RESUMO
In mammals, odour information within the olfactory bulb (OB) is processed by complex neural circuits before being ultimately represented in the action potential activity of mitral/tufted cells (M/Ts). Cholecystokinin-expressing (CCK+) superficial tufted cells (sTCs) are a subset of tufted cells that potentially contribute to olfactory processing in the OB by orchestrating M/T activity. However, the exact role of CCK+ sTCs in modulating odour processing and olfactory function in vivo is largely unknown. Here, we demonstrate that manipulating CCK+ sTCs can generate perception and induce place avoidance. Optogenetic activation/inactivation of CCK+ sTCs exerted strong but differing effects on spontaneous and odour-evoked M/T firing. Furthermore, inactivation of CCK+ sTCs disrupted M/T odour encoding and impaired olfactory detection and odour discrimination. These results establish the role of CCK+ sTCs in odour representation and olfactory behaviours. KEY POINTS: Mice could perceive the activity of CCK+ sTCs and show place avoidance to CCK+ sTC inactivation. Optical activation of CCK+ sTCs increased the percentage of cells with odour response but reduced the odour-evoked response in M/Ts in awake mice. Optical inactivation of CCK+ sTCs greatly decreased spontaneous firing and odour-evoked response in M/Ts. Inactivation of CCK+ sTCs impairs the odour decoding performance of M/Ts and disrupts odour detection and discrimination behaviours in mice. These results indicate that CCK+ sTCs participate in modulating the odour representation and maintaining normal olfactory-related behaviours.
Assuntos
Colecistocinina , Bulbo Olfatório , Animais , Feminino , Masculino , Camundongos , Colecistocinina/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurônios/fisiologia , Odorantes , Bulbo Olfatório/fisiologia , Percepção Olfatória/fisiologia , Optogenética , Olfato/fisiologiaRESUMO
PURPOSE: Study the efficacy of olfactory training in smell recovery. METHODS: An extensive search was performed through different databases in order to find articles analyzing the efficacy of olfactory training as a treatment for olfactory dysfunction. Methodological quality of primary studies within the final sample was assessed following PRISMA guidelines. Standardized mean differences in pre-post olfactory training groups, and also in experimental-control and pre-follow up if possible, were computed by Hedges' g effect size statistic. Each effect size was weighted by its inverse variance. RESULTS: Final sample was composed of 36 articles (45 pre-post effect sizes). Contrasts were performed separately for odor identification, odor discrimination, odor threshold and general olfactory function. Moderate to large and heterogeneous effect was obtained for olfactory function (g = 0.755, k = 45, SE = 0.093, CI 95% = [0.572, 0.937]), different moderators had a significant effects, such as, training duration, age and anosmia diagnosis. CONCLUSION: Olfactory training was found to have a positive and significant effect on rehabilitating the olfactory function.
RESUMO
BACKGROUND: Olfactory threshold (OT) is a marker of short-term inflammatory activity in multiple sclerosis (MS). OBJECTIVE: To investigate whether OT predicts long-term MS clinical disease course. METHODS: This was a 6-year prospective longitudinal study on MS patients at the MS clinic Innsbruck. Clinical visits assessing the occurrence of relapses, Expanded Disability Status Scale (EDSS) scores, and disease-modifying treatment (DMT), were conducted biannually. OT testing was performed at baseline (BL), year 1 (Y1), year 2 (Y2) and year 6 (Y6), using the threshold subscore of the "Sniffin' Sticks" test. Cognitive function was assessed by the Symbol Digit Modalities Test. RESULTS: Of 139 MS patients, 92 were eligible for Y6 follow-up. 68% experienced relapses, 53% EDSS worsening, 29% progression independent of relapse activity (PIRA) and 41% cognitive deterioration. OT scores were lower at BL, Y1 and Y2 in patients requiring DMT escalation. In multivariable analysis, higher OT scores at BL, Y1, Y2 and Y6 were associated with lower risk of relapse (hazard ratio, HR: 0.65-0.92) and EDSS worsening (HR: 0.86-0.89), while no associations were found for PIRA and cognitive deterioration. CONCLUSIONS: OT is a potential surrogate marker for long-term inflammatory disease activity and DMT failure in MS.
