Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 96
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Neurosci ; 39(37): 7321-7331, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31270155

RESUMO

Sensorimotor deficits are prevalent in many neurodevelopmental disorders like autism, including one of its common genetic etiologies, a 600 kb reciprocal deletion/duplication at 16p11.2. We have previously shown that copy number variations of 16p11.2 impact regional brain volume, white matter integrity, and early sensory responses in auditory cortex. Here, we test the hypothesis that abnormal cortical neurophysiology is present when genes in the 16p11.2 region are haploinsufficient, and in humans that this in turn may account for behavioral deficits specific to deletion carriers. We examine sensorimotor cortical network activity in males and females with 16p11.2 deletions compared with both typically developing individuals, and those with duplications of 16p11.2, using magnetoencephalographic imaging during preparation of overt speech or hand movements in tasks designed to be easy for all participants. In deletion carriers, modulation of beta oscillations (12-30 Hz) were increased during both movement types over effector-specific regions of motor cortices compared with typically developing individuals or duplication carriers, with no task-related performance differences between cohorts, even when corrected for their own cognitive and sensorimotor deficits. Reduced left hemispheric language specialization was observed in deletion carriers but not in duplication carriers. Neural activity over sensorimotor cortices in deletion carriers was linearly related to clinical measures of speech and motor impairment. These findings link insufficient copy number repeats at 16p11.2 to excessive neural activity (e.g., increased beta oscillations) in motor cortical networks for speech and hand motor control. These results have significant implications for understanding the neural basis of autism and related neurodevelopmental disorders.SIGNIFICANCE STATEMENT The recurrent ∼600 kb deletion at 16p11.2 (BP4-BP5) is one of the most common genetic etiologies of ASD and, more generally, of neurodevelopmental disorders. Here, we use high-resolution magnetoencephalographic imaging (MEG-I) to define with millisecond precision the underlying neurophysiological signature of motor impairments for individuals with 16p11.2 deletions. We identify significant increases in beta (12-30 Hz) suppression in sensorimotor cortices related to performance during speech and hand movement tasks. These findings not only provide a neurophysiological phenotype for the clinical presentation of this genetic deletion, but also guide our understanding of how genetic variation encodes for neural oscillatory dynamics.

2.
Tex Heart Inst J ; 46(2): 139-142, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31236082

RESUMO

Reversible cerebral vasoconstriction syndrome is a rare disorder associated with neurologic symptoms secondary to diffuse cerebral vasospasm. Cardiac involvement in this disease is exceedingly rare. A 50-year-old woman was admitted to our hospital for evaluation of chest pain. During a 3-year period, she had been admitted multiple times because of chest pain and elevated serum cardiac enzymes. Transthoracic echocardiograms showed transient wall-motion abnormalities; however, coronary angiograms revealed no coronary artery disease. At the current admission, she had a thunderclap headache, and cerebral angiograms revealed diffuse cerebral vasoconstriction that improved after verapamil infusion, confirming the diagnosis of reversible cerebral vasoconstriction syndrome. The patient was treated successfully with oral diltiazem and had no recurrence of symptoms. We describe what we think is the first reported case of coronary artery spasm in association with reversible cerebral vasoconstriction syndrome. Future research should be focused on identifying treatment options and defining the mechanisms by which the cerebral and coronary vasculature are affected.

