Background: Unlike the delayed pain syndrome, acute spontaneous limb pain is a very rare presentation of stroke. On the other hand, hemiballismus is mainly related to a lesion of the contralateral subthalamic nucleus however other anatomie locations exceptionally account for it.
Methods: After observing one patient showing hemiballismus associated. with ipsilateral acute limb pain at stroke onset, we retrospectively stud1ed more than 4000 patients of the Lausanne Stroke Registry (LSR) looking for acute painful symptoms associated with hemiballismus, differentiating the latter from choreo-athetosis, pseudoathetosis, dystonia tremor, asterixis and myoclonus.
Results-Case description: We only identified 6 patients with acute painful symptoms at stroke onset, and 15 subjects with hemiballismushemichorea. The observed patient was the only one who presented with acute pain associated with ipsilateral hemiballismus. He was a 74-year old man with atrial fibrillation, and complained at stroke onset of feeling an acute intense burning pain in his left arm, on admission he showed hemiballismus of his left hemibody. Neurological examination disclosed left inferior quadranopsia, sensory extinction with slight hypoesthesia, and distal paresis predominating on the left upper limb. Pain disappeared after 48 h; hemiballismus was managed with haloperidol. MRI showed acute in[arction of the right anterior P.arietal cortex extending to the adjacent white matter, whereas basal gangha, thalamus and the subthalamic region were intact.
Discussion: Acute limb pain in stroke should be regarded as exceptional, and has been described with hemispheric, thalamic and bulbar involvement. Interruption of thalamo-parietal projections is probably the responsible mechanism. On the other side, hemiballismus associated with lesions interrupting subthalamic-pallidal and striato-pallidal connections, as well as cortico-striatal fibers, has been rarely reported in acute stroke (about 0.4 % in the LSR). Only the described patient showed the presentation of acute pain associated with ipsilateral hemiballismus, in whom a disturbance of the direct basal ganglia pathway caused by the parietal lesion possibly explains the movement disorder. In contrast with isolated hemiballismus, we believe that simultaneous occurrence of acute limb pain with hemiballismus points to an anterior parietal stroke.