Assuntos
Progressão da Doença , Recidiva , Humanos , Feminino , Masculino , Adulto , Estudos Longitudinais , Pessoa de Meia-Idade , Limiar Sensorial/fisiologia , Estudos Prospectivos , Biomarcadores , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/fisiopatologia , Esclerose Múltipla Recidivante-Remitente/fisiopatologia , Esclerose Múltipla/fisiopatologia , Esclerose Múltipla/complicações , Avaliação da Deficiência , Olfato/fisiologiaRESUMO
Background: Olfactory testing is emerging as a potentially effective screening method for identifying mild cognitive impairment in the elderly population. Objective: Olfactory impairment is comorbid with mild cognitive impairment (MCI) in older adults but is not well-documented in subdomains of either olfactory or subtypes of cognitive impairments in older adults. This meta-analysis was aimed at synthesizing the differentiated relationships with updated studies. Methods: A systematic search was conducted in seven databases from their availability to April 2023. A total of 38 publications were included, including 3,828 MCI patients and 8,160 healthy older adults. Two investigators independently performed the literature review, quality assessment, and data extraction. The meta-analyses were conducted with Stata to estimate the average effects and causes of the heterogeneity. Results: Compared to normal adults, MCI patients had severe impairments in olfactory function and severe deficits in specific domains of odor identification and discrimination. Olfactory impairment was more severe in patients with amnestic mild cognitive impairment than in patients with non-amnestic MCI. Diverse test instruments of olfactory function caused large heterogeneity in effect sizes. Conclusion: Valid olfactory tests can be complementary tools for accurate screening of MCI in older adults.
RESUMO
BACKGROUND: The important wood-boring pest Batocera horsfieldi has evolved a sensitive olfactory system to locate host plants. Odorant-binding proteins (OBPs) are thought to play key roles in olfactory recognition. Therefore, exploring the physiological function of OBPs could facilitate a better understanding of insect chemical communications. RESULTS: In this research, 36 BhorOBPs genes were identified via transcriptome sequencing of adults' antennae from B. horsfieldi, and most BhorOBPs were predominantly expressed in chemosensory body parts. Through fluorescence competitive binding and fluorescence quenching assays, the antenna-specific BhorOBP28 was investigated and displayed strong binding affinities forming stable complexes with five volatiles, including (+)-α-Pinene, (+)-Limonene, ß-Pinene, (-)-Limonene, and (+)-Longifolene, which could also elicit conformation changes when they were interacting with BhorOBP28. Batocera horsfieldi females exhibited a preference for (-)-Limonene, and a repellent response to (+)-Longifolene. Feeding dsOBP19 produced by a bacteria-expressed system with a newly constructed vector could lead to the knockdown of BhorOBP28, and could further impair B. horsfieldi attraction to (-)-Limonene and repellent activity of (+)-Longifolene. The analysis of site-directed mutagenesis revealed that Leu7, Leu72, and Phe121 play a vital role in selectively binding properties of BhorOBP28. CONCLUSION: By modeling the molecular mechanism of olfactory recognition, these results demonstrate that BhorOBP28 is involved in the chemoreception of B. horsfieldi. The bacterial-expressed dsRNA delivery system gains new insights into potential population management strategies. Through the olfactory process concluded that discovering novel behavioral regulation and environmentally friendly control options for B. horsfieldi in the future. © 2024 Society of Chemical Industry.
