Olfactory Sulcus Depth Research Articles

Olfactory bulb volume and olfactory sulcus depth in patients with Behçet's disease.

To investigate olfactory bulb volume and olfactory sulcus depth in patients with Behçet's disease, using magnetic resonance imaging. Cranial magnetic resonance imaging scans of 27 adults with Behçet's disease (10 males and 17 females) and 27 healthy controls were examined. Olfactory bulb volume and olfactory sulcus depth were measured on coronal, T2-weighted, spectral pre-saturation with inversion recovery sequences. Bilateral olfactory bulb volume and right-sided olfactory sulcus depth were significantly lower in the Behçet's disease group than in the control group (p < 0.05). Left-sided olfactory sulcus depth increased with Behçet's disease duration. In both groups, olfactory bulb volume was significantly higher in the left than the right side. There were no gender differences for olfactory bulb volume and olfactory sulcus depth. Positive correlations were determined between right- and left-sided olfactory bulb volume values and between right- and left-sided olfactory sulcus depth values. Behçet's disease may decrease olfactory functions, related to lower olfactory bulb volume and olfactory sulcus depth. The affected vascular system and possibly damaged neural system, nasal mucosal lesions, and prolonged nasal mucociliary clearance time may cause olfactory dysfunction. Patient follow up is recommended, with magnetic resonance imaging examinations of the olfactory system if necessary.

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

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. 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. 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). 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.

Olfactory function in patients with nonsyndromic orofacial clefts and their unaffected relatives.

Nonsyndromic orofacial clefting is one of the most frequently occurring congenital conditions. The aim of the study was to investigate the prevalence and nature of reduced olfactory function in patients with nonsyndromic cleft lip and/or cleft palate (NSCL/P) and their unaffected first-degree relatives. Olfactory function was tested using the Sniffin' Sticks identification test in patients with NSCL/P, in their unaffected relatives, and in control subjects. MR imaging was performed to measure olfactory bulb (OB) volumes and olfactory sulcus (OS) depths. A reduced olfactory function was seen in significantly more patients with NSCL/P (p = .002) than in control subjects, regardless of the cleft type. Strikingly, unaffected relatives of patients with NSCL/P also had a higher rate of hyposmia (p = .001). In hyposmic patients, the OB volumes (left: p = .01 and right: p = .003) and the depth of the left OS (p = .02) were significantly smaller than in controls. In hyposmic relatives, both OS depths (left: p = .02 and right: p = .03) were significantly smaller. Patients with NSCL/P and their unaffected relatives have an increased prevalence of reduced olfactory function, associated with changes in the central olfactory structures.

Olfactory bulb atrophy in migraine patients.

Osmophobia and headache triggered by odors are commonly seen in migraine, and these are symptoms that differentiate migraine from other primary headaches. Since these odor-related symptoms are disease-specific, we aimed to measure the volume of olfactory bulb and depth of olfactory sulcus in migraine patients. A total of 93 subjects, consisting of 62 episodic migraine (32 with osmophobia, 30 without osmophobia) patients and 31 healthy controls, were included in this study. Diagnosis and classification of migraine were performed according to the beta version criteria of International Classification of Headache Disorders (ICHD-3 Beta version). Beck depression and beck anxiety inventory were applied to the patients, and the measurement of bilateral olfactory bulb volume (OBV) and olfactory sulcus depth (OSD) was performed manually in the brain magnetic resonance imaging (MRI). More significantly in the left OBV, low OBV has been determined in migraine patients compared to the control group (p < 0.001, p = 0.020). When migraine patients with or without osmophobia were compared to the control group; OBV was determined to be the lowest in migraine group with osmophobia, and left-weighted bilateral OBV was determined to be low (p < 0.001, p = 0.046). No statistically significant difference was determined between groups in OSD measurements (p = 0.646, p = 0.490). Left-weighted bilateral OBV atrophy determined in migraine patients may be guiding for the clarification of migraine pathophysiology and enlightening of the relation between migraine and odor.