3.
Pediatr Radiol ; 49(9): 1192-1200, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31177318

RESUMO

BACKGROUND: Diffusion-tensor imaging (DTI) depicts the movement of water through columns of cartilage and newly formed bone and provides information about velocity of growth and growth potential. OBJECTIVE: To determine the correlation between DTI tractography parameters of the distal femoral physis and metaphysis and the height change after DTI in pubertal and post-pubertal children. MATERIALS AND METHODS: We retrospectively analyzed DTI images of the knee in 47 children with a mean age of 14.1 years in a 2-year period. In sagittal echoplanar DTI studies, regions of interest were placed in the femoral physis. Tractography was performed using a fractional anisotropy threshold of 0.15 and a maximum turning angle of 40°. The sample was divided to assess short-term and long-term growth after DTI. Short-term growth (n=25) was the height change between height at MRI and 1 year later. Long-term growth (n=36) was the height gain between height at MRI and at the growth plateau. RESULTS: For the short-term group, subjects with larger tract volume (R2=0.40) and longer track lengths (R2=0.38) had larger height gains (P<0.01). For the long-term group, subjects with larger tract volume (R2=0.43) and longer track lengths (R2=0.32) had a larger height gain at the growth plateau (P<0.01). Intra- and inter-observer variability were good-excellent. CONCLUSION: Follow-up data of growth 1 year after DTI evaluation and at skeletal maturity confirms that DTI parameters are associated with the amount of post-imaging growth.

4.
Psychother Res ; : 1-8, 2019 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-31119983

RESUMO

Psychotherapists may offer patients more or less involvement when deciding on a treatment. The aim of the present research was to examine whether perceptions of the treatment and therapist differ when a therapist uses a paternalistic style in making treatment decisions or a more collaborative approach, in which the patient helps in selecting treatment. In the study, 172 participants, recruited from a university setting and a national sample, listened to a simulated conversation representing either a paternalism or informed-choice model of a therapist-patient interaction. The participants then rated their expectation the treatment would help the patient, their perception of the therapist's trustworthiness, and their own preference for relying on clinicians for knowledge and decisions. Analysis indicated that among participants preferring to rely on clinicians, perceptions did not differ reliably based on the type of interaction they heard. However, participants wanting more involvement in treatment choices perceived greater treatment effectiveness and clinician trustworthiness for the interaction in which the patient was offered treatment choices. These results suggest that if therapists adopt a collaborative approach, it has the potential to enhance perceptions of individuals preferring the collaborative style without negatively affecting those who prefer less involvement in treatment decisions.

5.
Pediatr Radiol ; 49(8): 1032-1041, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31001665

RESUMO

OBJECTIVE: The aim is to evaluate the age-related changes and relationship of renal apparent diffusion coefficient (ADC) against the morphological and functional changes detected by functional magnetic resonance urography (fMRU) in children with pelvicalyceal dilation, with suspected or known ureteropelvic junction obstruction. MATERIALS AND METHODS: We retrospectively analyzed fMRUs with diffusion-weighted imaging (DWI) of the kidney in 35 subjects (25 males; median age: 7.1 years, range: 0.3-22.7 years) with 70 kidneys (40 with pelvicalyceal dilation and 30 with no pelvicalyceal dilation). Inclusion criteria were pelvicalyceal dilation, the absence of duplex kidneys and no ureteric dilation. DWI was performed with 3 diffusion gradient directions (b values = 0, 200, 500, 800 and 1,000 s/mm2). Metrics for fMRU included calyceal and renal transit times (CTT, RTT), time-to-peak (TTP), differential renal function based on volume (vDRF), Patlak number (pDRF) and combined volume and Patlak number (vpDRF). The grades of pelvicalyceal dilation, cortical thinning and corticomedullary differentiation were evaluated. The relationship between ADC values and the fMRU parameters was analyzed. RESULTS: ADC increases with age in kidneys without pelvicalyceal dilation (R2=0.37, P<0.001). Renal ADC does not correlate with any of the morphological or fMRU parameters (P>0.07). The median ADC of kidneys without pelvicalyceal dilation was 3.73×10-3 mm2/s (range: 2.78-5.37×0-3 mm2/s) and the median ADC of kidneys with pelvicalyceal dilation was 3.82×10-3 mm2/s (range: 2.70-5.70×10-3 mm2/s). There was no correlation between ADC and the absolute differences of vDRF or pDRF (P>0.33). CONCLUSION: Renal ADC does not correlate with morphological and functional results of fMRU changes in children with pelvicalyceal dilation due to suspected or known ureteropelvic junction obstruction.