Assuntos
Quirópteros , Proteínas de Insetos , Receptores Odorantes , Receptores Odorantes/genética , Receptores Odorantes/metabolismo , Receptores Odorantes/química , Animais , Proteínas de Insetos/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/química , Feminino , Antenas de Artrópodes/metabolismo , Filogenia , MasculinoRESUMO
OBJECTIVES: Olfactory dysfunction is an overlooked adverse effect of radiation therapy. This study is designed to find the effect of radiation therapy on olfactory function in head and neck malignancy excluding tumors of nose and nasopharynx and correlate the olfactory changes with the radiotherapy dose. METHOD: This prospective observational study was done over a 2-year period in 34 participants with head and neck malignancies who underwent radiation therapy (RT). The participants olfaction was evaluated subjectively with Italian Nose Obstruction Symptom Evaluation (I-NOSE) scale and objectively by a modified I-Smell test which included an olfactory identification score and an olfactory threshold score at 5 time points. The beginning of RT (T0), at 2 weeks of RT(T1), end of RT (T2), 1 month follow-up (T3), and 3-month follow-up (T4). The near maximum dose to the nasal cavity (D2%) and mean dose to the nasal cavity (Dmean) were calculated for all participants and correlated with olfactory function. RESULTS: A total of 34 patients with head neck malignancy were recruited. The median I-NOSE score reached maximum at the end of radiation and decreased to baseline at 3 months follow-up (P < .001). The olfactory identification score, olfactory threshold score, and median combined olfactory score showed a significant decrease at the end of radiation therapy compared to Pre-radiation therapy values. There was a significant but incomplete recovery in the 3-month follow-up period (P < .001). CONCLUSION: There was a significant deterioration in quality of life for olfaction, olfactory identification, and olfactory threshold at the completion of radiotherapy. At 3 months follow-up, though there was no complete recovery of olfaction, it did not have an adverse effect on the quality of life.
Assuntos
Neoplasias de Cabeça e Pescoço , Transtornos do Olfato , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Neoplasias de Cabeça e Pescoço/radioterapia , Transtornos do Olfato/etiologia , Transtornos do Olfato/fisiopatologia , Estudos Prospectivos , Idoso , Adulto , Olfato/fisiologia , Olfato/efeitos da radiação , Lesões por Radiação/fisiopatologia , Lesões por Radiação/etiologia , Dosagem Radioterapêutica , Cavidade Nasal/efeitos da radiação , Cavidade Nasal/fisiopatologiaRESUMO
BACKGROUND: Different previous studies indicated olfactory function as a predictor of several types of cognitive impairment, in particular related to neurodegenerative disease. However, scanty data are available on the role of odor threshold (OT), odor discrimination (OD), and odor identification (OI) as a predictor of cognitive impairment. The aim of this study was to evaluate potential correlations between each factor of the olfactory function versus each specific cognitive domain of the Montreal Cognitive Assessment (MoCA) test on healthy subjects in relation to gender and age. METHODS: Sniffin' Sticks and MoCA tests were used to determine olfactory function and cognitive abilities, respectively. RESULTS: In men, significant correlations were found in OT versus language index score and OI versus language and executive index score, while in women, OD and OI were correlated to visuospatial index score. CONCLUSIONS: Our data suggested that olfactory function (OT, OD, and OI) may be considered a predictor for cognitive impairment in relation to gender and age.
RESUMO
Reverse chemical ecology has been widely applied for the functional characterization of olfactory proteins in various arthropods, but few related studies have focused on parasitic wasps. Here, the odorant carrier Niemann-Pick C2 protein of Baryscapus dioryctriae (BdioNPC2b) was studied in vitro and in vivo. Ligand binding analysis revealed that BdioNPC2b most strongly bound to 2-butyl-2-octenal and which compound could elicit an EAG response and attracted B. dioryctriae adults. Moreover, this odorant attractant significantly improved the reproductive efficiency of B. dioryctriae compared to that of the control. Then, the relationship between BdioNPC2b and 2-butyl-2-octenal was validated by RNAi, and site-directed mutagenesis revealed the involvement of three key residues of BdioNPC2b in binding to 2-butyl-2-octenal through hydrogen bonding. Our findings provide not only a deeper understanding of the olfactory function of NPC2 in wasps but also useful information for improving the performance of the parasitoid B. dioryctriae as a biological control agent.
