Crossed Cerebellar Diaschisis in Alzheimer's Disease.

BACKGROUND: We describe the phenomenon of crossed cerebellar diaschisis (CCD) in four subjects diagnosed with Alzheimer's disease (AD) according to the National Institute on Aging - Alzheimer Association (NIA-AA) criteria, in combination with 18F-FDG PET and 11C-PiB PET imaging. METHODS: 18F-FDG PET showed a pattern of cerebral metabolism with relative decrease most prominent in the frontal-parietal cortex of the left hemisphere and crossed hypometabolism of the right cerebellum. 11C-PiB PET showed symmetrical amyloid accumulation, but a lower relative tracer delivery (a surrogate of relative cerebral blood flow) in the left hemisphere. CCD is the phenomenon of unilateral cerebellar hypometabolism as a remote effect of supratentorial dysfunction of the brain in the contralateral hemisphere. The mechanism implies the involvement of the cortico-ponto-cerebellar fibers. The pathophysiology is thought to have a functional or reversible basis but can also reflect in secondary morphologic change. CCD is a well-recognized phenomenon, since the development of new imaging techniques, although scarcely described in neurodegenerative dementias. RESULTS: To our knowledge this is the first report describing CCD in AD subjects with documentation of both 18F-FDG PET and 11C-PiB PET imaging. CCD in our subjects was explained on a functional basis due to neurodegenerative pathology in the left hemisphere. There was no structural lesion and the symmetric amyloid accumulation did not correspond with the unilateral metabolic impairment. CONCLUSION: This suggests that CCD might be caused by non-amyloid neurodegeneration. The pathophysiological mechanism, clinical relevance and therapeutic implications of CCD and the role of the cerebellum in AD need further investigation.

Evaluación mediante mapas estadísticos paramétricos de los cambios de la perfusión cerebral en pacientes con estenosis de la arteria carótida sometidos a endarterectomía / Evaluation by “statistical parametric mapping” of the cerebral perfusion changes in patients with carotid artery stenosis after endarterectomy

La eficacia de la endarterectomía carotídea (EC) en los accidentes cerebrovasculares producidos por estenosis carotídea puede ser evaluada mediante la tomografía computarizada de emisión de fotón único de perfusión cerebral, utilizando SPM (statistical parametric mapping ‘mapas estadísticos paramétricos’).Material y métodosSe incluyeron en el estudio 12 pacientes con estenosis significativa de la arteria carótida que fueron sometidos a endarterectomía. A todos se les realizó un estudio de perfusión cerebral con 99mTc-etilen cisteinato dietilester (ECD) basal tras la endarterectomía. Mediante los SPM se comparó de forma independiente el estudio basal/poscirugía con el grupo control formado por 20 pacientes y se obtuvieron los correspondientes SPM. Se valoraron los cambios tanto en extensión (o número de vóxeles) como en intensidad (cambio en el valor de T) de las zonas significativamente hipoperfundidas y el sentido de estos cambios.ResultadosEn el grupo de 12 pacientes se observó una mejoría de la perfusión cerebral posquirúrgica, en 5 pacientes con disminución en la extensión de las zonas hipoperfundidas del 50,56% y de intensidad del 30,9% de media. Cuatro pacientes mostraron un aumento en la extensión de la hipoperfusión cerebral del 85,53% y de la intensidad del 34,21% de media. En tres pacientes no se apreciaron cambios significativos entre ambos estudios.ConclusionesEl SPM ha demostrado ser una herramienta útil que permite objetivar los cambios de flujo sanguíneo cerebral que se producen tras la intervención quirúrgica, valorando los cambios en extensión e intensidad de las zonas significativamente hipoperfundidas(AU)

