Fetal Cerebellar Vermis Assessment by MRI. What Does It Add?

Background: Posterior fossa anomalies (PFAs) are considered one of the commonest brain anomalies identified by the fetal imaging techniques. The current study aims to estimate the significance of cerebellar vermis assessment by fetal MRI in fetal brain malformations. Patients and Methods: The study was conducted at a tertiary University hospital in Upper Egypt. Data were gathered prospectively from sixty pregnant women with sonographically diagnosed fetal brain malformations referred for Magnetic Resonance Imaging (MRI) between April 2015 and May 2019 followed by postpartum neonatal MRI brain examination for non-terminated and live birth cases. Results: Of the sixty fetuses with brain malformations, additional cerebellar vermis findings were seen on MRI in 10 cases (16.6%). Fetal MRI sensitivity, specificity, positive and negative predictive values were 100% that were in correlation with those of prenatal ultrasound turned out to be significantly higher. Conclusion: This study recommends fetal MRI for cerebellar vermis assessment in fetal brain malformations to guide the clinical management.

Wernicke's encephalopathy in a rectal cancer patient with atypical radiological features:A case report

BACKGROUND Wernicke's encephalopathy is a disease caused by thiamine deficiency.The lesions usually involve the periphery of the aqueduct,midbrain,tectum,third ventricle,papillary body,and thalamus.It is very rare to affect the vermis and cerebellar hemispheres.CASE SUMMARY We report a 77-year-old female patient admitted to the emergency department of our hospital for 2 d of unconsciousness.Brain magnetic resonance imaging showed increased diffusion weighted imaging signals in the bilateral thalamus,periventricular regions of the third ventricle,corpora quadrigemina,vermis,and cerebellar hemispheres.Wernicke's encephalopathy was considered.She was given thiamine therapy and became conscious after the treatment.CONCLUSION Wernicke's encephalopathy may have various imaging manifestations.Clinicians should keep in mind that Wernicke’s encephalopathy may occur in patients who experience prolonged periods of malnutrition.

Changes in brain activation patterns according to cross-training effect in serial reaction time task An functional MRI study

Cross-training is a phenomenon related to motor learning, where motor performance of the untrained limb shows improvement in strength and skill execution following unilateral training of the homologous contralateral limb. We used functional MRI to investigate whether motor performance of the untrained limb could be improved using a serial reaction time task according to motor sequential learning of the trained limb, and whether these skill acquisitions led to changes in brain activation patterns. We recruited 20 right-handed healthy subjects, who were randomly allocated into training and control groups. The training group was trained in performance of a serial reaction time task using their non-dominant left hand, 40 minutes per day, for 10 days, over a period of 2 weeks. The control group did not receive training. Measurements of response time and percentile of response accuracy were performed twice during pre- and post-training, while brain functional MRI was scanned during performance of the serial reaction time task using the untrained right hand. In the training group, prominent changes in response time and percentile of response accuracy were observed in both the untrained right hand and the trained left hand between pre- and post-training. The control group showed no significant changes in the untrained hand between pre- and post-training. In the training group, the activated volume of the cortical areas related to motor function （i.e., primary motor cortex, premotor area, posterior parietal cortex） showed a gradual decrease, and enhanced cerebellar activation of the vermis and the newly activated ipsilateral dentate nucleus were observed during performance of the serial reaction time task using the untrained right hand, accompanied by the cross-motor learning effect. However, no significant changes were observed in the control group. Our findings indicate that motor skills learned over the 2-week training using the trained limb were transferred to the opposite homologous limb, and motor skill acquisition of the untrained limb led to changes in brain activation patterns in the cerebral cortex and cerebellum.