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1.
JAMA ; 331(13): 1109-1121, 2024 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-38497797

RESUMO

Importance: Since 2015, US government and related personnel have reported dizziness, pain, visual problems, and cognitive dysfunction after experiencing intrusive sounds and head pressure. The US government has labeled these anomalous health incidents (AHIs). Objective: To assess whether participants with AHIs differ significantly from US government control participants with respect to clinical, research, and biomarker assessments. Design, Setting, and Participants: Exploratory study conducted between June 2018 and July 2022 at the National Institutes of Health Clinical Center, involving 86 US government staff and family members with AHIs from Cuba, Austria, China, and other locations as well as 30 US government control participants. Exposures: AHIs. Main Outcomes and Measures: Participants were assessed with extensive clinical, auditory, vestibular, balance, visual, neuropsychological, and blood biomarkers (glial fibrillary acidic protein and neurofilament light) testing. The patients were analyzed based on the risk characteristics of the AHI identifying concerning cases as well as geographic location. Results: Eighty-six participants with AHIs (42 women and 44 men; mean [SD] age, 42.1 [9.1] years) and 30 vocationally matched government control participants (11 women and 19 men; mean [SD] age, 43.8 [10.1] years) were included in the analyses. Participants with AHIs were evaluated a median of 76 days (IQR, 30-537) from the most recent incident. In general, there were no significant differences between participants with AHIs and control participants in most tests of auditory, vestibular, cognitive, or visual function as well as levels of the blood biomarkers. Participants with AHIs had significantly increased fatigue, depression, posttraumatic stress, imbalance, and neurobehavioral symptoms compared with the control participants. There were no differences in these findings based on the risk characteristics of the incident or geographic location of the AHIs. Twenty-four patients (28%) with AHI presented with functional neurological disorders. Conclusions and Relevance: In this exploratory study, there were no significant differences between individuals reporting AHIs and matched control participants with respect to most clinical, research, and biomarker measures, except for objective and self-reported measures of imbalance and symptoms of fatigue, posttraumatic stress, and depression. This study did not replicate the findings of previous studies, although differences in the populations included and the timing of assessments limit direct comparisons.


Assuntos
Família , Governo , Masculino , Humanos , Feminino , Adulto , Biomarcadores , Fadiga , Medidas de Segurança
2.
JAMA ; 331(13): 1122-1134, 2024 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-38497822

RESUMO

Importance: US government personnel stationed internationally have reported anomalous health incidents (AHIs), with some individuals experiencing persistent debilitating symptoms. Objective: To assess the potential presence of magnetic resonance imaging (MRI)-detectable brain lesions in participants with AHIs, with respect to a well-matched control group. Design, Setting, and Participants: This exploratory study was conducted at the National Institutes of Health (NIH) Clinical Center and the NIH MRI Research Facility between June 2018 and November 2022. Eighty-one participants with AHIs and 48 age- and sex-matched control participants, 29 of whom had similar employment as the AHI group, were assessed with clinical, volumetric, and functional MRI. A high-quality diffusion MRI scan and a second volumetric scan were also acquired during a different session. The structural MRI acquisition protocol was optimized to achieve high reproducibility. Forty-nine participants with AHIs had at least 1 additional imaging session approximately 6 to 12 months from the first visit. Exposure: AHIs. Main Outcomes and Measures: Group-level quantitative metrics obtained from multiple modalities: (1) volumetric measurement, voxel-wise and region of interest (ROI)-wise; (2) diffusion MRI-derived metrics, voxel-wise and ROI-wise; and (3) ROI-wise within-network resting-state functional connectivity using functional MRI. Exploratory data analyses used both standard, nonparametric tests and bayesian multilevel modeling. Results: Among the 81 participants with AHIs, the mean (SD) age was 42 (9) years and 49% were female; among the 48 control participants, the mean (SD) age was 43 (11) years and 42% were female. Imaging scans were performed as early as 14 days after experiencing AHIs with a median delay period of 80 (IQR, 36-544) days. After adjustment for multiple comparisons, no significant differences between participants with AHIs and control participants were found for any MRI modality. At an unadjusted threshold (P < .05), compared with control participants, participants with AHIs had lower intranetwork connectivity in the salience networks, a larger corpus callosum, and diffusion MRI differences in the corpus callosum, superior longitudinal fasciculus, cingulum, inferior cerebellar peduncle, and amygdala. The structural MRI measurements were highly reproducible (median coefficient of variation <1% across all global volumetric ROIs and <1.5% for all white matter ROIs for diffusion metrics). Even individuals with large differences from control participants exhibited stable longitudinal results (typically, <±1% across visits), suggesting the absence of evolving lesions. The relationships between the imaging and clinical variables were weak (median Spearman ρ = 0.10). The study did not replicate the results of a previously published investigation of AHIs. Conclusions and Relevance: In this exploratory neuroimaging study, there were no significant differences in imaging measures of brain structure or function between individuals reporting AHIs and matched control participants after adjustment for multiple comparisons.