The efficacy of carotid endartectomy (CE) in cerebrovascular accidents produced by carotid stenosis can be evaluated with the cerebral perfusion with single photon emission tomography, using statistical parametric mapping (SPM).Material and methodsTwelve patients with significant carotid stenosis who underwent endartectomy were included in the study. All underwent a cerebral perfusion study with 99mTc-etilen cisteinato dietilester (ECD) at baseline and after the endartectomy. Using SPM, the baseline/post-surgery study was compared independently with the control group made up of 20 patients and the corresponding parametric statistical mappings were obtained. Changes in extension (kE or voxel number) and intensity (change in the T value) of the significantly hypoperfused zones and direction of these changes were evaluated.ResultsIn the group of 12 patients, improvement of the post-surgical cerebral perfusion was observed in 5 patients with an average 50.56% decrease in the extension of the hypoperfused zones and average 30.9% decrease of intensity. Four patients showed an average 85.53% increase in the extension of cerebral hypoperfusion and of 34.21% in intensity. No significant changes between both studies were found in three patients.ConclusionsSPM has been shown to be a useful tool that makes it possible to objectify the cerebral brain flow changes produced after the surgical intervention, evaluating the changes in extension and intensity of the significantly hypoperfused zones(AU)

[Evaluation by "statistical parametric mapping" of the cerebral perfusion changes in patients with carotid artery stenosis after endarterectomy]. / Evaluación mediante mapas estadísticos paramétricos de los cambios de la perfusión cerebral en pacientes con estenosis de la arteria carótida sometidos a endarterectomía.

UNLABELLED: The efficacy of carotid endartectomy (CE) in cerebrovascular accidents produced by carotid stenosis can be evaluated with the cerebral perfusion with single photon emission tomography, using statistical parametric mapping (SPM). MATERIAL AND METHODS: Twelve patients with significant carotid stenosis who underwent endartectomy were included in the study. All underwent a cerebral perfusion study with 99mTc-etilen cisteinato dietilester (ECD) at baseline and after the endartectomy. Using SPM, the baseline/post-surgery study was compared independently with the control group made up of 20 patients and the corresponding parametric statistical mappings were obtained. Changes in extension (k(E) or voxel number) and intensity (change in the T value) of the significantly hypoperfused zones and direction of these changes were evaluated. RESULTS: In the group of 12 patients, improvement of the post-surgical cerebral perfusion was observed in 5 patients with an average 50.56% decrease in the extension of the hypoperfused zones and average 30.9% decrease of intensity. Four patients showed an average 85.53% increase in the extension of cerebral hypoperfusion and of 34.21% in intensity. No significant changes between both studies were found in three patients. CONCLUSIONS: SPM has been shown to be a useful tool that makes it possible to objectify the cerebral brain flow changes produced after the surgical intervention, evaluating the changes in extension and intensity of the significantly hypoperfused zones.

[Stroke in a child due to hemoglobinopathy AS]. / Ictus en un niño por hemoglobinopatía AS.

INTRODUCTION: Falciform cell anaemia is a genetically determined haemoglobinopathy which in homozygote form (HbSS) is accompanied by neurological disorders in a quarter of the patients, mainly in the form of cerebral ischemia. Some authors consider the heterozygote (HbAS) form to be asymptomatic, although several such patients have been described with stroke. CLINICAL CASE: A white boy of 5 years of age had a cerebral infarct whilst travelling by car from his home town (222 meters above sea level) to the capital of the country (which is 2,600 meters above sea level). During the journey he complained of headache, vomiting and the onset of right hemiplegia. Angio-MR and CT showed the characteristic features of an infarct. SPECT showed hypoperfusion of left frontal predominance and of the basal ganglia bilaterally, but with left-sided predominance. Electrophoresis studies of his haemoglobin showed the present of AS haemoglobinopathy. We present the results of investigations done and a review of the literature. CONCLUSIONS: AS haemoglobinopathy, together with hypoxia due to altitude and possibly slight dehydration, were probably the causes of our patient's cerebral infarct. We recommended electrophoresis of haemoglobin in all patients (especially children and young adults) who present with stroke.

A way to reduce the radius of rotation in brain SPET with a single-head system.

To optimize spatial resolution in single photon emission tomography (SPET), it is essential to minimize the radius of rotation. In brain studies, different methods have been used to avoid shoulder interference when the radius of rotation is minimized: rectangular fields of view, modifications to the shielding around circular detectors and fan or cone beam collimators. However, few single-head systems can adopt these developments, particularly older cameras. A non-standard image acquisition method to reduce the radius of rotation in brain SPET with a single-head gamma camera is presented. The method applies a defined transformation to the original acquired images, maintaining the whole of the brain inside the field of view without shoulder interference and meeting the condition: pixel size < or = FWHM/3. With this method, it is possible to reduce the radius of rotation to 16 cm and to obtain a transaxial spatial resolution of 15.98 mm, which is 3.5 mm less than with the standard method used in our laboratory. This procedure was implemented for a Siemens Gammasonics ZLC 3700 gamma camera and has been validated in single-slice brain phantom studies. The method has the advantage of not requiring any complex or costly hardware.

