Neuroimagen en demencia. Correlación clínico-radiológica / Neuroimaging in dementia. Clinical-radiological correlation

La demencia es un síndrome caracterizado por un deterioro cognitivo crónico, adquirido, multidominio y que produce limitaciones funcionales significativas. La RM estructural es el estudio de imagen de elección en estos casos, dado que permite detectar los patrones de atrofia propios de las distintas enfermedades neurodegenerativas (enfermedad de Alzheimer, degeneración frontotemporal, demencia con cuerpos de Lewy), las lesiones vasculares asociadas a las demencias vasculares y varias patologías potencialmente reversibles (p.ej. tumores, hidrocefalia) o que requieren medidas de manejo especiales (p.ej. enfermedades priónicas). En casos seleccionados pueden utilizarse otros métodos de imagen, tales como la TC, la RM funcional, el SPECT con HMPAO o marcadores dopaminérgicos y el PET con FDG, marcadores de amiloide o marcadores dopaminérgicos. Las indicaciones de estos métodos no están aún bien establecidas, con lo que conviene utilizarlos en el contexto de unidades de demencia multidisciplinares

Dementia is a syndrome characterised by chronic, multi-domain, acquired cognitive impairment that causes significant functional limitations. MRI is the standard imaging study for these cases, since it enables detection of the atrophy patterns of the various neurodegenerative diseases (Alzheimer's disease, frontotemporal degeneration, Lewy body dementia), the vascular lesions associated with vascular dementia, and various potentially reversible diseases (for example, tumours, hydrocephaly) or diseases that require special management measures (for example, prion diseases). In certain cases other imaging methods can be used, such as CT, functional MRI, HMPAO SPECT or dopaminergic markers and FDG PET, amyloid markers or dopaminergic markers. The indications for these methods have not yet been clearly established, and therefore should be used in multidisciplinary dementia units

Neuroimaging in dementia. Clinical-radiological correlation. / Neuroimagen en demencia. Correlación clínico-radiológica.

Dementia is a syndrome characterised by chronic, multi-domain, acquired cognitive impairment that causes significant functional limitations. MRI is the standard imaging study for these cases, since it enables detection of the atrophy patterns of the various neurodegenerative diseases (Alzheimer's disease, frontotemporal degeneration, Lewy body dementia), the vascular lesions associated with vascular dementia, and various potentially reversible diseases (for example, tumours, hydrocephaly) or diseases that require special management measures (for example, prion diseases). In certain cases other imaging methods can be used, such as CT, functional MRI, HMPAO SPECT or dopaminergic markers and FDG PET, amyloid markers or dopaminergic markers. The indications for these methods have not yet been clearly established, and therefore should be used in multidisciplinary dementia units.

Resonancia magnética estructural en la epilepsia / Structural magnetic resonance imaging in epilepsy

La resonancia magnética (RM) estructural es la principal técnica de imagen en la epilepsia. En pacientes con crisis focales, detectar (y tipificar) una lesión estructural congruente con los datos electroclínicos permite tomar decisiones terapéuticas sin necesidad de acudir a otros medios diagnósticos más costosos o invasivos. La identificación de algunas lesiones aporta valor pronóstico, como en el caso de la esclerosis temporal medial (ETM), o puede ayudar al consejo genético, como en el caso de algunas alteraciones del desarrollo cortical (ADC). El objetivo de este trabajo es revisar el estado actual de las técnicas de RM estructural y proponer un protocolo básico de epilepsia, así como mencionar las indicaciones para realizar una RM estructural. También se revisará la semiología de las principales lesiones que causan epilepsia, como la ETM y las ADC, por su mayor frecuencia y por el especial impacto que la RM estructural ha demostrado en su diagnóstico y tratamiento (AU)

Magnetic resonance imaging is the main structural imaging in epilepsy. In patients with focal seizures, detection (and characterization) of a structural lesion consistent with electroclinical data allows therapeutic decisions without having to resort to other more expensive or invasive diagnostic procedures. The identification of some lesions may provide prognostic value, as in the case of Mesial Temporal Sclerosis (MTS) or may contribute to genetic counseling, as in the case of some Malformations of Cortical Development (MCD). The aim of this paper is to review the current state of structural MRI techniques, propose a basic protocol of epilepsy and mention the indications for structural MRI. Also, review the semiology of the main causes of epilepsy, with emphasis on MTS and MCD, by its highest frequency and by the special impact that MRI has shown in dealing with these entities (AU)

[Structural magnetic resonance imaging in epilepsy]. / Resonancia magnética estructural en la epilepsia.