Assuntos
Imagem de Tensor de Difusão , Substância Branca , Humanos , Feminino , Adulto , Masculino , Imagem de Tensor de Difusão/métodos , Reprodutibilidade dos Testes , Teorema de Bayes , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Imageamento por Ressonância Magnética/métodos , Neuroimagem , Substância Branca/patologia , Família , Governo , Medidas de Segurança
3.
J Pediatr Adolesc Gynecol ; 37(2): 126-131, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37863175

RESUMO

OBJECTIVE: Real-time tracking of menstrual bleeding is a barrier to research due to limitations with traditional data collection tools. This prospective cohort study utilized a mobile application (TDot app) in young adolescents aged 10-14 years to assess the relationship between heavy menstrual bleeding (HMB), dysmenorrhea, and activity limitation. METHODS: Menstrual cycles were captured over six months in real-time using the Pictorial Blood loss Assessment Chart (PBAC). A median PBAC score of >100 was used to identify participants with HMB. Participants also completed a modified WaLIDD (Working ability, Location, Intensity, Days of pain, Dysmenorrhea) scale. Impact of menses on daily activities was collected for each cycle. RESULTS: A total of 160 participants enrolled and 100 (63%) participants with ≥3 cycles recorded in the mobile app were analyzed. HMB was noted in 41% of participants. Median modified WaLIDD score was significantly higher in participants with HMB than those without HMB (p=0.01). No significant differences were found in activity limitations between participants with and without HMB (p=0.34). Median modified WaLIDD score for participants with activity limitation was significantly higher than those without activity limitation (p=0.01). CONCLUSION: Utilizing mobile app technology, we were able to gather real-time menstrual outcome data from young adolescents on heaviness of flow, dysmenorrhea and activity limitations. While we did not find that patients with HMB were more likely to have activity limitations, we did find that those with limitations had modestly higher dysmenorrhea scores. Future studies should focus on identifying additional variables that impact activity limitation during menstruation.


Assuntos
Menorragia , Aplicativos Móveis , Feminino , Humanos , Adolescente , Dismenorreia , Estudos Prospectivos , Menstruação
4.
Laryngoscope ; 133(10): 2770-2778, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-36583617

RESUMO

OBJECTIVES: To characterize otologic and audiologic manifestations in our NF1 cohort and explore the relationship between otologic and audiologic findings in a subset of patients with ear-related plexiform neurofibromas (PNs). METHODS: Audiologic and otologic clinical evaluations were conducted on 102 patients with NF1 in a natural history study (5-45 years; M = 14.4 years; Mdn = 14). Testing included pure tone and speech audiometry, middle ear function, neurodiagnostic auditory brainstem response (ABR), auditory processing, and MRIs of the head and neck region. Patients referred to this study had an overall higher incidence and burden of PNs than the overall NF1 population. RESULTS: The majority of subjects in this cohort had normal hearing sensitivity (81%) and normal middle ear function (78%). Nineteen participants had hearing loss that ranged in degree from mild to profound, with the majority in the mild range. Hearing loss was twice as likely to be conductive than sensorineural. In patients with ear-related PNs (n = 12), hearing loss was predominantly conductive (60%). Seventy-five percent of ears with PNs had atypical tympanometric tracings that could not be characterized by the classic categories. In all 20 patients with a PN in the temporal bone, the ear canal was affected, and the PNs often extended to the surrounding soft tissue regions. CONCLUSIONS: People with NF1-related PNs in the temporal bone and adjacent skull base should have audiometric and otologic monitoring. Addressing hearing concerns should be part of routine clinical evaluations in patients with NF1. Magnetic resonance imaging (MRI) should be performed in patients with NF1 who have hearing loss. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:2770-2778, 2023.


