Neuroimagen

MR de 7 Tesla en Esclerosis Múltiple

2011-05-28T01:05:00.000-07:00

7T T2*-weighted axial images from (A) an MS patient using the Axial1 protocol (in-plane resolution: 215 × 286 μm). Images demonstrate multiple foci of abnormality involving the deep WM structures, as well as the GM, WM, and lesion contrast achieved using this methodology, and (B) an MS patient with multiple lesions using the Axial2 protocol (in plane resolution: 195 × 260 μm), along with an enlarged image of highlighted selection which demonstrates sub-cortical WM lesions (arrows).

Demencia autoinmune

2011-05-28T00:50:00.000-07:00

Neuroimaging in patients with an immunotherapy-responsive cognitive disorder.

Magnetic resonance imaging: yellow arrows indicate areas of abnormality on fluid-attenuated inversion recovery (FLAIR). A, 36-year-old woman (patient 10 in Appendix 1) had fluctuating memory problems and was seropositive for glutamic acid decarboxylase-65 autoantibody. Bilateral hippocampal axial FLAIR abnormality, shown in A1, almost completely resolved after treatment with intravenous (IV) methylprednisolone (A2). B, 51-year-old woman (patient 20 in Appendix 1) had subacute fluctuating memory problems, multifocal neurologic examination findings, and evidence of autoimmunity (IgM antiphospholipid antibody). Symmetric confluent T2 signal abnormality in the white matter of both hemispheres (B1) decreased after treatment with IV methylprednisolone (B2). C, 60-year-old man (patient 41 in Appendix 1) had memory, language, and gait problems and was seropositive for both striational and glutamic acid decarboxylase-65 antibodies. Axial T1 magnetic resonance imaging with contrast demonstrated periventricular vessel enhancement (C1) and resolution after treatment (C2). D, 53-year-old woman (patient 29 in Appendix 1) had memory loss, hallucinations, and subsequent seizure; cerebrospinal fluid protein was elevated (>100 mg/dL), and she was seropositive for thyroid peroxidase antibodies and neuronal and muscle acetylcholine receptor antibodies. Axial FLAIR images show diffusely increased T2 signal in the midbrain (D1), which improved after treatment with IV methylprednisolone (D2). Multiple myeloma was diagnosed 18 months after neurologic presentation.

Positron emission tomographic imaging: Brain reconstructions (brighter color represents regions of hypometabolism) in a 58-year-old man (patient 21 in Appendix 1) who presented with personality change and memory problems and had elevated cerebrospinal fluid protein (>100 mg/dL). Hypometabolism, predominantly frontal and temporal (E1), improved after treatment with IV methylprednisolone (E2).

Single-photon emission computed tomographic brain imaging: Brain neuroimaging in a 35-year-old man (patient 22 in Appendix 1) who presented with vertigo and memory problems, had multiple coexisting autoimmune conditions, and was seropositive for muscle acetylcholine receptor and striational antibodies. Diffuse decrease in uptake in frontotemporoparietal regions (F1) was markedly improved globally after treatment with IV methylprednisolone (F2).

Encefalitis antiNMDA simulando neuromielitis óptica seronegativa

2011-05-28T00:41:00.000-07:00

Features of atypical anti-NMDA receptor encephalitis

MRI: (A) Initial contrast-enhancing lesion; (B) longitudinally extensive transverse myelitis; (C) continued development of contrast-enhancing lesions; (D) retrochiasmatic optic neuritis; (E, F) continued accumulation of T2/fluid-attenuated inversion recovery (FLAIR) hyperintense lesion burden, with sagittal FLAIR hyperintensities reminiscent of Dawson's fingers (E). Brain biopsy (from contrast-enhancing frontal lobe lesion): (G) perivascular infiltrate with associated reactive microgliosis; (H) widespread parenchymal destruction mediated by infiltrative lymphocytes and macrophages without selective demyelination; (I) prominent mixed perivascular infiltrate (macrophages, T- and B-lymphocytes with uncommon neutrophils and rare eosinophils). Western blot: (J) Western blot depicting the presence of several additional serum-derived autoantibodies reactive against cerebellar protein extract from control human brain.

Resonancia de alto campo del hipocampo

2011-05-28T00:39:00.000-07:00

21.1-Tesla MRI on postmortem brain sections of the hippocampus

Fixed postmortem samples were washed in phosphate-buffered saline and immersed in Fluorinert (3M, Corp). Utilizing a 21.1-T magnet (Bruker Avance console and Micro2.5 gradients) and 33-mm birdcage coil, 3-dimensional ¹H fast low angle shot (FLASH) scans (echo time/repetition time = 12/50 msec) were acquired in 3-dimensional at 50-μm isotropic resolution over 4.3 hours at 14°C. (A) Normal hippocampal and (B) sclerotic sections.

Uso del PET con Florbetapir para la detección del beta amiloide en la Enfermedad de Alzheimer

2011-05-13T10:44:00.000-07:00

El diagnóstico precoz de los pacientes con enfermedad de Alzheimer (EA) supone un constante desafío.Se estima que entre un 10-20% de los pacientes diagnosticados de EA en realidad no la presentan en el estudio anatomopatológico y que un 33% de pacientes con síntomas leves no pueden ser diagnosticados de EA. Por ello, los marcadores biológicos se han propuesto como una solución a este problema.

