Cortical hypointensity in T2-weighted gradient-echo sequences in patients with progressive multifocal leukoencephalopathy. / Hipointensidad cortical en secuencias eco de gradiente T2 en la leucoencefalopatía multifocal progresiva.

INTRODUCTION: Progressive multifocal leukoencephalopathy is a demyelinating disease of the central nervous system caused by the reactivation of the JC virus. This opportunistic encephalopathy mainly affects immunodepressed patients with stage III HIV infection, although in recent years it has also been found in association with treatment with immunosuppressors such as natalizumab. MRI plays an important role in both the early diagnosis and follow-up of this disease. Recently, it has been reported that hypointensities in U-fibers and cortex adjacent to white-matter lesions characteristic of the disease can be identified on T2-weighted gradient-echo and susceptibility-weighted sequences in patients with progressive multifocal leukoencephalopathy. OBJECTIVE: We aimed to analyze the presence and usefulness of cortical hypointensity on T2-weighted gradient-echo sequences in relation to the diagnosis of progressive multifocal leukoencephalopathy and to review the literature on the topic. MATERIAL AND METHODS: We analyze three cases of progressive multifocal leukoencephalopathy seen at our center in three patients with immunosuppression of different origins: one with stage III HIV infection, one with multiple sclerosis being treated with natalizumab, and one with rheumatoid arthritis being treated with rituximab. RESULTS: In all three cases MRI showed the cortical hypointensity adjacent to the white-matter lesion in the T2-weighted gradient-echo sequence. In the patient with multiple sclerosis, this sign appeared earlier than the abnormal signal in the white matter. The patient being treated with rituximab was diagnosed postmortem and the pathology findings correlated with the MRI findings. CONCLUSION: The finding of cortical hypointensity on T2-weighted gradient-echo MRI sequences seems to support the diagnosis of progressive multifocal leukoencephalopathy, regardless of the type of immunosuppression, so this finding should routinely assessed in patients suspected of having this disease.

Síndrome de Joubert: hallazgos en resonancia magnética convencional y tensor de difusión / Joubert syndrome: findings at conventional magnetic resonance image and at diffusion tensor imaging

Presentamos el caso de un paciente de 20 años con diagnóstico previo de parálisis cerebral infantil y que a la exploración física presentaba un trastorno del desarrollo. Se le realizó una tomografía computarizada (TC) craneal y una resonancia magnética (RM) craneal convencional con lo que se diagnosticó de síndrome de Joubert. Se completó el estudio con un tensor de difusión y una tractografía. En este artículo se revisan los hallazgos en las técnicas de imagen en este síndrome y la bibliografía (AU)

We present the case of a 20-year-old man previously diagnosed with cerebral palsy in whom a developmental disorder was detected at physical examination. After cranial CT and conventional cranial MRI, we diagnosed Joubert syndrome. We completed the study with diffusion tensor imaging and tractography. This article reviews the imaging findings for Joubert syndrome and the relevant literature (AU)

[Joubert syndrome: findings at conventional magnetic resonance image and at diffusion tensor imaging]. / Síndrome de Joubert: hallazgos en resonancia magnética convencional y tensor de difusión.

We present the case of a 20-year-old man previously diagnosed with cerebral palsy in whom a developmental disorder was detected at physical examination. After cranial CT and conventional cranial MRI, we diagnosed Joubert syndrome. We completed the study with diffusion tensor imaging and tractography. This article reviews the imaging findings for Joubert syndrome and the relevant literature.

[Leptomeningeal dissemination in an intestinal-type sinonasal adenocarcinoma: an uncommon presentation]. / Diseminación leptomeníngea en un carcinoma nasosinusal de tipo intestinal: una forma de presentación inusual.

We present the case of a patient with a 30-year history of exposure to sawdust who was diagnosed with mucinous intestinal-type sinonasal adenocarcinoma after histological examination. The patient presented with neurological symptoms; moreover, intra- and extra-cranial leptomeningeal involvement, which is exceedingly rare in this type of tumors, was observed at the time of diagnosis.

Degeneración walleriana bilateral de las fibras pontocerebelosas secundaria a ictus pontinos: presentación de 4 casos / Bilateral wallerian degeneration of the pontocerebellar fibers secondary to pontine stroke: a report of 4 cases

La degeneración walleriana es una desmielinización de los axones neuronales distales por una daño proximal de cualquier etiología.Se presentan los hallazgos de resonancia magnética en 4 pacientes con ictus de tronco y signos de degeneración walleriana de los haces pontocerebelosos. Para ello se revisan las resonancias magnéticas de 4 pacientes con lesiones pontinas en fase subaguda o crónica, y las alteraciones de señal en los pedúnculos cerebelosos medios. Los hallazgos en las secuencias potenciadas en T2 y en difusión se relacionan con el tiempo de evolución y la etiología del ictus (AU)

Wallerian degeneration occurs after demyelination of the distal neuronal axons due to proximal damage of any type.AbstractWe present the magnetic resonance findings in four patients with brainstem stroke and signs of Wallerian degeneration in the pontocerebellar tracts.AbstractWe reviewed the magnetic resonance studies in four patients with subacute or chronic stage pontine lesions and the signal alterations at the level of the medial cerebellar peduncles. We correlated the findings in T2-weighted sequences and diffusion-weighted sequences with the time of evolution and etiology of the stroke (AU)

[Bilateral wallerian degeneration of the pontocerebellar fibers secondary to pontine stroke: a report of 4 cases]. / Degeneración walleriana bilateral de las fibras pontocerebelosas secundaria a ictus pontinos: presentación de 4 casos.

Wallerian degeneration occurs after demyelination of the distal neuronal axons due to proximal damage of any type. We present the magnetic resonance findings in four patients with brainstem stroke and signs of Wallerian degeneration in the pontocerebellar tracts. We reviewed the magnetic resonance studies in four patients with subacute or chronic stage pontine lesions and the signal alterations at the level of the medial cerebellar peduncles. We correlated the findings in T2-weighted sequences and diffusion-weighted sequences with the time of evolution and etiology of the stroke.

[Radiopathologic update on dementias: postmortem magnetic resonance.]. / Actualización radiopatológica en demencias. Resonancia magnética posmortem.

Neurodegenerative diseases that course with dementia represent a public health problem that is growing in importance, mostly due to the aging of the population. Imaging techniques provide essential diagnostic and prognostic information. Some classifications of these diseases have recently been modified through the incorporation of histological, immunohistochemical, and genetic criteria. This article reviews the different radiological and pathological aspects of the most common diseases that course with dementia. We studied brains from our community's tissue bank with postmortem MRI and posterior histological examination and illustrate this exposition with images from the radiopathologic correlation.