Monochorea in chronic cerebral hypoperfusion with dopaminergic transmission disruption

Excerpt

A total of 1–4% of all patients with stroke develop some type of hyperkinetic or hypokinetic movement disorder, including chorea, ballism, athetosis, dystonia, myoclonus, akathisia, and parkinsonian symptoms [1]. Hemichorea has a similar pathophysiology to that of hemiballism and typically occurs immediately after acute vascular events affecting the subthalamic nucleus (STN). In the classic model of hyperkinesia, a lesion in the STN interferes with the transmission of the indirect pathway, leading to an increased excitatory output to the motor cortex from the thalamus. However, this model has limitations in the extent to which it can explain hemichorea/hemiballism [1]. There is little doubt that some cases are caused by lesions outside the STN, although their pathophysiology remains uncertain [1]. …