Research Article
Quantitative Changes in Cerebral Perfusion during Urinary
Urgency in Women with Overactive Bladder
Nisha G. Arya,
1
Steven J. Weissbart,
2
Sihua Xu,
3
Rupal Bhavsar,
3
and Hengyi Rao
3
1
Department of Obstetrics and Gynecology, Perelman School of Medicine, Te University of Pennsylvania, Philadelphia, PA, USA
2
Department of Urology, Stony Brook School of Medicine, Stony Brook, NY, USA
3
Center for Functional Neuroimaging, Department of Neurology, Perelman School of Medicine,
Te University of Pennsylvania, Philadelphia, PA, USA
Correspondence should be addressed to Nisha G. Arya; aryanisha2000@gmail.com
Received 18 May 2017; Accepted 16 July 2017; Published 17 August 2017
Academic Editor: Nader Pouratian
Copyright © 2017 Nisha G. Arya et al. Tis is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Purpose. To quantitatively measure changes in cerebral perfusion in select regions of interest in the brain during urinary urgency
in women with overactive bladder (OAB) using arterial spin labeling (ASL). Methods. Twelve women with OAB and 10 controls
underwent bladder flling and rated urinary urgency (scale 0–10). ASL fMRI scans were performed (1) in the low urgency state
afer voiding and (2) high urgency state afer drinking oral fuids. Absolute regional cerebral blood fow (rCBF) in select regions
of interest was compared between the low and high urgency states. Results. Tere were no signifcant diferences in rCBF between
the low and high urgency states in the control group. In the OAB group, rCBF (mean ± SE, ml/100 g/min) increased by 10–14%
from the low to the high urgency state in the right anterior cingulate cortex (ACC) (44.56 ± 0.59 versus 49.52 ± 1.49, < 0.05),
lef ACC (49.29 ± 0.85 versus 54.02 ± 1.46, < 0.05), and lef insula (50.46 ± 1.72 versus 54.99 ± 1.09, < 0.05). Whole-brain
analysis identifed additional areas of activation in the right insula, right dorsolateral prefrontal cortex, and pons/midbrain area.
Conclusions. Urinary urgency is associated with quantitative increase in cerebral perfusion in regions of the brain associated with
processing emotional response to discomfort.
1. Introduction
Urinary urgency, a sudden compelling desire to urinate that
is difcult to defer, is the main symptom of overactive bladder
(OAB), a functional disorder of bladder storage characterized
by the symptoms of urinary urgency, usually associated with
frequency and nocturia [1]. OAB afects approximately 15%
of US women and prevalence rates are higher in women
than men [2]. Common treatment options for OAB, such as
behavioral and pharmacologic therapy, have limited efcacy
[3]. Te development of more efcacious treatment for OAB
has been limited by a lack of understanding of the underlying
pathogenesis of OAB.
While bladder outlet obstruction caused by prostatic
enlargement is a common cause of OAB in men, anatomic
abnormalities of the urinary bladder have not been identifed
in women. Brain imaging studies in a related functional
bowel disorder, irritable bowel syndrome, have identifed
abnormalities in the processing of interoceptive stimuli in
the brain [4]. A similar abnormality in processing of aferent
signals may exist in women with OAB also. In meta-analyses
of brain imaging studies, majority performed using BOLD
fMRI, we and other authors have previously reported that
urinary urgency is associated with activation of several
cortical and subcortical regions that comprise the limbic
system, that is, region of the brain that processes emotional
response to pain and discomfort, such as anterior cingulate
cortex (ACC), insula, and prefrontal cortex (PFC) [5, 6].
However, the magnitude of activation in these regions has not
been measured; thus the precise relationship between urinary
urgency and the limbic cortex remains unclear.
Neural activity in the brain is tightly coupled with
regional cerebral blood fow (rCBF). Arterial spin labeling
(ASL) is a fMRI technique that allows quantitative measure-
ment of absolute cerebral perfusion [7]. Unlike PET scans
that require the administration of radioactive intravenous
Hindawi
BioMed Research International
Volume 2017, Article ID 2759035, 8 pages
https://doi.org/10.1155/2017/2759035