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Schizencephalies are abnormal clefts of the cerebral hemispheres that result from abnormal late neuronal migration and cortical organization. In the present study, we report a different type of unusual motor organization in a patient with a schizencephalic cleft in the right hemisphere and polymicrogyria in the opposite hemisphere. Despite similar brain pathology affecting the sensorimotor cortex, motor organization differed from previously known bilateral congenital brain lesions. We conducted a transcranial magnetic stimulation (TMS) and diffusion tensor image (DTI) study to confirm the motor organization. In this case, ipsilateral corticospinal projections to the paretic hands were observed during TMS of the less affected hemisphere, along with polymicrogyria, similar to the previous study. However, a crossed corticospinal tract to the paretic hand from the more severely affected hemisphere was observed in this case-a pattern of motor organization that has yet to be reported in this patient population. Our findings indicate that motor organization after early brain injury may be affected by the interhemispheric competition of the corticospinal system and bilateral brain lesions, thereby resulting in unilateral hemiparesis. [ABSTRACT FROM AUTHOR]

Objective: The identification of the corticospinal tract (CST) pathway with a deterministic fiber tracking approach is limited because of crossing fibers, especially for the hand fibers of the CST due to the crossing superior longitudinal fasciculus (SLF). We examined a patient with congenital bilateral perisylvian syndrome (CBPS) who did not have the SLF, in order to visualize CST hand fibers that were not affected by crossing fibers. Methods: A 10-year-old girl without the SLF due to CBPS and three normal healthy subjects participated in this study. We used a deterministic fiber tracking algorithm, and the regions of interest (ROIs) were drawn in the posterior limb of internal capsule (PLIC) and the primary motor cortex. The apparent diffusion coefficient (ADC), fractional anisotropy (FA), relative anisotropy (RA), and volume ratio (VR) were measured based on the extracted fiber tracts. Results: The ADC values were not different between the normal subjects and the patient with CBPS. The FA, RA, and VR values of the normal subjects were similar, but were relatively higher than those of the patient with CBPS. Conclusion: Our results clearly show the impact of the crossing fiber for the hand motor fibers of the CST pathway with deterministic tracking algorithms in diffusion tensor tractography. [ABSTRACT FROM AUTHOR]

Abstract: Diffusion tensor tractography (DTT) is known to be useful in detecting white matter lesions. In the current study, we report on two hemiparetic patients with risk factors who showed abnormalities of the corticospinal tract (CST) on diffusion tensor tractography (DTT) prior to the manifestation of hemiparesis. Two hemiparetic patients with risk factors (preterm, low birth weight) and six age-matched normal control subjects were enrolled to this study. Diffusion tensor imaging (DTI) was performed at the age of 43 weeks (patient 1) and 33 weeks (patient 2) using 1.5-T with a Synergy-L Sensitivity Encoding (SENSE) head coil. We measured fractional anisotropy (FA), apparent diffusion coefficients (ADCs), and fiber counts of the CST. There were no definite asymmetric findings on physical examination and conventional brain MRI. By contrast, DTT showed a unilateral CST disruption at the periventricular white matter, low FA values, and low CST fiber counts compared with those of the unaffected CST and controls. These patients were diagnosed with hemiparetic cerebral palsy when we re-evaluated these patients at the age of 6 years (patient 1) and 3 years of age (patient 2), respectively. In these two patients, DTT revealed abnormalities of the CST prior to the manifestation of hemiparesis. Therefore, it seems that DTT would be a useful modality in detecting CST abnormalities in advance of clinical manifestation in infants with high risk factors. [Copyright &y& Elsevier]

This study classified the severity of aphasia through the Western Aphasia Battery and determined the optimal cut-off value for each Language-Related White Matter fiber and their combinations, we further examined the correlations between Language-Related White Matter and Western Aphasia Battery subscores. This retrospective study recruited 64 patients with aphasia. Mild/moderate and severe aphasia were classified according to cut-off Aphasia Quotient score of 51 points. Diffusion tensor imaging and fractional anisotropy reconstructed Language-Related White Matter in multiple fasciculi. We determined the area under the covariate-adjusted receiver operating characteristic curve to evaluate the accuracy of predicting aphasia severity. The optimal fractional-anisotropy cut-off values for the individual fibers of the Language-Related White Matter and their combinations were determined. Their correlations with Western Aphasia Battery subscores were analyzed. The arcuate and superior longitudinal fasciculi showed fair accuracy, the inferior frontal occipital fasciculus poor accuracy, and their combinations fair accuracy. Correlations between Language-Related White Matter parameters and Western Aphasia Battery subscores were found between the arcuate, superior longitudinal, and inferior frontal occipital fasciculi and spontaneous speech, auditory verbal comprehension, repetition, and naming. Diffusion-tensor-imaging-based language-Related White Matter analysis may help predict the severity of language impairment in patients with aphasia following stroke. [ABSTRACT FROM AUTHOR]