Magnetic resonance imaging is the main structural imaging in epilepsy. In patients with focal seizures, detection (and characterization) of a structural lesion consistent with electroclinical data allows therapeutic decisions without having to resort to other more expensive or invasive diagnostic procedures. The identification of some lesions may provide prognostic value, as in the case of Mesial Temporal Sclerosis (MTS) or may contribute to genetic counseling, as in the case of some Malformations of Cortical Development (MCD). The aim of this paper is to review the current state of structural MRI techniques, propose a basic protocol of epilepsy and mention the indications for structural MRI. Also, review the semiology of the main causes of epilepsy, with emphasis on MTS and MCD, by its highest frequency and by the special impact that MRI has shown in dealing with these entities.

Neuritis del III par: diagnóstico por neuroimagen / Cranial nerve III neuritis: diagnosis by neuroimaging

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Avances en neurorradiología diagnóstica / Advances in diagnostic neuroradiology

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Migraña oftalmopléjica. Valor de la resonancia magnética / Ophthalmoplegic migraine: Value of magnetic resonance

La migraña oftalmopléjica es una rara entidad que suele iniciarse en la infancia y que se caracteriza por episodios recurrentes de cefalea migrañosa asociados a parálisis de pares craneales oculomotores, afectando con más frecuencia al tercer par. Su fisiopatología no es conocida, pero la teoría más reciente, que la considera un tipo de neuropatía, ha supuesto que en la última Clasificación Internacional de Cefaleas se incluya dentro del grupo de las neuralgias. El diagnóstico se basa en datos clínicos y en la exclusión de otras entidades. El hallazgo característico de engrosamiento y de realce con contraste del segmento cisternal del nervio oculomotor que se observa en la resonancia magnética (RM) apoya el diagnóstico. Se describe un caso compatible clínicamente, que presentó esta típica imagen en la RM y que tuvo una evolución favorable tras el tratamiento con corticoides (AU)

Ophthalmoplegic migraine is a rare entity, usually starting in chilhood, and characterized by recurrent episodes of migrainous headaches associated with an oculomotor cranial nerve palsy, most commonly affecting the third nerve. Its physiopathology remains unknown, but the most recent theory, that considers it as a neuropathy, has led to its inclusion in the last International Headache Classification into the group of neuralgias. Diagnosis is reliant on clinical grounds and the exclusion of other disorders. The characteristic finding of enlargement and enhancement with contrast of the cisternal portion of the oculomotor nerve, observed in Magnetic Resonance Imaging (MRI) has supported its diagnosis. We describe a clinically compatible case, supported by typical MRI images that progressed favourably following corticoids treatment (AU)

[Ophthalmoplegic migraine: value of magnetic resonance]. / Migraña oftalmopléjica. Valor de la resonancia magnética.

Ophthalmoplegic migraine is a rare entity, usually starting in childhood, and characterized by recurrent episodes of migrainous headaches associated with an oculomotor cranial nerve palsy, most commonly affecting the third nerve. Its physiopathology remains unknown, but the most recent theory, that considers it as a neuropathy, has led to its inclusion in the last International Headache Classification into the group of neuralgias. Diagnosis is reliant on clinical grounds and the exclusion of other disorders. The characteristic finding of enlargement and enhancement with contrast of the cisternal portion of the oculomotor nerve, observed in Magnetic Resonance Imaging (MRI) has supported its diagnosis. We describe a clinically compatible case, supported by typical MRI images that progressed favourably following corticoids treatment.

