Motorisch evozierte Potenziale (MEP) des externen urethralen Sphinkters zur Abklärung der neurogenen Inkontinenz querschnittverletzter Patienten

Zusammenfassung

Ziel: Prospektive Studie zur Diagnose neurogener Läsionen somato-motorisch efferenter Nerven des externen urethralen Sphinkters (EUS) mittels motorisch evozierter Potenziale (MEP) und simultaner Urodynamik (UD).

Patienten und Methoden: 9 gesunde Probanden und 33 Patienten (15 × traumatische Rückenmarkverletzung, 14 × Kaudaläsion und 4 × MS) mit neurogener Urin-Inkontinenz wurden neurologisch, urodynamisch und elektrophysiologisch untersucht. Die Evozierung von MEP-Antworten des EUS erfolgte mittels transkranieller (tk) und lumbosakraler (ls) Einzelpuls-Magnetstimulation. Ein Quotient aus tk/ls Latenzzeiten wurde berechnet, um periphere von zentralen Läsionen zu unterscheiden. Simultan zur EMG-Ableitung wurde über einen Druckmesskatheter mit integrierter Oberflächenelektrode die mechanische EUS-Druckantwort registriert.

Resultate: Bei 9 Probanden betrug die spinale Latenz 19,0 ms, die periphere Latenz 4,25 ms und der errechnete Quotient 4,4. Bei den Pat. mit Rückenmarkverletzung fanden sich eine signifikant verlängerte spinale Latenz von 22,7 ms bei normaler peripherer Latenz. Der Quotient lag mit 5,5 über dem Wert der Gesunden; 13 von diesen 15 Pat. litten unter einer neurogenen Inkontinenz. Pat. mit kompletter spinaler Läsion hatten nach tk Stimulation keine ableitbaren EUS-Antworten bei normalen peripheren Werten. Die Pat. mit MS zeigten ebenso deutlich verlängerte spinale Latenzen von 25,5 ms bei normalen peripheren Latenzen und einem Quotienten von 6,0, der auf eine spinale Läsion hinwies. 10 Patienten mit schwerer Kaudaläsion und Urin-Inkontinenz hatten normale spinale Latenzen jedoch verlängerte periphere Latenzen von 6,7 ms, wobei der erniedrigte Quotient von 3,4 einen Schaden der Kaudawurzeln anzeigte. Bei kompletter Kaudaläsion konnten weder spinale noch periphere MEPs des EUS ausgelöst werden. Tk-evozierte mechanische EUS-Druckantworten waren nur bei intakten resp. inkomplett verletzten spinalen und peripheren motorischen Nervenbahnen erhältlich, während solche nach ls Stimulation unabhängig einer spinalen Läsion nur bei Intaktheit oder Teilintegrität der sakralen Cauda equina-Wurzeln vorhanden waren.

Schlussfolgerungen: MEP- und Druck-Ableitungen des EUS erweisen sich als ergänzende und gut tolerierbare diagnostische Untersuchungen zur Abklärung neurogener Inkontinenz. Dabei können spinale von peripheren Läsionen der motorischen Efferenzen zum EUS differenziert werden.

Abstract

Purpose: A prospective study is presented that assessed neurogenic lesions of the somatic motor efferent potentials (MEP) and simultaneously recorded urodynamics (UD).

Materials and Methods: 9 healthy subjects and 33 patients - 15 × spinal cord injury, 14 × cauda equina lesions and 4 × multiple sclerosis (MS) - with neurogenic urinary incontinence were examined by means of urodynamics and electrophysiology. MEP responses from the EUS were evoked after transcranial (tc) and lumbosacral (ls) single pulse magnetic stimulation. A ratio out of tc/ls latencies was calculated to distinguish between central and peripheral lesions. The mechanical EUS pressure responses were recorded simultaneously with the EMG recordings using a microtipp pressure transducer catheter with an integrated bipolar surface electrode.

Results: In 9 healthy subjects the spinal latency was 19.0 ms, the peripheral latency was 4.25 ms and the ratio was 4.4. In patients with spinal cord lesion, spinal latency was significantly delayed (22.7 ms), whereas peripheral latency was normal. The ratio increased to 5.5. Of these 15 patients, 13 suffered from neurogenic incontinence. Patients with a complete spinal lesion showed no EUS responses after tc stimulation, whereas peripheral answers were normally elicitable. Patients with MS showed significantly longer spinal latencies (25.5 ms). The increased ratio of 6.0 indicated a spinal lesion. Of the patients with severe cauda equina lesions and urinary incontinence, 10 had normal spinal latencies, but longer peripheral latencies of 6.7 ms. The ratio of 3.4 indicated a lesion of the sacral caudal roots. In patients with complete cauda injury, neither spinal nor peripheral responses could be evoked. Tc-evoked mechanical pressure responses from the EUS could only be recorded in intact or incompletely injured spinal and peripheral motor nervous pathways, whereas they could be evoked after ls stimulation only in cases with partially preserved sacral caudal roots independent of a spinal lesion.

