Deep-Brain Stimulation Improves Some Urinary Function in Patients With Parkinson Disease

Deep-brain stimulation (DBS) is effective in improving some urinary functions in patients with Parkinson disease, according to new study findings, which found that females with the disease responded better than males.

For patients who do not respond to conservative treatments, clinical researchers often recommend DBS surgery, which applies high-frequency electrical stimulation to deep brain structures. The treatment has proven to be effective in treating motor system disorders in patients with Parkinson disease, but its effect on urinary dysfunctions has not been widely investigated.

The researchers analyzed responses of 416 patients from the United Kingdom diagnosed with Parkinson disease, 220 of whom received DBS surgery.

Compared with patients who did not receive the surgery, patients who received the surgery experienced improvements in urinary frequency, urgency, and incontinence. However, there were no marked differences in relief of nocturia, residual urine, and dysuria.

These improvements were assessed using 4 tools:

• American Urological Association Symptom Index (AUA-SI), which has patients rate, on a scale of 0 to 5, how bothersome their urinary symptoms are, including incomplete emptying, frequency, urgency, straining, and nocturia
• Overactive Bladder Symptom Score (OAB-SS), which assesses daytime frequency, nighttime frequency, urgency, and urinary incontinence
• Quality of Life Scale (QOL), which measures 5 conceptual domains of quality of life
• Urodynamic testing, which assesses how the bladder and urethra are performing

Prior to surgery, nocturia was the most prevalent (63.7%) urinary symptom, followed by urinary frequency (55.8%), residual urine (43.8%), urinary urgency (38%), dysuria (36.1%), and urinary incontinence (17.8%).

Compared with scores prior to surgery, postoperative OAB-SS and urinary symptom scores during bladder storage were significantly improved. While the AUA-SI, symptom score during urination, and QOL were somewhat improved following surgery, the differences were not statistically significant.

Urinary functions improved across the board among females following DBS surgery, including with the OAB-SS, AUA-SI, symptoms during bladder storage and urination, and QOL. Meanwhile, men experienced significant improvements in OAB-SS and bladder storage and slight improvements in AUA-SI score, symptoms during urination, and QOL.

“Numerous questions still remain on the neurophysiological basis for the therapeutic mechanisms of action of DBS,” wrote the researchers. “It is speculated by various studies that DBS may bring about changes in neurogenesis and micro-environment, and then activate the neuronal network by changes of synapses.”

The researchers added that DBS-induced synaptic events could change the balance of neurotransmitters within the stimulated brain network and then rescue memory and synaptic activity.

Reference

Zong H, Meng F, Zhang Wei G, Zhao H. Clinical study of the effects of deep brain stimulation of urinary dysfunctions in patients with Parkinson's disease [published online June 25, 2019]. Clin Interv Aging. doi: 10.2147/CIA.S204368.