Assuntos
Vespas , Animais , Vespas/genética , Aldeídos , Proteínas de Transporte/metabolismo , OlfatoRESUMO
Few population-based studies including younger adults have examined the potential of olfactory function tests to capture the degree of atrophy in memory-associated brain regions, which cannot be adequately explained by cognitive function tests screening for cognitive impairment. This population-based study investigated associations between high-resolution olfactory test data with few odours and grey matter volumes (GMVs) of the left and right hippocampi, amygdala, parahippocampi, and olfactory cortex, while accounting for differences in cognitive decline, in 1444 participants (aged 31-91 years). Regression analyses included intracranial volume (ICV)-normalised GMVs of eight memory-related regions as objective variables and age, sex, education duration, smoking history, olfaction test score, and the Montreal Cognitive Assessment-Japanese version (MoCA-J) score as explanatory variables. Significant relationships were found between olfactory test scores and ICV-normalised GMVs of the left and right hippocampi and left amygdala (p = 0.020, 0.024, and 0.028, respectively), adjusting for the MoCA-J score. The olfactory test score was significantly related to the right amygdalar GMV (p = 0.020) in older adults (age ≥ 65 years). These associations remained significant after applying Benjamini-Hochberg multiple testing correction (false discovery rate < 0.1). Therefore, olfactory and cognitive function tests may efficiently capture the degree of atrophy in the hippocampi and amygdala, especially in older adults.
Assuntos
Tonsila do Cerebelo , Cognição , Substância Cinzenta , Hipocampo , Imageamento por Ressonância Magnética , Humanos , Idoso , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Transversais , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Tonsila do Cerebelo/patologia , Tonsila do Cerebelo/diagnóstico por imagem , Hipocampo/patologia , Hipocampo/diagnóstico por imagem , Idoso de 80 Anos ou mais , Cognição/fisiologia , Adulto , Imageamento por Ressonância Magnética/métodos , Disfunção Cognitiva/patologia , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/diagnóstico por imagem , Testes Neuropsicológicos , Atrofia , Olfato/fisiologia , Tamanho do ÓrgãoRESUMO
Obesity, linked to chronic diseases, poses a global health challenge. While the role of the olfactory system in energy homeostasis is well-documented in rodents, its role in metabolism regulation and obesity in humans remains understudied. This review examines the interplay between olfactory function and metabolic alterations in human obesity and the effects of bariatric surgery on olfactory capabilities in humans. Adhering to PRISMA guidelines, a systematic review and meta-analysis was conducted, focusing exclusively on original human studies. From 51 articles, 14 were selected for the meta-analysis. It was found that variations in olfactory receptor genes influence the susceptibility to odors and predisposition to weight gain and poor eating habits. Bariatric surgery, particularly sleeve gastrectomy, shows significant improvements in olfactory function (SMD 2.37, 95% CI [0.96, 3.77], I = 92%, p = 0.001), especially regarding the olfactory threshold (SMD -1.65, 95% CI [-3.03, -0.27], I = 81%, p = 0.02). There is a bidirectional relationship between olfactory function and metabolism in humans. Bariatric surgery improves olfactory perception in obese patients, but it is still unclear if impacting the olfactory system directly affects eating behavior and the energy balance. However, these findings open novel avenues for future studies addressing the olfactory system as a novel target to alter systemic metabolism in humans.
RESUMO
Abstract Introduction Nasoseptal flap is widely used in reconstruction of the skull base to prevent cerebrospinal fluid leakage after surgery for skull base lesions. There has been a debate on whether more severe olfactory dysfunction occurs after nasoseptal flap elevation than the conventional trans-sphenoidal approach. Objective To compare the long-term recovery patterns associated with nasoseptal flap and the conventional trans-sphenoidal approach. Methods The subjects were divided into the conventional trans-sphenoidal approach group and the nasoseptal flap elevation group. We followed up self-reported olfactory score using the visual analogue scale and threshold discrimination identification (TDI) score of the Korean Version of the Sniffin Stick test II for 12 months, with olfactory training. Results The study included 31 patients who underwent the trans-sphenoidal approach. Compared with preoperative status, the mean visual analogue scale and TDI scores in the conventional trans-sphenoidal approach group recovered 2 months postoperatively, while in the nasoseptal flap elevation group the visual analogue scale and TDI scores recovered 6 months and 3 months after surgery, respectively. Twelve months after surgery, the visual analogue scale and TDI scores in the conventional trans-sphenoidal approach group were 9.3 ± 0.5 and 28.5 ± 4.3, while those from the nasoseptal flap elevation group were 8.9 ± 1.5 and 27.2 ± 4.7 (p = 0.326; 0.473). Only one of the patients in the nasoseptal flap elevation group had permanent olfactory dysfunction. Conclusion The olfactory function recovered more gradually in the nasoseptal flap elevation group than in the conventional trans-sphenoidal approach group, but there was no difference between the two groups after 6 months.