Ictus en un niño por hemoglobinopatía AS / Stroke in a child due to as haemoglobinopathy

Introducción. La anemia de células falciformes es una hemoglobinopatía genéticamente determinada, que en su forma homocigota (HbSS) se acompaña de alteraciones neurológicas en una cuarta parte de los pacientes, principalmente en forma de isquemia cerebral. Algunos autores plantean que la forma heterocigota (HbAS) es asintomática, a pesar de haberse comunicado varios casos de pacientes con ictus. Caso clínico. Paciente masculino, blanco, que a los 5 años de edad sufrió un infarto cerebral mientras realizaba un viajeen auto desde su pueblo, que se encuentra a 222 metros sobre el nivel del mar, a la capital de su país que está situada a una altura de 2 600 metros. Durante el viaje presentó cefalea, vómitos y se instauró una hemiplejia derecha. La angio RM y la TC demostraron la lesión de infarto y la SPECT mostró hipoperfusión de predominio frontal izquierdo así como en regiones de ganglios basales bilaterales pero de predominio izquierdo. El estudio de electroforesis de hemoglobina demostró la presencia de hemoglobinopatía AS. Se presenta el resultado de los estudios realizados y se realiza una revisión de la literatura. Conclusiones. La hemoglobinopatía AS más la hipoxia por la altura y la posible deshidratación ligera fueron probablemente los factores causales del infarto cerebral en nuestro paciente. Recomendamos la realización de electroforesis de hemoglobina a todos los pacientes, fundamentalmente a niños y a adultos jóvenes que presenten ictus(AU)

A way to reduce the radius of rotation in brain SPET with a single-head system

To optimize spatial resolution in single photon emission tomography (SPECT), it is essential to minimize the radius of rotation. In brain studies, different methods have been used to avoid shoulder interference when the radius of rotation is minimized: rectangular fields of view, modifications to the shielding around circular detectors and fan or cone beam collimators. However, few single-head systems can adopt these developments, particularly older cameras. A non-standard image acquisition method to reduce the radius of rotation in brain SPET with a single-head gamma camera is presented. The method applies a defined transformation to the original acquired images, maintaining the whole of the brain inside the field of view without shoulder interference and meeting the condition: pixel size <= FWHM/3. With this method, it is possible to reduce the radius of rotation to 16 cm and to obtain a transaxial spatial resolution of 15.98 mm less than with the standard method used in our laboratory. This procedure was implemented for a Siemens Gammasonics ZLC 3700 gamma camera and has been validated in single-slice brain phantom studies. The methods has the advantage of not requiring and complex or costly hardware (AU)

Flujo sanguíneo cerebral regional mediante SPECT con [99m-Tc]-HM-PAO en pacientes con enfermedad de Parkinson / Regional cerebral blood flow by [99mTc]-HM-PAO brain SPECT in patients with Parkinso'n disease

Se correlacionó el flujo sanguíneo cerebral regional (FSCr) mediante SPECT con [99m-Tc] HM-PAO con las características clínicas más importantes en 25 pacientes con enfermedad de Parkinson idiopáÜica (EP) y se comparó con un grupo control de 9 individuos sanos apareados en edad. Se calcularon índices de actividad relativa en 11 pares de regiones de interés (ROIs) corticales y subcorticales. Además, se determinó un índice de asimetría izquierdo-derecha para cada para de ROIs. Aunque se observaron asimetrías y déficits de la perfusión estriatal en varios pacientes, los valores medios no fueron diferentes a los del grupo control. No se encontró una relación entre el FSCr y los siguientes parámetros clínicos: lateralidad, signo predominante, tiempo de evolución y estadío de la enfermedad. Sólo se observaron diferencias estadísticamente significativas en las regiones temporales de ambos hemisferios cerebrales (p<0,05) y asociada al deterioro cognitivo global. En 7 casos con demencia asociada (DSM-III-R) se observó una disminución bilateral significativa del FSCr de las ROLs temporales (p<0,05) y parietal posterior (p<0,05). Estos resultados sugieren que la perfusión a nivel temporal está asociada a la función cognitiva global y que la técnica de SPECT con [99m TE]-HM-PAO es especialmente útil para apoyar, junto a criterios clínicos y neuropsicológicos, la presencia de un síndrome demencial en pacientes con EP (AU)

