SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Kallmann's syndrome is characterized by hypogonadotropic hypogonadism and anosmia. Postmortem studies have revealed either hypoplasia or aplasia of the rhinencephalon, respectively, in patients with hyposmia and anosmia. This anatomical defect has now been demonstrated in vivo in four patients with Kallmann's syndrome by magnetic resonance imaging.
OBJECTIVE: The purpose of this study was to evaluate patients with reduced or no sense of smell since birth for sites of abnormality by MR imaging. MATERIALS AND METHODS: Twenty-five patients who reported no olfactory function since birth were evaluated by olfactory testing, sinonasal endoscopy, and MR imaging. Surface coil and head coil images of the olfactory bulbs, olfactory tracts, subfrontal cortex, and temporal lobes in contiguous 3-mm sections were obtained. Two reviewers determined unilateral olfactory bulb and tract volumes and temporal lobe volumes in two separate sessions. Qualitative grading for olfactory bulb, olfactory tract, olfactory sulcus, subfrontal region, hippocampus, and temporal lobe damage also was performed. RESULTS: The absence of olfactory bulbs and tracts (68-84%) or the presence of hypoplasia (16-32%) was noted in all cases. Eight individuals had Kallmann's syndrome (hypogonadotropic hypogonadism with anosmia). Temporal and/or frontal lobe volume loss was noted in five individuals and was mild in all but one individual. CONCLUSION: Congenital anosmia or hyposmia appears to be an olfactory bulb-olfactory tract phenomenon rather than a cerebral process.
This is a report of the alpha interferon-induced acute anosmia in a 37-year old patient with chronic hepatitis C. This exceptionally rare side-effect started in our patient as a smelling problem 2 weeks after the initiation of the therapy, and anosmia is still present 13 months after the discontinuation of the alpha interferon. We presume that neurotoxic mechanism could be responsible for this side-effect.
We report here a series of 118 patients (79% women) who developed dysomia after acute rhinitis. Mean age was 59 years. Mean follow-up after the initial rhinal episode was 36 months. The dominant olfactory disorder was anosmia (71% of the patients) and dysgeusia in 71%. The prognosis of anosmia was poor as it persisted in 50% of the patients. Six patients (5%) recovered normal olfaction after a delay of 11 months. Partial recovery was observed in 45% of the patients with a mean 14-month delay. Recovery of olfaction was thus observed within the first year. Parosmia was also frequent (59% of the patients). In two out of three cases, parosmia persisted. Improvement generally occurred during the first 18 months. These olfactory disorders have an impact on the patients' psychic equilibrim since a depressive syndrome was observed in 60% of the cases.
We present two cases demonstrating congenital anosmia. In both cases, magnetic resonance imaging (MRI) has served to highlight an interesting clinical oddity. To date, there has only been one study of the use of MRI in the assessment of patients with congenital anosmia who do not have Kallmann's syndrome.
BACKGROUND AND PURPOSE: Anosmias with chromosomal disorders has been well investigated. However, isolated anosmia (IA) has received less attention, although it occurs more frequently. We compared frontobasal structures in patients with IA since birth or early childhood with those in control subjects. METHODS: Imaging findings obtained in 16 patients with IA were compared with those obtained in eight control subjects. Imaging was performed with a standard quadrature head coil at 1.5 T. T1-weighted spin-echo (coronal plane perpendicular to frontal skull base; section thickness, 3 mm; pixels, 0.43 x 0.39 mm) and sagittal T1-weighted magnetization-prepared rapid gradient-echo (voxels, 1.0 x 1.0 x 1.0 mm) sequences were performed. We assessed the length and depth of the olfactory sulcus, olfactory bulb volume, and olfactory sulcus depth in the plane of the posterior tangent through the eyeballs (PPTE). RESULTS: Five patients with IA had bilateral hypoplastic olfactory bulbs. Three patients with IA had hypoplastic olfactory bulbs on the right and aplastic olfactory bulbs on the left. Eight patients with IA had bilaterally aplastic olfactory bulbs. The depth of the olfactory sulcus at the level of the PPTE was smaller in patients with IA than in control subjects. The depth of the olfactory sulcus was greater on the right than on the left, and there was no overlap. Among patients with IA, the depth of the olfactory sulcus differed significantly between those with and those without visible olfactory tracts. CONCLUSION: The depth of the olfactory sulcus at the level of the PPTE reflects the presence of olfactory tracts. The presence or absence of the olfactory tract may therefore have some association with cortical growth of the olfactory sulcus region. The olfactory sulcus is deeper on the right than on the left, particularly in patients with IA. We speculate that olfaction may be processed predominantly in the right hemisphere.
