Polyregional and hemispheric syndromes: a study of these uncommon first attacks in a CIS cohort.

Clinically isolated syndromes (CIS) classically refer to optic neuritis (ON), brainstem or spinal cord syndromes. Less common first episodes suggestive of central nervous system (CNS) demyelination, such as hemispheric or clinically polyregional syndromes, have been only slightly studied. The aim of this study was to describe these CIS topographies in our cohort of patient with a CIS. We evaluated 320 patients with a CIS, and classified the topographies of the attacks according to clinical symptoms only into CIS of the optic nerve (123), brainstem (78), spinal cord (89), hemispheric (6), polyregional (12) or undetermined (12) topographies. Patients underwent brain MRI within three months of their first attack, and again 12 months later. Conversion to multiple sclerosis (MS), determined either clinically or by magnetic resonance imaging (MRI), was evaluated according to topography. Hemispheric and polyregional syndromes were closer to brainstem or spinal cord syndromes than ON in clinical and MRI conversion terms, although a statistical analysis was not performed because of the small number of patients. There are differences between several studies in the definition, and, therefore, the prevalence of these so-called atypical CIS. Consensus on the denomination and definition of these syndromes must be reached.

Baseline MRI predicts future attacks and disability in clinically isolated syndromes.

OBJECTIVE: To determine the relation between baseline MRI and both conversion to multiple sclerosis (MS) and development of disability in a cohort of patients with clinically isolated syndromes (CIS). METHODS: From 1995 to 1998, 175 consecutive patients with CIS underwent brain MRI within 3 months of their first attack and again 12 months and 5 years later. We studied the number and location of lesions at baseline and development of new T2 lesions. We also analyzed conversion to MS and development of disability (Expanded Disability Status Scale [EDSS] > or = 3.0). RESULTS: We included 156 patients with CIS followed for a median of 7 years. Compared to the reference group with 0 Barkhof criteria at baseline MRI, patients with one or two Barkhof criteria showed an adjusted hazard ratio (HR) of 6.1 (2.2 to 16.6) and patients with three to four Barkhof criteria of 17.0 (6.7 to 43) for conversion to MS and differentiated patients with low, medium, and high conversion risk. EDSS at year 5 correlated with baseline number of Barkhof criteria (r = 0.46, p < 0.0001). When categorizing by number of baseline lesions, similar results were seen. Patients with a baseline MRI with three to four Barkhof criteria had an adjusted HR of 3.9 (1.1 to 13.6) for reaching EDSS > or = 3.0. Only 10% of the latter had disability at year 5, but 40% reached this at 8 years. CONCLUSIONS: Baseline MRI determines the risk for converting to clinically definite multiple sclerosis and correlates with disability at 5 years. The proportion of patients developing disability is low during the first 5 years but rapidly increases shortly after.

Distribution territories and causative mechanisms of ischemic stroke.

Ischemic stroke prognosis, risk of recurrence, clinical assessment, and treatment decisions are influenced by stroke subtype (anatomic distribution and causative mechanism of infarction). Stroke subtype diagnosis is better achieved in the early phase of acute ischemia with the use of multimodal MR imaging. The pattern of brain lesions as shown by brain MR imaging can be classified according to a modified Oxfordshire method, based on the anatomic distribution of the infarcts into six groups: (1) total anterior circulation infarcts, (2) partial anterior circulation infarcts, (3) posterior circulation infarcts, (4) watershed infarcts, (5) centrum ovale infarcts, and (6) lacunar infarcts. The subtype of stroke according to its causative mechanism is based on the TOAST method, which classifies stroke into five major etiologic groups: (1) large-vessel atherosclerotic disease, (2) small-vessel atherosclerotic disease, (3) cardioembolic source, (4) other determined etiologies, and (5) undetermined or multiple possible etiologies. The different MR imaging patterns of acute ischemic brain lesions visualized using diffusion-weighted imaging and the pattern of vessel involvement demonstrated with MR angiography are essential factors that can suggest the most likely causative mechanism of infarction. This information may have an impact on decisions regarding therapy and the performance of additional diagnostic tests.

Conversion to multiple sclerosis after a clinically isolated syndrome of the brainstem: cranial magnetic resonance imaging, cerebrospinal fluid and neurophysiological findings.

