Dados do Trabalho

Título

Motor Cortex Hypointensity in Suscetibility Weighted Imaging: a radiologic biomarker of Amyotrophic Lateral Sclerosis?

Resumo

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease of the central nervous system characterized by progressive loss of upper (UMN) and lower motor neurons that results in loss of voluntary movement control. The diagnosis of definite ALS is based on clinical or electrophysiological evidence of lesions in the two afore mentioned motor segments. The presence of hypointensity in the motor cortex in the magnetic susceptibility sequence (SWI) may indicate injury to the UMN. The objective was to verify the presence of hypointensity in the motor cortex in SWI of brain magnetic resonance imaging (MRI) in patients diagnosed with ALS, its correlation with clinical characteristics and also the association with corticospinal tract (CST) radiologic findings in the magnetization sequence transfer (MT) of the same patients. This is a descriptive study that evaluated data from 20 patients with ALS and 20 control subjects. The exams were performed at the same imaging center and analyzed by the same radiologist with experience in neuroimaging. Clinical data were collected from medical records. Statistical analysis was performed using Bioestat 5.0 software. The statistical significance of the variables was verified using the T test and the linear regression test, with alpha levels of 0.01 and 0.05, respectively. Clinical variables did not statistically influence the presence of hypointensity in the motor cortex of ALS patients, however in control group there was a statistical significance of older age in the presence of hypointensity. When comparing the presence of hypointensity in ALS patients and healthy individuals, this finding occurred especially in ALS subjects. There was also a statistical influence of the CST hyperintensity of the MT on the presence of hypointensity in the motor cortex in SWI. It was concluded that the presence of hypointensity in the motor cortex of ALS patients is not influenced by clinical variables despite being more frequent in ALS patients than in healthy individuals. Age can influence the presence of hypointensity in healthy individuals, but in the ALS group there was no such relationship, which may represent neurodegeneration caused by the disease itself. Some patients with hypointensity at SWI in the cortex also presented hyperintensity in the CST at MT, finding that suggest a possible to use the SWI as another tool for detecting lesions in the UMN and thus help in ALS diagnosis.