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

To compare the measurements of olfactory bulb volume and olfactory sulcus depth in patients with migraine and a control group. The study included the cranial MRI (1.5T) 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. 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. 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.

Evaluation of idiopathic olfactory loss with chemosensory event-related potentials and magnetic resonance imaging.

BackgroundIdiopathic olfactory loss (IOL) accounts for a sizable fraction of olfactory dysfunction, but very little is known about its etiology and electrophysiological changes in the olfactory pathway.MethodsWe analyzed the physiology of IOL using chemosensory event‐related potentials (ERPs) (olfactory and trigeminal: oERP and tERP) and olfactory pathway magnetic resonance imaging (MRI) measured in adult patients with IOL and healthy controls. Subjective olfactory function was measured by Toyota and Takagi (T&T) olfactometry and Sniffin’ Sticks (SS).ResultsOlfactory function was worse in patients with IOL compared to controls (T&T, p < 0.001; SS, p < 0.001). oERPs could be evoked in 17 IOL patients. Signals in these patients showed lower amplitude in the N1 and P2 waves than controls (p < 0.05 for both), but there were no difference in latency between the 2 groups (p > 0.05). tERP were detected in all patients and controls; there were no differences in latency and nor amplitude between the 2 groups (p > 0.05). The olfactory bulb (OB) volume was significantly smaller in the IOL group than controls (p < 0.001), but there was no difference in the olfactory sulcus depth between groups (p > 0.05). Better olfactory function was associated with increasing magnitude of N1 amplitude in oERPs (p < 0.05) and increasing OB volume (p < 0.05).ConclusionIOL patients show neurophysiologic deficits and some anatomic differences compared to healthy controls.

Olfactory cortex and Olfactory bulb volume alterations in patients with post-infectious Olfactory loss.

Upper respiratory tract infection (URI) is one of the most common etiology of olfactory loss. Previous studies demonstrated that both olfactory bulb (OB) volume and sulcus (OS) depth decreased in patients with post-infectious olfactory loss (PIOL) compared to normal controls. The aim of our study was to observe alterations of central olfactory pathways in patients with PIOL. T1 weighted magnetic resonance images were acquired in 19 PIOL patients and 19 age- and sex-matched control subjects on a 3T scanner. Voxel-based morphometry (VBM) was performed using VBM8 toolbox and SPM8 in a Matlab environment. We also analyzed OB volume in coronal T2-weighted images. Whole-brain analysis revealed a significant gray matter volume loss in the right orbitofrontal cortex (OFC) in patients group. Further analysis with region of interest exhibited a significant negative correlation between gray matter volume in right OFC as well as OB volume and the duration of olfactory loss in these patients (r = -0.566 and r = -0.535 both P < 0.05, respectively). In conclusion, the morphological alterations in the right OFC and OB might contribute to the pathogenic mechanism of olfactory dysfunction after upper respiratory tract infection.

Brain neurodevelopmental markers related to the deficit subtype of schizophrenia

Deficit schizophrenia is a homogeneous subtype characterized by a trait-like feature of primary and prominent negative symptoms, but the etiologic factors related to this specific subtype remain largely unknown. This magnetic resonance imaging study aimed to examine gross brain morphology that probably reflects early neurodevelopment in 38 patients with deficit schizophrenia, 37 patients with non-deficit schizophrenia, and 59 healthy controls. Potential brain neurodevelopmental markers investigated in this study were the adhesio interthalamica (AI), cavum septi pellucidi (CSP), and surface morphology (i.e., olfactory sulcus depth, sulcogyral pattern, and number of orbital sulci) of the orbitofrontal cortex (OFC). The subtype classification of schizophrenia patients was based on the score of Proxy for the Deficit Syndrome. The deficit schizophrenia group had a significantly shorter AI compared with the non-deficit group and controls. The deficit group, but not the non-deficit group, was also characterized by an altered distribution of the OFC sulcogyral pattern, as well as fewer posterior orbital sulcus compared with controls. Other neurodevelopmental markers did not differentiate the deficit and non-deficit subgroups. These results suggest that the deficit subtype of schizophrenia and its clinical manifestation may be at least partly related to prominent neurodevelopmental pathology.