BACKGROUND AND AIM: Conversion to multiple sclerosis (MS) after optic neuritis and myelitis has been thoroughly studied; however, limited data are available regarding conversion to MS after a clinically isolated syndrome of the brainstem (CISB). The aim of this study was to investigate conversion to MS in patients with CISB. METHODS: Fifty-one patients with CISB were prospectively studied. Cranial magnetic resonance imaging (MRI), determination of oligoclonal bands (OBs) in the cerebrospinal fluid (CSF) and evoked potentials (EPs) were performed. Based on conversion to MS at follow-up, the sensitivity, specificity, accuracy and positive and negative predictive values of these tests were calculated. RESULTS: Clinically definite MS developed in 18 (35%) patients after a mean follow-up of 37 months. Paty's MRI criteria showed a sensitivity of 89%, a specificity of 52% and an accuracy of 65%; Fazekas' criteria showed a sensitivity of 89%, a specificity of 48% and an accuracy of 63%; Barkhof's criteria showed a sensitivity of 78%, a specificity of 61% and an accuracy of 67%. The presence of OBs in the CSF showed a sensitivity of 100%, a specificity of 42% and an accuracy of 63%. No differences for neurophysiological parameters were found between patients who did and those who did not convert to MS. CONCLUSION: Fulfilling Paty's, Fazekas' or Barkhof's MRI criteria and the presence of OBs in the CSF are associated with a higher risk of conversion to MS in patients with CISB. Determination of OBs in the CSF has the greatest sensitivity of all tests. Barkhof's MRI criteria have greater specificity (although less than previously published for mixed cohorts of clinically isolated syndromes) in predicting conversion to MS for CISB than either Paty's or Fazekas' criteria.

New diagnostic criteria for multiple sclerosis: application in first demyelinating episode.

BACKGROUND: Recently developed diagnostic criteria for MS (McDonald criteria) indicate that in patients with a single demyelinating episode (clinically isolated syndromes [CIS]), evidence for dissemination in space and time, essential for diagnosis, may be provided by MRI. OBJECTIVE: To assess the usefulness of these new criteria in patients with CIS suggestive of MS. METHODS: A total of 139 patients with CIS followed for a median of 3 years underwent brain MRI within 3 months of their first attack and again 12 months later. The number and location of lesions at baseline, the development of new lesions at follow-up, and the results of CSF examination (which, if positive, requires fewer MR abnormalities for diagnosis) were analyzed. The new McDonald criteria (incorporating MRI) were compared to the existing Poser diagnostic criteria and their accuracy was evaluated. RESULTS: At 12 months, 11% had clinically definite MS according to the Poser criteria compared to 37% with the McDonald criteria. Eighty percent of patients fulfilling these new criteria developed a second clinical episode within a mean follow-up of 49 months. The new criteria showed a sensitivity of 74%, specificity of 86%, and accuracy of 80% in predicting conversion to clinically definite MS. CONCLUSION: One year after symptom onset, more than three times as many patients with CIS were diagnosed with MS using new diagnostic criteria incorporating MRI results compared to older criteria. However, the proposed MRI criteria require further prospective studies to optimize sensitivity and specificity.

Normalization of T2 signal abnormalities in hemispheric white matter with liver transplant.

OBJECTIVE: To determine whether edema can be assessed by MRI using T2-weighted signal intensity of hemispheric white matter in cirrhotic patients. METHODS: Fast-FLAIR and magnetization transfer images were obtained before (24) and after (11) liver transplantation. T2-weighted abnormalities on baseline scans and their time-course changes were analyzed and compared with MT ratios (MTR). RESULTS: Fast-FLAIR baseline images showed faint to substantial, bilateral, symmetric increased signal intensity along the hemispheric white matter in or around the corticospinal tract in 23/24 patients. After liver transplantation the signal abnormalities gradually recovered. This gradual decrease in signal intensity correlated with an increase in MTR values. CONCLUSION: Asymptomatic symmetric high-signal intensity in the hemispheric white matter on fast-FLAIR MR images is present in cirrhosis. Normalization of this finding after successful liver transplantation and its correlation with MTR values suggest that this signal abnormality reflects mild edema.

Magnetization transfer ratio values and proton MR spectroscopy of normal-appearing cerebral white matter in patients with liver cirrhosis.

