Clinical and anatomical factors associated with thalamic dyskinesias

To define the clinical and anatomical factors associated with dyskinesias f ollowing thalamic infarction, we performed neurological examination and thr ee-dimensional brain magnetic resonance imaging for 23 patients with thalam ic infarction. We measured the total volumes and the largest diameters of t he lesions on axial and coronal images. Using the atlas of human thalamus, we investigated the damaged thalamic nuclei. We compared the means of the v olumes and the largest diameters of the lesions, and the frequencies of dam aged thalamic nuclei between patients with and without thalamic dyskinesias . Seven (two pseudochoreoathetosis and five dystonia) of the 23 patients wi th thalamic infarction developed dyskinesias. No specific neurological defi cits at the onset of stroke predicted the development of dyskinesias. The m ean volume of the lesions of patients with dyskinesias (739 mm(3)) was sign ificantly larger than that of those without dyskiensias (92.9 mm(3)). The m eans of the largest axial (11.6 mm) and coronal (10.8 mm) diameters were si gnificantly larger in patients with dyskinesias, compared to those (axial, 7.1 mm; coronal, 6.4 mm) of patients without dyskinesias. Patients with dys kinesias had damage in the centromedian (CM) thalamic nucleus more frequent ly compared to those without dyskinesias. Patients with-a large thalamic,in farction involving the CM nucleus are more likely to develop dyskinesias. ( C) 2001 Elsevier Science B.V. All rights reserved.