RESUMO
Abstract Introduction: Functions attributed to androgens have increased, ranging from the role in hypothalamic-pituitary-gonadal axis and reproductive behaviors to modulation of cognition, mood and some other functions. Sex differences and changes in circulating sex hormones affect human sensory function. In the literature, authors reported this kind of influence for olfaction predominantly in females. Objective: To investigate the effects of low testosterone levels on olfactory functions in males, in this prospective clinical study. Methods: Male patients diagnosed with prostate cancer were included. Thirty-nine patients with prostate cancer whose testosterone levels were lower than 50 ng/dL due to castration, were the study group. Thirty-one patients with prostate cancer who were not castrated with testosterone levels higher than 50 ng/dL were selected as the control group. Acoustic rhinometry and peak nasal inspiratory flow tests were performed for all participants; and for evaluation of olfactory function, both groups completed the Connecticut chemosensory clinical research center olfactory test. Results: The mean ages of the patients and controls were 69.6 ± 7.2 (57-89) and 66.3 ± 5.8 (50-78) years, respectively (= 0.039). There was a significant difference between groups in terms of testosterone levels (p < 0.0001). The multivariate logistic regression revealed testosterone level as the only predictive factor determining the difference between the groups. In terms of olfactory parameters, all scores were lower in the emasculated group (butanol threshold test p = 0.019, identification p = 0.059, and Connecticut center score p = 0.029) There was a significant correlation between testosterone levels and olfactory parameters (p = 0.023; p = 0.025 for identification and Connecticut center scores, respectively). Conclusion: Low testosterone levels in males have negative effects on olfactory functions. Further molecular research is required to understand the connection between testosterone and olfaction.
Resumo Introdução: As funções atribuídas aos andrógenos aumentaram, variam desde o papel no eixo hipotálamo-hipófise-gonadal e comportamentos reprodutivos até a modulação da cognição, humor e outras funções. As diferenças entre os sexos e as mudanças nos hormônios sexuais circulantes afetam a função sensorial humana. Na literatura, os autores relataram esse tipo de influência para o olfato, principalmente no sexo feminino. Objetivo: Investigar os efeitos dos baixos níveis de testosterona nas funções olfativas em homens, neste estudo clínico prospectivo. Método: Pacientes do sexo masculino com diagnóstico de câncer de próstata foram incluídos no estudo. Compreenderam o grupo de estudo 39 pacientes com câncer de próstata cujos níveis de testosterona eram inferiores a 50 ng/dL devido à castração. Foram determinados como grupo controle 31 pacientes com câncer de próstata que não foram emasculados, com níveis de testosterona superiores a 50 ng/dL. Testes de rinometria acústica e pico de fluxo inspiratório nasal foram feitos para todos os participantes; e para avaliação da função olfativa, ambos os grupos concluíram o teste olfativo do Connecticut chemosensory clinical research center. Resultados: A média da idade dos pacientes e controles foi de 69,6 ± 7,2 (57 ± 89) e 66,3 ± 5,8 (50 ± 78) anos, respectivamente (= 0,039). Houve uma diferença significante entre os grupos em relação a níveis de testosterona (p < 0,0001). A regressão logística multivariada revelou o nível de testosterona como o único fator preditivo que determinou a diferença entre os grupos. Em termos de parâmetros olfativos, todos os escores foram menores no grupo castrado (teste do limiar de butanol p = 0,019, identificação p = 0,059 e escore do Connecticut center p = 0,029). Houve uma correlação significante entre o nível de testosterona e os parâmetros olfativos (p = 0,023; p = 0,025 para identificação e escore do Connecticut center, respectivamente). Conclusão: Baixos níveis de testosterona em homens têm efeito negativo na função olfativa. Mais pesquisas moleculares são necessárias para entender a conexão entre testosterona e olfação.