6.
Hum Brain Mapp ; 40(11): 3288-3298, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30977235

RESUMO

Age-related changes in resting-state (RS) neural rhythms in typically developing children (TDC) but not children with autism spectrum disorder (ASD) suggest that RS measures may be of clinical use in ASD only for certain ages. The study examined this issue via assessing RS peak alpha frequency (PAF), a measure previous studies, have indicated as abnormal in ASD. RS magnetoencephalographic (MEG) data were obtained from 141 TDC (6.13-17.70 years) and 204 ASD (6.07-17.93 years). A source model with 15 regional sources projected the raw MEG surface data into brain source space. PAF was identified in each participant from the source showing the largest amplitude alpha activity (7-13 Hz). Given sex differences in PAF in TDC (females > males) and relatively few females in both groups, group comparisons were conducted examining only male TDC (N = 121) and ASD (N = 183). Regressions showed significant group slope differences, with an age-related increase in PAF in TDC (R2 = 0.32) but not ASD (R2 = 0.01). Analyses examining male children below or above 10-years-old (median split) indicated group effects only in the younger TDC (8.90 Hz) and ASD (9.84 Hz; Cohen's d = 1.05). In the older ASD, a higher nonverbal IQ was associated with a higher PAF. In the younger TDC, a faster speed of processing was associated with a higher PAF. PAF as a marker for ASD depends on age, with a RS alpha marker of more interest in younger versus older children with ASD. Associations between PAF and cognitive ability were also found to be age and group specific.

7.
Brain Connect ; 9(5): 425-436, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30900464

RESUMO

Studies suggest that individuals with autism spectrum disorder (ASD) exhibit altered electrophysiological alpha to gamma phase-amplitude coupling (PAC). Preliminary reports with small samples report conflicting findings regarding the directionality of the alpha to gamma PAC alterations in ASD. The present study examined resting-state activity throughout the brain in a relatively large sample of 119 children with ASD and 47 typically developing children. Children with ASD demonstrated regionally specific abnormalities in alpha to low-gamma PAC, with increased alpha to low-gamma PAC for a central midline source and decreased PAC at lateral sources. Group differences in local gamma-band power did not account for the regional group differences in alpha to low-gamma PAC. Moreover, local alpha power did not significantly modulate alpha to low-gamma PAC estimates. Finally, PAC estimates were correlated with Social Responsiveness Scale (SRS) indicating clinical relevance of the PAC metric. In conclusion, alpha to low-gamma PAC alterations in ASD demonstrate a heterogeneous spatial profile consistent with previous studies and were related to symptom severity.

8.
Abdom Radiol (NY) ; 44(5): 1867-1872, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30783727

RESUMO

OBJECTIVE: To compare diffusion tensor imaging (DTI) of the kidneys and its derived parameters in children with autosomal recessive polycystic kidney disease (ARPKD) versus healthy controls. METHODS: In a prospective IRB-approved study, we evaluated the use of DTI to compare kidney parenchyma FA values in healthy controls (age-matched children with no history of renal disease) versus patients with ARPKD. A 20-direction DTI with b-values of b = 0 s/mm2 and b = 400 s/mm2 was used to acquire data in coronal direction using a fat-suppressed spin-echo echo-planar sequence. Diffusion Toolkit and TrackVis were used for analysis and segmentation. TrackVis was used to draw regions of interest (ROIs) covering the entire volume of the renal parenchyma, excluding the collecting system. Fibers were reconstructed using a deterministic fiber tracking algorithm. The FA values based on the ROI data, mean length, and volume of the tracks based on the fiber tracking data were recorded. RESULTS: Eight healthy controls (mean age = 12.9 years ± 4.0; 1/8 males) and six ARPKD participants (mean age = 13.8 years ± 8.5; 5/6 males) were included in the study. Compared to healthy controls, patients with ARPKD had significantly lower FA values (0.33 ± 0.03 vs. 0.25 ± 0.02, p = 0.002) and mean track length (16.73 ± 3.43 vs. 11.61 ± 1.29 mm, p = 0.005). CONCLUSION: DTI of the kidneys shows significantly lower FA values and mean track length in children and young adults with ARPKD compared to normal subjects. DTI of the kidney offers a novel approach for characterizing renal disease based on changes in diffusion anisotropy and kidney structure.

