OBJECTIVES: To investigate feasibility, reproducibility and age dependency of sensory evoked cortical potentials (SEPs) after electrical stimulation of different localizations in the lower urinary tract (LUT) in a cohort of middle-aged healthy women.
SUBJECTS AND METHODS: In a group of ten healthy middle-aged women (mean height: 165±5cm; mean age: 43±6 years), electrical stimulation (0.5 and 3Hz) was applied to bladder dome, trigone, proximal and distal urethra. SEPs were recorded at the Cz electrode with reference to Fz. All measurements were repeated three times with an interval of three to five weeks. Current perception thresholds (CPT), SEP latencies and amplitudes were analysed. Results were compared to a group of younger women published previously.
RESULTS: LUT SEPs demonstrated 2 positive (P1, P2) and 1 negative peak (N1). The mean N1 latency was 108.9±7.8ms, 116.2±10.7ms, 113.2±13.4ms, and 131.3±35.6ms for bladder dome, trigone, proximal and distal urethra, respectively. N1 latencies - except for the distal urethra - were significantly shorter compared to younger women. Taking all data, i.e. young and middle-aged women, into account, there was a significant negative correlation between the variable age and CPT/dome (r = -0.462, p = 0.04) and N1 latency/dome (r = -0.605, p = 0.005) and a significant positive correlation between the variable age and N1P2 amplitude/dome (r = 0.542, p = 0.014).
CONCLUSION: LUT-SEPs can be induced in middle-aged women with reliable N1 responses. Unexpectedly, N1 responses reveal a shortening with increasing age particularly when compared to younger women. Changes in sensory afferents may be explained by age related qualitative reorganizations within the urothelium and suburothelium potentially altering afferent nerve excitability and may have an impact on the development of non-neurological LUT disorders (e.g. overactive bladder) in women.
Written by:
Gregorini F, Knüpfer S, Liechti MD, Schubert M, Curt A, Kessler TM, Mehnert U. Are you the author?
Neuro-Urology, Spinal Cord Injury Centre & Research, University of Zürich, Balgrist University Hospital, Zürich, Switzerland.
Reference: BJU Int. 2015 Jan 28. Epub ahead of print.
doi: 10.1111/bju.13066
PubMed Abstract
PMID: 25626360