Urinary tract dysfunction in Parkinson's disease: a review

Introduction Parkinson's disease is an extrapyramidal neurological disorder. Although motor symptoms are a predominant feature of the condition, non-motor symptoms have also been recognized. Urinary symptoms are frequently present in patients affected with Parkinson's disease (PD). Symptoms such as urgency, frequency, nocturia and urge incontinence significantly impact the patient's quality of life. We discuss the urinary dysfunction seen in patients with Parkinson's disease and consider the pathophysiology, important differentials, the investigations and management options for such patients. Materials and methods An extensive search was performed using the PubMed (R)/EMBASE (R) databases to identify the available literature on urinary disturbances and Parkinson's disease. Reference was also made to current national guidelines on Parkinson's disease. Results Urinary disturbances are frequently observed in sufferers of Parkinson's disease resulting in significant impact to the individual's quality of life. Studies report that storage symptoms are present in 57-83% of patients, whereas voiding symptoms are seen in 17-27% patients. Out of all the urinary symptoms, nocturia is the most common complaint in >60% patients with PD. Urgency occurs in 33-54% of patients, whilst frequency is experienced by 16-36% of patients. Detrusor overactivity (DO) is the commonest cystometric abnormality in patients with PD. The rate of neurogenic DO in patients with PD is 45-93%. The main differential to consider is Multiple System Atrophy (MSA) in which all patients are ultimately afflicted with urinary disturbance. It is well recognized that patients initially diagnosed with PD may in fact have MSA, and it is important to distinguish the two as their urological management is different. Patients presenting with refractory LUTS with concurrent PD should undergo full urodynamic investigation including cystometry, flowmetry and ultrasonography before treatment is initiated. Discussion Referral to a urologist is advised in those with persistent or refractory urinary complaints. Urodynamic evaluation allows determination of the underlying bladder disorder; however, post-void residuals suffice in the uncomplicated patient. The pathophysiology of urinary dysfunction and current investigation and treatment modalities are discussed.