Study design, materials and methods
We retrospectively evaluated those patients with CMT disease diagnosed at the Neurology Department of our Tertiary Hospital and referred to our Urology Department since 2008 due to lower urinary tract symptoms (LUTS). We reviewed their clinical charts regarding the age at CMT disease diagnosis, type of CMT disease and the presence of other comorbidities which could cause LUTS. We collected data on urinary symptoms, urodynamic and ultrasonographic findings, physical and neurological examination and therapeutic approach.
Results
Seven patients were referred to our department due to the presence of LUTS. They were 3 male and 4 female, with median age at the moment of LUTS onset of 55 (29-67) years and median time from the diagnosis of the neuropathy to the onset of LUTS was 14 (1-37) years. In four cases the type of the CMT disease was known, being CMT1 in 3 cases and CMT 3 in 1 case (Table 1). Other previous or current pathologies which could impair the function of the lower urinary tract were not identified in any patient.
The majority of patients (5) reported voiding symptoms. All male patients presented acute urinary retention. Three patients reported urinary incontinence and two patients presented recurrent urinary tract infection. No patient reported storage symptoms other than incontinence.
In one patient a uroflowmetry with postvoid residual volume ultrasound measurement was performed with no further filling or voiding cystometry due to low impact of LUTS symptoms in his daily life. In the other 6 patients, a uroflowmetry, PVR measurement, filling cystometry and a pressure/flow study was completed. The urodynamic findings were neurogenic acontractile detrusor in 2 patients, detrusor underactivity in one patient with a BCI of 22 and a BVE of 94.5% with micturition assisted by abdominal straining, a delayed opening time in one patient, a neurogenic detrusor overactivity in one patient and a urodynamic stress incontinence in one patient. In one patient the urodynamic test was normal. No cases of bladder outflow obstruction were detected.
In the ultrasound exam, there was no deterioration of the upper urinary tract in any patient. Neurogenic acontractile detrusor was treated with the placement of and indwelling bladder catheter or with clean intermitent catheterization (CIC). The case of detrusor underactivity was managed conservatively with no need of CIC due to the acceptable BVE and a postvoid residual volume < 150ml. The patient with the delayed opening time was managed with alpha blockers, being asymptomatic in the successive clinical visits. The patient with neurogenic detrusor overactivity was treated with intradetrusor Botulinum Toxin injection, after failure of anticholinergic treatment. All cases of stress urinary incontinence were treated conservatively with pelvic floor muscle rehabilitation.Mean follow-up was 45.9 months (10.5-75.5). At this time, no changes at the initial treatment strategies were needed.
Interpretation of results
Charcot-Marie-Tooth Syndrome (CMT) is the most prevalent peripheral sensory-motor inherited neuropathy (1). Despite having no effect on the autonomic system, Krhut et al demonstrated higher occurrence of LUTS in CMT patients using validated questionnaires (2). To our knowledge, urodynamic findings in these patients have been hardly reported (3). So far, our study constitutes the longest series of CMT patients with LUTS studied with urodynamics.
LUTS are rare in CMT patients but voiding symptoms are the most prevalent. Voiding symptoms in CMT patients correlate with impairment of detrusor contractility in urodynamics studies. There is no deterioration of the upper urinary tract due to high bladder pressure in CMT patients.