9.
Neurosci Lett ; 698: 140-145, 2019 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-30599264

RESUMO

The auditory mismatch field (MMF) is a pre-attentive processing component, reflecting neural discrimination and inhibitory processing. Abnormal MMFs have been reported in children with autism spectrum disorder (ASD) along with an association with abnormal language comprehension; however, relatively little is known about MMF abnormalities to contrasting vowel stimuli in adults with ASD. To better understand the neurophysiological mechanisms underlying auditory language discrimination of vowel stimuli in individuals with ASD, magnetoencephalography was used to measure MMFs during an auditory oddball paradigm with vowel stimuli (/a/ and /u/) in adults with ASD. MMFs arising from left and right superior temporal gyrus are reported from nine high-functioning right handed males with ASD (22.22 ± 5.74yrs) and sixteen typically developing (TD) right handed males (27.25 ± 6.63yrs). The MMF was delayed in adults with ASD (188.90 ± 5.8 ms) as compared to the TD participants (173.08 ± 4.31 ms, p < 0.05). Replicating previous findings in children, the earlier M100 component to single stimulus tokens was also delayed in adults with ASD (108.59 ± 4.1 ms) compared to the TD participants (94.60 ± 3.0 ms, p < 0.05). However, there was no correlation between delayed M100 latency and MMF latency. Furthermore, whereas TD participants showed a leftward lateralization of MMF amplitude, participants with ASD showed an opposite (rightward) lateralization. Findings suggest that adults with ASD have hemispherically- and temporally- abnormal auditory discrimination processing in addition to and distinct from abnormal neurophysiological mechanisms in earlier cortical responses.


Assuntos
Percepção Auditiva , Transtorno do Espectro Autista/fisiopatologia , Estimulação Acústica , Adulto , Transtorno do Espectro Autista/psicologia , Humanos , Magnetoencefalografia , Masculino , Adulto Jovem
10.
Brain Connect ; 9(3): 263-272, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30588822

RESUMO

Altered gamma-band electrophysiological activity in individuals with autism spectrum disorder (ASD) is well documented, and analogous gamma-band alterations are recapitulated in several preclinical murine models relevant to ASD. Such gamma-band activity is hypothesized to underlie local circuit processes. Gamma-band cross-frequency coupling (CFC), a related though distinct metric, interrogates local neural circuit signal integration. Several recent studies have observed perturbed gamma-band CFC in individuals with ASD, although the direction of change remains unresolved. It also remains unclear whether murine models relevant to ASD recapitulate this altered gamma-band CFC. As such, this study examined whether mice with parvalbumin (PV) cell-specific ablation of NMDA-R1 (PVcre/NR1fl/fl) demonstrated altered gamma-band CFC as compared with their control littermates (PVcre/NR1+/+-mice that do not have the PV cell-specific ablation of NMDA-R1). Ten mice of each genotype had 4 min of "resting" electroencephalography recorded and analyzed. First, resting electrophysiological power was parsed into the canonical frequency bands and genotype-related differences were subsequently explored so as to provide context for the subsequent CFC analyses. PVcre/NR1fl/fl mice exhibited an increase in resting power specific to the high gamma-band, but not other frequency bands, as compared with PVcre/NR1+/+. CFC analyses then examined both the standard magnitude (strength) of CFC and the novel metric PhaseMax-which denotes the phase of the lower frequency signal at which the peak higher frequency signal power occurred. PVcre/NR1fl/fl mice exhibited altered PhaseMax, but not strength, of gamma-band CFC as compared with PVcre/NR1+/+ mice. As such, this study suggests a potential novel metric to explore when studying neuropsychiatric disorders.


