Clinical Review

The Nonmotor Symptoms of Parkinson’s Disease: Update on Diagnosis and Treatment

Journal of Clinical Outcomes Management. 2014 February;21(2)

 

References

Treatments for constipation include dietary modification, increased fluid intake, and mild exercise. Macrogol significantly improved constipation in PD patients and was very well tolerated in a randomized placebo-controlled study [149]. Lubiprostone, a GI active prostaglandin, is also effective in the short-term treatment of constipation in a placebo-controlled trial [150].

Gastroparesis: Epidemiology and Treatment

Gastroparesis, like constipation, is related to enteric dopaminergic cell loss and degeneration of the dorsal motor nucleus of the vagus [151]. Patients experience gastroparesis as early satiety, full sensation, and nausea. Decreased gastric motility leads to retention of food as well as medications, which can slow absorption and delay onset of action for many medications including levodopa. Domperidone has both prokinetic and antiemetic properties, which have been beneficial in the treatment of gastroparesis [152], but its use is not currently approved in the United States.

Dysphagia: Epidemiology and Treatment

Dysphagia is associated with more advanced stages of PD as well as a significant increase in morbidity. Swallow exercises have demonstrated improvement of dysphagia [153]. The impact of levodopa therapy on dysphagia in the literature is controversial. Videofluoroscopic examination is the most common method for evaluation of swallowing disorders and provides important information for speech-language pathologists regarding recommendations for dietary modifications [154]. Adjustment of medication regimens to avoid an oral route is also helpful. This includes Parcopa, orally disintegrating carbidopa/levodopa tablets, and transdermal approaches like the rotigotine patch. For some patients, enteral nutrition is needed and placement of nasogastric tubes or percutaneous endoscopic gastrostomy tubes are an option.

Sialorrhea (Drooling)

Epidemiology

Difficulty handling oral secretions due to impaired or infrequent swallowing results in sialorrhea in up to 75% of PD patients [155], which is a significant embarrassment for most patients [156]. PD patients with drooling have difficulty speaking, eating, and engaging in social interactions, which significantly impacts perceived quality of life [157].

Treatment Options

Botulinum toxin (A and B) injections into the submandibular or parotid glands have demonstrated efficacy in multiple double-blind, randomized, placebo-controlled studies for the treatment of sialorrhea in PD patients; however, injections are associated with greater invasiveness and cost [158–160]. Glycopyrrolate, an anticholinergic drug, was also efficacious in the treatment of sialorrhea in the short term in a double-blind, randomized, placebo-controlled study [161]. Alternatively, gum chewing increases swallow frequency, improves drooling, and also shows a benefit with dysphagia [162].

Genitourinary Disturbances

Bladdery dysfunction: Epidemiology and Treatment

Bladder dysfunction in PD is often secondary to hyperactivity of the detrusor muscle leading to urinary urgency, increased urinary frequency, and nocturia. Less commonly, hypoactive detrusor muscle causes difficulty with initiation of urination, delayed bladder emptying, and recurrent infections. Urinary disturbances may occur before the onset of motor symptoms or early on in the disease course [12]. Disease severity is associated with greater urinary disturbances, and more than 50% of advanced PD patients report severe bladder symptoms [163].

Anticholinergic medications such as oxybutynin, solifenacin, and tolterodine are commonly used in the treatment of detrusor hyperactivity and demonstrate significant improvement in detrusor pressure in a recent systemic review and meta-analysis [164]. PD patients on these agents should be closely monitored for side effects including cognitive impairment, somnolence, hallucinations, confusion, and blurred vision. Other treatments include botulinum toxin injections into the detrusor muscle, which has demonstrated safety and efficacy in a recent systematic review [165].

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