Skip to Main Content
Home Books Pharmacotherapy Quick Guide

Chapter 56: Parkinson Disease

INTRODUCTION

  • Parkinson disease (PD) has highly characteristic neuropathologic findings and a clinical presentation, including motor deficits and, in some cases, mental deterioration.

PATHOPHYSIOLOGY

  • Two hallmark features in the substantia nigra pars compacta are loss of neurons and presence of Lewy bodies. The degree of nigrostriatal dopamine loss correlates positively with severity of motor symptoms.

  • Reduced activation of dopamine1 and dopamine2 receptors results in greater inhibition of the thalamus and reduced activation of the motor cortex. Clinical improvement may be tied to restoring activity more at the dopamine2 receptor than at the dopamine1 receptor.

CLINICAL PRESENTATION

  • PD develops insidiously and progresses slowly over many years.

  • Initial symptoms may be sensory, but as the disease progresses, one or more classic primary features present (eg, resting tremor, rigidity, bradykinesia, and postural instability that may lead to falls).

  • Resting tremor is often the sole presenting complaint. However, only two thirds of PD patients have tremor on diagnosis, and some never develop this sign. Tremor is present most commonly in the hands, often begins unilaterally, and sometimes has a characteristic “pill-rolling” quality. Resting tremor is usually abolished by volitional movement and is absent during sleep.

  • Muscular rigidity involves increased muscular resistance to passive range of motion and can be cogwheel in nature. It commonly affects both upper and lower extremities; neck and facial muscles may be affected.

  • Intellectual deterioration is not inevitable, but some patients deteriorate in a manner indistinguishable from Alzheimer disease.

  • Nonmotor symptoms are common and must be identified, treated, and monitored (Table 56–1).

TABLE 56–1Nonmotor Symptoms and Possible Treatments
View Table|Favorite Table|Download (.pdf)
TABLE 56–1 Nonmotor Symptoms and Possible Treatments
Symptom Possible Treatments
Anxiety Cognitive behavioral therapy, selective serotonin reuptake inhibitors, venlafaxine, minimize “off” times.
Cognitive impairment Eliminate anticholinergic agents. Add cholinesterase inhibitor.
Constipation Fiber, hydration, exercise, laxatives, stool softeners.
Daytime sleepiness Proper night time sleep hygiene, reduce dose of dopamine agonist, referral to sleep specialist to rule out apnea and sleep disorders.
Depression Selective serotonin reuptake inhibitor, newer-generation serotonin norepinephrine reuptake inhibitor, cognitive behavioral therapy.
Drooling Local injection of botulinum toxin, atropine sublingual drop, glycopyrrolate, ipratropium sublingual spray.
Dysphagia Referral to speech therapist, dysphagia diet, avoid anticholinergic medications, manage dry mouth.
Fatigue Caffeine, armodafinil, modafinil, proper night time sleep hygiene, referral to sleep specialist to rule out sleep disorder.
Falling Referral to physical therapy; assistance with ambulation, minimize risk for bone fractures, treat osteoporosis.
Hallucinations/psychosis Eliminate adjunctive medications, especially anticholinergic agents and dopamine agonists. Add clozapine, quetiapine, pimavanserin.
Impulse control disorder Discontinue dopamine agonist or add clozapine, quetiapine, or naltrexone
Insomnia Nonbenzodiazepine GABAA agonists, trazodone.
Orthostatic hypotension Reduce dose of alpha-blockers, dopamine agonist, diuretics, vasodilators. Abdominal compression, add salt and water to diet, water boluses, fludrocortisone, midodrine, droxidopa, pyridostigmine.
Overactive bladder Behavioral therapies (eg, bladder training, fluid management, pelvic floor muscle exercises), ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.

This site uses cookies to provide, maintain and improve your experience. MHE Privacy Center Close