is a neurological sign
that presents as a movement disorder
, characterised by unilateral wild, large amplitude
flinging movements of the arm and leg, normally causing falls and preventing postural maintenance.
It is caused by a lesion
in the contralateral subthalamic nucleus
or its connections, usually in patients with a history
, or following TB meningitis
. The subthalamic nucleus normally regulates the globus pallidus
by exciting the GPi, which in turn normally inhibits the ventral anterior nucleus
, ventral lateral nucleus
and lateral dorsal nucleus
of the thalamus
. The reduced discharge in both causes disinhibition of the thalamus and consequent involuntary stimulation of the motor cortex. Altered dopaminergic feedback mechanisms may also be involved.
Chemical treatment is via dopamine
blockade, or via surgical lesions to the globus pallidus, lenticular fasciculus or VL nucleus of thalamus.
The prognosis is rather favourable both vitally and functionally