Assuntos
Ritmo Gama/fisiologia , Receptores de N-Metil-D-Aspartato/metabolismo , Receptores de N-Metil-D-Aspartato/fisiologia , Animais , Transtorno do Espectro Autista/fisiopatologia , Modelos Animais de Doenças , Eletroencefalografia/métodos , Fenômenos Eletrofisiológicos/fisiologia , Imagem por Ressonância Magnética/métodos , Masculino , Camundongos , Camundongos Endogâmicos , Parvalbuminas/farmacologia , Descanso/fisiologia
11.
Psychother Res ; : 1-18, 2018 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-30345911

RESUMO

Psychotherapy dropout is often regarded as an indicator of treatment failure; however, evidence of a relationship between dropout and outcome has not been well established. The current research consisted of three meta-analytic studies, the results of which found (a) individuals who dropped out began treatment more distressed than those who completed therapy, (b) individuals who dropped out of therapy were more distressed at posttreatment than individuals who completed therapy, and (c) treatments with higher rates of dropout were also less effective for the treatment completers. Dropout may particularly signal poor outcomes for shorter treatments. The continued ambiguity in the meaning of dropout is discussed as well as the promising potential for future research in the area of dropout as it relates to outcome. Clinical and methodological significance of this article: The findings from this meta-analytic review suggest that treatments with greater numbers of dropouts appear to be less effective and individuals who drop out of therapy report greater distress than completers. Dropout may particularly signal poor outcomes for shorter treatments. As such, these findings may impact how researchers and clinicians choose to regard, track, and address drop out in its various forms. The potential ambiguity of judging treatment effectiveness based on whether clients leave treatment early is explored.

12.
Omega (Westport) ; 78(1): 3-23, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30286687

RESUMO

The centrality of a loss to a bereaved individual's identity is associated with greater symptomatology, whereas meaning made of a loss is associated with positive outcomes. This article examines meaning made as a moderator of the relationship between event centrality and symptomatology. Our sample consisted of 204 bereaved undergraduate university students. Centrality was assessed using the Centrality of Events Scale, meaning made was assessed using the Integration of Stressful Life Experiences Scale, and symptomatology was assessed using the posttraumatic stress disorder Checklist-Civilian and Inventory of Complicated Grief-Revised. Meaning made had a significant moderating effect on the relationship between centrality and both measures of symptomatology. At lower levels of meaning made, centrality had a strong and positive association with symptomatology; at higher levels of meaning made, this association became weaker. These results suggest that meaning made is the key to understanding how centrality affects bereavement outcomes.