Linfomatosis cerebral como causa de leucoencefalopatía / Lymphomatosis cerebri as the cause of leukoencephalopathy

La linfomatosis cerebral (LC) es un tipo poco frecuente de linfoma primario del sistema nervioso centralcaracterizado por la afectación difusa e infiltrante de la sustancia blanca cerebral sin formar una masa. Objetivo. Presentar el caso de una paciente con LC para llamar la atención sobre la existencia de esta enfermedad, raramente diagnosticada, y sobre su presentación inicial en la resonancia magnética (RM) como leucoencefalopatía. Caso clínico. Mujer de 56 años que inició un cuadro de demencia subaguda. La tomografía axial computarizada y la RM craneal revelaron una afectación extensa, difusa y bilateral de la sustancia blanca, núcleos basales, mesencéfalo y protuberancia, sin efecto masa ni captación de contraste. Biopsia estereotáxica de la sustancia blanca, no concluyente, que mostró un infiltrado inflamatorio mononuclearmixto, de células B y T, de disposición perivascular. No se observó atipia citológica. Se realizó tratamiento con corticoides, con lo que se obtuvo mejoría clínica y radiológica en los dos primeros meses. Al siguiente mes se produjo un deterioro clínico rápido con somnolencia y empeoramiento de la marcha. La RM mostró un aspecto más heterogéneo de la lesión, con efecto masa sobre estructuras adyacentes y realce parcheado del contraste. Una biopsia cerebral en cuña llevó al diagnóstico de linfoma de células B de alto grado. Conclusiones. La apariencia radiológica e histológica de la LC puede no ser la habitual de los linfomas primarios del sistema nervioso central, y su presentación clínica puede ser similar a la de otros procesos difusos de afectación de la sustancia blanca (gliomatosis cerebral, enfermedades inflamatorias de la sustancia blanca como la enfermedad de Behçet, la enfermedad de Sjögren o el lupus eritematoso sistémico)

Lymphomatosis cerebri (LC) is an infrequent type of primary lymphoma of the central nervous systemthat is characterised by diffuse, infiltrating involvement of the white matter of the brain without the formation of a mass. Aim. To report the case of a patient with LC in order to draw attention to this disease, which is rarely diagnosed, and to its initialpresentation in magnetic resonance imaging (MRI) as leukoencephalopathy. Case report. Our patient was a 56-year-old female who had clinical signs and symptoms of sub-acute dementia. Computerised axial tomography and MRI of the head revealed extensive, diffuse and bilateral involvement of the white matter, basal nuclei, mesencephalon and pons, with no masseffect or contrast enhancement. A stereotactic biopsy of the white matter (which was not conclusive) showed a perivascular mixed mononuclear-cell inflammatory infiltrate of B and T cells. No cytologic atypia was observed. Treatment was establishedwith corticoids, which produced a clinical and radiological improvement in the first two months. During the next month the patient underwent rapid clinical deterioration with sleepiness and a worsening of the ability to walk. In an MRI scan the lesion had a more heterogeneous appearance with mass effect on adjacent structures and patchy contrast enhancement. A wedge biopsy of brain tissue led to a diagnosis of high-grade B-cell lymphoma. Conclusions. The imaging and histological appearance of LC may not be the one typically found in primary lymphomas of the central nervous system, and its clinical presentation may be similar to that of other diffuse processes involving compromise of the white matter (cerebral gliomatosis, inflammatory diseases of the white matter, such as Behçet’s disease, Sjögren’s disease or systemic lupus erythematosus)

[Lymphomatosis cerebri as the cause of leukoencephalopathy]. / Linfomatosis cerebral como causa de leucoencefalopatía.

INTRODUCTION: Lymphomatosis cerebri (LC) is an infrequent type of primary lymphoma of the central nervous system that is characterised by diffuse, infiltrating involvement of the white matter of the brain without the formation of a mass. AIM: To report the case of a patient with LC in order to draw attention to this disease, which is rarely diagnosed, and to its initial presentation in magnetic resonance imaging (MRI) as leukoencephalopathy. CASE REPORT: Our patient was a 56-year-old female who had clinical signs and symptoms of sub-acute dementia. Computerised axial tomography and MRI of the head revealed extensive, diffuse and bilateral involvement of the white matter, basal nuclei, mesencephalon and pons, with no mass effect or contrast enhancement. A stereotactic biopsy of the white matter (which was not conclusive) showed a perivascular mixed mononuclear-cell inflammatory infiltrate of B and T cells. No cytologic atypia was observed. Treatment was established with corticoids, which produced a clinical and radiological improvement in the first two months. During the next month the patient underwent rapid clinical deterioration with sleepiness and a worsening of the ability to walk. In an MRI scan the lesion had a more heterogeneous appearance with mass effect on adjacent structures and patchy contrast enhancement. A wedge biopsy of brain tissue led to a diagnosis of high-grade B-cell lymphoma. CONCLUSIONS: The imaging and histological appearance of LC may not be the one typically found in primary lymphomas of the central nervous system, and its clinical presentation may be similar to that of other diffuse processes involving compromise of the white matter (cerebral gliomatosis, inflammatory diseases of the white matter, such as Behçet's disease, Sjögren's disease or systemic lupus erythematosus).

