DEVELOPMENTAL MEDICINE AND CHILD NEUROLOGY. 197 1, 13

8 Berger, F. M., Bradley, W. (1946) ‘The pharmacological propzrties of Y $3 dihydroxy-y-(2-methyl-

9. Lenman, J . A. R. (1970) ‘The use of drugs in the treatment of spasticity.’ Proc. roy. SOC. Med., 63, 935. 10. Cook, J. B., Nathan, P. W. (1967) ‘On the site of action of diazepam in spasticity in man.’J. neurol. Sci.,

11. Carter, C . H., Gustafson, S . R. (1965) Drugs in Neurospastic Disorders. Springfield, Ill.: C . C . Thomas. 12. Wilson, L. A. (1970) ‘The management of spasticity and rigidity using parenteral diazepam.’ Geront.

13. Wilson, L. A., McKechnie, A. A. (1966) ‘Oral diazepam in the treatment of spasticity in paraplegia,

14. Bazemore, A,, Elliott, K. A. C., Florey, E. (1956) ‘Factor I and gamma-amino-butyric acid.’ Nature

15. Eccles, J . C . (1969) The Inhibitory Pathways of the Central Nervous System. Liverpool: Liverpool

16. Birkmayer, W., Dmielczyk, W., Weiler, G. (1967) ‘Zur Objektivierbarkeit des myotonolytischen

17. Jones, R. F., Burke, D., Marosszeky, J. E., Gillies, J. D. (1970) ‘A new agent for the control of spasti-

18. Pedersen. E., Arlein-Soborg, P., Grynderup, V., Henriksen, 0. (1970) ‘GABA derivative in spasticity.’

phenoxy)-propane (Myanesin).’ Brit. J. Pharmacol., 1, 265.

5, 33.

clin., 12, 168.

a double-blind trial and subsequent impressions.’ ,%of. med. J. , 11,46.

(Lond.), 178, 1052.

University Press.

Effektes ekes Aminobuttersaurederivates (Ciba 34647-Ba).’ Wien. med. Wschr., 117, 7 .

city.’ J . Neurol Neurosurg. Psychiat., 33, 464.

Acta neurol. scand., 46, 257.

PREDICTION OF URINARY CONTINENCE IN MYELOMENINGOCELE

THE normal bladder has two opposite and alternating functions: storage and evacuation. Balance and co-ordination between the two depend on central nervous system control. If t h s mechanism is defective, separation of the opposing functions breaks down so that evacuation occurs during storage and storage during evacuation. The results are incontinence and urinary stagnation. In children, this situation is usually due to myelomeningocele.

Completely normal bladder function occurs in no more than 5 per cent of children suffering from myelomeningocele. The incidence of ‘reasonable continence’ varies from 11 per cent1 to 30 per cent2, the difference reflecting variation in selection, age, training and, no doubt, the authors’ standards. Time will tell whether a given cfuld will become continent; in ECKSTEIN’S opinion2, if continence is not achieved by the age of three years it is unlikely to be attained later. With increasing emphasis on neonatal assessment, recent studies have sought ways of predicting continence in the young infant with myelomeningocele.

The vertebral level of the lesion has been advocated as a guide3, following claims that cervical and upper thoracic lesions are likely to be associated with normal bladder func- tion2T 4 9 5. This is, however, almost certainly due to the fact that the lesions in question were simple meningoceles, myelomeningoceles being rare at these sites. KIRK LAND^ found no correlation between the level of the lesion and the neurological deficit in the bladder, and STARK^ found only a limited association between sacral lesions and complete bladder paralysis.

The neurological level as determined by examination of the lower limbs is more useful. If the legs are normal or show only a mild upper motor neurone lesion, bladder function is usually unimpaired’. In the 3-5 per cent of patients in whom the lesion is asymmetrical (hemimyelomeningocele) with sparing of one leg, normal bladder function can also be expected7* s. Good correlation has been demonstrated between detrusor activity and preservation of either voluntary or reflex function in lower limb muscles innervated from S2-4, i.e. lateral hamstrings, calves, foot intrinsics and anal sphincter. 92 per cent of infants with clinical S2-4 function had an active detrusor compared with only 12.5 per cent of

388

ANNOTATIONS

those with flaccid paralysis below S17710. Detrusor activity is, however, by no means synonomous with continence.