Associations of olfactory bulb and depth of olfactory sulcus with basal ganglia and hippocampus in patients with Parkinson’s disease

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by hyposmia in the preclinical stages. We investigated the relationships of olfactory bulb (OB) volume and olfactory sulcus (OS) depth with basal ganglia and hippocampal volumes. The study included 25 patients with PD and 40 age- and sex-matched control subjects. Idiopathic PD was diagnosed according to published diagnostic criteria. The Hoehn and Yahr (HY) scale, the motor subscale of the Unified Parkinson’s Disease Rating Scale (UPDRS III), and the Mini-Mental State Examination (MMSE) were administered to participants. Volumetric measurements of olfactory structures, the basal ganglia, and hippocampus were performed using magnetic resonance imaging (MRI). OB volume and OS depth were significantly reduced in PD patients compared to healthy control subjects (p<0.001 and p<0.001, respectively). The OB and left putamen volumes were significantly correlated (p=0.048), and the depth of the right OS was significantly correlated with right hippocampal volume (p=0.018). We found significant correlations between OB and putamen volumes and OS depth and hippocampal volume. Our study is the first to demonstrate associations of olfactory structures with the putamen and hippocampus using MRI volumetric measurements.

Olfactory bulb and olfactory sulcus depths are associated with disease duration and attack frequency in multiple sclerosis patients

Background and purpose: Multiple sclerosis (MS) is a neuroinflammatory and neurodegenerative disease that progresses to axonal loss and demyelinization. Olfactory dysfunction in patients with MS has been reported frequently. We were interested in the associations of olfactory bulb (OB) and olfactory sulcus depth (OSD) with disease duration and attack frequency.Methods: We included 25 patients with MS and 30 age- and sex-matched controls in this study. The Expanded Disability Status Scale, Beck Depression Inventory, and Mini Mental State Examination were applied. OB, OSD, and magnetic resonance imaging plaque numbers were calculated.Results: OB volume and OSD in patients with MS were significantly lower than those in the control group (right and left OB: p<0.001; right OSD: p=0.001; and left OSD: p=0.039). Disease duration was negatively correlated with right and left OB volume (right OB: r=−0.434, p=0.030 and left OB: r=−0.518, p=0.008). Attack frequency was negatively correlated with left OB volume and left OSD (left OB: r=−0.428, p=0.033 and left OSD: r=−0.431, p=0.032).Conclusions: The OB and OSD were atrophied significantly in patients with MS, and this was correlated with disease duration and attack frequency. The left side tended to be dominant.

Sniffin' Sticks and olfactory system imaging in patients with Kallmann syndrome.

The relationship between olfactory function, rhinencephalon and forebrain changes in Kallmann syndrome (KS) have not been adequately investigated. We evaluated a large cohort of male KS patients using Sniffin' Sticks and MRI in order to study olfactory bulb (OB) volume, olfactory sulcus (OS) depth, cortical thickness close to the OS, and olfactory phenotype. Olfaction was assessed administering Sniffin' Sticks®, in 38 KS patients and 17 controls (by means of Screening 12 test®). All subjects underwent magnetic resonance imaging (MRI) to study OB volume, sulcus depth, and cortical thickness. Compared to controls, KS patients showed smaller OB volume (p<0.0001), reduced sulcus depth (p<0.0001), and thicker cortex in the region close to the OS (p<0.0001). Anosmic KS patients had smaller OB than controls and hyposmic KS patients; there was no difference between hyposmic KS patients and controls. OB volume correlated with Sniffin' Sticks score (r = 0.64; p < 0.001), OS depth (p<0.0001) and, inversely, with cortical thickness changes (p<0.0001). Sniffin' Sticks showed an inverse correlation with cortical thickness (r = -0.5; p<0.0001) and a trend toward a statistically significant correlation with OS depth. The present study provides further evidence of the strict relationship between olfaction and OB volume. The strong correlation between OB volume and the overlying cortical changes highlights the key role of rhinencephalon in forebrain embryogenesis.