Resonancia magnética funcional de la corteza visual: estudio de las relaciones entre la intensidad del estímulo y la respuesta BOLD / Functional magnetic resonante imaging of the visual cortex relation between stimulus intensity and bold response

Introducción. La investigación sobre la visión ocupa un lugar central en neurociencia. Nuevas técnicas de neuroimagen, como la resonancia magnética funcional (RMf), permiten aumentar el conocimiento sobre el funcionamiento del sistema visual rápidamente y de forma no invasiva. El presente estudio examina el efecto de pequeños cambios en la intensidad de un estímulo sobre la respuesta de la corteza visual. Objetivos. Analizar la reacción de la corteza visual ante diferentes intensidades de una fuente luminosa, y examinar las posibles diferencias en la respuesta BOLD entre controles y sujetos con fotofobia. Sujetos y métodos. Se realizo una RMf (3 T) a 20 controles y a 20 sujetos con fotofobia, durante la estimulación visual con diferentes intensidades de luz. Se cuantificó la respuesta BOLD, tanto el área como a la intensidad del cambio de señal, en el córtex occipital. Resultados. Se encontró una relación directa entre la intensidad de los estímulos y la respuesta de la corteza occipital, con cambios significativos en el área de activación y con tendencia similar (aunque no significativa) en la intensidad de la respuesta BOLD. Además, la respuesta cortical es más pronunciada en sujetos con fotofobia, sobre todo en intensidades bajas e intermedias. Conclusiones. La RMf se muestra como una técnica válida y robusta para el registro de respuestas consistentes y reproducibles entre distintos sujetos y grupos, tanto para el estudio del funcionamiento normal de la corteza occipital como en casos de respuesta anómala, lo que abre la posibilidad de utilizarla en estudios clínicos

Introduction. Visual system is a high interest topic in neuroscience research. The new neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), allow us to quickly improve our knowledge on the visual system using non-invasive methods. This work examines the effect of small changes in the intensity of a visual stimulus over the BOLD response in the visual cortex. Aims. To perform a detailed analysis of the visual cortex reaction to different intensities of a light source and to verify the ties between the intensity of the visual stimulus and the cortical response. Subjects and methods. Using fMRI (3 T), we registered BOLD response (area and intensity of the signal change) in 20 photophobic patients and 20 controls while viewing different stimulus intensities from a light source. Results. We found a direct relation between stimulus intensity and occipital response. We show that cortical reactivity is higher in patients with photophobia than normal controls, specially for the lower and medium intensities. Conclusions. fMRI is a valid and robust technique to register consistent and reproducible responses in different groups of subjects. It is useful for the study of normal cortex functioning as well as for clinical use

[Functional magnetic resonance imaging of the visual cortex: relation between stimulus intensity and bold response]. / Resonancia magnética funcional de la corteza visual: estudio de las relaciones entre la intensidad del estímulo y la respuesta BOLD.

INTRODUCTION: Visual system is a high interest topic in neuroscience research. The new neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), allow us to quickly improve our knowledge on the visual system using non-invasive methods. This work examines the effect of small changes in the intensity of a visual stimulus over the BOLD response in the visual cortex. AIMS: To perform a detailed analysis of the visual cortex reaction to different intensities of a light source and to verify the ties between the intensity of the visual stimulus and the cortical response. SUBJECTS AND METHODS: Using fMRI (3 T), we registered BOLD response (area and intensity of the signal change) in 20 photophobic patients and 20 controls while viewing different stimulus intensities from a light source. RESULTS: We found a direct relation between stimulus intensity and occipital response. We show that cortical reactivity is higher in patients with photophobia than normal controls, specially for the lower and medium intensities. CONCLUSIONS: fMRI is a valid and robust technique to register consistent and reproducible responses in different groups of subjects. It is useful for the study of normal cortex functioning as well as for clinical use.