Assuntos
Surdez , Perda Auditiva , Neurofibroma Plexiforme , Neurofibromatose 1 , Humanos , Criança , Adulto Jovem , Neurofibromatose 1/complicações , Neurofibroma Plexiforme/complicações , Audiometria , Audição , Perda Auditiva/diagnóstico , Perda Auditiva/etiologia
5.
Otolaryngol Head Neck Surg ; 166(2): 357-362, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-33971761

RESUMO

OBJECTIVE: Loeys-Dietz syndrome (LDS) is a rare genetic connective tissue disorder resulting from TGF-ß signaling pathway defects and characterized by a wide spectrum of aortic aneurysm, arterial tortuosity, and various extravascular abnormalities. This study describes the audiologic, otologic, and craniofacial manifestations of LDS. STUDY DESIGN: Consecutive cross-sectional study. SETTING: Tertiary medical research institute. METHODS: Audiologic and clinical evaluations were conducted among 36 patients (mean ± SD age, 24 ± 17 years; 54% female) with genetically confirmed LDS. Cases were categorized into genetically based LDS types 1 to 4 (TGFBR1, TGFBR2, SMAD3, TGFB2, respectively). Audiometric characteristics included degree and type of hearing loss: subclinical, conductive, mixed, and sensorineural. RESULTS: LDS types 1 to 4 included 11, 13, 5, and 7 patients, respectively. In LDS-1, 27% had bilateral conductive hearing loss; 9%, unilateral mixed; and 36%, subclinical. In LDS-2, 38% had conductive hearing loss and 38% subclinical. In LDS-3 and LDS-4, 40% and 43% had bilateral sensorineural hearing loss, respectively. Degree of hearing loss ranged from mild to moderate. Bifid uvula was observed only in LDS-1 (55%) and LDS-2 (62%). Submucosal/hard cleft palates were primarily in LDS-1 and LDS-2. Posttympanostomy tympanic membrane perforations occurred in 45% (10/22 ears) of LDS-1 and LDS-2. There were 4 cases of cholesteatoma: 3 middle ear (LDS-1 and LDS-2) and 1 external ear canal (LDS-3). CONCLUSION: Conductive hearing loss, bifid uvula/cleft palate, and posttympanostomy tympanic membrane perforation are more common in LDS-1 and LDS-2 than LDS-3 and LDS-4, while sensorineural hearing loss was present only in LDS-3 and LDS-4. These LDS-associated key clinical presentations may facilitate an early diagnosis of LDS and thus prompt intervention to prevent related detrimental outcomes.


Assuntos
Perda Auditiva/genética , Adolescente , Adulto , Idoso , Audiometria , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Síndrome de Loeys-Dietz/genética , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
6.
Am J Audiol ; 30(3S): 800-809, 2021 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-34549989

RESUMO

Purpose Specific classes of antibiotics, such as aminoglycosides, have well-established adverse events producing permanent hearing loss, tinnitus, and balance and/or vestibular problems (i.e., ototoxicity). Although these antibiotics are frequently used to treat pseudomonas and other bacterial infections in patients with cystic fibrosis (CF), there are no formalized recommendations describing approaches to implementation of guideline adherent ototoxicity monitoring as part of CF clinical care. Method This consensus statement was developed by the International Ototoxicity Management Working Group (IOMG) Ad Hoc Committee on Aminoglycoside Antibiotics to address the clinical need for ototoxicity management in CF patients treated with known ototoxic medications. These clinical protocol considerations were created using consensus opinion from a community of international experts and available evidence specific to patients with CF, as well as published national and international guidelines on ototoxicity monitoring. Results The IOMG advocates four clinical recommendations for implementing routine and guideline adherent ototoxicity management in patients with CF. These are (a) including questions about hearing, tinnitus, and balance/vestibular problems as part of the routine CF case history for all patients; (b) utilizing timely point-of-care measures; (c) establishing a baseline and conducting posttreatment evaluations for each course of intravenous ototoxic drug treatment; and (d) repeating annual hearing and vestibular evaluations for all patients with a history of ototoxic antibiotic exposure. Conclusion Increased efforts for implementation of an ototoxicity management program in the CF care team model will improve identification of ototoxicity signs and symptoms, allow for timely therapeutic follow-up, and provide the clinician and patient an opportunity to make an informed decision about potential treatment modifications to minimize adverse events. Supplemental Material https://doi.org/10.23641/asha.16624366.


