Evidence of occult dysautonomia in Fowler's syndrome: alteration of cardiovascular autonomic function tests in female patients presenting with urinary retention.
To assess the hypothesis that an occult impairment of the autonomic system might represent one of the mechanisms of urinary disturbance in Fowler's syndrome (FS), in which the pathophysiology of urinary retention is the predominant feature. We prospectively investigated 10 women (mean age 43.7 years) with FS, diagnosed by assessing both voiding-phase dysfunction (complete or incomplete retention with a residual urine volume of >150 mL, and a maximum flow rate of <15 mL/s), abnormalities of striated urethral sphincter electromyography (decelerating bursts and complex repetitive discharges), the presence of polycystic ovaries and absence of any apparent usual causes (obstructive, neurological diseases). The women had a urodynamic investigation, electromyographic examination, cystoscopy, brain and spinal cord magnetic resonance imaging (MRI) and cardiovascular autonomic function tests (CAFTs, i.e. heart rate variability to deep breathing, cold-pressor test, Valsalva ratio, blood pressure response to standing, and sympathetic skin responses), for parasympathetic and sympathetic functions. Evidence of dysautonomia, as classically described, was defined by two or more positive CAFTs. The mean duration of symptoms was 7.9 years; there was urinary retention in six patients (one complete and five incomplete) and the other four complained of straining to void, diminished stream and hesitancy. Five patients were using intermittent self-catheterization. Six patients had two or more positive CAFTs and were considered to have dysautonomia. In all 10 women the clinical neurological and urological examinations were normal with no apparent clinical symptoms of dysautonomia (blurred vision, pupil abnormalities, clinical manifestations of postural hypotension, gastrointestinal symptoms). Brain and spinal cord MRI, cystoscopy, bladder and kidney ultrasonography, sacral-evoked latencies and cortical-evoked responses after pudendal nerve stimulation were normal. There was an occult impairment of the autonomic system in women with FS; this condition might be a pure bladder expression of a generalized but occult dysautonomia, which in some cases might be diagnosed using CAFTs.