Conclusions: MEP and evoked pressure responses from the EUS proved to be an additional and well-tolerable diagnostic tool in the assessment of neurogenic incontinence. Spinal and peripheral lesions of the motor efferent pathways to the EUS can thereby be distinguished.

Schlüsselwörter:

Motorisch evozierte Potenziale - neurogene Inkontinenz - Querschnittverletzung - Urodynamik - externer urethraler Sphinkter

Key words:

Evoked potential motor - Neurogenic incontinence - Spinal cord injuries - Urodynamics - External urethral sphincter

Literatur

• 1 Vodusek D B. Electromyogram, evoked sensory and motor potentials in neurology.  Neurophysiol Clin. 1997;  27 204-210
• 2 Vodusek D B. Evoked potential testing.  Urol Clin North Am. 1996;  23 427-446
• 3 Merton P A, Morton H B. Stimulation of the cerebral cortex in the intact human subject.  Nature. 1980;  185 227-228
• 4 Barker A T, Freestone I L, Jalinous R, Merton P A, Morton H B. Magnetic stimulation of the human brain.  J Physiol. 1985;  369 3
• 5 Eisen A. Cortical and peripheral nerve magnetic stimulation.  Methods clin Neurophysiol. 1992;  3 65-84
• 6 Clarke C E, Modarres-Sadeghi H, Twomey J A, Burt A A. Prognostic value of cortical stimulation in spinal cord injury.  Paraplegia. 1994;  32 554-560
• 7 Ingram D A, Thompson A J, Swash M. Central motor conduction in multiple sclerosis: evaluation of abnormalities revealed by transcutaneous magnetic stimulation of the brain.  J Neurol Neurosurg Psychiat. 1988;  51 487-494
• 8 Cowan J MA, Dick J PR, Day B L, Rothwell J C, Thompson P D, Marsden C D. Abnormalities in central motor pathway conduction in multiple sclerosis.  Lancet. 1984;  2 304-307
• 9 Curt A, Keck M E, Dietz V. Functional outcome following spinal cord injury: Significance of motor evoked potentials.  Arch Phys Med Rehabil. 1998;  79 81-86
• 10 Dvorak J, Herdmann J, Vohanka S. Motor evoked potentials by means of magnetic stimulation in disorders of the spine.  Methods clin Neurophysiol. 1992;  3 45-64
• 11 Caramia M D, Pardal A M, Zarola F, Rossini P M. Electric vs magnetic trans-cranial stimulation of the brain in healthy humans: a comparative study of central motor tracts’ “conductivity” and “excitability”.  Brain Res. 1989;  479 89-104
• 12 Ertekin C, Hansen M V, Larsson L E, Sjödahl R. Examination of the descending pathway to the external anal sphincter and pelvic floor muscles by transcranial cortical stimulation.  Electroenceph Clin Neurophysiol. 1990;  75 500-510
• 13 Pelliccioni G, Scarpino O, Piloni V. Motor evoked potentials recorded from external anal sphincter by cortical and lumbo-sacral magnetic stimulation: normative data.  J Neurol Sci. 1997;  149 69-72
• 14 Opsomer R J, Van Cangh P J, Humblet Y, Abi Aad A, Rossini P M. Motor evoked potentials of the perineal floor. Preliminary results.  Ann Urol. 1989;  23 484-486
• 15 Opsomer R J, Caramia M D, Zarola F, Pesce F, Rossini P M. Neurophysiological evaluation of central-peripheral sensory and motor pudendal fibres.  Electroencephalogr Clin Neurophysiol. 1989;  74 260-270
• 16 Loening-Baucke V, Read N W, Yamada T, Barker A T. Evaluation of the motor and sensory components of the pudendal nerve.  Electroencephalogr Clin Neurophysiol. 1994;  93 35-41
• 17 Jost W H, Ecker K W, Schimrigk K. Surface versus needle electrodes in determination of motor conduction time to the external anal sphincter.  Int J Colorectal Dis. 1994;  9 197-199
• 18 Tabaraud F, Hugon J, Salle J Y, Boulesteix J M, Vallat J M, Dumas M. Study of central motor pathways using cortical magnetic stimulation and spinal electrical stimulation: results in 20 normal subjects.  Rev Neurol. 1989;  145 690-695
• 19 Sato T, Konishi F, Kanazawa K. Variations in motor evoked potential latencies in the anal sphincter system with sacral magnetic stimulation.  Dis Colon Rectum. 2000;  43 966-970