The olfactory system is made up of the olfactory epithelium, bulbs and tracts, together with olfactory areas in the brain. Anosmia may results from benign and malignant nasal sinus lesions, but also from lesions involving the CNS structures involved in olfaction. The purpose of this article is to review the different diagnose of anosmia and their CT or MR imaging characteristics.
Kallmann syndrome is a genetically heterogeneous disease characterized by hypogonadotropic hypogonadism and anosmia. Six families in which the disorder followed an X-linked inheritance were investigated by linkage analysis. Diagnostic criteria were uniformly applied and included tests for hypogonadotropic hypogonadism and anosmia. Close linkage was found by using the hypervariable repeated sequence CRI-S232 (DXS278) previously mapped to Xp22.3. At a maximum lod score of 6.5, the recombination fraction was calculated as .03. Of 30 fully informative meioses, one recombination between the disease locus and the loci recognized by probe CRI-S232 was observed. When an independent approach is used, these results confirm the X-linked Kallmann syndrome assignment previously made by deletion mapping, and allow definitive localization of the syndrome assignment previously made by deletion mapping, and allow definitive localization of the syndrome to the Xp22.3 region. This opens the way to carrier detection and to the identification of a gene responsible for this disorder.
The sense of smell in dogs infected with canine distemper virus (CDV) was examined by use of EEG olfactometry, behavioral olfactometry, and electro-olfactography. Infection with CDV was confirmed by a direct immunofluorescence technique in 8 active cases and was suggested by clinical history compatible with canine distemper 10 to 26 weeks earlier in 6 cases. Pathologic alterations of the olfactory mucosa in 3 clinically affected dogs was examined by light microscopy. Infection with CDV was found to be associated with anosmia and lack of recorded responses on electro-olfactogram in 8 of 8 dogs with clinical signs of acute distemper from naturally acquired infections. Anosmia was found in 5 of 6 dogs that had recovered from acute distemper 10 to 26 weeks earlier. The sixth dog had hyposmia, with abnormalities on the electro-olfactogram. Histologic examination was not performed on the 6 dogs that had recovered. Histologic lesions observed at necropsy in 3 dogs that had had clinical signs of acute distemper were those of subacute purulent rhinitis and atrophy of the olfactory epithelium. Altered olfactory function could be explained by mucopurulent exudate blocking odors from olfactory receptors in the acutely affected dogs, but alteration of olfactory function in the dogs that had recovered without clinical evidence of rhinitis could not be explained.
The familial occurrence of hypogonadism and anosmia (Kallmann-Syndrome) is reported in a 15 5/12 year old boy and his 20 7/12 year old sister, who in addition has a ventricular septal defect. To establish the diagnosis it is important to examine the patient with hypogonadism for anosmia since voluntary information is rarely obtained. Quite often there are additional, associated anomalies which have to be searched for carefully.
The importance of olfaction in perception of flavor by flavor-validating dogs was studied. The flavor-validation technique is widely used by pet food manufacturers to determine if a given formula is perceived by dogs as having the flavor of a specific meat. Five Beagles were trained as flavor validators; 2 dogs were trained to select beef and 3 to select lamb from a panel of 4 meats. When the dogs had been trained to select the correct meat on 100% of the trials, they were made anosmic. Reversible peripheral anosmia was produced in the dogs by inflating a cuff on a surgically implanted tracheostomy tube. When the cuff was inflated, air entered the trachea via the tracheostomy tube, rather than via the nasal cavity, and the percentage of correct choices on the flavor-validating test fell to 62 +/- 14%. When the tracheostomy tubes were removed, performance returned to 100% correct. The nasal cavities of 3 dogs were infused with zinc sulfate to produce a more complete and longer-lasting anosmia. The percentage of correct choice on the flavor-validation test fell to 24 +/- 5%. These findings indicate that the flavor-validation test is based primarily on one sensory modality, that of olfaction; therefore, formulas selected by flavor-validating dogs may smell similar to the specific meat, but do not necessarily taste similar to that meat.
On MRI, the authors were able to demonstrate the contused lesions of bilateral rectal gyri near the crista galli in all of five cases of traumatic anosmia. Thin slice coronal and sagittal images of MRI were very useful for detecting the lesions. Conventional CT scans failed to demonstrate the lesions in 3 out of the 5 cases, but, even in these cases, MRI was able to clearly depict the contused lesions of bilateral rectal gyri. Therefore, the depicted lesions of bilateral rectal gyri on MRI can be evidence of traumatic anosmia and this may be very significant in medico-legal cases.
Sex dimorphic patterns of exploratory behavior in the open-field, passive defensive behavior and emotionality were studied in anosmic rats. It was show that the long-time anosmia increased the level of exploratory and locomotor activities in male rats and changed their behavior in stress situations from passive to active form. Anosmia didn't change characteristics of these forms of behavior in female rats.