13.
Pediatr Radiol ; 2018 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-30298211

RESUMO

BACKGROUND: Ureteropelvic junction (UPJ) obstruction is a common cause of renal injury in children. Indications for surgery are still controversial. Currently, there is no threshold to differentiate patients with suspected UPJ obstruction requiring surgery from the ones that do not, or to predict renal outcome after surgery. Several studies have demonstrated that diffusion tensor imaging (DTI) results may correlate with microstructural changes in the kidneys. OBJECTIVE: To evaluate the feasibility of using DTI to identify UPJ obstruction kidneys. MATERIALS AND METHODS: We analyzed functional MR urography (fMRU) with renal DTI (b=0 and b=400, 20 directions, 1.5 Tesla, no respiratory triggering) in 26 kidneys of 19 children (mean age: 6.15 years) by comparing 13 kidneys with UPJ obstruction configuration that underwent pyeloplasty following the fMRU, and 13 anatomically normal age- and gender-matched kidneys. DTI tractography was reconstructed using a fractional anisotropy threshold of 0.10 and an angle threshold of 55°. User-defined regions of interest (ROIs) of the renal parenchyma (excluding collecting system) were drawn to quantify DTI parameters: fractional anisotropy, apparent diffusion coefficient (ADC), track length and track volume. The failure rate was evaluated. RESULTS: All DTI parameters changed with age; fractional anisotropy decreased (P<0.032). Track volume and track length increased (P<0.05). ADC increased with age in normal kidneys (P<0.001) but not in UPJ obstruction kidneys (P=0.11). After controlling for age, the fractional anisotropy (UPJ obstruction mean: 0.18, normal kidney mean: 0.21; P=0.001) and track length (UPJ obstruction mean: 11.9 mm, normal kidney mean: 15.4 mm; P<0.001) were lower in UPJ obstruction vs. normal kidneys. There was a trend toward a higher ADC in UPJ obstruction kidneys vs. normal kidneys (P=0.062). The failure rate in UPJ obstruction kidneys due to technical limitations of DTI was 13/26 (50%). CONCLUSION: We demonstrated that fractional anisotropy is lower in UPJ obstruction than in normal kidneys. It is necessary to improve this technique to increase the success rate and to perform more studies to evaluate if a decrease in fractional anisotropy can differentiate UPJ obstruction kidneys from hydronephrotic kidneys without UPJ obstruction.

14.
Curr Opin Pulm Med ; 24(5): 487-494, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29979212

RESUMO

PURPOSE OF REVIEW: Sarcoidosis is a multisystem disease of unknown cause. Obesity can affect many physiological factors. The relationship between obesity and sarcoidosis is unclear, and can been described as posing a 'chicken and egg' scenario for the patient as it is not always clear whether it is a consequence of, or a risk factor for any disease. The purpose of this review is to examine the dual roles of obesity on sarcoidosis morbidity and the incidence. RECENT FINDINGS: Obesity magnifies the symptoms of sarcoidosis and corticosteroid therapy increases BMI. Prospective epidemiologic studies started to explore the role of obesity as a potential risk factor for sarcoidosis. Three studies in the United States, and one study in Denmark, have demonstrated significantly increased risks of sarcoidosis among obese compared with nonobese patients; risk estimates ranged from 1.42 [95% confidence interval (CI), 1.07-1.89] to 3.59 (95% CI, 2.31-5.57). SUMMARY: Obesity can be both a consequence of sarcoidosis treatment, and a contributor to disease risk likely through the pro-inflammatory environment of obesity. Prospective epidemiologic cohort studies are needed to explore the cause of sarcoidosis and insight into possible avenues of treatment development and prevention.

15.
Death Stud ; : 1-4, 2018 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-30015579
16.
Am J Respir Crit Care Med ; 197(6): P9-P10, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29543101
17.
Ann Clin Transl Neurol ; 5(1): 92-97, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29376095

RESUMO

In this repeated measures case study, we show that sensory deafferentation after limb amputation leads to changes in cortical somatotopic maps which are reversible after restoration of sensory input. Using magnetoencephalography (MEG), we observed in a child with bilateral hand transplants large-scale shifts in somatosensory lip cortical representation from anatomic hand area to anatomic face region. After recovery of tactile sensation in the digits, responses to finger stimulation were localized to orthotopic sensory cortex, but with atypical electrophysiologic features (amplitude and frequencies).