Recientemente ha sido publicado un estudio, todavía preliminar, (JAMA. 2011;305(3):275-283) de un nuevo biomarcador (Florbetapir-F 18) para su uso en imágenes por Tomografía por emisión de positrones (PET). Los autores demuestran en el estudio una correlación de las imágenes de Florbetapir-PET "in vivo" con la densidad de beta-amiloide en los estudios necrópsicos postmorten.

El Florbetapir se une al Compuesto B Pittsburgh como marcador para imágenes de PET que muestra la presencia "in vivo" de los depósitos cerebrales de beta-amiloide propios de la EA. La ventaja del Florbetapir-F 18 con respecto al Compuesto B Pittsburgh, es que este último al usar el Carbono-11 como isótopo presenta una menor vida media (20 minutos) que el Fluor-18 (isótopo del Florbetapir).

Los estudios previos demostraban la alta afinidad y especificidad del Florbetapir con el Beta-amiloide. Además, su rápido aclaramiento (en el caso de que no se haya fijado al beta-amiloide) cerebral lo hace ser un excelente biomarcador para su uso en el PET.

Chiari + Siringomielia

2011-05-12T04:43:00.000-07:00

Fístula Carótido-Cavernosa

2011-05-12T04:40:00.000-07:00

Embolismo gaseoso

2011-05-07T00:58:00.000-07:00

Paciente con derrame pleural metaneumónico que tras tratamiento con pleurodesis quimica con fibrinolíticos sufre embolismo cerebral gaseoso. Recuperación completa tras tratamiento en cámara hiperbárica.
(Texto completo)

Degeneración hepatocerebral crónica adquirida

2011-04-01T11:00:00.000-07:00

Publicado en REV NEUROL 2011;52:435-436

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

2011-03-18T14:10:00.001-07:00

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

2010-12-13T11:13:00.000-08:00

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

2010-12-08T03:10:00.000-08:00

Gliblastoma multiforme

Leer caso clínico completo (en inglés).

Tumor de unión bulbomedular

2010-01-23T01:13:00.000-08:00

Descripción de la RM y TC craneal

2009-11-30T10:06:00.000-08:00

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

2009-11-28T15:50:00.000-08:00

Meningioma

2009-11-28T15:49:00.001-08:00

Angioma cavernoso

2009-11-28T15:47:00.000-08:00

MAV cerebral

2009-11-28T15:33:00.001-08:00

Hemorragia parenquimatosa

2009-11-28T15:32:00.001-08:00

Evolución radiológica de los ictus

2009-11-28T15:31:00.001-08:00

Infarto cerebral agudo

2009-11-28T15:30:00.001-08:00

Reperfusión

2009-11-28T15:28:00.000-08:00

Hemorragia subaracnoidea

2009-11-28T14:19:00.000-08:00

Hematoma subdural crónico

2009-11-28T14:18:00.001-08:00

Hematoma subdural agudo

2009-11-28T14:17:00.002-08:00

Hematoma epidural

2009-11-28T14:17:00.001-08:00

Contusión hemorrágica

2009-11-28T14:15:00.001-08:00

Mielinolisis central pontina

2009-03-08T00:11:00.000-08:00

La mielinolisis central pontina (MCP) es una entidad caracterizada por la destrucción de mielina en la base de la protuberancia, generalmente asociada con enolismo, corrección rápida
de la hiponatremia y otras alteraciones electrolíticas. Se describe la clínica, factores etiopatogénicos, neuroimagen y evolución de una serie de pacientes con diagnóstico de mielinolisis central pontina/extrapontina (MCP/E).

Se ha publicado en español una serie en Neurología 166 2009;24(3):165-169

Dissecting Aneurysm of the Posterior Cerebral Artery

2009-03-08T00:07:00.000-08:00

A 43-year-old man presented with acute-onset hemianesthesia involving the right arm, the right leg, and the right side of the face. Six weeks earlier, he had a moderate occipital headache that lasted for 3 days. Diffusion-weighted magnetic resonance imaging (MRI) of the brain showed a thalamic lesion of restricted diffusion on the left side (Panel A, arrow), which was consistent with acute posterior choroidal-artery infarction. T2-weighted MRI scans, a magnetic resonance angiogram, and a computed tomographic angiogram (Panels B, C, and D, respectively) revealed a dilatation of the left posterior cerebral artery, with a double lumen — that is, a true circulating lumen (Panels B, C, and D, lower arrows) and a false noncirculating lumen (Panels B, C, and D, upper arrows), divided by an intimal flap (Panel B, arrowheads), suggesting a dissecting aneurysm. Angiography confirmed an aneurysm of the posterior cerebral artery (Panel E, arrows). The patient reported no specific risk factor (e.g., trauma) for arterial dissection. Uncomplicated occlusion of the aneurysm and the parent posterior cerebral artery was achieved with endovascular coils (Panel F). A few weeks later, progressive, painless paresthesias occurred in the right hemibody, which were unchanged at a 1-year follow-up visit. Dissecting intracranial aneurysms typically present with infarction (due to stenosis or embolism) or subarachnoid hemorrhage (due to rupture). Treatment options include conservative management, administration of antiplatelet agents, anticoagulation, and surgical or endovascular intervention. Therapeutic occlusion of the posterior cerebral artery distal to the perforating arteries to the thalamus and brain stem is often well tolerated because of collateral circulation.

