Spect cerebral e ressonancia magnetica na doença de Machado-Joseph

AUTOR(ES)
DATA DE PUBLICAÇÃO

2001

RESUMO

Machado-Joseph disease (MJD) is the most frequently encountered autossomal dominant spinocerebellar ataxia in Brazil and in most parts of the eastem world. There are no reports on brain SPECT imaging with 99mTc-HMPAOand magnetic resonance imaging (MRI) in patients with genetically proven MJD (MJD/SCA3). Objectives : The purpose of this report was to perform brain SPECT imaging with 99mTc-HMPAOand 1 1RIto evaluate the cerebral structure and function of patients with MJD/SCA3 and to determine if there is correlation between the magnitude of the metabolic and structural abnormalities with the duration of the disease, signs and symptoms and the length of the expanded CAG repeat. Materiais aod Methods: Twelve patients with MJD/SCA3, 8 males, 4 females, ages ranging from 22 to 67 years, mean 39 years were studied. The patients were submitted to brain SPECT imaging and :MRI on the same day. The control group fo r brain SPECT imaging consisted of 42 normal volunteers, 22 females, 20 males, ages ranging from 22 to 66 years, mean 32.6 years. The :MRIcontrol group consisted of 17 normal volunteers, 13 females, 4 males, ages ranging from 21 to 62 years, mean 32.2 years. Brain SPECT images were performed injecting 99mTc-HMPAOwith patients resting in a dark, quiet room and images acquired in a gamma camera. Transaxial, coronal and sagittal images obtained were submitted to visual and semi-quantitative ana1ysis.The thalami were used as a reference, with regions of interest being p1aced in the cerebral and cerebellar cortex. MRI images were obtained in a 2 Tesla system with coronal, saggital, transaxial and 3D (volumetric) acquisitions. The cerebellar and vermis volumes were obtained. Results : There was a positive correlation between perfusion abnormalities identified by visual analysis in the brain SPECT images in the parietallobes and vermis with the structural abnormalities on the :MRI.Brain SPECT images identified, by visual analysis, more perfusion abnormalities in the inferior portion of the frontallobes, mesial and lateral portions of the temporallobes, basal ganglia, and cerebellar hemispheres. :MRI identified more abnormalities in the pons and superior frontal lobes. Olives atrophy was identified by :MRI. Semi-quantitative ana1ysis showed a significant difference of perfusion in the inferior and superior ftontal lobes, lateral temporallobes, parietallobes, left basal ganglia, cerebelar hemispheres and vermis when compared to the control group. There was a statistica1lysignificantdifference between the vermis and cerebellar volumes when compared to the MRI control group. No significant difference was observed of the perfusion abnormalities or anatomical abnormalities with the magnitude of the ataxia or clinical type. No significant correIation was observed between perfusion abnormalities in the vennis and volwnetric abnormalities in the cerebellar hemispheres and the duration of the disease, however, there was a tendency towards an inverse reIationship between cerebelIar perfusion abnormalities and vennis volumetric abnormalities and the duration of the disease. There was a significant correIation between the presence of extra-pyramidal symptoms and perfusion of the left parietallobe. No reIationship was observed between the length ofthe expanded CAG repeat and the perfusion of the cerebral and cerebelIar cortex or the volume of the vennis. There was a tendency towards an inverse reIationship between the volwne of the cerebelIar hemispheres with the length of the expanded CAG repeat. Conclusions : Brain SPECT llnaging with 99mTc-HMPAOand MRI were able to demonstrate perfusion and structural abnormalities in the cerebral and cerebelIar cortices of patients with MJD/SCA3. Brain SPECT imagjng and MRI are non-invasive methods capable of identifying sub-clinical abnormalities in these patients

ASSUNTO(S)

radioisotopos ataxia cortex cerebral hemisferios cerebrais

Documentos Relacionados