Clinical and surgical management of holocervical spinal cord ependymomas.

Background:Spinal ependymomas are rare tumors of the central nervous system, and those spanning the entire cervical spine are atypical. Here, we present two unusual cases of holocervical (C1-C7) spinal ependymomas. Case Description:Two patients, a 32-year-old female and a 24-year-old male presented with neck pain, motor, and sensory deficits. Sagittal MRI confirmed hypointense lesions on T1 and hyperintense regions on T2 spanning the entire cervical spine. These were accompanied by cystic cavities extending caudally into the thoracic spine and rostrally to the cervicomedullary junction. Both patients underwent gross total resection of these lesions and sustained excellent recoveries. Conclusion:Two holocervical cord intramedullary ependymomas were safely and effectively surgically resected without incurring significant perioperative morbidity

Widespread white matter and conduction defects in PSEN1-related spastic paraparesis

The mechanisms underlying PSEN1 mutation-associated spastic paraparesis (SP) are not clear. We compared diffusion and volumetric magnetic resonance measures between 3 persons with SP associated with the A431E mutation and 7 symptomatic persons with PSEN1 mutations without SP matched for symptom duration. We performed amyloid imaging and central motor and somatosensory conduction studies in one subject with SP. We found decreases in fractional anisotropy and increases in mean diffusivity in widespread white matter areas including the corpus callosum, occipital, parietal, and frontal lobes in PSEN1 mutation carriers with SP. Volumetric measures were not different and amyloid imaging showed low signal in sensorimotor cortex and other areas in a single subject with SP. Electrophysiological studies demonstrated both slowed motor and sensory conduction in the lower extremities in this same subject. Our results suggest that SP in carriers of the A431E PSEN1 mutation is a manifestation of widespread white matter abnormalities not confined to the corticospinal tract that is at most indirectly related to the mutation’s effect on APP processing and amyloid deposition

Información Investigador: Coutin Churchman, Pedro Eduardo

Resumen Curricular Doctor en Medicina, Universidad de La Habana, Cuba. Especialista de Primer Grado en Fisiología Normal y Patológica, Universidad de La Habana, Cuba. Especialista de Segundo Grado en Fisiología Normal y Patológica, Universidad de La Habana, Cuba.Doctorado33 - 2005; 28 - 2001Mayo de 2007Doctor en Medicina+58 274 2401471Facultad de [email protected] anterior # 8222569

Evoked potential correlates of right hemisfere involvement in the processing of a second language

The probe evoked potential paradigm was used to assess the relative engagement of both cerebral hemispheres in 10 Spanish-speaking subjects and in 12 subjects for whom Spanish was a second language, during the processing of verbal material presented in Spanish while listening to an irrelevant distractor (music), both presented acoustically through the same channel. Although the distractor condition produced attenuation of the probe EP, it was symmetrical in both groups. In agreement with previous findings, the probe EP showed task-specific activation in the left hemisphere during the activity of listening to the verbal material in the Spanish-speaking subjects, for whom the material was in their native language. However, the opposite effect, i.e. right hemisphere activation, was observed in the non-native group, suggesting an increased participation of the right hemisphere in the processing of foreign language [email protected]@gmail.co

Marcadores discursivos en hablantes sanos y afásicos: el caso especial de ‘y’

Este estudio presenta una comparación del uso de los marcadores discursivos (MDs)1 empleados por tres grupos de personas: 20 personas sanas, 25 pacientes con daño cerebral izquierdo y 10 pacientes con daño cerebral derecho. El análisis de varianza (ANOVA) muestra que aunque hay diferencia significativa (p= ,000) respecto al número total de marcadores en el habla de los tres grupos examinados, no la hay en cuanto a la cantidad relativa empleada por cada grupo. Se encuentra también un predominio de ‘y’ como marcador en todos los grupos. En todos ellos, la frecuencia de ‘y’ es alrededor del doble del marcador más próximo. Se propone que ‘y’ tiene características que le permiten convertirse en el marcador por omisión. Por otra parte se plantea que los MD, a pesar de ser unidades fonética y semánticamente de poco peso son tan importantes en la orientación del discurso, que su uso se preserva en la [email protected] study compares the use of discourse markers (DMs) in three different populations: 20 speakers with no cerebral damage, 25 patients with left hemisphere damage and 10 patients with right hemisphere damage. The analysis of variance (ANOVA) shows significance (p= .000) concerning total use of discourse markers between groups, but no significance in the relative use of DMs. The study also found a prevalence of ‘y’ whose frequency doubles that of other discourse markers. We suggest ‘y’ has the features of a ‘default marker’ in all populations. Finally, we propose that DMs, in spite of their reduced phonetic and semantic weight, are so important in the orientation of discourse that its use is preserved in aphasia