• 20 Herdmann J, Enck P, Zacchi-Deutschbein P, Ostermann U. Speed and pressure characteristics of external anal sphincter contractions.  Am J Physiol. 1995;  269 G225-231
• 21 Dressler D, Schönle P W, Neubauer H. Central motor conduction time to bulbocavernosus muscle: evaluation by magnetic brain stimulation and testing of bulbocavernosus reflex.  J Neurol. 1990;  237 239-241
• 22 Ghezzi A, Callea L, Zaffaroni M, Montaniani R, Tessera G. Motor potentials of bulbocavernosus muscle after transcranial and lumbar magnetic stimulation: comparative study with bulbocavernosus reflex and pudendal evoked potentials.  J Neurol Neurosurg Psychiatry. 1991;  54 524-526
• 23 Jost W H, Schimrigk K. A new method to determine pudendal nerve motor latency and central motor conduction time to the external anal sphincter.  Electroenceph Clin Neurophysiol. 1994;  93 237-239
• 24 Herdmann J, Bielefeldt K, Enck P. Quantification of motor pathway to the pelvic floor in humans.  Am J Physiol. 1991;  260 G720-G723
• 25 Osterhage J, Ludolph A C, Masur H. Evozierte Potentiale in der Diagnostik der erektilen Dysfunktion.  Kontinenz. 1993;  2 175-181
• 26 Dvorak J, Herdmann J, Theiler R, Grob D. Magnetic stimulation of motor cortex and motor roots for painless evaluation of central and peripheral motor pathways. Normal values and clinical application in disorders of the lumbar spine.  Spine. 1991;  16 955-961
• 27 Thiry A J, Deltenre P F. Neurophysiological assessment of the central motor pathway to the external urethral sphincter in man.  Br J Urol. 1989;  63 515-519
• 28 Eardley I, Nagendran K, Kirby R S, Fowler C J. A new technique for assessing the efferent innervation of the human striated urethral sphincter.  J Urol. 1990;  144 948-951
• 29 Mathers S E, Ingram D A, Swash M. Electrophysiology of motor pathways for sphincter control in multiple sclerosis.  J Neurol Neurosurg Psychiatry. 1990;  53 955-960
• 30 Eardley I, Nagendran K, Lecky B, Chapple C, Kirby R S, Fowler C J. The neurophysiology of the striated urethral sphincter in multiple sclerosis.  Br J Urol. 1991;  67 81-88
• 31 Snooks S J, Swash M. Perineal nerve and transcutaneous spinal stimulation: new methods for investigation of the urethral striated sphincter musculature.  Br J Urol. 1984;  56 406
• 32 Snooks S J, Swash M. Abnormalities of the innervation of the urethral striated sphincter musculature in incontinence.  Br J Urol. 1984;  56 401-405
• 33 Vodusek D B, Zidar J. Perineal motor evoked responses.  Neurourol Urodynam. 1988;  7 abstract 52 236
• 34 Brodak P P, Bidair M, Joseph A, Szollar S, Juma S. Magnetic stimulation of the sacral roots.  Neurourol Urodyn. 1993;  12 533-540
• 35 Kiff E S, Swash M. Normal proximal and delayed distal conduction in the pudendal nerves of patients with idiopathic (neurogenic) faecal incontinence.  J Neurol Neurosurg Psychiatry. 1984;  47 820-823
• 36 Jost W H. Motorisch evozierte Potentiale zum Beckenboden.  In: Neurologie des Beckenbodens. Chapman & Hall, London, Weinheim 1997: 109-120
• 37 Jameson J S, Rogers J, Chia Y W, Misiewicz J J, Henry M M, Swash M. Pelvic floor function in multiple sclerosis.  Gut. 1994;  35 388-390
• 38 Swash M, Snooks S J. Slowed motor conduction in lumbosacral nerve roots in cauda equina lesions: a new diagnostic technique.  J Neurol Neurosurg Psychiatry. 1986;  49 808-816
• 39 Kiff E S, Swash M. Slowed conduction in the pudendal nerves in idiopathic (neurogenic) faecal incontinence.  Br J Surg. 1984;  71 614-616
• 40 Schurch B. The predictive value of plantar flexion of the toes in the assessment of neuropathic voiding disorders in patients with spine lesion at the thoracolumbar level.  Arch Phys Med Rehabil. 1999;  80 681-686
• 41 Snooks S J, Swash M. The innervation of the muscles of continence.  Ann R Coll Surg Engl. 1986;  68 45-49
• 42 Nordling J, Meyhoff H H. Dissociation of urethral and anal sphincter activity in neurogenic bladder dysfunction.  J Urol. 1979;  122 352-356
