**Dysphagia in Parkinson's Disease**

Rosane Sampaio Santos, Carlos Henrique Ferreira Camargo, Edna Márcia da Silva Abdulmassih and Hélio Afonso Ghizoni Teive

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/60983

**1. Introduction**

Parkinson's disease (PD) is the second most common neurodegenerative disorder among the elderly after Alzheimer's disease. It affects around 1% of the population over 65 years of age and has a prevalence of 4% or more among individuals over the age of 85 years [1]. The condition is primarily the result of a progressive, chronic loss of dopaminergic neurons in the substantia nigra and striatum and presents with or without intracytoplasmic Lewy body deposits [1-3]. A monogenic etiology is found in only around 5% of cases. In cases that do not have a monogenic etiology, the condition is known as sporadic or idiopathic PD and occurs as a result of interaction between a series of hereditary and environmental factors [3].

Bradykinesia, tremors, rigidity, and postural instability are the main motor signs of PD [4]. PD also presents with a series of non-motor manifestations, including changes in behavior, cognition, learning, and the autonomic nervous system. Dysautonomias are major complica‐ tions of PD and include orthostatic (postural) hypotension (OH), constipation, anhydrosis, erectile dysfunction, sialorrhea, dysphagia, esophageal dysmotility, gastroparesis, irritable bladder symptoms, and nocturia [5-7].

Dysphagia is a problematic and sometimes dangerous feature of PD. Oropharyngeal dyspha‐ gia can have a negative impact on quality of life [8,9] and increases the risk of aspiration pneumonia, which is often a cause of death in PD [10,11]. Subjective dysphagia occurs in one third of PD patients. Objectively measured dysphagia rates are much higher, with four out of

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five patients being affected. The prevalence of dysphagia in four studies was between 72% and 87%, with a pooled prevalence estimate of 82% (95% CI 77%–87%), suggesting that while the condition is common in PD, patients do not always report swallowing difficulties unless asked. This under-reporting calls for a proactive clinical approach to dysphagia, particularly in light of the serious clinical consequences of the condition [12].

The aim of this chapter is to show dysphagia as a symptom/sign and an important cause of disability in patients with PD.
