Introduction and overview of Parkinson's disease

Patients with Parkinson's disease (PD) face surgery more often than their age-matched counterparts due in large part to orthopedic and other injuries provoked by the gait and balance difficulties in advanced stages of the illness. General surgical procedures are at least as common in PD as in their age-matched counterparts, but the perioperative management can be complicated given the nature of the illness and its treatments. Recent advances in neurosurgical techniques and an improved understanding of the pathophysiology of motor symptoms in PD has led to a renewed interest and an increase in the number of patients undergoing various neurosurgical procedures for PD. This chapter provides an overview of the principles and preoperative management of patients with PD and other Parkinsonian states.

Parkinson's disease is an adult-onset neurodegenerative disorder characterized by progressive slowness of movement (bradykinesia), muscular rigidity, stooped posture, tremor, postural instability, and varying degrees of cognitive impairment. It affects close to 1 million Americans, with an annual incidence of 20 new cases per 10,000 and a prevalence of 59–187 cases per 100,000 [1–3]. The median age of onset is 60 years and the mean duration of the disease from diagnosis to death is 15 years [4]. Its pathology is concentrated in the brain and consists of selective degeneration of the nigrostriatal dopaminergic pathway and the presence of alpha synuclein pathology including Lewy bodies and Lewy neurites in surviving mesencephalic dopamine neurons, as well as in other brainstem and cortical neurons [5]. Biochemically, the denervation results in striatal dopamine depletion which is linked to the above signs and symptoms [6]. The cause of selective neuronal death, and therefore the etiology of PD is unknown, although hereditary and environmental factors are thought to play a role.