[Hydrogen spectroscopy in neurology]. / Espectroscopia de hidrógeno en neurología.

for a long time to the research field despite its unquestionable diagnostic value. The availavility of programs able to automatically obtain a spectrum, and the current possibility of estimating easily the relationship among its different peaks, have approached this diagnostic technology to the current clinical situation. With hydrogen MRI spectroscopy (MRS) it is possible to obtain additional information which make it possible to distinguish among different neurological alterations with similar morphological appearance, such as cerebral tumors and pseudotumoral types of inflammatory processes, or tumor recurrence and radionecrosis. On other occasions, it makes it possible to detect alterations which are invisible by imaging study, such as medial temporal sclerosis, or multiple sclerosis. It is also very useful in following-up many alterations, either in their natural history, as in Alzheimers disease, or in order to monitor treatments on cerebral tumors or infectious processes. However, MRS does not often show pathognomonic patterns, so it is always recommended to consider it not just in the clinical context, but as inseparable part of an MR study, either structural or functional (diffusion, perfusion), since it is this is how it provides more useful information from a clinical point of view.

Espectroscopia de hidrógenoen neurología / Hydrogen spectroscopy in neurology

La espectroscopia es una técnica conocida desde los comienzos de la resonancia magnética, que a pesar de su indudable valor diagnóstico, debido a dificultades técnicas en su mayor parte, ha permanecido restringida durante largo tiempo al ámbito de la investigación. La incorporación de programas capaces de obtener un espectro de forma automática, así como la posibilidad actual de estimar fácilmente la relación entre los diferentes picos de éste, han acercado a la clínica diaria esta técnica diagnóstica, que está demostrando gran utilidad. Mediante la espectroscopia de hidrógeno es posible obtener información complementaria que permite distinguir entre diferentes alteraciones neurológicas con aspecto morfológico similar, como los tumores cerebrales y formas seudotumorales de procesos inflamatorios, o la recidiva tumoral y la radionecrosis. En otras ocasiones permite detectar alteraciones no visibles en un estudio de imagen, como en la esclerosis temporal mesial o la esclerosis múltiple. También es de gran valor en el seguimiento de muchas alteraciones, tanto en su historia natural, como en la enfermedad de Alzheimer, como para monitorizar tratamientos en tumores cerebrales o procesos infecciosos. La espectroscopia de hidrógeno, sin embargo, no presenta frecuentemente patrones patognomónicos, por lo que es siempre recomendable valorarla no sólo en el contexto clínico sino como parte inseparable de un estudio de imagen por resonancia magnética tanto estructural como en ocasiones funcional (difusión, perfusión), ya que es de esta manera como aporta una información más útil desde el punto de vista clínico (AU)

[Naso-intestinal intubation with weighted tubes. A new modification of an old technique]. / Intubación nasointestinal con sondas lastradas. Una modificación nueva a una técnica antigua.

We have studied the spontaneous transpyloric passage of 25 weighted nasointestinal tubes using a modified technique slightly different from the standard one. Instead of introducing the entire tube in the stomach in the very first moment, we have only introduced at the beginning approximately 70 cm and afterwards, with the patient in the right lateral decubitus position, each 15 minutes we continued introducing 15 cm each time for a total period of one hour. X-ray controls were done 3, 24 and 48 hours after the first introduction. Fifteen tubes (60%) had passed to the small intestine in the first 3 hours, 21 (84%) had reached it before 24 hours and 23 (92%) had passed the pylorus before 48 hours. The others two tubes did not pass the pylorus in 48 hours nor did they pass after the administration of metoclopramide. We thus conclude that this technique simplifies the intubation of the small intestine. We recommend to control the position of the tube by X-ray film 24 hours after the positioning. If after this period the tube is still in the stomach, it should be repositioned using radiological or endoscopic assistance in those cases that the delivery of an intestinal solution is desired.