Subcortical reorganization in amyotrophic lateral sclerosis
- 270 Downloads
The cerebral cortex reorganizes in response to central or peripheral lesions. Although basal ganglia and cerebellum are key components of the network dedicated to movement control, their role in motor reorganization remains elusive. We therefore tested if slowly progressive neurodegenerative motor disease alters the subcortical functional anatomy of the basal ganglia-thalamo-cerebellar circuitry. Ten patients with amyotrophic lateral sclerosis (ALS) and ten healthy controls underwent functional magnetic resonance imaging (fMRI), while executing a simple finger flexion task. Cued by an acoustic trigger, they squeezed a handgrip force transducer with their right hand at 10% of their maximum voluntary contraction force. Movement frequency, amplitude, and force were controlled. Statistical parametric mapping of task-related BOLD-response revealed increased activation in ALS patients as compared to healthy controls. The main activation increases were found in the supplementary motor area, basal ganglia, brainstem, and cerebellum. These findings suggest that degeneration of cortical and spinal motor neurons in ALS leads to a recruitment of subcortical motor structures. These subcortical activation patterns strongly resemble functional activation in motor learning and might therefore represent adaptations of cortico-subcortical motor loops as a—albeit finally ineffective—mechanism to compensate for the ongoing loss of motor neurons in ALS.
KeywordsAmyotrophic lateral sclerosis Basal ganglia Cerebellum Magnetic resonance imaging Neuronal plasticity
This work was supported by the NRW-Nachwuchsgruppe Kn2000 of the Nordrhein-Westfalen Ministry of Education and Research (Fö.1KS9604/0), the Interdisciplinary Center of Clinical Research Münster (IZKF Projects FG2, Kne3/074/04, FG4), the Innovative Medizinische Forschung Münster (KN520301), the Deutsche Forschungsgemeinschaft (Kn 285/6-1 and 6-3), the Amyotrophic Lateral Sclerosis Association, and the Muscular Dystrophy Association—ALS Division.
- Brooks BR (1994) El Escorial World Federation of Neurology criteria for the diagnosis of amyotrophic lateral sclerosis. Subcommittee on Motor Neuron Diseases/Amyotrophic Lateral Sclerosis of the World Federation of Neurology Research Group on Neuromuscular Diseases and the El Escorial “Clinical limits of amyotrophic lateral sclerosis” workshop contributors. J Neurol Sci 124(Suppl):96–107CrossRefPubMedGoogle Scholar
- Carpentier AC, Constable RT, Schlosser MJ, de Lotbiniere A, Piepmeier JM, Spencer DD, Awad IA (2001) Patterns of functional magnetic resonance imaging activation in association with structural lesions in the rolandic region: a classification system. J Neurosurg 94:946–954PubMedCrossRefGoogle Scholar
- Henningsen H, Knecht S, Deppe M, Bremer J, Mock B, Konrad C, Kolan M, Wheat J, Edgar T, Sorenson JA, Turski P, Brooks BR (1998) Common recruitment pattern of associative motor areas in patients with degeneration of cortical pyramidal cells, as measured by fMRI. Neuroimage 7:S1001Google Scholar
- Jueptner M, Frith CD, Brooks DJ, Frackowiak RS, Passingham RE (1997a) Anatomy of motor learning. II. Subcortical structures and learning by trial and error. J Neurophysiol 77:1325–1337Google Scholar
- Jueptner M, Stephan KM, Frith CD, Brooks DJ, Frackowiak RS, Passingham RE (1997b) Anatomy of motor learning. I. Frontal cortex and attention to action. J Neurophysiol 77:1313–1324Google Scholar
- Konrad C, Henningsen H, Jansen A, Knecht S (2005) Comparing brain activation across groups with different motor abilities. J Neurol: DOI: 10.1007/s00415-005-0973-yGoogle Scholar
- Wiesendanger M, Rouiller EM, Kazennikov O, Perrig S (1996) Is the supplementary motor area a bilaterally organized system? In: Luders HO (ed) Supplementary sensorimotor area. Lippincott-Raven, Philadelphia, pp 85–94Google Scholar