Surgical treatment of Parkinson's disease

Abstract

Parkinson's disease (PD) is one of the most common neurodegenerative diseases. Its pathogenesis is based on diminution of neurons in substantia nigra, that under normal conditions acts as the source of dopamine in nigrostriatal circuit. The decline of dopamine concentration caused by death of dopaminergic neurons is responsible for the appearance of symptoms typical for the mentioned disease. Along with pharmacotherapy, with its most impressive success - that is delivery of the precursor of dopamine (L-DOPA) to the central nervous system--surgical methods are developed for treatment of PD. The basis of these approaches consist of "switching off" the nigrostriatal structures that are overactive due to lack of inhibiting action performed normally by dopamine. Stereotactic neurosurgery - enabling safe access to the region of basal ganglia, thalamus and subthalamic nucleus can be an important solution for many patients with the PD unresponding to pharmacological therapy. Depending on the procedure irreversible lesions or stimulation leading to reversible block can be done in order to restore physiological functional conditions within nigrostriatal circuit. The new, experimental method of curing PD is transplantaton of dopaminergic rich neurons from fetal mesencephalic tissue. Despite very promising results, this procedure is very controversial due to ethical problems concerning aspects of fetal graft acquisition. In the authors' point of view, the only chance for making the concept of neurotransplantation applicable is the use of neural stem cells that are able not only to renew dopaminergic neuron population, but also, thanks to gene therapy--introducing key substances (e.g. thyrosine hydroxylase, glial cell line-derived neurotrophic factor) and elimination the cause of parkinsonian disturbances.