 49 girls included in the PP group and 76 healthy girls constituting the control group. Volumetric and length measurements were performed on a magnetic resonance imaging (MRI) scan by using manual segmentation of slices. Results The mean OB volume (73.41 ± 17.21 mm3) and PH (4.96 ± 1.01 mm) were significantly higher in the PP group (p = 0.001 and p = 0.001, respectively). The mean volume difference between the right and left bulbs (1.52 ± 1.87) was higher in the PP group (p = 0.03). The body surface (1.05 ± 0.16 m2) was larger in the PP group (p = 0.09). There was a high correlation between the OB volume and PH (r125 = 0.716). There was a moderate correlation between the body surface and OB volume (r125 = 654), and a weak correlation between the former (S) and the PH (r125 = 452). Conclusions This study showed that there is a strong correlation between increased OB volume and PH in cases with PP. It indicates that increased OB volume may be a strong clue that olfactory functions play a role in pubertal timing in humans, although it does not show definitive proof of a causal relationship.

Evaluation of Olfactory Bulb Volumes in Patients With Rheumatoid Arthritis: A Retrospective Study.

Objectives: This study aims to evaluate olfactory bulb (OB) volume in patients with rheumatoid arthritis (RA) using magnetic resonance imaging. Patients and methods: In this retrospective and case-control study, OB volumes of 37 RA patients (6 males, 31 females; mean age 48.6±10.8 years; range, 18 to 65 years) were compared with those of 36 healthy control subjects (5 males, 31 females; mean age 46.5±6.9 years; range, 22 to 62 years). OB images were gained with a protocol of 256×256 matrix and a 24-cm field of view, repetition time=5000 milliseconds (TR 5000 msec), echo time=130 milliseconds (TE 130 msec), number of excitations=2 (NEX 2) and a 5 mm slice thickness. OB volume was computed with the aid of the above images using three dimensional views. The surface of each slice area was calculated in mm2 and all surfaces were added and multiplied by front-back length to obtain a volume in mm3. Results: Left (70.5±14.4 vs. 91.1±12.2 mm3), right (73.9±15.1 vs. 91.2±12.4 mm3), and total (144.5±27.4 vs. 182.8±21.5 mm3) OB volumes were significantly lower in the RA group than in the control group (all p<0.05). Conclusion: Patients with RA may be under risk of decreased OB volumes and related impaired odor functions which might affect the quality of life and activities of daily living adversely.