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Pallidal lesions. Structural and functional magnetic resonance imaging
S F Bucher1, K C Seelos, R C Dodel
1Department of Neurology, Klinikum Grosshadern, Ludwig-Maximilians-University, Munich, Germany.
Archives of Neurology
|July 1, 1996
Summary
Functional MRI reveals distinct globus pallidus (GP) lesion patterns. GPi lesions correlate with hyperkinetic signs, while GPe lesions link to hypokinetic signs, offering insights into movement disorders.
Area of Science:
- Neuroscience
- Neurology
- Radiology
Background:
- The globus pallidus (GP) is crucial for motor control.
- Understanding the functional anatomy and pathophysiology of its external (GPe) and internal (GPi) divisions is vital for diagnosing movement disorders.
Purpose of the Study:
- To noninvasively investigate the functional anatomy and pathophysiologic characteristics of the GPe and GPi using advanced neuroimaging techniques.
Main Methods:
- High-resolution magnetic resonance imaging (MRI), including T2-weighted sequences, was employed.
- Functional activation within the GP during hand movements was assessed by counting activated voxels.
Main Results:
- Bilateral hyperintense GP lesions were observed in all patients.
- GPi lesions were associated with dystonic syndromes, while GPe lesions were linked to akinetic-rigid syndromes.
- Reduced GP activation was noted in patients compared to controls, with activation predominantly contralateral to hand movement.
Conclusions:
- GPi lesions may cause hyperkinetic symptoms by reducing inhibitory pallidal output to the thalamus.
- GPe lesions might lead to hypokinetic symptoms due to increased thalamic inhibition.
- Neuronal activation within lesion sites indicates the presence of viable functional tissue.