RESUMEN
INTRODUCTION: Thalamic tumors are rare and uncommonly manifest as movement disorders, including hemidystonia. Despite this association, little is known about the evolution of hemidystonia. CASE DESCRIPTION: We report on a 11-year-old boy who complained of hypaesthesia and fine motor problems in the left hand. A magnetic resonance imaging showed a large mass in the right thalamus. Stereotactic biopsy revealed a WHO grade 4 astrocytoma, and the patient underwent normofractioned radiochemotherapy with proton-beam radiation and temozolomide. Three months later, a spastic hemiparesis developed on the left side, which progressed over months. Over the following months, the hemiparesis slowly improved, but hemidystonia in the same side developed. This was accompanied with radiological evidence of tumor regression, showing a persistent lesion in the ventral posterolateral and the intralaminar thalamus. CONCLUSION: This case illustrates the unusual and complex temporal course of appearance and disappearance of hemidystonia along with the regression and growth in glioblastoma involving the thalamus.