Orbitofrontal sulcogyral pattern and olfactory sulcus depth in the schizophrenia spectrum.

Morphological changes in the orbitofrontal cortex (OFC), such as an altered sulcogyral pattern of the 'H-shaped' orbital sulcus and a shallow olfactory sulcus, have been demonstrated in schizophrenia, possibly reflecting deviations in early neurodevelopment. However, it remains unclear whether patients with schizotypal features exhibit similar OFC changes. This magnetic resonance imaging study examined the OFC sulcogyral pattern (Types I, II, III, and IV) and olfactory sulcus morphology in 102 patients with schizophrenia, 47 patients with schizotypal disorder, and 84 healthy controls. The OFC sulcogyral pattern distribution between the groups was significantly different on the right hemisphere, with the schizophrenia patients showing a decrease in Type I (vs controls and schizotypal patients) and an increase in Type III (vs controls) expression. However, the schizotypal patients and controls did not differ in the OFC pattern. There were significant group differences in the olfactory sulcus depth bilaterally (schizophrenia patients<schizotypal patients<controls). Our findings suggest that schizotypal disorder, a milder form of schizophrenia spectrum disorders, partly shares the OFC changes (i.e., altered depth of the olfactory sulcus) with schizophrenia, possibly reflecting a common disease vulnerability. However, altered distribution of the OFC pattern specific to schizophrenia may at least partly reflect neurodevelopmental pathology related to a greater susceptibility to overt psychosis.

Volume of olfactory bulb and depth of olfactory sulcus in 378 consecutive patients with olfactory loss.

The aim of this study was to investigate the olfactory bulb (OB) and sulcus (OS) in a large group of patients who have been well-characterized in terms of olfactory function, with a specific focus on the comparison between patients with olfactory loss due to chronic rhinosinusitis, head trauma, or acute infections. A retrospective study of 378 patients with olfactory loss was performed. Orthonasal olfactory function was assessed with the"Sniffin' Sticks" test kit, including tests for odor threshold, odor discrimination, and odor identification. Magnetic resonance imaging analyses were focused on OB volume and OS depth. Major results of the present study included the (1) demonstration of a correlation between olfactory function and OB volume across the various pathologies in a very large group of subjects; (2) the three functional tests exhibited a similar degree of correlation with OB volume. (3) The right, but not the left OS correlated with olfactory function; in addition, (4) OS was negatively correlated with age. In contrast to OS, (5) no side differences were found for the OB. Finally, (6) the three different causes of olfactory loss exhibited different patterns of results for the three olfactory tests. The present data suggest that the morphological assessment of the OB volume and OS depth produces useful clinical indicators of olfactory dysfunction.