Assuntos
Humanos , Masculino , Feminino , Transtornos do Olfato , Olfato , Testosterona , Estudos Prospectivos , Rinometria AcústicaRESUMO
Introducción: La cirugía endoscópica transesfenoidal en la exéresis de patología hipofisaria ha sido ratificada dentro de la mejores opciones para conseguir abordajes exitosos. Para cerrar la brecha ósea, se puede utilizar el colgajo nasoseptal, el cual lograría un cierre adecuado y seguro, evitando complicaciones como persistencia de fístulas de líquido cefalorraquídeo. Dentro de los probables efectos secundarios de este colgajo se señala la presencia de anosmia o hiposmia. Objetivo: Nuestro objetivo es mostrar los resultados obtenidos empleando la técnica del colgajo nasoseptal y la evaluación del olfato posoperatorio. Material y método: Incluimos 14 pacientes con diagnóstico de adenoma hipofisiario intervenidos en nuestro servicio entre diciembre 2014 a diciembre 2015. Se evaluaron diversos parámetros entre otros, olfatometría pre y posoperatorias. A todos se les realizó la técnica endoscópica transesfenoidal. Efectuando la disección del colgajo con la técnica tipo Hadad. La exéresis tumoral fue realizada por neurocirujano, se cubrió la osteotomía con este colgajo. Resultados: De los 14 pacientes, 13 llegaron al estado olfativo preoperatorio. 1 paciente se mantuvo hipósmico mantenidamente. En nuestro estudio, no hemos encontrado deterioro significativo en la calidad del sentido del olfato. Así como tampoco observamos otras complicaciones. Conclusiones: Esta experiencia aún inicial, estimamos que podría ya esbozar una tendencia de mantención de la función olfativa en este tipo de cirugía.
Introduction: Transsphenoidal endoscopic surgery resection of pituitary pathology has been ratified within the best options for successful approaches. To close the gap bone, you can use the nasoseptal flap, which achieved an adequate and secure closure, preventing complications such as persistent cerebrospinal fluid leaks. Among possible side effects of this flap anosmia-hyposmia noted. Aim: Our goal is to show the results obtained using the technique of nasoseptal flap and postoperative evaluation of smell. Material and method: We included 14 patients with a diagnosis of pituitary adenoma surgery in our department between December 2014 to December 2015. Various parameters were evaluated pre and post operative, specially olfactory function. All underwent transsphenoidal endoscopic technique. Performing dissection flap with the technical type Hadad. The tumor resection was performed by neurosurgeon, osteotomy covered with this flap. Results: Of the 14 patients, 13 reached the olfactory preoperative state. 1 patient remained with hyposmia. In our study, we found no significant deterioration in the quality of the sense of smell. Not other complications were found. Conclusions: This is an initial experience, and we estimate that could outline a trend of maintaining olfactory function in this surgery approach.
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Adenoma/cirurgia , Endoscopia/métodos , Neoplasias Hipofisárias/cirurgia , Seio Esfenoidal/cirurgia , Adenoma/fisiopatologia , Epidemiologia Descritiva , Septo Nasal/irrigação sanguínea , Neoplasias Hipofisárias/fisiopatologia , Olfato/fisiologia , Retalhos Cirúrgicos , Resultado do TratamentoRESUMO
ABSTRACT. Olfactory perception, although restricted to just a few contexts in everyday life, is key in medicine. Several dementia conditions have been associated with early loss of olfactory discrimination. Despite the fact that several brain areas have been associated with olfaction in functional magnetic resonance imaging (fMRI), the mechanisms by which emotional valence is conveyed to the brain are not fully understood. Methods. In this study, we compared cerebral activations by olfactory stimuli using different emotional valence stimuli on event-related fMRI. We used three standard olfactory odorants with different valence (positive, neutral and negative). Forty-three healthy subjects (22 males) were scanned on a 3.0T MR system. Olfactory stimulation was attained through a delivery system synchronized with image acquisition and subjects´ breathing instructions. fMRI data analysis was performed by the FSL package (Oxford University) including head movement correction, GLM modeling of the neurovascular (BOLD) response and group activation maps produced at p<0.05 and corrected for multiple comparison. Results. Increased cerebral responses within the anterior cingulate, amygdaloid nuclei, as well as the dorsolateral prefrontal, occipital and orbitofrontal cortices were observed in positive and negative valence conditions, while response to neutral valence arousal was less intense and not observed in the amygdaloid complex. The most significant statistical response aroused from the stimuli clusters was observed in the negative condition. Conclusion. The results of the present study support the hypothesis that neutral stimuli may be more sensitive to early losses in pathological conditions, particularly dementia.