18.
Radiology ; 286(1): 217-226, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28786752

RESUMO

Purpose To identify developmental neuroradiologic findings in a large cohort of carriers who have deletion and duplication at 16p11.2 (one of the most common genetic causes of autism spectrum disorder [ASD]) and assess how these features are associated with behavioral and cognitive outcomes. Materials and Methods Seventy-nine carriers of a deletion at 16p11.2 (referred to as deletion carriers; age range, 1-48 years; mean age, 12.3 years; 42 male patients), 79 carriers of a duplication at 16p11.2 (referred to as duplication carriers; age range, 1-63 years; mean age, 24.8 years; 43 male patients), 64 unaffected family members (referred to as familial noncarriers; age range, 1-46 years; mean age, 11.7 years; 31 male participants), and 109 population control participants (age range, 6-64 years; mean age, 25.5 years; 64 male participants) were enrolled in this cross-sectional study. Participants underwent structural magnetic resonance (MR) imaging and completed cognitive and behavioral tests. MR images were reviewed for development-related abnormalities by neuroradiologists. Differences in frequency were assessed with a Fisher exact test corrected for multiple comparisons. Unsupervised machine learning was used to cluster radiologic features and an association between clusters and cognitive and behavioral scores from IQ testing, and parental measures of development were tested by using analysis of covariance. Volumetric analysis with automated segmentation was used to confirm radiologic interpretation. Results For deletion carriers, the most prominent features were dysmorphic and thicker corpora callosa compared with familial noncarriers and population control participants (16%; P < .001 and P < .001, respectively) and a greater likelihood of cerebellar tonsillar ectopia (30.7%; P < .002 and P < .001, respectively) and Chiari I malformations (9.3%; P < .299 and P < .002, respectively). For duplication carriers, the most salient findings compared with familial noncarriers and population control participants were reciprocally thinner corpora callosa (18.6%; P < .003 and P < .001, respectively), decreased white matter volume (22.9%; P < .001, and P < .001, respectively), and increased ventricular volume (24.3%; P < .001 and P < .001, respectively). By comparing cognitive assessments to imaging findings, the presence of any imaging feature associated with deletion carriers indicated worse daily living, communication, and social skills compared with deletion carriers without any radiologic abnormalities (P < .005, P < .002, and P < .004, respectively). For the duplication carriers, presence of decreased white matter, callosal volume, and/or increased ventricle size was associated with decreased full-scale and verbal IQ scores compared with duplication carriers without these findings (P < .007 and P < .004, respectively). Conclusion In two genetically related cohorts at high risk for ASD, reciprocal neuroanatomic abnormalities were found and determined to be associated with cognitive and behavioral impairments. © RSNA, 2017 Online supplemental material is available for this article.


Assuntos
Transtorno Autístico , Encéfalo/diagnóstico por imagem , Deleção Cromossômica , Transtornos Cromossômicos , Variações do Número de Cópias de DNA/genética , Deficiência Intelectual , Imagem por Ressonância Magnética/métodos , Adolescente , Adulto , Transtorno Autístico/diagnóstico por imagem , Transtorno Autístico/epidemiologia , Transtorno Autístico/genética , Encéfalo/patologia , Criança , Pré-Escolar , Transtornos Cromossômicos/diagnóstico por imagem , Transtornos Cromossômicos/epidemiologia , Transtornos Cromossômicos/genética , Cromossomos Humanos Par 16/genética , Análise por Conglomerados , Estudos Transversais , Feminino , Deleção de Genes , Duplicação Gênica/genética , Humanos , Lactente , Deficiência Intelectual/diagnóstico por imagem , Deficiência Intelectual/epidemiologia , Deficiência Intelectual/genética , Masculino , Pessoa de Meia-Idade , Adulto Jovem
19.
Exp Neurol ; 299(Pt B): 308-316, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28587872