Assuntos
Fibrose Cística , Aminoglicosídeos/efeitos adversos , Antibacterianos/efeitos adversos , Fibrose Cística/complicações , Fibrose Cística/diagnóstico , Fibrose Cística/tratamento farmacológico , Audição , Testes Auditivos , Humanos
7.
Clin Infect Dis ; 73(9): e2789-e2798, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-33383587

RESUMO

BACKGROUND: Cryptococcal meningoencephalitis (CM) is a major cause of mortality in immunosuppressed patients and previously healthy individuals. In the latter, a post-infectious inflammatory response syndrome (PIIRS) is associated with poor clinical response despite antifungal therapy and negative cerebrospinal fluid (CSF) cultures. Data on effective treatment are limited. METHODS: Between March 2015 and March 2020, 15 consecutive previously healthy patients with CM and PIIRS were treated with adjunctive pulse corticosteroid taper therapy (PCT) consisting of intravenous methylprednisolone 1 gm daily for 1 week followed by oral prednisone 1 mg/kg/day, tapered based on clinical and radiological response plus oral fluconazole. Montreal cognitive assessments (MOCA), Karnofsky performance scores, magnetic resonance imaging (MRI) brain scanning, ophthalmic and audiologic exams, and CSF parameters including cellular and soluble immune responses were compared at PIIRS diagnosis and after methylprednisolone completion. RESULTS: The median time from antifungal treatment to steroid initiation was 6 weeks. The most common symptoms at PIIRS diagnosis were altered mental status and vision changes. All patients demonstrated significant improvements in MOCA and Karnofsky scores at 1 month (P < .0003), which was accompanied by improvements in CSF glucose, white blood cell (WBC) count, protein, cellular and soluble inflammatory markers 1 week after receiving corticosteroids (CS) (P < .003). All patients with papilledema and visual field deficits also exhibited improvement (P < .0005). Five out of 7 patients who underwent audiological testing demonstrated hearing improvement. Brain MRI showed significant improvement of radiological findings (P = .001). CSF cultures remained negative. CONCLUSIONS: PCT in this small cohort of PIIRS was associated with improvements in CM-related complications with minimal toxicity in the acute setting.


Assuntos
Cryptococcus , Meningite Criptocócica , Meningoencefalite , Corticosteroides/uso terapêutico , Antifúngicos/uso terapêutico , Fluconazol , Humanos , Meningite Criptocócica/tratamento farmacológico , Meningoencefalite/tratamento farmacológico
8.
Am J Med Genet C Semin Med Genet ; 184(3): 618-630, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32866347

RESUMO

The spectrum of peroxisomal disorders is wide and comprises individuals that die in the first year of life, as well as people with sensorineural hearing loss, retinal dystrophy and amelogenesis imperfecta. In this article, we describe three patients; two diagnosed with Heimler syndrome and a third one with a mild-intermediate phenotype. We arrived at these diagnoses by conducting complete ophthalmic (National Eye Institute), auditory (National Institute of Deafness and Other Communication Disorders), and dental (National Institute of Dental and Craniofacial Research) evaluations, as well as laboratory and genetic testing. Retinal degeneration with macular cystic changes, amelogenesis imperfecta, and sensorineural hearing loss were features shared by the three patients. Patients A and C had pathogenic variants in PEX1 and Patient B, in PEX6. Besides analyzing these cases, we review the literature regarding mild peroxisomal disorders, their pathophysiology, genetics, differential diagnosis, diagnostic methods, and management. We suggest that peroxisomal disorders are considered in every child with sensorineural hearing loss and retinal degeneration. These patients should have a dental evaluation to rule out amelogenesis imperfecta as well as audiologic examination and laboratory testing including peroxisomal biomarkers and genetic testing. Appropriate diagnosis can lead to better genetic counseling and management of the associated comorbidities.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/genética , Amelogênese Imperfeita/genética , Perda Auditiva Neurossensorial/genética , Proteínas de Membrana/genética , Unhas Malformadas/genética , Transtornos Peroxissômicos/genética , Adolescente , Adulto , Amelogênese Imperfeita/complicações , Amelogênese Imperfeita/diagnóstico , Amelogênese Imperfeita/patologia , Criança , Feminino , Aconselhamento Genético , Perda Auditiva Neurossensorial/complicações , Perda Auditiva Neurossensorial/diagnóstico , Perda Auditiva Neurossensorial/patologia , Humanos , Masculino , Unhas Malformadas/complicações , Unhas Malformadas/diagnóstico , Unhas Malformadas/patologia , Linhagem , Transtornos Peroxissômicos/complicações , Transtornos Peroxissômicos/diagnóstico , Transtornos Peroxissômicos/patologia , Fenótipo , Degeneração Retiniana/diagnóstico , Degeneração Retiniana/genética , Degeneração Retiniana/patologia , Adulto Jovem
9.
PLoS Biol ; 11(9): e1001648, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24019759

