ABSTRACT
Amyotrophic lateral sclerosis (ALS) is a predominantly clinical and electromyographic diagnosis. Conventional MRI reveals atrophy of the motor system, particularly the pyramidal tract, in the advanced stages but does not provide a sensitive measure of disease progression. Three patients with different principal symptoms of ALS, i.e., with predominant involvement of the upper (UMN) or lower (UMN) motor neurons, or bulbar disease, respectively, underwent serial clinical examination including lung function tests, conventional MRI, and diffusion tensor imaging (DTI). MRI demonstrated changes in of the pyramidal tract without measurable variation on follow-up. The patient with UMN involvement showed remarkable progressive loss of diffusion anisotropy in the pyramidal tract. DTI might be useful, together with clinical follow-up, as an objective morphological marker in therapeutic trials.
Subject(s)
Amyotrophic Lateral Sclerosis/pathology , Diffusion Magnetic Resonance Imaging , Pyramidal Tracts/pathology , Anisotropy , Disease Progression , Female , Follow-Up Studies , Humans , Male , Middle AgedSubject(s)
Choristoma/diagnosis , Kidney Diseases/diagnosis , Pyelonephritis/etiology , Ureter , Urethral Diseases/diagnosis , Anastomosis, Surgical , Choristoma/surgery , Female , Glycosuria , Humans , Infant , Kidney Diseases/diagnostic imaging , Pyelonephritis/diagnostic imaging , Radionuclide Imaging , Ureter/diagnostic imaging , Ureter/surgery , Urethral Diseases/diagnostic imaging , Urethral Diseases/surgery , Urinary Bladder/surgery , UrographyABSTRACT
Echoplanar functional magnetic resonance imaging was used to monitor activation changes of brain areas while subjects viewed apparent motion stimuli and while they were engaged in motion imagery. Human cortical areas MT (V5) and MST were the first areas of the 'dorsal' processing stream which responded with a clear increase in signal intensity to apparent motion stimuli as compared with flickering control conditions. Apparent motion of figures defined by illusory contours evoked greater activation in V2 and MT/MST than appropriate control conditions. Several areas of the dorsal pathway (V3A, MT/MST, areas in the inferior and superior parietal lobule) as well as prefrontal areas including FEF and BA 9/46 responded strongly when subjects merely imagined moving stimuli which they had seen several seconds before. The activation during motion imagery increased with the synaptic distance of an area from V1 along the dorsal processing stream. Area MT/MST was selectively activated during motion imagery but not during a static imagery control condition. The comparison between the results obtained with objective motion, apparent motion and imagined motion provides further insights into a complex cortical network of motion-sensitive areas driven by bottom-up and top-down neural processes.
