Fowler's syndrome: a primary disorder of urethral sphincter relaxation

Abstract

Key content Urinary retention is a relatively uncommon presentation in young women. Women with Fowler's syndrome are often found to have an abnormally elevated urethral pressure profile, increased urethral sphincter volume and characteristically abnormal electromyography of the urethral sphincter. The only treatment that has been found to restore voiding in women with Fowler's syndrome is sacral neuromodulation. Sphincter injections of botulinum toxin are a possible outpatient‐based alternative. Learning objectives To review the typical symptoms and signs associated with Fowler's syndrome. To share the current understanding about why this condition may occur. To understand how to evaluate and treat a woman with suspected Fowler's syndrome. Ethical issues Fowler's syndrome should be considered in women presenting with urinary retention where the cause for retention is uncertain.

Retention of urine in women is alleviated by uterosacral ligament repair: implications for Fowler's syndrome

“…In an attempt to compensate, the forward muscle vectors stretch distal vagina forward beyond the vertical red line shown in Figure 3 to close (constrict) the distal urethra beyond what is normally required; at the same time, the rhabdosphincter contractility increases and this is recorded as an increase in urethral pressure, Table1. These events explain the 'catheter grabbing' oft described in FS [1, 3] and also, Fowler’s descriptions of x-ray video studies carried out in 17 women, which showed urethral obstruction at the region of the striated sphincter in all 12 who could still void.…”

“…One of the two key diagnostic elements of FS, characteristic EMG changes in the rhabdosphincter (RS), was found by Tawadros et al [4] to occur in normal women, usually around the luteal phase of their menstrual cycle. PCOD, initially said to be a frequent concomitant feature of FS, but subsequently retracted [2, 3], is not accompanied by a luteal phase as PCOD patients, by definition, do not ovulate. Thus, of the original criteria for FS, only 'obstructed micturition' or urinary retention remains as the one constant diagnostic feature.…”

“…FS retention was at first assumed to occur from urinary rhabdosphincter spasm or contraction due to aberrant electrical activity – complex repetitive discharges and repetitive motor unit bursts – in rhabdosphincter (RS) muscle fibers [1, 3]. However, this EMG activity occurs in normal women [4].…”

“…Even a small compensatory narrowing of distal urethral diameter, from 4 mm to 3.5 mm, would increase the head of pressure required to drive the urine from the bladder from 100 cm to 172 cm water (Figure 4). We emphasize that only about half the patients described by Panicker et al [3] as ‘Fowler's syndrome’ showed the EMG abnormality that was at first thought to be both characteristic and causative [1]. Since this feature is now recognized in about 30% of normal women [22] during the luteal phase of their menstrual cycles [4], this cannot be the sole cause of the syndrome of urinary retention in young women.…”

“…In a later report, chronic pelvic pain was a feature of 50% of patients [2], with half of these on opiates; indeed, opiate abuse was then suggested as a possible risk factor. In 2018, Panicker et al noted that of 61 women referred to the National Hospital in Queen Square, London, only a third were confirmed as having the syndrome, a diagnosis based on an abnormal urinary sphincter EMG, although the urinary difficulties were similar in those with or without EMG abnormality [3]. However, the EMG features described by Fowler in idiopathic urinary retention in young women have since been found in 53% of a group of normal healthy women, when the recordings were made in the luteal phase of the menstrual cycle.…”