RESUMO. Apesar de praticamente restrita a alguns contextos na rotina diária, a percepção de estímulos olfativos é bastante relevante em medicina. Várias condições patológicas, e em particular as demências, estão associadas à perda precoce da capacidade de discriminação e percepção olfativa. Apesar de estudos de ressonância magnética funcional (RMf), terem identificado várias áreas cerebrais relacionadas à percepção olfativa, ainda não sabemos quais destas são moduladas pela valência emocional do estímulo olfativo. Neste estudo investigamos o padrão de resposta cerebral à odorantes com diferentes valências emocionais em indivíduos saudáveis estudados por RMf relacionada à eventos. Métodos. Comparamos a resposta cerebral em um desenho de RMf relacionado à eventos e com uso de três estímulos olfatórios padronizados e com diferentes valências emocionais (positiva, neutra e negativa). Quarenta e três indivíduos normais (22 homens) foram estudados por RMf relacionada à eventos em aparelho de 3T. A estimulação olfativa foi realizada por meio de sistema sincronizado à aquisição das imagens e às instruções dadas aos sujeitos. A análise dos dados foi feita por meio do software FSL (Universidade de Oxford) e incluiu correções de movimento, modelagem de sinal com técnica GLM e mapas de grupo com nível de significância < 0,5. Resultados. As respostas cerebrais no cíngulo anterior, bem como no córtex dorsolateral pré-frontal, occipital e órbitofrontal foram observadas nas condições de valência positiva e negativa, porém a resposta ao estímulo neutro foi menos intensa e não foi observada em complexos amigdaloides. A resposta estatística mais significante foi observada no cluster de estímulos com valência negativa. Conclusão. Estes dados representam evidências para a hipótese de que possivelmente a perda da percepção discriminativa de estímulos com valência emocional neutra pode ser mais sensível em relação às manifestações iniciais de condições patológicas, inclusive demências.
Assuntos
Humanos , Olfato , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , OdorantesRESUMO
The idiopathic Parkinson disease (IPD) is traditionally diagnosed by motor signs, but non-motor symptoms and signs are frequent and may help in the clinical diagnosis. PURPOSE: To evaluate the olfactory function in Brazilian healthy subjects, patients with early-onset PD (EOPD) and late-onset PD (LOPD) using the Sniffin' Sticks odor-identification test (SST). METHOD: We studied 70 patients with IPD (19 EOPD and 51 LOPD) and 70 controls matched for gender, age and years of schooling. Subjects with dementia and loss of smell for other reasons were excluded. RESULTS: The SST showed a significant difference (p<0.001) between groups: control groups (12.0±0.3), EOPD (8.3±0.7), and LOPD (6.7±0.4) when the groups were adjusted for gender, age, disease duration, and years of schooling. CONCLUSION: Both groups of IPD patients presented olfactory impairments, but those whose symptoms started before 45 years-old (EOPD) had better sense of smell than the LOPD patients.
A doença de Parkinson idiopática (DPI) tradicionalmente é diagnosticada pelos sinais motores, porém os sinais e sintomas não-motores são freqüentes. OBJETIVO: Avaliar a função olfatória em sujeitos brasileiros saudáveis e em pacientes com doença de Parkinson precoce (DPP) e doença de Parkinson tardia (DPT) utilizando o teste Sniffin' Sticks (TSS) de identificação de odores. MÉTODO: Setenta pacientes com DPI (19 DPP e 51 DPT) e 70 controles pareados para as variáveis gênero, idade e anos de escolaridade foram estudados. Foram excluídos sujeitos com demência e/ou perda de olfato por outros motivos. RESULTADOS: O TSS mostrou uma diferença significativa (p<0,001) entre os grupos controle (12,0±0,3), DPP (8,3±0,7) e DPT (6,7±0,4) quando os grupos foram ajustados para sexo, idade, duração da doença e anos de escolaridade. CONCLUSÃO: Pacientes com DPI apresentam redução do olfato, sendo mais importante entre aqueles com DPT. A disfunção olfatória pode ser uma ferramenta muito útil no diagnóstico de DPI.