BACKGROUND AND PURPOSE: Hepatic encephalopathy in cirrhotic patients may be the clinical manifestation of disturbed cerebral cell volume homeostasis. The aim of this study was to investigate the presence of significant changes in magnetization transfer ratio (MTR) values, which could reflect an increase in free water within the brain of patients with liver cirrhosis, and to correlate these findings with minimal hepatic encephalopathy and proton MR spectroscopy ((1)H-MRS) abnormalities. METHODS: Twenty-four patients with liver cirrhosis and eight healthy control volunteers were included in the study. MR imaging studies included conventional T1- and T2-weighted imaging, (1)H-MRS, and magnetization transfer imaging. MTR and (1)H-MRS values were obtained from normal-appearing white matter and were correlated with each other and with the presence of minimal hepatic encephalopathy. RESULTS: (1)H-MRS showed a decrease in choline and myo-inositol and an increase in glutamine + glutamate with respect to creatine + phosphocreatine. MTR values were significantly decreased in cirrhotic patients when compared with healthy control volunteers, although this decrease was not significantly higher in the patients with minimal hepatic encephalopathy. The decreases in MTR values correlated with increases in glutamine + glutamate. CONCLUSION: The MTR decrease in patients with liver cirrhosis may be caused by low-grade astrocytic swelling produced as a response to the osmotic stress occurring in these patients. However, in this cross-sectional study, we did not find a correlation between MTR decrease and the presence of minimal hepatic encephalopathy, probably because of limitations in MTR quantification techniques.

[Conversion to clinically definite multiple sclerosis after isolated spinal cord syndrome: value of brain and spinal MRI]. / Conversión a esclerosis múltiple clínicamente definida tras un síndrome medular aislado: valor de la resonancia magnética craneal y medular.

BACKGROUND: Isolated spinal cord syndrome might be due to a first episode of multiple sclerosis. The aim of the study was to determine the clinical usefulness and paraclinical characteristics and of spinal and brain MR imaging predicting conversion to clinically definite multiple sclerosis (CDMS) in patients with an isolated spinal cord syndrome. PATIENTS AND METHODS: We have evaluate thirty-eight patients with isolated spinal cord syndrome. A clinical protocol, lumbar puncture, evoked potential and brain-spinal cord MRI were performed. RESULTS: Twenty two percent of the patients fulfilling brain MRI Paty criteria (p < 0.01), 54.5% Fazekas (p = 0.007) and 80% of patients fulfilling Barkhof criteria (p = 0.009) presented CDMS. The spinal MR imaging from CDMS patients was always abnormal, showing cervical and marginal location with a diameter < 2 cm. CONCLUSION: Brain MRI is strongly predictive of the risk of developing CDMS and spinal cord MRI may increase the sensitivity to detect conversion to CDMS.

Isolated demyelinating syndromes: comparison of CSF oligoclonal bands and different MR imaging criteria to predict conversion to CDMS.

AIM OF THE STUDY: To evaluate and compare the capacity of oligoclonal bands (OB) and three sets of MR imaging criteria to predict the conversion of clinically isolated syndromes (CIS) to clinically definite multiple sclerosis (CDMS). PATIENTS AND METHODS: One hundred and twelve patients with CIS were prospectively studied with MR imaging and determination of OB. Based on the clinical follow-up (conversion or not conversion to CDMS), we calculated the sensitivity, specificity accuracy, positive and negative predictive value of the OB, and MR imaging criteria proposed by Paty et al, Fazekas et al and Barkhof et al. RESULTS: CDMS developed in 26 (23.2%) patients after a mean follow-up of 31 months (range 12-62). OB were positive in 70 (62.5%) patients and were associated with a higher risk of developing CDMS. OB showed a sensitivity of 81%, specificity of 43%, accuracy of 52%, positive predictive value (PPV) of 30% and negative predictive value (NPV) of 88%. Paty and Fazekas criteria showed the same results with a sensitivity of 77%, specificity of 51%, accuracy of 57%, positive predictive value of 32% and negative predictive value of 88%. Barkhof criteria showed a sensitivity of 65%, specificity of 70%, accuracy of 69%, PPV of 40% and NPV of 87%. The greatest accuracy was achieved when patients with positive OB and three or four Barkhof's criteria were selected. CONCLUSIONS: We observed a high prevalence of OB in CIS. OB and MR imaging (Paty's and Fazekas' criteria) have high sensitivity. Barkhof's criteria have a higher specificity. Both OB and MR imaging criteria have a high negative predictive value.

Lesión postraumática de la arteria carótida.Valoración del diagnóstico clinicorradiológico / Posttraumatic lesion of the carotid artery. Evaluation of the clinico-radiological diagnosis

Introducción. Las lesiones vasculares postraumáticas de la arteria carótida (LPAC) son poco frecuentes pero tienen una elevada morbimortalidad por lo cual es importante su diagnóstico y tratamiento precoz. Objetivo. Revisar los hallazgos clínicos y radiológicos de la LPAC con la hipótesis de que existen signos que permiten su diagnóstico precoz. Pacientes y métodos. Estudio retrospectivo de 9 pacientes (p) con LPAC. Resultados. La causa fue un accidente de tráfico (4 p), precipitación (1p) o un movimiento brusco cervical aislado (4 p). La clínica inicial era de dolor cervical (1 p), hipoacusia (1p), síndrome de Claude-Bernard-Horner (4 p) o síntomas de un ataque vascular cerebral (6 p). La TC craneal mostraba un infarto cerebral de arteria cerebral media (6 p), una hemorragia subaracnoidea (1 p) o era normal (3 p). El diagnóstico de la lesión vascular se realizó mediante resonancia magnética (9 p), arteriografía (5 p) y ecografía-Doppler (4 p). Las lesiones vasculares fueron: estenosis grave por trombosis mural (3 p), oclusión por trombosis completa (4 p) y pseudoaneurisma (2p).Conclusiones. La LPAC se debe sospechar tras un traumatismo craneofacial-cervical cuando ha habido un movimiento cervical brusco, cuando existe un síndrome de Claude-Bernard-Horner o cuando se demuestra un infarto cerebral de arteria cerebral media (AU)

MRI findings in Möbius syndrome: correlation with clinical features.

The authors studied the MRI findings of three patients with Möbius syndrome. Möbius syndrome is a rare congenital disorder characterized by complete or partial facial diplegia accompanied by other cranial nerve palsies. MRI demonstrated brainstem hypoplasia with straightening of the fourth ventricle floor, indicating an absence of the facial colliculus. These MRI features suggest the diagnosis of Möbius syndrome and correlate with the clinical and neurophysiologic findings.

[Diffusion-weighted magnetic resonance in the diagnosis of acute subcortical infarcts]. / Difusión por resonancia magnética en el diagnóstico de los infartos subcorticales agudos.

INTRODUCTION: The diagnostic efficacy of radiological studies in acute subcortical infarcts is limited by the low sensitivity of conventional computerized tomography (CT) and magnetic resonance (MR) in detecting small-sized infarcts, and the difficulty in differentiating acute from chronic lesions. Diffusion-weighted MR (DMR) has shown great sensitivity and specificity in the detection of small vessel ischemic lesions during the acute phase. OBJECTIVE: To determine the diagnostic value of DMR in the study of patients with subcortical infarcts during the acute phase. PATIENTS AND METHODS: We made a prospective analysis of 100 consecutive patients with a clinical diagnosis of subcortical infarct. In all cases MR examination was done within the first 10 days (average 3.9 days) following onset, using conventional and diffusion-weighted sequences. RESULTS: In all cases the DMR showed the presence of ischemic lesions which explained, at least partly, the clinical features of the stroke. In 42 patients (42%) the DMR gave relevant information for diagnosis, as compared with the conventional MR studies, by confirming the presence of an ischemic lesion responsible for the clinical picture. The percentage rose to 50% when the examination was done within the first two days. CONCLUSIONS: DMR gives useful information in a high percentage of patients with acute subcortical infarcts. This is due to its great sensitivity in the detection of acute lesions of small size, and capacity to distinguish acute from chronic lesions.

Magnetic resonance anatomic study of iliocava junction and left iliac vein positions related to L5-S1 disc.

STUDY DESIGN: An in vivo anatomic study analyzing the venous anatomy in the lumbosacral area was performed. OBJECTIVES: To obtain in vivo data concerning iliocava junction and left common iliac vein positions at L5-S1. SUMMARY OF BACKGROUND DATA: The left common iliac vein and the iliocava junction are at risk during L5-S1 anterior lumbar interbody fusion. Anatomic studies have demonstrated great interindividual variability in this vascular anatomy. METHODS: Magnetic resonance angiography was used to study 134 patients. Image processing was carried out with maximum intensity projection algorithm and the maximum intensity projection and addition algorithm. Iliocava junction position was measured in the maximum intensity projection and addition image. Four groups of junction position were established: very high, high, low, and very low. The left common iliac vein position was measured in axial magnetic resonance images, and three groups were established: lateral, intermediate, and medial. To describe the operative window delimited by the venous structures at L5-S1, the study population was classified into 12 configurations by combining junction position and vein position values. RESULTS: Very high lateral included 3.76% of the patients, high lateral 48.12%, high intermediate 10.53%, high medial 0.75%, low lateral 15.04%, low intermediate 4.51%, low medial 6.77%, very low lateral 0.75%, very low intermediate 2.26%, and very low medial 7.52%. Medial vein position was significantly more frequent in men. CONCLUSIONS: In 18.05% of the study population, the venous structures overlapped the center of the L5-S1 disc, reducing the operative window.

Difusión por resonancia magnética en el diagnóstico de los infartos subcorticales agudos / Diffusion-weighted magnetic resonance in the diagnosis of acute subcortical infarcts

Introducción. La eficacia diagnóstica de los estudios radiológicos en los infartos subcorticales agudos se ve limitada por la baja sensibilidad de la tomografía computarizada (TC) y la resonancia magnética (RM) convencional en la detección de infartos de pequeño tamaño, y en su dificultad para diferenciar las lesiones agudas de las crónicas. La difusión por RM (DRM) ha demostrado elevada sensibilidad y especificidad en la detección de lesiones isquémicas de pequeño vaso en fase aguda. Objetivo.Determinar el valor diagnóstico de la DRM en el estudio de pacientes con infartos subcorticales durante la fase aguda. Pacientes y métodos. Se han analizado de forma prospectiva 100 pacientes consecutivos con el diagnóstico clínico de infarto subcortical. A todos ellos se les realizó un examen de RM dentro de los primeros 10 días (media 3,9 días) tras su instauración, utilizando secuencias convencionales y de difusión. Resultados. La DRM mostró en todos los pacientes la existencia de lesiones isquémicas que explicaban, al menos de forma parcial, la clínica del ictus. En 42 pacientes (42 por ciento) la DRM aportó información diagnóstica relevante en comparación con el estudio convencional de RM, al confirmar la presencia de una lesión isquémica responsable del cuadro clínico. El porcentaje ascendía al 50 por ciento si la exploración se realizaba en los dos primeros días. Conclusiones. La DRM ofrece información útil en un alto porcentaje de pacientes con infartos subcorticales agudos. Ello se debe a su elevada sensibilidad en la detección de lesiones agudas de pequeño tamaño, y a su capacidad para diferenciar las lesiones agudas de las crónicas (AU)

Isolated demyelinating syndromes: comparison of different MR imaging criteria to predict conversion to clinically definite multiple sclerosis.

BACKGROUND AND PURPOSE: Various authors have developed criteria to classify MR imaging findings that suggest the possibility of multiple sclerosis. The purpose of this study was to evaluate and compare the capacity of three sets of MR imaging criteria for predicting the conversion of isolated demyelinating syndromes to clinically definite multiple sclerosis. METHODS: Seventy patients with clinically isolated neurologic symptoms suggestive of multiple sclerosis were prospectively studied with MR imaging. The MR imaging findings were evaluated by two independent neuroradiologists who were blinded to clinical follow-up data. Based on the clinical outcome at follow-up (presence of a second attack that established clinically definite multiple sclerosis), the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the criteria proposed by Paty et al, Fazekas et al, and Barkhof et al were calculated. RESULTS: Clinically definite multiple sclerosis developed in 22 (31%) patients after a mean follow-up time of 28.3 months. The criteria proposed by Paty et al and those proposed by Fazekas et al showed identical results: sensitivity, 86%; specificity, 54%; accuracy, 64%; positive predictive value, 46%; and negative predictive value, 89%. The criteria proposed by Barkhof et al showed the following: sensitivity, 73%; specificity, 73%; accuracy, 73%; positive predictive value, 55%; and negative predictive value, 85%. CONCLUSION: The four dichotomized MR imaging parameters proposed by Barkhof et al are more specific and accurate than the criteria proposed by Paty et al or Fazekas et al for predicting conversion to clinically definite multiple sclerosis.

[Post-traumatic lesion of the carotid artery. Evaluation of the clinico-radiological diagnosis]. / Lesión postraumática de la arteria carótida. Valoración del diagnóstico clinicorradiológico.

INTRODUCTION: Posttraumatic vascular lesions of the carotid artery (PLCA) are infrequent but have a high morbid-mortality, so early diagnosis and treatment is important. OBJECTIVE: To review the clinical and radiological findings of the PLCA with the hypothesis that there are signs which permit early diagnosis. PATIENTS AND METHODS: A retrospective study of 9 patients (p) with PLCA. RESULTS: The cause was road traffic accident (4p), fall (1p) or a single abrupt cervical movement (4p). The initial clinical feature was cervical pain (1p), deafness (1p), Claude-Bernard-Horner syndrome (4p) or symptoms of a cerebral vascular accident (6p). Cranial CT showed a cerebral infarct in the territory of the middle cerebral artery (6p), subarachnoid hemorrhage (1p) or normal (3p). Diagnosis of the vascular lesion was made using magnetic resonance (9p), arteriography (5p) and echo-Doppler (4p). The vascular lesions were: severe stenosis due to a mural thrombosis (3p), complete obstruction due to thrombosis (4p) and pseudoaneurysm (2p). CONCLUSIONS: PLCA should be suspected following craniofacial-cervical trauma when there was an abrupt neck movement, a Claude-Bernard-Horner syndrome is present or a cerebral infarct in the territory of the middle cerebral artery is shown.

[Vertebrobasilar abnormalities in patients with hemifacial spasm: MR-angiography findings]. / Alteraciones del sistema arterial vertebrobasilar en pacientes con hemiespasmo facial: hallazgos mediante angio-RM.

INTRODUCTION: Hemifacial spasm (HFS) is a disorder characterized by a complex of symptoms with hyperactive motor dysfunction of the facial nerve. It is indicated that HFS in the majority of cases can be caused by a blood vessel compressing the nerve adjacent to the brainstem. PATIENTS AND METHODS: We studied and treated 44 patients with HFS. Magnetic resonance imaging (MR) and MR-angiography of the brain were performed in patients with HFS to asses the presence of an artery of the vertebrobasilar system compressing the root of the facial nerve. We evaluate the response to treatment with Botulinum toxin in these cases. 14 patients were excluded (6 patients presented HFS due to other lesions and in 8 patients the MR was not performed). The remaining 30 patients with idiopathic HFS underwent MR/MRA (3D-FISP) and it was also performed in 14 patients with synkineses after facial palsy to be used as controls. RESULTS: The MRA documented an abnormal position of the arteries surrounding the facial nerve (ipsilaterally to HFS) in 22 patients. The compressing artery was the PICA in 3 patients (10%), the AICA in 3 patients, the vertebral artery in 7 patients and the basilar artery in 8 patients, one patient showed a combined compression by AICA and PICA. The remaining 8 patients had a normal MRI. At the control group only one patient presented an abnormal AICA and the other had a normal MRI-MRA. Patients were followed-up for 22.4 months and after Botulinum toxin treatment patients kept 4.81 months free of symptoms. CONCLUSIONS: We recommend to perform MR studies in all HFS patients to rule out a secondary cause of the disease and MRA to evaluate the underlying vertebrobasilar abnormalities if surgery is planned. Botulinum toxin is a useful treatment in these patients and only after its failure, microvascular decompression will be considered.

Spontaneous ventriculostomy: report of three cases revealed by flow-sensitive phase-contrast cine MR imaging.

Spontaneous ventriculostomy is a rare condition that occurs with the spontaneous rupture of a ventricle, resulting in a communication between the ventricular system and the subarachnoid space. Three cases of spontaneous ventriculostomy through the floor of the third ventricle that occurred in cases of chronic obstructive hydrocephalus are presented. The communication was identified via flow-sensitive phase-contrast cine MR imaging. Spontaneous ventriculostomy is probably a result of a rupture of the normally thin membrane that forms the floor of the third ventricle and, with long-standing obstructive hydrocephalus, creates an internal drainage pathway that spontaneously compensates for the hydrocephalus.

Radiologic findings in two cases of acute Schmörl's nodes.

We describe two cases of atypical acute Schmörl's nodes, one benign, the other on a tumoral vertebra. In both cases, MR imaging showed a decreased vertebral T1 signal and a slightly increased T2 signal. These signal intensities are indistinguishable from tumoral disease or inflammatory lesions. The identification of endplate defects or intranuclear cleft bending of the disk by either CT or MR may be helpful for the correct diagnosis of acute Schmörl's nodes.