Five patients suffering post-traumatic anosmia were studied at the University of Colorado Health Sciences Center, Denver. Each patient underwent psychophysical testing, clinical evaluation, and olfactory biopsy. The biopsy specimens were examined ultrastructurally and were found to vary from normal tissues. The overall appearance of the olfactory epithelium in the post-traumatic patient is disrupted and the receptor cells are distorted. Large numbers of axons are located near the basement membrane and can often be found in bundles throughout the epithelium, extending even to the mucosal surface. Olfactory cilia are rarely seen in epithelia obtained from post-traumatic patients. Bald olfactory vesicles, often containing basal bodies, are frequently observed. We postulate that in these cases, the olfactory epithelium regenerates following head trauma and the receptor cells attempt to send axons centrally. However, the cribriform plate has undergone fibrotic healing and the axons are unable to penetrate it and make contact with olfactory bulb neurons.
Ultrastructural alterations were present in biopsy specimens of olfactory epithelia taken from two patients with anosmia. In both cases, the olfactory epithelia presented a disorganized appearance when viewed by transmission electron microscopy. The number of ciliated olfactory receptors was reduced; few olfactory vesicles were present at the epithelial surface. Where present, the olfactory vesicles usually lacked cilia. Since both patients had a history of head trauma, we speculate that the fila olfactoria may have been severed at the level of the cribriform plate. The histopathologic changes in the olfactory receptors that were revealed by electron microscopy may have resulted from the inability of regenerating axons to reach their normal site of synaptic contact--the second-order neurons (mitral cells) in the olfactory bulb of the brain.
OBJECTIVE: To establish the efficacy of topical corticosteroid nasal spray treatment of severe olfactory loss associated with severe nasal and sinus disease. DESIGN: Efficacy before and after open-label trial of topical corticosteroid nasal spray used exclusively in the head-down-forward position. SETTING: Taste and smell clinic of a university teaching hospital and research facility. PATIENTS: Taste and smell clinic patients with anosmia or severe hyposmia associated with paranasal sinus disease and nasal polyposis including 39 of 45 patients recruited from 1988 to 1994 who completed the topical corticosteroid treatment course and returned for subsequent testing. INTERVENTION: At least 8 weeks of treatment with flunisolide (Nasalide), 2 sprays in each nostril twice a day, with concurrent antibiotic treatment of any bacterial infection. MAIN OUTCOME MEASURES: Subjective olfactory symptoms, objective olfactory function tests, and otolaryngological evaluation (including endoscopic examination). RESULTS: Olfactory scores significantly improved following treatment (P < .001); signs of nasal and sinus disease significantly decreased (P < .001); and 26 (66%) of the patients reported a subjective improvement in their sense of smell. CONCLUSION: Topical corticosteroid nasal spray administered in a head-down-forward position is an effective treatment of severe olfactory loss associated with severe nasal and sinus disease.
Among 18 NIH probands with anosmia and hypogonadotropic hypogonadism (AHH), seven had affected relatives and three had consanguineous parents. Both sexes were equally affected and parents were phenotypically normal. Parental age was not increased. Cleft lip and palate occurred in both eugonadal and hypogonadal persons, a previously reported association that may represent variable expression of AHH. Diabetes mellitus, usually insulin-dependent, was frequent in probands and their families. Other common traits included obesity, cryptorchidism, and hearing loss. All probands were chromosomally normal. The frequency of some dermatoglyphic traits of probands differed from normal, but no trait was unique to AHH. Segregation analysis of our proband sibships was consistent with a hypothesis of autosomal-recessive inheritance with variable expression. However, genetic heterogeneity was apparent when previous reports of familial AHH were surveyed. An X-linked or male sex-limited autosomal-dominant form with unilateral renal agenesis, mental retardation, and hypotelorism has been observed. The infrequent reports of direct male-to-male transmission limit characterization of an autosomal-dominant form of AHH. Our phenotypic analysis suggests that the traits of mental retardation, renal anomalies, hypotelorism, diabetes, and hearing loss may help to distinguish various forms of AHH, whereas cryptorchidism, clefts, and obesity appear in several types of families. At present, genetic counseling is dependent upon establishing inheritance pattern after examination for the known associated anomalies.
We describe a large, three generation kindred in which 16 individuals were affected with alopecia, hyposmia or anosmia, conductive deafness associated with protruding ears, microtia, and/or atresia of the external auditory canal, hypogonadotropic hypogonadism due to LH/FSH deficiency, and a greater than normal tendency to dental caries. Variable manifestations include mild facial asymmetry, mental retardation, congenital heart defect, and cleft palate. This seems to be a previously undescribed pleiotropic autosomal dominant trait with variable expressivity. The manifestations can be explained on the basis of involvement of the ectoderm and neuroectoderm of the first and second branchial arches, of Rathke's pouch, and of the diencephalon.