RESUMO

Oocytes are stockpiled with proteins and mRNA that are required to drive the initial mitotic divisions of embryogenesis. But are there proteins specific to meiosis whose levels must be decreased to begin embryogenesis properly? The Drosophila protein Cortex (Cort) is a female, meiosis-specific activator of the Anaphase Promoting Complex/Cyclosome (APC/C), an E3 ubiquitin ligase. We performed immunoprecipitation of Cortex followed by mass spectrometry, and identified the Polo kinase inhibitor Matrimony (Mtrm) as a potential interactor with Cort. In vitro binding assays showed Mtrm and Cort can bind directly. We found Mtrm protein levels to be reduced dramatically during the oocyte-to-embryo transition, and this downregulation did not take place in cort mutant eggs, consistent with Mtrm being a substrate of APC(Cort). We showed that Mtrm is subject to APC(Cort)-mediated proteasomal degradation and have identified a putative APC/C recognition motif in Mtrm that when mutated partially stabilized the protein in the embryo. Furthermore, overexpression of Mtrm in the early embryo caused aberrant nuclear divisions and developmental defects, and these were enhanced by decreasing levels of active Polo. These data indicate APC(Cort) ubiquitylates Mtrm at the oocyte-to-embryo transition, thus preventing excessive inhibition of Polo kinase activity due to Mtrm's presence.


Assuntos
Ciclossomo-Complexo Promotor de Anáfase/metabolismo , Proteínas Cdc20/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Drosophila/metabolismo , Oócitos/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Ciclossomo-Complexo Promotor de Anáfase/genética , Animais , Proteínas de Ciclo Celular/biossíntese , Linhagem Celular , Regulação para Baixo , Proteínas de Drosophila/antagonistas & inibidores , Proteínas de Drosophila/biossíntese , Drosophila melanogaster/embriologia , Drosophila melanogaster/genética , Desenvolvimento Embrionário/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Meiose , Ligação Proteica , Proteínas Serina-Treonina Quinases/antagonistas & inibidores
10.
Proc Natl Acad Sci U S A ; 110(13): E1222-31, 2013 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-23479640

RESUMO

Drosophila melanogaster Polo kinase physically interacts with, and is repressed by, the Matrimony (Mtrm) protein during oogenesis. Females heterozygous for a deletion of the mtrm gene display defects in chromosome segregation at meiosis I. However, a complete absence of Mtrm results in both meiotic catastrophe and female sterility. We show that three phosphorylated residues in an N-terminal region in Mtrm are required for Mtrm::Polo binding. However, this binding is noncanonical; it does not require either a complete S-pS/pT-P motif in Mtrm or key residues in the Polo-box domain of Polo that allow Polo to bind phosphorylated substrates. By using fluorescence cross-correlation spectroscopy to characterize the Mtrm::Polo interaction in vivo, we show that a sterile α-motif (SAM) domain located at the C terminus of Mtrm increases the stability of Mtrm::Polo binding. Although Mtrm's C-terminal SAM domain is not required to rescue the chromosome segregation defects observed in mtrm/+ females, it is essential to prevent both meiotic catastrophe and the female sterility observed in mtrm/mtrm females. We propose that Polo's interaction with the cluster of phosphorylated residues alone is sufficient to rescue the meiosis I defect. However, the strengthening of Mtrm::Polo binding mediated by the SAM domain is necessary to prevent meiotic catastrophe and ensure female fertility. Characterization of the Mtrm::Polo interaction, as well as that of other Polo regulators, may assist in the design of a new class of Polo inhibitors to be used as targeted anticancer therapeutic agents.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas de Drosophila/metabolismo , Meiose/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Proteínas de Drosophila/genética , Drosophila melanogaster , Feminino , Masculino , Fosforilação/fisiologia , Ligação Proteica/fisiologia , Proteínas Serina-Treonina Quinases/genética , Estrutura Terciária de Proteína , Espectrometria de Fluorescência
11.
Eur J Nucl Med Mol Imaging ; 30(2): 301-5, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12552350

