Degeneración hepatocerebral crónica adquirida

 

Publicado en REV NEUROL 2011;52:435-436

Secuencias de difusión en RM para el estudio del mecanismo de deglución

Introduction Understanding the relevance of neural pathways that control human swallowing and related behaviours is paramount to correctly identifying and treating swallowing disorders. We aimed to evaluate these connections using complimentary imaging modalities in vivo.

Methods In 13 healthy adults (3 Male/10 Female, 27–62 years old) Transcranial Magnetic Stimulation (TMS) evoked pharyngeal motor responses were recorded via a swallowed intraluminal catheter and used to assess motor cortical pharyngeal representation in both hemispheres.1 Thereafter, event-related 3T functional magnetic resonance imaging (fMRI) was applied to assess blood-oxygen-level-dependent signal changes (compared to rest) in response to a pseudo-randomised order of water and saliva swallowing in addition to a tongue elevation task. Swallow related behaviour was monitored using a pressure feedback belt around the subjects' neck. Distortion-corrected diffusion weighted imaging (DWI) data were then acquired for probabilistic tractography to determine anatomical fibre tracts. Task-related fMRI activations were identified in SPM8 and used to seed unconstrained multi-fibre probabilistic tractography independently in each hemisphere.2 These results were compared with TMS inter-hemispheric differences.

Results TMS data revealed 12/13 subjects had asymmetric motor representation (lateralised dominance) for the pharynx (6 left, 6 right) with significantly larger responses observed in the lateralised projection (p < 0.001). FMRI data (figure 1) also revealed asymmetric activations in both sensorimotor cortices in each subject for the different tasks which were used as seed regions for tractography. Largest activations were observed in primary motor cortices (Brodmann Area (BA) 4) after water swallowing, predominantly right lateralised. By contrast, tongue elevation and saliva swallowing produced a greater number of left lateralised brain areas, particularly pre- and supplementary-motor cortex (BA 6) as well as areas involved with language and speech processing (BA 22,40,44). Tractography revealed larger tract volumes in the hemispheric dominant projection predicted by TMS compared to the non-dominant projection for water but not for saliva swallowing or tongue elevations (p < 0.001).

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Figure 1

OC-078 fMRI activation for swallowing and related behaviours

Conclusion Using multimodal imaging we have performed a detailed mapping of the network of neural pathways that contribute to human swallowing and its related behaviours. Our data also provide further evidence for cerebral asymmetry and its relevance in the control of human swallowing.                                  

Signo de santiaguiño en la atrofia multisistémica

El santiaguiño (Scyllarus arctus) es una variedad muy sabrosa y apreciada de marisco, que se cría en las rías gallegas. Debe su nombre al distintivo de su concha en forma de cruz, que recuerda a la cruz de Santiago. Este cada vez más escaso manjar ya habitaba con toda seguridad la ría de Arousa, a la que, según la tradición jacobea, arribaron los discípulos de Santiago el Mayor con el cuerpo de su maestro martirizado y decapitado en Tierra Santa en el año 41 d.C. y embarcado en el puerto de Haifa en una barca de piedra. La cruz de la protuberancia (concha) en combinación con la atrofia vermiana (cola) y hemisférica conforman la silueta del santiaguiño. El “signo del santiaguiño” estaba en 4 pacientes con AMSc de una serie de 11 pacientes con AMS estudiada en nuestro centro.

Corte axial del estudio de RM potenciado en T2, en el que se observa una hiperseñal centropontina en cruz, con atrofia cerebelosa vermiana y hemisférica, que configuran la silueta de un santiaguiño.

Tomado de

I. Pereiro a, M. Arias b, I. Requena. Signo de santiaguiño en la atrofia multisistémica. Neurología 2010 doi:10.1016/j.nrl.2010.04.005

Un caso de "crisis endocrinológica" en una paciente con ceguera subaguda

Gliblastoma multiforme

Leer caso clínico completo (en inglés).

Tumor de unión bulbomedular

Descripción de la RM y TC craneal

En el siguiente Knol (en inglés) hay disponible una descripción resumida de las técnicas de neuroimagen: Resonancia y Scanner; sus ventajas e inconvenientes, cómo se obtienen las imágenes y cuál es su uso en la clínica.
Ver Knol

Metástasis

Meningioma

Angioma cavernoso