Olfactory function in patients with idiopathic Parkinson's disease

To analyze the correlation between olfactory bulb (OB) volume with depth of olfactory sulcus (OS) and olfactory function in patients with idiopathic Parkinson's disease (IPD). One hundred patients with IPD between January 2011 to December 2013 in Tianjin Huanhu Hospotal were compared with one hundred controls in terms of olfactory function T&T testing, OB volume and depth of OS assessed with Magnetic resonance imaging (MRI). One hundred IPD patients were investigated and estimated H-Y degrees, UPDRS, MMSE, MoCA. SPSS 13.0 software was used to analyze the data. T&T olfactory testing revealed that IPD patients (3.0 ± 0.3) had higher scores than controls (1.3 ± 0.2, t = 2.537, P < 0.01). Both men and women with IPD were affected by the same extent of olfactory loss (t = 0.893, P > 0.05). Both men and women as controls were affected by the same extent of olfactory loss(t = 1.184, P > 0.05). OB volume of left side in IPD patients was (34.25 ± 5.14) mm(3), right side was (35.79 ± 5.28)mm(3), average OB volume was (35.28 ± 5.21) mm(3); OB volume of left side in controls was (47.38 ± 6.47) mm(3), right side was (47.75 ± 6.51) mm(3), average OB volume was (47.53 ± 6.49) mm(3); OB volume were lower in IPD patients as compared to controls (t value were 2.876, 2.747, 2.798, all P < 0.01). OS depth study revealed no statistical difference between IPD patients and controls (t value were 0.914, 0.987, 0.951, all P > 0.05). Olfactory discriminate threshold was negatively correlated with average OB volume in IPD patients and controls (r value were -0.537,-0.526, both P < 0.05); was no correlated with average depth of OS (r value were -0.142, -0.157, both P > 0.05). There was relation between the average OB volume and UPDRS III, UPDRS, the degree of H-Y in IPD patients (r value were 0.312, -0.419, -0.358, all P < 0.05). However the average OB volume was not related to the course of disease (r = -0.089, P > 0.05). The OB volume is lower in IPD patients as compared to controls, the depth of OS have no significant changes in IPD patients; The OB volume is correlated with olfactory function, the depth of OS is not correlated with olfactory function; Olfactory function lower degree is accordance with serious degree in IPD patients, is not accordance with the course of disease.

Evaluation of post-traumatic anosmia with MRI and chemosensory ERPs.

Magnetic resonance imaging (MRI) and chemosensory event-related potentials (ERPs) are important methods to evaluate olfactory function, but there is lack of study to explore the application of MRI and chemosensory ERPs in the patients with traumatic anosmia. The data of 26 post-traumatic anosmic patients and 21 healthy controls were retrospectively surveyed; olfaction and olfactory pathway of all participants were measured clinically using the T&T olfactometer, the Sniffin' Sticks, chemosensory ERPs and MRI. All patients were anosmic based on complaints and clinical examinations. In five patients, the olfactory bulb volume was significantly lower than control group. In 18 patients, the olfactory sulcus (OS) depth was similar to control group, but all the participants had a deeper right OS (right = 7.79 ± 1.31, left = 7.06 ± 1.44, p < 0.01). Olfactory ERPs (oERPs) could be evoked in 17 patients, but these signals showed longer latencies and lower amplitude than controls in the N1 (latency p < 0.05, amplitude p < 0.01) and P2 (latency p < 0.01, amplitude p < 0.05) waves. Nine traumatic anosmic patients had no identifiable oERPs; most of them had olfactory center injury. Trigeminal ERPs were detected in all anosmic patients and controls; patients had longer latencies for N1 (p < 0.05) and P2 (p < 0.05) waves, while there was no similar change in amplitude. Older subjects had smaller OB volume and OS depth. Closed head injury could induce anosmia; the severity extent, injury site and subsequent consciousness are related to the olfaction. oERP is the gold standard for olfactory subjective examination; MRI could indicate the lesions on the olfactory pathway and reflect the possibility of detectable oERPs.

Olfactory function in patients with mild cognitive impairment

To analyze the correlation between olfactory bulb (OB) volume, depth of olfactory sulcus (OS) and olfactory function in patients with mild cognitive impairment (MCI). Fifty patients with MCI were compared with fifty controls in terms of olfactory function T&T testing, OB volume and depth of OS assessed with magnetic resonance imaging (MRI). SPSS 13.0 software was used to analyze the data. T&T olfactory testing revealed that MCI patients had higher scores than controls (t = 3.142, P < 0.05). Both men and women with MCI were affected by the same extent of olfactory loss(t = 0.973, P > 0.05). Both men and women as controls were affected by the same extent of olfactory loss (t = 1.092, P > 0.05).OB volume of left side in MCI patients was (36.35 ± 4.09) mm(3), right side was (36.57 ± 4.13) mm(3), average OB volume was (36.47 ± 4.12) mm3; OB volume of left side in controls was (46.65 ± 6.23) mm(3), right side was (46.83 ± 6.27) mm(3), average OB volume was (46.71 ± 6.25)mm(3); OB volumes were lower in MCI patients as compared with controls (t value was 3.113, 3.145 and 3.132, all P < 0.01).OS depth study revealed no statistical different between MCI patients and controls (t value was 0.876,0.952 and 0.904, all P > 0.05). Olfactory discriminate threshold was negatively correlated with OB volume in MCI patients and controls (r value was -0.643, -0.541, both P < 0.05); was no correlated with depth of OS (r value was -0.167 and -0.183, both P > 0.05). Olfactory discriminate threshold was negatively correlated with cognitive impairment degree in MCI patients (r value was -0.427, -0.418 and -0.399, all P < 0.05), average OB volume was positively correlated with cognitive impairment degree in MCI patients (r value was 0.364, 0.383 and 0.379, all P < 0.05). The OB volumes are lower in MCI patients as compared with controls, the depth of OS show no significant changes in MCI patients. The OB volume is correlated with olfactory function, the depth of OS is not correlated with olfactory function. Cognitive impairment degree in MCI patients is accordance with olfactory function lower degree. The olfactory loss may be a earlier period and objective diagnosis indicator for MCI patients.

