Functional connectivity within prefrontal cortex in patients with overactive bladder based on rs-fNIRS measurement synchronous urodynamic monitoring / 中华泌尿外科杂志

ABSTRACT

Objective:To detect the abnormalities within the functional connectivity (FC) of the prefrontal cortex (PFC) in patients with overactive bladder (OAB) and to explore its central pathogenesis.Methods:Seven OAB patients (OAB group, 6 females, mean age 47.6±16.0 years) and 13 healthy controls [HC] (HC group, 10 females, mean age 49.9±9.2 years) were prospectively enrolled from August to December 2020. All subjects underwent rs-fNIRS scanning synchronized with urodynamic monitoring, and two rs-fNIRS scans were performed when the bladder was empty and when the desire to void was strong/urodynamic monitoring indicated detrusor hyperactivity (DO). The Pearson's correlation coefficients (r value, i. e., FC value) between time series of the 22 channels were calculated, and a 22×22 FC matrix for each subject was obtained. A paired-sample t-test ( P<0.05, FDR corrected) was used to compare the difference in FC values between the HC group and the OAB group when the bladder was empty and the desire to void was strong. A two-sample t-test ( P<0.05, FDR corrected) was used to compare the group differences in FC values between OAB and HC groups. Results:In this study, 7 patients were included in the OAB group, including 1 male and 6 female. The mean age was (47.6±16.0) years old. In HC group, 13 healthy subjects were included, including 3 males and 10 females. The mean age was (49.9±9.2) years. There was no significant difference in baseline data between the two groups, including age, sex composition, years of education, handedness and urgency score at the second scan ( P>0.05). Residual urine volume in both groups was less than 10 ml. The OABSS score, 3-day urine diary parameters (frequency of urination/24 h, frequency of urinary incontinence/24 h, frequency of urgency/24 h) and maximum detrusor pressure during urine storage in OAB group were significantly higher than those in HC group, with statistical significance ( P<0.01). The average urination volume/time, bladder capacity at first sensation and maximum bladder capacity in OAB group were significantly lower than those in HC group, and the differences were statistically significant ( P<0.01). In the process of bladder filling to strong desire to void, the detrusor pressure in HC group was stable without DO, and 6 cases in OAB group had DO. Compared to empty bladder state, healthy subjects with strong desire to void showed significantly increased FC within PFC in 5 Brodmann area (BA9, BA10, BA44, BA45, BA46)and 13 edges, such as the BA9(left dorsolateral prefrontal cortex [DLPFC] ch 4, 5, 7 and right DLPFC ch 3), BA10(left frontopolar area ch 12, 21 and right frontopolar area ch 10, 18), BA44(left pars opercularis Broca's area ch 15), BA45(left pars triangularis ch 22), BA46(left DLPFC ch 6, 14); significantly decreased FC in 3 brain regions (BA9, BA10 and BA46) and 2 edges, such as the BA9(left DLPFC ch 7), BA10(left frontopolar area ch21 and right frontopolar area ch 17), BA46(right DLPFC ch 9). There was no significant difference in FC within PFC between OAB and HC groups with empty bladder. However, during the strong desire to void state, the FC within PFC in OAB patients was significantly abnormal when compared with HC. OAB patients showed significantly increased FC within PFC in 4 brain regions (BA9, BA10, BA45 and BA46) and 4 edges, such as the BA9(right DLPFC ch 1 and left DLPFC ch 7), BA10(right frontopolar area ch 17), BA45(left pars triangularis ch 22), BA46(right DLPFC ch 9, 16); significantly decreased FC in 3 brain regions (BA9, BA10 and BA46) and 4 edges, such as the BA9 (right DLPFC ch 3 and left DLPFC ch 4), BA10(left frontopolar area ch 12, 21), BA46(left DLPFC ch 14) Conclusion:Compared with HC group, the PFC in OAB group showed significant abnormalities, which may lead to "dyssynergia" of PFC internal functions, result in frontal lobe dysfunction, involving sensory integration, motivation drive, emotional control and decision whether to urinate or not, etc., leading to urinary control dysfunction, which manifested as typical clinical symptoms of OAB. Our findings contribute to the understanding of the central pathogenesis of OAB and may provide a theoretical basis for the emergence of targeted brain therapy in the future.