RESUMO

Vagus nerve stimulation (VNS) has gained recognition as a treatment for refractory epilepsies where surgical treatment is not possible. While it appears that this treatment is effective in some patients, the mechanism of action is not clearly understood. The purpose of this study was to clarify findings of other positron emission tomography and single-photon emission tomography (SPET) investigations by measuring the acute effect of VNS on patients who have normal cerebral anatomy on magnetic resonance imaging and who have not previously been exposed to VNS. We investigated six subjects (two males and four females, mean age 29.5 years, range 21-39 years) with intractable epilepsy. One patient had primary generalised epilepsy causing generalised tonic-clonic seizures; the remaining five patients had localisation-related epilepsy causing complex partial seizures. SPET imaging was performed using 250 MBq of (99m)Tc-HMPAO and a four-scan paradigm - two with and two without stimulation. The stimulation began at VNS current levels of 0.25 mA and was increased according to the limit of patients' tolerance, usually defined by coughing or discomfort. The stimulating waveform was of continuous square wave pulses of 500 micro s duration at 30 Hz. Image analysis was by SPM99. Reduced perfusion during stimulation was observed in the ipsilateral brain stem, cingulate, amygdala and hippocampus and contralateral thalamus and cingulate. The study provides further evidence of the involvement of the limbic system in the action of vagal nerve stimulation.


Assuntos
Terapia por Estimulação Elétrica/métodos , Epilepsia/diagnóstico por imagem , Epilepsia/terapia , Tecnécio Tc 99m Exametazima , Nervo Vago/fisiopatologia , Adulto , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Circulação Cerebrovascular , Doença Crônica , Epilepsia/fisiopatologia , Feminino , Humanos , Sistema Límbico/irrigação sanguínea , Sistema Límbico/diagnóstico por imagem , Sistema Límbico/fisiopatologia , Masculino , Compostos Radiofarmacêuticos , Tomografia Computadorizada de Emissão de Fóton Único/métodos
12.
Eur J Nucl Med Mol Imaging ; 30(2): 296-300, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12552349

RESUMO

An acetylcholine deficit remains the most consistent neurotransmitter abnormality found in Alzheimer's disease and various therapeutic agents have been targeted at this. In this study we investigated the action of Donepezil, a cholinesterase inhibitor that has few side-effects. In particular we set out to investigate whether muscarinic acetylcholine receptor (mAChR) availability influences the response to this therapy. We used the novel single-photon emission tomography (SPET) tracer (R, R)[(123)I]I-quinuclidinyl benzilate (R, R[(123)I]I-QNB), which has high affinity for the M1 subtype of mAChR. Regional cerebral perfusion was also assessed using technetium-99m hexamethylpropylene amine oxime. We investigated 20 patients on Donepezil treatment and ten age-matched controls. The results showed a reduction in (R, R)[(123)I]I-QNB binding in the caudal anterior cingulate in patients compared with controls and relatively high binding in the putamen and rostral anterior cingulate, suggesting a relative sparing of mAChR in these regions. The main finding of the study was that mAChR availability as assessed by (R, R)[(123)I]I-QNB binding did not distinguish responders from non-responders. Interestingly, we found that the extent of cognitive improvement showed no positive correlation with (R, R)[(123)I]I-QNB binding in any brain region but was inversely related to binding in the insular cortex. This suggests that, within the advised cognitive performance band for use of Donepezil, response is greater in those patients with evidence of a more marked cholinergic deficit. A larger study should investigate this.


Assuntos
Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/tratamento farmacológico , Indanos/administração & dosagem , Piperidinas/administração & dosagem , Quinuclidinil Benzilato/análogos & derivados , Receptores Muscarínicos/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/metabolismo , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Circulação Cerebrovascular , Inibidores da Colinesterase/administração & dosagem , Donepezila , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Quinuclidinil Benzilato/farmacocinética , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Receptor Muscarínico M1 , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Estatística como Assunto , Tecnécio Tc 99m Exametazima , Distribuição Tecidual , Resultado do Tratamento
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