The Disrupted-in-Schizophrenia-1 Ser704Cys polymorphism and brain neurodevelopmental markers in schizophrenia and healthy subjects.

Increasing evidence has implicated the role of Disrupted-in-Schizophrenia-1 (DISC1), a potential susceptibility gene for schizophrenia, in early neurodevelopmental processes. However, the effect of its genotype variation on brain morphologic changes related to neurodevelopmental abnormalities in schizophrenia remains largely unknown. This magnetic resonance imaging study examined the association between DISC1 Ser704Cys polymorphism and a range of brain neurodevelopmental markers [cavum septi pellucidi (CSP), adhesio interthalamica (AI), olfactory sulcus depth, and sulcogyral pattern (Types I, II, III, and IV) in the orbitofrontal cortex (OFC)] in an all Japanese sample of 75 schizophrenia patients and 87 healthy controls. The Cys carriers had significantly larger CSP than the Ser homozygotes for both schizophrenia patients and healthy controls. The Cys carriers also exhibited a reduction in the Type I pattern of the right OFC in the healthy controls, but not in the schizophrenia patients. The DISC1 Ser704Cys polymorphism did not affect the AI and olfactory sulcus depth in either group. These results suggested a possible role of the DISC1 genotype in the early neurodevelopment of human brains, but failed to show its specific role in the neurodevelopmental pathology of schizophrenia.

Is there an association between olfactory bulb volume and the Keros type of fossa olfactoria?

The purpose of this study was to investigate the relationship between the volume of the olfactory bulb (OB), the depth of the olfactory sulcus (OS), the depth of the fossa olfactoria (FO), and the height of the OB. A total of 54 patients participated (9 women and 45 men; mean [SD] age, 27 [38] y; range, 20-45 y). Magnetic resonance imaging was performed with a 1.5-T system (slice thickness, 1 mm). Measurements of the right and left OB volumes were performed through manual segmentation of the coronal slices. We measured the depth of the FO on the basis of Keros classification on coronal magnetic resonance images. The depth of the OS was measured on the coronal plane at the posterior tangent through the orbital globes. The height of the OB was measured on the coronal plane of the cribriform plate at the highest portion of the OB. The mean (SD) right OB volume was measured to be 52.21 (13.73) mm3 with a range between 33.90 and 95.70 mm3. The mean (SD) left OB volume was measured to be 53.98 (13.31) mm3 with a range between 31.20 and 94.10 mm3. Type 1, type 2, and type 3 Keros ratios of the FO bilaterally were 12.9% (7/54), 68.5% (37/54), and 3.7% (2/54), respectively. There was no significant relationship between the OB volume and ipsilateral Keros type of FO (right side: P = 0.208; left side: P = 0.164). Similarly, there was no significant relationship between the OB volume and depth of OS on both sides (right side: P = 0.073; left side: P = 0.065). There was no significant association between the Keros type of the right FO and depth of the OS (right side: P = 0.812; left side P = 0.863). We conclude that there is no statistical correlation between the OB volume and depth of the FO (Keros type). From the current study, it may be concluded that the depth of the FO may develop largely independent from OB volumes. The individuals without smell disorder have a wide range in OB volume. The method of OB volume measurement that we described is a valid measure of real OB volumes with high reproducibility.

