The use of pudendal nerve somatosensory evoked potentials in probable multiple sclerosis

Bladder dysfunction is the presenting symptom in 2% of patients affected by multiple sclerosis (MS) and may be present in up to 78% of them. Abnormalities of somatosensory evoked potentials of the pudendal nerve (pSEP) have been found by many authors in patients affected by clinically defined MS, but little is known of diagnostic reliability of pSEP in early stage of MS. The aim of the study was to evaluate the sensitivity of pSEP in patients affected by probable MS. Sixteen patients, 11 females and 5 males, aged between 18 and 45 years (mean age 28.9), affected by clinically probable MS, were studied. Six of them reported retention or urge incontinence, pSEP with P1 (P40) scalp wave was analyzed. Ali patients also underwent visual evoked potentials (VEP), SEP of median and tibial nerves (mSEP, tSEP), brainstem acustic evoked potentials (BAEPs), Magnetic Resonance Imaging (MRI) of the brain and cerebrospinal fluid (CSF) evaluation. Urodynamic study with simultaneous measurement of intravesical, intraurethral and abdominal pressures with external sphincter electromyography was performed. Abnormalities of the evoked potentials were found in all patients. Our findings seem to indicate ah early and frequent involvement of the bladder control pathways in patients affected by MS and a high rate of subclinical disorders. ©1999, Editrice Kurtis.