ABSTRACT
OBJECTIVE: We wanted to investigate the usefulness of event-related (ER) functional MRI (fMRI) for the assessment of cortical visual impairment in infants with periventricular leukomalacia (PVL). MATERIALS AND METHODS: FMRI data were collected from 24 infants who suffered from PVL and from 12 age-matched normal controls. Slow ER fMRI was performed using a 3.0T MR scanner while visual stimuli were being presented. Data analysis was performed using Statistical Parametric Mapping software (SPM2), the SPM toolbox MarsBar was used to analyze the region of interest data, and the time to peak (TTP) of hemodynamic response functions (HRFs) was estimated for the surviving voxels. The number of activated voxels and the TTP values of HRFs were compared. Pearson correlation analysis was performed to compare visual impairment evaluated by using Teller Acuity Cards (TAC) with the number of activated voxels in the occipital lobes in all patients. RESULTS: In all 12 control infants, the blood oxygenation level-dependent (BOLD) signal was negative and the maximum response was located in the anterior and superior part of the calcarine fissure, and this might correspond to the anterior region of the primary visual cortex (PVC). In contrast, for the 24 cases of PVL, there were no activated pixels in the PVC in four subjects, small and weak activations in six subjects, deviated activations in seven subjects and both small and deviated activations in three subjects. The number of active voxels in the occipital lobe was significantly correlated with the TAC-evaluated visual impairment (p < 0.001). The mean TTP of the HRFs was significantly delayed in the cases of PVL as compared with that of the normal controls. CONCLUSION: Determining the characteristics of both the BOLD response and the ER fMRI activation may play an important role in the cortical visual assessment of infants with PVL.
Subject(s)
Female , Humans , Infant , Infant, Newborn , Male , Case-Control Studies , Evoked Potentials, Visual , Image Interpretation, Computer-Assisted , Leukomalacia, Periventricular/physiopathology , Magnetic Resonance Imaging/methods , Photic Stimulation , Pilot Projects , Visual Acuity , Visual Cortex/physiopathologyABSTRACT
TEMA: a paralisia cerebral espástica do tipo diplégica (PC-D) é freqüentemente relacionada à Leucomalácia Periventricular (LPV), a qual geralmente afeta fibras motoras descendentes do córtex de associação e fibras de associação das funções visuais, auditivas e somestésicas. OBJETIVO: verificar o desempenho de crianças com PC-D quanto às habilidades psicolingüísticas. MÉTODO: participaram deste estudo oito indivíduos de ambos os sexos e idade cronológica variando de quatro a seis anos, diagnosticados como PC-D, confirmadas na ressonância magnética a lesão tipo LPV. Foram avaliados por meio do Teste de Illinois de Habilidades Psicolinguísticas (TIHP), Teste de Vocabulário por Imagens Peabody (TVIP), considerando o desempenho cognitivo, o grau de distúrbio motor e o desempenho nos subtestes auditivos e visuais do TIHP. RESULTADOS: os resultados apontaram correlação significante entre desempenho cognitivo e TVIP e a mesma correlação foi confirmada entre o desempenho do TVIP e o subteste de recepção auditiva do TIHP, considerando a idade psicolingüística. Na comparação entre as habilidades auditivas e visuais, os participantes tiveram melhor desempenho nas atividades que envolviam habilidades visuais, confirmando a correlação significante no subteste de associação. Houve correlação estatisticamente significante entre o grau de distúrbio motor e o desempenho psicolingüístico, confirmando a influência do distúrbio motor nestas atividades. CONCLUSÃO: as crianças com PC-D e sinais sugestivos de LPV apresentaram prejuízo nas habilidades psicolingüísticas, justificando a necessidade de estudos adicionais nesta área com o intuito de conhecer melhor o desenvolvimento destas habilidades.
BACKGROUND: spastic diplegic cerebral palsy (D-CP) is frequently related to periventricular leukomalacia (PVL), which usually affects the descending motor fibers of the association cortex and association fibers of the visual, auditory and somesthesic functions. AIM: to verify the performance of children with D-CP regarding their psycholinguistic skills. METHOD: participants were eight individuals of both genders and with chronological ages varying from four to six years, diagnosed with D-CP, having PVL confirmed through magnetic resonance. These children were evaluated through the Illinois Test of Psycholinguistic Abilities (ITPA) and the Peabody Picture Vocabulary Test (PPVT), considering the cognitive performance, the level of motor impairment and the performance in the auditory and visual subtests of the ITPA. RESULTS: the results pointed to a significant correlation between the cognitive performance and the PPVT. The same correlation was confirmed between the PPVT and the subtest of auditory reception of the ITPA, when considering the psycholinguistic age. In the comparison between the auditory and visual abilities, the participants demonstrated a better performance in the activities that involved visual abilities, indicating a significant correlation in the association subtest. There was a statistically significant correlation between the level of motor impairment and the psycholinguistic performance, confirming the influence of the motor impairment in these activities. CONCLUSION: the children with D-CP and with suggestive signs of PVL presented deficits in the psycholinguistics abilities, justifying the need of additional studies in this area in order to investigate the development of these abilities.