Olfactory function in patients with idiopathic rapid eye movement sleep behavior disorder

To analyze the correlation between olfactory bulb (OB) volume with depth of olfactory sulcus (OS) and olfactory function in patients with idiopathic rapid eye movement sleep behavior disorder (iRBD). Fifty patients with iRBD and fifty controls were assessed with polysomnography (PSG). The results of olfactory function T & T testing, OB volume and depth of OS assessed with magnetic resonance imaging (MRI) were compared. SPSS 11.0 software was used to analyze the data. T & T olfactory testing revealed that iRBD patients had higher scores (3.1 ± 0.5) than those in controls (0.6 ± 0.1), and the difference was significant (t = 7.913, P < 0.05). Both men and women with iRBD were affected by the same extent of olfactory loss (t = 1.015, P > 0.05). OB volume of left side in iRBD patients was (33.75 ± 4.11) mm(3), right side was (34.57 ± 4.21) mm(3), average OB volume was (33.94 ± 4.15) mm(3); OB volume of left side in controls was (51.68 ± 7.71) mm(3), right side was (52.31 ± 7.77) mm(3), average OB volume was (51.94 ± 7.74) mm(3); OB volume were lower in iRBD patients as compared to controls (t value were 9.013, 8.889 and 8.923, all P < 0.01). OS depth study revealed no statistical difference between iRBD patients and controls (t value were 0.923, 0.897 and 0.904, all P > 0.05). Olfactory discriminate threshold was negatively correlated with OB volume in iRBD patients (r = -0.61, P < 0.05), but no correlated with depth of OS (r = -0.24, P > 0.05). The OB volume was lower in iRBD patients as compared to controls. The depth of OS showed no significant changes in iRBD patients. The OB volume was correlated with olfactory function, while the depth of OS was no correlated with olfactory function.

Anatomic Olfactory Structural Abnormalities in Congenital Smell Loss

There are 2 groups of patients with congenital smell loss: group 1 (12% of the total), in which patients exhibit a familial smell loss in conjunction with severe anatomical, somatic, neurological, and metabolic abnormalities such as hypogonadotropic hypogonadism; and a larger group, group 2 (88% of the total), in which patients possess a similar degree of smell loss but without somatic, neurological, or anatomical abnormalities or hypogonadism. Both groups are characterized by similar olfactory dysfunction, and both have been reported to have absent or decreased olfactory bulbs and grooves, which indicates some overlap in olfactory pathophysiology and anatomy. The purpose of this study was to evaluate patients with congenital smell loss, primarily among group 2 patients, comparing brain magnetic resonance imaging (MRI) results in patients with types of hyposmia. Forty group 2 patients were studied by measurements of taste (gustometry) and smell (olfactometry) function and by use of MRI in which measurements of olfactory bulbs, olfactory sulcus depth, olfactory grooves, and hippocampal anatomy were performed. Anatomical results were compared with similar studies in group 1 patients and in 22 control subjects with normal sensory function. Olfactometry was abnormal in all patients with no patient reporting ever having normal olfaction. No patient had a familial history of smell loss. On MRI, all exhibited at least 1 abnormality in olfactory system anatomy, including absence or decreased size of at least 1 olfactory bulb, decreased depth of an olfactory sulcus, and abnormalities involving hippocampal anatomy with hippocampal malrotations. One patient had bilateral bulb duplication. Normal subjects with normal smell and taste function exhibited some but very few or significant neuroanatomical changes on MRI. Although both groups have similar abnormalities of smell function, group 2 patients demonstrate anatomical anomalies in olfactory structures that are neither as common nor as severe as in group 1 patients. Group 2 patients can have a wide range of olfactory anatomical abnormalities.