Flujo sanguíneo cerebral regional mediante Spect con [99m-Tc]-HM-PAO en pacientes con enfermedad de Parkinson / Regional cerebral blood flow by Spect whit [99m-Tc]-HM-PAO in patients whit Parkinson disease

Se correlacionó el flujo cerebral regional (FSCr) mediante SPECT con [99m-Tc]-HM-PAO con las características clínicas más importantes en 25 pacientes con enfermedad de Parkinson idiopática (EP) y se comparó con un grupo control de 9 individuos sanos apareados en edad. Se calcularon índices de actividad relativa en 11 pares de regiones de interés (ROIs) corticales y subcorticales. Además, se determinó un índice de asimetría izquierdo-derecha para cada par de ROIs. Aunque se observaron asimetrías y déficits de la perfusión estriatal en varios pacientes, los valores medios no fueron diferentes a los del grupo control. No se encontró una relación entre el FSCr y los siguientes parámetros clínicos: lateralidad, signo predominante, tiempo de evolución y estadío de la enfermedad. Sólo se observaron diferencias estadísticamente significativas en las regiones temporales de ambos hemisferios cerebrales (p < 0,05) y asociada al deterioro cognitivo global. En 7 casos con demencia asociada (DSM-III-R) se observó una disminución bilateral significativa del FSCr de las ROIs temporales (p < 0,01 - lado izquierdo, p < 0,05 - lado derecho), frontales (p < 0,05) y parietal posterior (p < 0,05). Estos resultados sugieren que la perfusión a nivel temporal está asociada a la función cognitiva global y que la técnica de SPECT con [99m-TE]-HM-PAO es especialmente útil para apoyar, junto a criterios clínicos y neuropsicológicos, la presencia de un síndrome demencial en pacientes con EP (AU)

Flujo sanguíneo cerebral regional mediante Spect con [99m-Tc]-HM-PAO en pacientes con enfermedad de Parkinson / Regional cerebral blood flow by Spect whit [99m-Tc]-HM-PAO in patients whit Parkinson disease

Se correlacionó el flujo cerebral regional (FSCr) mediante SPECT con [99m-Tc]-HM-PAO con las características clínicas más importantes en 25 pacientes con enfermedad de Parkinson idiopática (EP) y se comparó con un grupo control de 9 individuos sanos apareados en edad. Se calcularon índices de actividad relativa en 11 pares de regiones de interés (ROIs) corticales y subcorticales. Además, se determinó un índice de asimetría izquierdo-derecha para cada par de ROIs. Aunque se observaron asimetrías y déficits de la perfusión estriatal en varios pacientes, los valores medios no fueron diferentes a los del grupo control. No se encontró una relación entre el FSCr y los siguientes parámetros clínicos: lateralidad, signo predominante, tiempo de evolución y estadío de la enfermedad. Sólo se observaron diferencias estadísticamente significativas en las regiones temporales de ambos hemisferios cerebrales (p < 0,05) y asociada al deterioro cognitivo global. En 7 casos con demencia asociada (DSM-III-R) se observó una disminución bilateral significativa del FSCr de las ROIs temporales (p < 0,01 - lado izquierdo, p < 0,05 - lado derecho), frontales (p < 0,05) y parietal posterior (p < 0,05). Estos resultados sugieren que la perfusión a nivel temporal está asociada a la función cognitiva global y que la técnica de SPECT con [99m-TE]-HM-PAO es especialmente útil para apoyar, junto a criterios clínicos y neuropsicológicos, la presencia de un síndrome demencial en pacientes con EP

Flujo sanguíneo cerebral regional mediante SPECT con [99m-Tc]-HM-PAO en pacientes con enfermedad de Parkinson / Regional cerebral blood flow by [99mTc]-HM-PAO brain SPECT in patients with Parkinso'n disease

