Effect of cerebrospinal fluid shunt surgery on lower urinary tract dysfunction in idiopathic normal pressure hydrocephalus

AIMS

To examine the outcomes of lower urinary tract symptoms (LUTS) and urodynamic test results after cerebrospinal fluid (CSF) shunt surgery in idiopathic normal pressure hydrocephalus (iNPH).

METHODS

Records of 48 patients (33 men; 15 women), who met the definite iNPH criteria and underwent CSF shunt surgery, were retrospectively analyzed. LUTS and their impact on quality of life (QOL) were evaluated using an all-or-none questionnaire targeting four symptoms, the Overactive Bladder Symptoms Score (OABSS), and the QOL index. Urodynamic investigations included filling cystometry and pressure-flow studies performed before and after surgery.

RESULTS

Forty-seven (98%) patients complained of LUTS, 41 (87%) patients of whom experienced LUTS improvement after surgery. The OABSS and QOL index, which before surgery were 6.8 ± 0.7 and 4.1 ± 0.4, respectively, significantly decreased to 4.6 ± 0.6 and 3.2 ± 0.3, respectively, after surgery. The maximum cystometric capacity (174.9 ± 13.3 mL to 222.4 ± 14.7 mL) and bladder compliance (35.8 ± 4.4 ml/cmH₂ O to 52.1 ± 5.4 ml/cmH₂ O) significantly increased after surgery. Detrusor overactivity, which was observed in 37 (77%) patients preoperatively, became undetectable in 7 patients postoperatively. Voiding dysfunction (defined as maximum flow rate <10 mL/s or post-void residual >100 mL) was observed in 29 (60%) patients, 22 (75%) of whom had detrusor underactivity before surgery. None of the voiding urodynamic parameters significantly improved postoperatively.

CONCLUSIONS

iNPH is often associated with LUTS and both storage and voiding dysfunctions. CSF shunt surgery improved LUTS and storage dysfunction, with limited effects on voiding dysfunction.