Zona Incerta - Parkinsons Disease

Parkinsons Disease

Parkinsons Disease might disrupt the zona incerta as it is hyperactive in parkinsonian experimental animals. In humans with Parkinsons Disease, surgical lesion of the zona incerta alleviates their parkinsonian motor symptoms.

Deep brain stimulation of the subthalamic nucleus in those with Parkinson Disease has identified the zona incerta as a promising target area for effective therapy. Unlike deep bilateral stimulation of the ventral lateral nucleus such stimulation of the zona incerta improves all aspects of tremor including both the distal and proximal parts of limbs and the body more generally. This also occurs without dysarthria and disequilibrium as this stimulation does not interrupt proprioceptive sensation and the processing of the fine motor skill movements of vocal cords.

Researchers observed that "The ventral lateral nucleus has long been established as an effective surgical target for controlling distal limb tremor, including Parkinson Disease tremor. However, because it receives predominantly cerebellar afferents and no direct basal ganglia afferents, the reason why it is effective in controlling Parkinson Disease tremor has remained a paradox. The conduction of abnormal oscillations generated in the basal ganglia in Parkinson Disease to the ventral lateral nucleus via zona incerta would therefore explain this paradox and also explain why we observed such a potent anti-tremor effect from stimulating zona incerta in our patients with Parkinson Disease"

The study further noted that deep brain stimulation upon the zona incerta "is effective in suppressing all components of tremor affecting both the distal and proximal part of the body. These results, if replicated in larger randomised controlled studies, have important implications for our current surgical management of patients with tremor and point to a more promising target area than the ventral lateral nucleus of the thalamus."