Se correlacionó el flujo sanguíneo cerebral regional (FSCr) mediante SPECT con [99m-Tc] HM-PAO con las características clínicas más importantes en 25 pacientes con enfermedad de Parkinson idiopáÜica (EP) y se comparó con un grupo control de 9 individuos sanos apareados en edad. Se calcularon índices de actividad relativa en 11 pares de regiones de interés (ROIs) corticales y subcorticales. Además, se determinó un índice de asimetría izquierdo-derecha para cada para de ROIs. Aunque se observaron asimetrías y déficits de la perfusión estriatal en varios pacientes, los valores medios no fueron diferentes a los del grupo control. No se encontró una relación entre el FSCr y los siguientes parámetros clínicos: lateralidad, signo predominante, tiempo de evolución y estadío de la enfermedad. Sólo se observaron diferencias estadísticamente significativas en las regiones temporales de ambos hemisferios cerebrales (p<0,05) y asociada al deterioro cognitivo global. En 7 casos con demencia asociada (DSM-III-R) se observó una disminución bilateral significativa del FSCr de las ROLs temporales (p<0,05) y parietal posterior (p<0,05). Estos resultados sugieren que la perfusión a nivel temporal está asociada a la función cognitiva global y que la técnica de SPECT con [99m TE]-HM-PAO es especialmente útil para apoyar, junto a criterios clínicos y neuropsicológicos, la presencia de un síndrome demencial en pacientes con EP

Regional cerebral blood flow by brain SPECT 99Tcm-HMPAO in patients with Parkinson disease before and after foetal tissue transplantation: report of four cases

Serial evaluation of regional cerebral blood flow (rCBF) was performed by brain single photon emission computed tomography (SPECT) 99Tcm-HMPAO (hexamethylpropylene amine oxime) in four patients with Parkinson's disease who showed motor complications associated with pre-operation L-dopa treatment and received stereotactic foetal tissue transplantation in the right caudate nucleus and putamen. The rCBF was studied 12 h off drug treatment before transplantation and 1, 6 and 12 months after operation. The study included four age matched healthy volunteers. In the pre-surgical studies, all cases showed hypoperfusion in the bilateral temporal and parietal regions. Also, in two patients moderate hypoperfusion was fond on the contralateral side most clinically affected. In the post-surgical studies, a generalized decrease of the cortical rCBF was assessed in all casesqhn studied one month after grafting, improving after six month. In the striatal region, no significant changes were observed in the study aafter one month, but there were differences after six months, when all patients showed a significant increase to the right side (per cent change of 16, 11, 9 and 14, respectively). In the study 12 months after grafting, no significant changes were found compared with the six month study. The changes in rCBF observed after surgery in all patients were accompanied by a progressive improvement in their neurological performance, mainly because the motor complications associated with L-dopa therapy and daily dose requirement were reduced, also improving the drug response. These results suggest that the increase of perfusion at the implantation site may be related to the graf's viability (AU)

Regional cerebral blood flow by brain SPECT 99Tcm-HMPAO in patients with Parkinson disease before and after foetal tissue transplantation: report of four cases

Serial evaluation of regional cerebral blood flow (rCBF) was performed by brain single photon emission computed tomography (SPECT) 99Tcm-HMPAO (hexamethylpropylene amine oxime) in four patients with Parkinson's disease who showed motor complications associated with pre-operation L-dopa treatment and received stereotactic foetal tissue transplantation in the right caudate nucleus and putamen. The rCBF was studied 12 h off drug treatment before transplantation and 1, 6 and 12 months after operation. The study included four age matched healthy volunteers. In the pre-surgical studies, all cases showed hypoperfusion in the bilateral temporal and parietal regions. Also, in two patients moderate hypoperfusion was fond on the contralateral side most clinically affected. In the post-surgical studies, a generalized decrease of the cortical rCBF was assessed in all casesqhn studied one month after grafting, improving after six month. In the striatal region, no significant changes were observed in the study aafter one month, but there were differences after six months, when all patients showed a significant increase to the right side (per cent change of 16, 11, 9 and 14, respectively). In the study 12 months after grafting, no significant changes were found compared with the six month study. The changes in rCBF observed after surgery in all patients were accompanied by a progressive improvement in their neurological performance, mainly because the motor complications associated with L-dopa therapy and daily dose requirement were reduced, also improving the drug response. These results suggest that the increase of perfusion at the implantation site may be related to the graf's viability