RESUMO

INTRODUCTION: Fractional anisotropy (FA) of the optic radiations has been associated with vision deficit in multiple intrinsic brain pathologies including NF1 associated optic pathway glioma, but hand-drawn regions of interest used in previous tractography methods limit consistency of this potential biomarker. We created an automated method to identify white matter tracts in the optic radiations and compared this method to previously reported hand-drawn tractography. METHOD: Automated tractography of the optic radiation using probabilistic streamline fiber tracking between the lateral geniculate nucleus of the thalamus and the occipital cortex was compared to the hand-drawn method between regions of interest posterior to Meyer's loop and anterior to tract branching near the calcarine cortex. Reliability was assessed by two independent raters in a sample of 20 healthy child controls. Among 50 children with NF1-associated optic pathway glioma, the association of FA and visual acuity deficit was compared for both tractography methods. RESULTS: Hand-drawn tractography methods required 2.6±0.9min/participant; automated methods were performed in <1min of operator time for all participants. Cronbach's alpha was 0.83 between two independent raters for FA in hand-drawn tractography, but repeated automated tractography resulted in identical FA values (Cronbach's alpha=1). On univariate and multivariate analyses, FA was similarly associated with visual acuity loss using both methods. Receiver operator characteristic curves of both multivariate models demonstrated that both automated and hand-drawn tractography methods were equally able to distinguish normal from abnormal visual acuity. CONCLUSION: Automated tractography of the optic radiations offers a fast, reliable and consistent method of tract identification that is not reliant on operator time or expertise. This method of tract identification may be useful as DTI is developed as a potential biomarker for visual acuity.


Assuntos
Imagem de Tensor de Difusão/métodos , Processamento de Imagem Assistida por Computador/métodos , Neurofibromatose 1/patologia , Glioma do Nervo Óptico/patologia , Acuidade Visual , Vias Visuais/patologia , Substância Branca/patologia , Adolescente , Anisotropia , Automação , Estudos de Casos e Controles , Criança , Feminino , Corpos Geniculados/patologia , Humanos , Masculino , Ilustração Médica , Lobo Occipital/patologia , Glioma do Nervo Óptico/genética , Glioma do Nervo Óptico/fisiopatologia , Tálamo/patologia , Córtex Visual/patologia
20.
Radiology ; 284(1): 210-218, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28156202

RESUMO

Purpose To determine the changes of diffusion-tensor imaging (DTI) and tractography in the distal femur and proximal tibia related to age, sex, and height. Materials and Methods Following institutional review board approval, with waiver of consent and with HIPAA compliance, the authors retrospectively analyzed DTI images of the knee in 151 children, 73 girls (median age, 14.1 years; range, 6.5-17.8 years) and 78 boys (median age, 16.6 years; range, 6.9-17.9 years), studied from January 2013 to October 2014. At sagittal echo-planar DTI (20 directions, b values of 0 and 600 sec/mm2), regions of interest were placed in the tibial and femoral physes. Using a fractional anisotropy threshold of 0.15 and an angle threshold of 40°, the authors performed tractography and measured apparent diffusion coefficient (ADC) and tract length and volume. Changes related to age, sex, and height were evaluated by using fitted nonlinear polynomial functions on bootstrapped samples. Results Femoral tract volume and length increased and then decreased with age (P < .001); the peaks of femoral tract volume are consistent with the growth spurt, occurring earlier in girls (10.8 years) than in boys (13.0 years) (P < .001). Girls had smaller tract volumes in comparison to boys (P = .013). ADC peaks 2 years earlier than tract volume (girls at 9.3 years, boys at 11.0 years). Girls with greater than 50th percentile of height had longer tracts and greater tract volumes compared with girls with less than 50th percentile (P < .020). DTI parameters of boys do not correlate with percentile of height (P > .300). Conclusion DTI of the physis and metaphysis shows greater tract length and volumes in subjects who are at ages when the growth is fastest. ADC and tract length and volume have an earlier and smaller peak in girls than in boys. Femoral tract length and volume are larger in taller girls. © RSNA, 2017.


Assuntos
Imagem de Tensor de Difusão/métodos , Epífises/diagnóstico por imagem , Desenvolvimento Musculoesquelético , Adolescente , Antropometria , Biomarcadores/análise , Criança , Pré-Escolar , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Estudos Retrospectivos , Fatores Sexuais , Razão Sinal-Ruído
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA