Predictors of perfusion computed tomography alterations in stroke mimics attended as stroke code.

BACKGROUND AND PURPOSE: Stroke mimics (SMs) account for a significant number of patients attended as stroke code (SC) with an increasing number over the years. Recent studies show perfusion computed tomography (PCT) alterations in some SMs, especially in seizures. The objective of our study was to evaluate the clinical characteristics and PCT alterations in SMs attended as SC in order to identify potential predictors of PCT alterations in SMs. METHODS: A retrospective study was performed including all SC activations undergoing a multimodal CT study including non-enhanced computed tomography (CT), CT angiography and PCT, as part of our SC protocol, over 39 months. Patients with a final diagnosis of SM after complete diagnosis work-up were therefore selected. Clinical variables, diagnosis, PCT alteration patterns and type of map affected (Tmax or time to peak, cerebral blood flow and cerebral blood volume) were registered. RESULTS: Stroke mimics represent up to 16% (284/1761) of SCs with a complete multimodal study according to our series. Amongst SMs, 26% (74/284) showed PCT alterations. PCT abnormalities are more prevalent in seizures and status epilepticus and the main pattern is alteration of the time to peak map, of unilateral hemispheric distribution or of non-vascular territory. In our series, the independent predictors of alteration in PCT in SMs are aphasia, female sex and older age. CONCLUSIONS: Perfusion computed tomography alterations can be found amongst almost a third of SMs attended as SC, especially older women presenting with aphasia with a final diagnosis of epileptic seizures and status epilepticus.

Language hemispheric dominance analyzed with magnetic resonance DTI: correlation with the Wada test.

OBJECTIVE: Language lateralization is a major concern in some patients with pharmacoresistant epilepsy who will face surgery; in these patients, hemispheric dominance testing is essential to avoid further complications. The Wada test is considered the gold standard examination for language localization, but is invasive and requires many human and material resources. Functional MRI and tractography with diffusion tensor imaging (DTI) have demonstrated that they could be useful for locating language in epilepsy surgery, but there is no evidence of the correlation between the Wada test and DTI MRI in language dominance. METHODS: The authors performed a retrospective review of patients who underwent a Wada test before epilepsy surgery at their institution from 2012 to 2017. The authors retrospectively analyzed fractional anisotropy (FA), number and length of fibers, and volume of the arcuate fasciculus and uncinate fasciculus, comparing dominant and nondominant hemispheres. RESULTS: Ten patients with temporal lobe epilepsy were reviewed. Statistical analysis showed that the mean FA of the arcuate fasciculus in the dominant hemisphere was higher than in the nondominant hemisphere (0.369 vs 0.329, p = 0.049). Also, the number of fibers in the arcuate fasciculus was greater in the dominant hemisphere (881.5 vs 305.4, p = 0.003). However, no differences were found in the FA of the uncinate fasciculus or number of fibers between hemispheres. The length of fibers of the uncinate fasciculus was longer in the dominant side (74.4 vs 50.1 mm, p = 0.05). Volume in both bundles was more prominent in the dominant hemisphere (12.12 vs 6.48 cm3, p = 0.004, in the arcuate fasciculus, and 8.41 vs 4.16 cm3, p = 0.018, in the uncinate fasciculus). Finally, these parameters were compared in patients in whom the seizure focus was situated in the dominant hemisphere: FA (0.37 vs 0.30, p = 0.05), number of fibers (114.4 vs 315.6, p = 0.014), and volume (12.58 vs 5.88 cm3, p = 0.035) in the arcuate fasciculus were found to be statistically significantly higher in the dominant hemispheres. Linear discriminant analysis of FA, number of fibers, and volume of the arcuate fasciculus showed a correct discrimination in 80% of patients (p = 0.024). CONCLUSIONS: The analysis of the arcuate fasciculus and other tract bundles by DTI could be a useful tool for language location testing in the preoperative study of patients with refractory epilepsy.

Prediction of Laterality in Temporal Lobe Epilepsy Using White Matter Diffusion Metrics.

BACKGROUND: Diagnostic methods of the epileptogenic area continue to be a challenge in epilepsy surgery research. We hypothesized that temporal lobe epilepsy (TLE) will result in white matter changes that can be detected using diffusion tensor imaging. Measurement of white matter diffusivity will therefore be useful for presurgical assessment. METHODS: Twelve patients with TLE who had undergone temporal lobectomy and amygdalohippocampectomy were included. In 6 patients, magnetic resonance imaging (MRI) showed evidence of mesial temporal sclerosis (m-TLE), whereas the 6 remaining MRI studies were informed without any abnormality (nl-TLE). All had excellent outcomes from surgery. Patients were compared with 12 age- and sex-matched controls. Five pairs of white matter fiber tracts were traced, and fiber tract fractional anisotropy and mean diffusivity were calculated. RESULTS: There were several alterations in diffusion parameters in white matter tracts, both ipsilateral and on the contralateral side, these alterations were more pronounced in the hemisphere ipsilateral to the epileptogenic focus. m-TLE patients had more alterations on ipsilateral side than nl-TLE patients, but similar alterations on contralateral side and bilateral fornix. The discriminant function analysis successfully lateralized all the patients with left TLE, 83.3% of the patients with right TLE, and all nl-TLE. CONCLUSIONS: Our results suggest that there are alterations in diffusion parameters in white matter tracts both in m-TLE and nl-TLE patients. Diffusion tensor imaging could be a useful presurgical tool to help establish the laterality of TLE, including patients with "normal" MRI. Further studies with a larger number of patients would be necessary to confirm these results.

Papel de la imagen por tensor de difusión en el estudio prequirúrgico de la epilepsia del lóbulo temporal / The role of diffusion tensor imaging in the pre-surgical study of temporal lobe epilepsy

Introducción. La imagen por tensor de difusión (DTI) es una técnica no invasiva que puede ser utilizada para evaluar la integridad de la sustancia blanca cerebral. Objetivo. Investigar la utilidad de la DTI en pacientes con epilepsia del lóbulo temporal (ELT) y ver su relación con la lateralización del foco epileptógeno en estos pacientes. Pacientes y métodos. Se analizan 11 pacientes diagnosticados de ELT según el protocolo de evaluación prequirúrgica de nuestra unidad de epilepsia, y libres de crisis a los dos años de la realización de una lobectomía temporal más amigdalohipocampectomía (técnica de Spencer). Como parte de su estudio preoperatorio, se realiza una resonancia magnética cerebral de 1,5 T con secuencia de tensor de difusión y se estudian, mediante un análisis basado en vóxel, las diferencias en la conectividad entre el hemisferio intervenido y el contralateral. Resultados. Comparado con el hemisferio contralateral, se observó una reducción de la anisotropía fraccional estadísticamente significativa (p < 0,05) en el cuerpo calloso, el cíngulo, el fascículo longitudinal superior, las radiaciones talámicas anteriores, la cápsula interna, los núcleos ventral lateral y pulvinar del tálamo, el fascículo frontooccipital inferior, el fascículo uncinado, el fascículo longitudinal inferior y el giro parahipocampal ipsilaterales al foco epileptógeno. Conclusiones. La caracterización de las anormalidades en la conectividad de la sustancia blanca cerebral, a través de la DTI en pacientes con ELT, puede tener un valor importante para la lateralización del foco epileptógeno en la evaluación prequirúrgica. Serían necesarios estudios con un número más elevado de pacientes para confirmar estos resultados (AU)

Introduction. Diffusion tensor imaging (DTI) is a non-invasive technique that can be used to assess the integrity of the white matter in the brain. Aims. To investigate the usefulness of DTI in patients with temporal lobe epilepsy (TLE) and to observe its relationship with lateralisation of the epileptogenic focus in these patients. Patients and methods. We analysed 11 patients diagnosed with TLE in accordance with the pre-surgical protocol of our epilepsy unit, and who were seizure-free two years after performing a temporal lobectomy plus amygdalohippocampectomy (Spencer technique). As part of their pre-operative study, a 1.5 T magnetic resonance brain scan with diffusion tensor imaging was performed. A voxel-based analysis was then employed to study the differences in connectivity between the hemisphere that underwent surgery and the contralateral hemisphere. Results. Compared with the contralateral hemisphere, a statistically significant reduction in fractional anisotropy (p < 0.05) was observed in the corpus callosum, the cingulate, the superior longitudinal fasciculus, the anterior thalamic radiations, the internal capsule, the ventral lateral and pulvinar nuclei of the thalamus, the inferior frontooccipital fasciculus, the uncinate fasciculus, the inferior longitudinal fasciculus and the parahippocampal gyrus, all ipsilateral to the epileptogenic focus. Conclusions. The characterisation of the abnormalities in the connectivity of the cerebral white matter, by means of DTI in patients with TLE, can be a valuable aid for the lateralisation of the epileptogenic focus in the pre-surgical evaluation of these patients. Further studies with a higher number of patients would be needed to confirm these results (AU)

Infratentorial angioleiomyoma: case report and review of the literature.

INTRODUCTION: Intracranial angioleiomyomas are extremely rare lesions. Only 22 intracranial angioleiomyomas have been described in the literature and only three were infratentorial. CASE REPORT: We report a case of an infratentorial angioleiomyoma in a 43 year-old-man, who underwent a brain computer tomography because of hearing loss. The MRI showed a 1.4 cm tumor, initially described as a meningioma, with progressive enhancement after gadolinium injection, an augmented apparent diffusion coefficient and a generalized metabolite decreased in the spectroscopy. The lesion was surgically removed through a suboccipital approach with a good evolution and without postoperative complications. In the immunohistological study, the lesion was mainly composed of multiple vessels and the immunohistochemistry was positive for actin and caldesmon. Two years after surgery, no recurrence has been found in the MRI. CONCLUSION: Angioleiomyomas diagnostic may be complex, but some radiological features could help in the differential diagnostic. Angioleiomyomas are benign tumors associated with favorable outcomes after total resection, that in our case, did not show a significant bleeding risk.

TITLE: Angioleiomioma infratentorial: caso clinico y revision de la bibliografia.Introduccion. Los angioleiomiomas intracraneales son lesiones muy poco frecuentes. Solo se han descrito 22 casos en la bibliografia hasta la actualidad, unicamente tres de ellos de localizacion infratentorial. Caso clinico. Varon de 43 años con un angioleiomioma infratentorial descubierto de forma incidental tras la realizacion de una tomografia computarizada por hipoacusia. La resonancia magnetica mostro una tumoracion de 1,4 cm, descrita inicialmente como un meningioma, con un realce progresivo tras la administracion de gadolinio, un aumento del coeficiente de difusion aparente y un descenso generalizado de metabolitos en la espectroscopia. La lesion se reseco quirurgicamente mediante un abordaje suboccipital con buena evolucion y sin complicaciones postoperatorias. En el estudio histologico, la lesion presentaba un abundante componente vascular, y en la tincion inmunohistoquimica era positiva para actina y caldesmona. Dos años despues de la cirugia, el paciente no presentaba recurrencia en la resonancia magnetica de control. Conclusion. El diagnostico de los angioleiomiomas puede ser complejo, pero algunas de sus caracteristicas radiologicas pueden facilitarlo. Los angioleiomiomas son tumores benignos asociados con un resultado funcional favorable tras su reseccion completa, que en nuestro caso no presento un alto riesgo de sangrado.

Angioleiomioma infratentorial: caso clínico y revisión de la bibliografía / Infratentorial angioleiomyoma: case report and review of the literature

Introducción. Los angioleiomiomas intracraneales son lesiones muy poco frecuentes. Sólo se han descrito 22 casos en la bibliografía hasta la actualidad, únicamente tres de ellos de localización infratentorial. Caso clínico. Varón de 43 años con un angioleiomioma infratentorial descubierto de forma incidental tras la realización de una tomografía computarizada por hipoacusia. La resonancia magnética mostró una tumoración de 1,4 cm, descrita inicialmente como un meningioma, con un realce progresivo tras la administración de gadolinio, un aumento del coeficiente de difusión aparente y un descenso generalizado de metabolitos en la espectroscopia. La lesión se resecó quirúrgicamente mediante un abordaje suboccipital con buena evolución y sin complicaciones postoperatorias. En el estudio histológico, la lesión presentaba un abundante componente vascular, y en la tinción inmunohistoquímica era positiva para actina y caldesmona. Dos años después de la cirugía, el paciente no presentaba recurrencia en la resonancia magnética de control. Conclusión. El diagnóstico de los angioleiomiomas puede ser complejo, pero algunas de sus características radiológicas pueden facilitarlo. Los angioleiomiomas son tumores benignos asociados con un resultado funcional favorable tras su resección completa, que en nuestro caso no presentó un alto riesgo de sangrado (AU)

Introduction. Intracranial angioleiomyomas are extremely rare lesions. Only 22 intracranial angioleiomyomas have been described in the literature and only three were infratentorial. Case report. We report a case of an infratentorial angioleiomyoma in a 43 year-old-man, who underwent a brain computer tomography because of hipoacusia. The MRI showed a 1.4 cm tumor, initially described as a meningioma, with progressive enhancement after gadolinium injection, an augmented apparent diffusion coefficient and a generalized metabolite decreased in the spectroscopy. The lesion was surgically removed through a suboccipital approach with a good evolution and without postoperative complications. In the inmunohistological study, the lesion was mainly composed of multiple vessels and the immunohistochemistry was positive for actina and caldesmon. Two years after surgery, no recurrence has been found in the MRI. Conclusion. Angioleiomyomas diagnostic may be complex, but some radiological features could help in the differential diagnostic. Angioleiomyomas are benign tumors associated with favorable outcomes after total resection, that in our case, did not show a significant bleeding risk (AU)

Quiste óseo aneurismático frontal. Caso clínico y revisión de la bibliografía / Frontal aneurysmal bone cyst. A case report and review of the literature

Introducción. El quiste óseo aneurismático (QOA) craneal es un hallazgo patológico infrecuente, diagnosticado habitualmente en pacientes jóvenes. Se define como una lesión benigna formada por cavidades hemáticas limitadas por septos osteoconectivos y células gigantes tipo osteoclastos; estas características histológicas son comunes a los QOA extracraneales. Clínicamente se manifiestan como tumoraciones craneales en la mayoría de los pacientes, las cuales pueden ser dolorosas y presentan un tamaño variable. Se realiza una revisión bibliográfica de los QOA frontales publicados hasta la fecha, incluyendo un caso tratado recientemente en nuestro servicio. Caso clínico. Mujer de 29 años, sin antecedentes de traumatismo craneoencefálico previo, valorada por presentar una lesión craneal frontal derecha no dolorosa y fija. El estudio radiológico demostró la presencia de una lesión craneal lítica de bordes bien delimitados y esclerosis marginal, con captación periférica y lineal de contraste en el estudio con resonancia magnética cerebral. Se intervino a la paciente y se extirpó la lesión en su totalidad. La evolución postoperatoria transcurrió sin incidencias, y el diagnóstico anatomopatológico definitivo fue QOA craneal. Conclusión. El QOA craneal es una entidad patológica de características histológicas y radiológicas bien definidas, a pesar de que su etiopatogenia actualmente no es completamente conocida. La resección tumoral completa se considera el tratamiento de elección, el cual con frecuencia es curativo y conlleva un buen pronóstico del paciente a largo plazo (AU)

Introduction. Cranial aneurysmal bone cyst (ABC) is a rare pathological finding that is usually diagnosed in young patients. It is defined as a benign lesion made up of intervillous spaces limited by connective bone tissue septa and osteoclast-type giant cells; these histological characteristics are common to extracranial ABC. Clinically, in most patients, they manifest as cranial tumours which may be painful and vary in size. About 100 cases of cranial ABC have been reported in the literature. We present a literature review of the cases of frontal ABC reported to date, including one that was recently treated in our own service. Case report. A 29-year-old female, with no history of traumatic brain injury, who was examined due to the presence of a fixed, painless frontal cranial lesion on the right-hand side. The results of a radiological study revealed the presence of a lytic cranial lesion with well-delimited edges and marginal sclerosis; peripheral and linear contrast enhancement was also observed in the magnetic resonance imaging of the brain. The patient was submitted to a surgical intervention and the entire lesion was removed. There were no incidents in the post-operative period and the definitive pathological diagnosis was cranial ABC. Conclusions. Cranial ABC is a pathological condition with well-defined histological and radiological characteristics, despite the fact that its aetiopathogenesis is still not fully understood. Complete excision of the tumour is considered to be the preferred treatment, which often leads to full recovery of the patient and also offers a good long-term prognosis (AU)

Kernohan-Woltman notch phenomenon caused by an acute subdural hematoma.

Uncal herniation through the tentorial notch is occasionally associated with false localizing ipsilateral hemiparesis, known as the Kernohan-Woltman notch phenomenon (KWNP). We report an 81-year-old female who presented with a decreased level of consciousness, a right mydriasis and an ipsilateral motor deficit caused by a large right hemispheric subdural hematoma that was immediately evacuated. The patient recovered well, although her right hemiplegia persisted. A follow-up MRI showed a residual lesion in the left cerebral peduncle, corresponding to KWNP. The presence of such a structural lesion suggests a poor prognosis for recovery from the initial motor deficit.