• 43 Maynard Jr F M, Bracken M B, Creasay G, Ditunno Jr J F, Donovan H, Ducker T B, Garber S L, Marino R J, Stover S L, Tator C H, Waters R L, Wildberger E, Young W. International standards for neurological and functional classification of spinal cord injury.  Spinal cord. 1997;  35 266-274
• 44 Stöhrer M, Goepel M, Kondo A, Kramer G, Madersbacher H, Millard R, Rossier A B, Wyndaele J J. The standardization of terminology in neurogenic lower urinary tract dysfunction: with suggestions for diagnostic procedures. International Continence Society Standardization Committee.  Neurourol Urodyn. 1999;  18 139-158
• 45 Lapides J, Friend C R, Ajemian E P, Reus W S. Denervation supersensitivity as a test for neurogenic bladder.  Surg Gynec Obstet. 1962;  114 123-126
• 46 Bors E, Comarr A E. Neurological urology. Physiology of micturition. Ist neurological disorders and sequelae. Basel: Karger 1971: 129ff
• 47 Rossier A B, Fam B A. 5-microtransducer catheter in evaluation of neurogenic bladder function.  Urology. 1986;  17 371-378
• 48 Hess C W, Mills K R, Murray N MF. Magnetic stimulation of the human brain: facilitation of motor responses by voluntary contraction of ipsilateral and contralateral muscles with additional observations on an amputee.  Neurosci lett. 1986;  71 235-240
• 49 Day B L, Dick J PR, Marsden C D, Thompson P D. Differences between electrical and magnetic stimulation of the human brain.  J Physiol. 1986;  378 36P
• 50 Tabaraud F, Hugon J, Chazot F, Moreau J J, Vidal J, Vallat J M, Dumas M. Motor evoked responses after lumbar spinal stimulation in patients with L5 or S1 radicular involvement.  Electroencephalogr Clin Neurophysiol. 1989;  72 334-339
• 51 Ugawa Y, Terao Y, Hanajima R, Sakai K, Kanazawa I. Facilitatory effect of tonic voluntary contraction on response to motor cortex stimulation.  Electroencephalogr Clin Neurophysiol. 1995;  97 451-454
• 52 Gosling J A, Dixon J S. Light and electron microscopic observations on the human external urethral sphincter.  J Anat. 1979;  129 abstract D.7 216p
• 53 Lemieux M C, Kamm M A. Pudendal nerve terminal motor latency (PNTML): Ihre klinische Relevanz.  Kontinenz. 1992;  1 85-86
• 54 Amarenco G, Kerdraon J. Pudendal nerve terminal sensitivity latency: technique and normal values.  J Urol. 1999;  161 103-106
• 55 Jost W H, Derouet H, Kaiser T. Electromyography of the sphincter vesicae externus muscle. Technique, indications and outcome.  Urologe A. 1997;  36 356-361
• 56 Eardley I, Quinn N P, Fowler C J. et al . The value of urethral electromyography in the differential diagnosis of parkinsonism.  Br J Urol. 1989;  64 360-362
• 57 Snooks S J, Swash M. Motor conduction velocity in the human spinal cord: slowed conduction in multiple sclerosis and radiation myelopathy.  J Neurol Neurosurg Psychiatry. 1985;  48 1135-1139
• 58 Hess C W, Mills K R, Murray N MF, Schriefer T N. Magnetic brain stimulation: central motor conduction studies in multiple sclerosis.  Ann Neurol. 1987;  22 744-752
• 59 Mc Donald W I. Pathophysiology in multiple sclerosis.  Brain. 1974;  97 179-196
• 60 Gunnarson M, Ahlmann S, Lindström S, Rosén I, Mattiasson A. Cortical magnetic stimulation in patients with genuine stress incontinence: Correlation with results of pelvic floor exercises.  Neurourol Urodyn. 1999;  18 437-445
• 61 Schurch B, Hauri D, Rodic B, Curt A, Meyer M, Rossier A B. Botulinum-A-toxin as a treatment of detrusor-sphincter dyssynergia: a prospective study in 24 spinal cord injury patients.  J Urol. 1996;  155 1023-1029
• 62 Galloway N TM, El-Galley R ES, Sand P K, Appell R A, Russell H W, Carlan S J. Extracorporeal Magnetic innervation therapy for stress urinary incontinence.  Urology. 1999;  53 1108-1111

1 Diese Arbeit wurde durch den Schweizerischen Nationalfonds (3200052562) sowie durch das International Institute for Research in Paraplegia (P55/99) unterstützt.