Reference:

Renard D, Milhaud D. Images in clinical medicine. Dissecting aneurysm of the posterior cerebral artery. N Engl J Med. 2007 Dec 13;357(24):e27.

Occlusion and Reperfusion of the Middle Cerebral Artery

2009-03-08T00:03:00.000-08:00

A 65-year-old woman with chronic atrial fibrillation was admitted for an elective exchange of an implanted defibrillator for idiopathic dilated cardiomyopathy. To facilitate this procedure, warfarin was withheld for 5 days. Before the procedure was performed, acute-onset right hemiparesis and expressive dysphasia developed. Urgent noncontrast computed tomography (CT) of the brain and CT angiography of the intracranial and extracranial arterial circulation confirmed an acute occlusion of the M2 segment of the middle cerebral artery, which was consistent with the presence of an embolus (Panel A, arrow). Ninety-five minutes after the onset of neurologic deficits, the patient was given a bolus dose and 1-hour infusion of tissue plasminogen activator. Repeat CT angiography, performed 25 hours after thrombolysis, showed reperfusion of the middle cerebral artery and cortical branches in the sylvian fissure on the left side (Panel B), which correlated with resolution of the neurologic deficits. Early administration of a thrombolytic agent is essential for optimal neurologic recovery. The patient has had no further neurologic symptoms, with no measurable deficit.

Reference:
Ryan R, Brophy DP. Images in clinical medicine. Occlusion and reperfusion of the middle cerebral artery. N Engl J Med. 2007 Dec 13;357(24):2495.

Megavertebral izquierda

2008-11-21T10:52:00.001-08:00

Hemiespasmo hemifacial izquierdo asociado a arteria displásica "megavertebral" izquierda.

Mielitis isquémica

2008-11-21T10:44:00.000-08:00

Paciente con paraparesia espástica progresiva que muestra en la RM mielitis isquémica asociada a MAV dural espinal (flecha).

Sordera súbita y nistagmus por Arnold-Chiari

2008-10-25T09:07:00.000-07:00

Si bien no son las manifestaciones clínicas más conocidas, una malformación tipo Arnold-Chiari, asociada en este caso a siringomielia, puede causar sordera súbita y nistagmus. Además el paciente había sufrido un episodio de amnesia global transitoria.

RM y PET de un paciente con Amnesia Global Transitoria de origen epiléptico

2008-09-08T01:56:00.000-07:00

Esta imagen tomada de un artículo de Nature Clinical Practice Neurology (ver texto completo) muestra: (A) Secuencia FLAIR durante el episodio, con hiperseñal en el hipocampo izquierdo. (B) PET durante el mismo episodio mostrando hipermetabolismo sobre la zona anterior del hipocampo izquierdo y (C) PET al mes del episodio mostrando normalización del metabolismo en dicho territorio.

En base a estos hallazgos los autores sugieren un origen comicial como etiología más probable de este trastorno (transient epileptic amnesia).

CADASIL

2008-08-26T23:11:00.000-07:00

Lesiones típicas del CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy):

Imagen superior: La RM craneal muestra cambios de señal importantes en la sustancia blanca subcortical y en los ganglios basales, hiperintensas en T2.
Imagen inferior: Las imágenes de microscopía electrónica de la biopsia de piel muestra depósito granular en la capa media arteriolar.

Papiledema asociado a trombosis venosa cerebral

2008-08-20T01:26:00.000-07:00

A) Venografía mostrando trombosis parcial del seno sagital superior, la tórcula y la porción proximala de los senos transversos (flechas). B). Venografía de seguimiento mostrando mejoría en el flujo venoso con trombosis leve residual. C). Secuencia "Fast-spin echo T2" mostrando protusión del nervio óptico sobre el globo ocular (flecha). D). Aproximación de la imagen vista en C.

Neurofibromas plexiformes en paciente con Neurofibromatosis tipo 1

2008-08-17T09:25:00.000-07:00

Una de las complicacíones más frecuentes en la neurofibromatosis tipo 1 es la aparición de neurofibromas plexiformes que en su crecimiento pueden comprometer las estructuras vecinas. En este caso apreciamos neurofibromas plexiformes de gran tamaño en la región cervical y en la base del cráneo con ausencia de parte de la estructura ósea.

Diplopia y proptosis por aneurisma carotídeo gigante

2008-08-06T14:04:00.000-07:00

Esta paciente desarrolló de forma subaguda una diplopia binocular y exoftalmos del ojo derecho demostrándose en el TC de cráneo simple una imagen vascular ocupante de espacio sugestiva de aneurisma carotídeo gigante.