Observation of micturition is also rewarding. The normal newborn infant is not incontinent: he voids with a proud, parabolic stream and is then dry for two hours or more. Such behaviour in the infant with a myelomeningocele is encouraging but unusual. By contrast, frequent, small volume dribbling, increased by crying, movement, or suprapubic pressure, is a poor omen for later continence. Assuming that the ability to initiate a stream depends on detrusor activity and its interruption on the sphincter, ERICSSON et u I . ~ compared children with constant dribbling and those with partial continence (dry periods for more than one hour). They concluded that preservation of detrusor activity was more important than sphincteric function in ensuring at least partial continence. Their test is. however, not feasible in infancy.

Direct cystometry, i.e. intravesical pressure recording through a percutaneously inserted catheter, is more physiological than conventional cystometryl’. Using the newer technique in infants suffering from myelomeningocele, both COOPER‘, and STARK; found that in only about one third was detrusor activity completely absent. In the remainder the activity present ranged from poorly co-ordinated reflex contractions to a basically normal pattern, i .e. a slow rise of only 5-10 mm Hg pressure during filling, peak voiding pressure of <60 mm Hg and effective emptying (residual volume <20 ml). Of patients fulfilling these criteria, COOPER^^ considered that as many as 70 per cent would achieve continence, the precise number depending also on the integrity of sensation and cortico-spinal control, which are difficult to assess in infancy; by contrast, no more than 15 per cent of those with abnormal reflex activity and only 27 per cent with inert bladders were likely to become continent even with manual expression.

Direct cystometry can greatly augment the value of clinical examination in predicting bladder control in the infant with myelomeningocoele. Early detection of the unsafe bladder with outlet obstruction is, however, still the main reason for recommending complete bladder assessment in every patient before the age of three months.

GORDON STARK Royal Hospital for Sick Children, Edinburgh.

REFERENCES 1. Cooper, D. G. W. (1968) ‘Detrusor action in children with myelomeningocele.’ Arch. Dis. Childh.,

2. Eckstein, H. B. (1968) ‘Urinary control in children with myelomeningocele.’ Brit. J . LJrul., 40, 191. 3. Ericsson, N. O., Hellstrom, A., Nergirdh, A,, Rudhe, U. (1970) ‘Factors promoting urinary and anal

4. Doran, P. A., Guthkelch, A. N. (1963) ‘Studies in spina bifida. Part 4. The frequency and extent of

5. Smith, E. D. (1965) Spina Bifida and the Total Care of the Spinal Myelomeningocele. Springfield, Ill.:

6. Kirkland, I. S. (1962) ‘Urinary tract problems in spina bifida.’ Develop. Med. Child Neurol., 4, 314. 7. Stark, G. D. (1968) ‘The pathophysiology of the bladder in mye1omeningoc:le and its correlation with

8. Duckworth, T., Sharrard, W. J. W., Lister, J. , Seymour, N. (1968) ‘Hemimyelocele.’ Develup. Med.

9. Ericsson, N. O., Hellstrom, A., Nergirdh, A., Rudhe, U. (1970) ‘Unilateral neurological defect in

10. Stark, G. D. (1971) ‘The nature and causes of paraplegia in myelorneningocele.’Purupl~~giu (in the press.) 11. Whitaker, J., Johnston, G. S. (1966) ‘Urinary flow rate with two techniques of bladder pressure measure-

12. Cooper, D. G. W. (1968) ‘Bladder studies in children with neurogenic incontinence.’ Brif. J . Urol., 40,157.

3 83

43,427.

continence in children with myelomeningocele.’ Actu puediut. seund., 59, 491.

paralysis.’ J. Neurul. Neurosurg. Psychiut., 26, 545.

C . C. Thomas.

the neurological picture.’ Develop. Med. Child Neurol., Suppl. 16, 76.

Child Neurol , Suppl 16, 69.

myelomeningocele with normal bladder function.’ Actu puediut. scarid., 59, 487.

ment.’ Invest. Urol., 4, 235.