DEVELOPMENTAL MEDICINE AND CHILD NEUROLOGY. 1980,22

This would come at 13 or 14, or even 15, irrespective of what surgery has been done. It requires very little muscular function to walk when there is no soft-tissue tightness; for that reason, stretching exercises are helpful.

The first patient on whom we performed surgical procedures had been in a wheelchair for six months. We operated on him in 1962, and prolonged his walking with braces for some three years. The elongation, or section, of the achilles tendon is to be deplored, except when one is committed to using long leg-braces, because it does remove the stabilization effect on the knee of the equinus foot. I t is not to be done unless one accepts the inevitability of the long leg-brace. We frequently use an ankle-foot orthosis when there is subtalar weakness and the parents do not want posterior tibial transfer. Incidentally, it is very easy to continue walking with simply a short leg-cast after a posterior tibial transfer, since the equinus foot provides the knee stability.

I disagree with the concept that a spinal brace has any effect on the scoliosis. As has been pointed out by many people, the scoliosis is the result of asymmetrical forces on a growing spine. This occurs when patients are in a chair, which is 10 or 11 years of age, and in my opinion is associated with the sling seat and the asymmetrical use of one arm. This can be prevented or minimized if the wheelchair seat holds the individual in hyperextension. There is absolutely no corrective ability by a spinal brace in paralytic scoliosis associated with Duchenne dystrophy, in my opinion. We have opted for stabilization of the spine in the presence of a progressive scoliosis, knowing full well that later on the scoliosis will significantly interfere with ventilation and aggravate the ventilatory muscle weakness which already occurs and compromises respiratioii.

In short, as well,as the psychological benefits of prolonging walking for the individual, there is also a physiological benefit. Certainly the excess weight that one sees in many Duchenne patients can be prevented or minimized as the individual continues walking. We have had two patients who have developed a Pickwickian syndrome as a complication of obesity and late-stage dystrophy.

In my opinion, the reason why there is controversy and why so few clinics use the techniques of selective surgery and selective bracing in prolonging walking is that there is a very poor understanding of the pathokinesiology of Duchenne muscular dystrophy.

Department of Physical Medicine, The Ohio State University, Dodd Hall, 472 West 8th Avenue, Columbus, Ohio 43210.

ERNEST w. JOHNSON. M.D.

Neurological Complications of Cystinuria SIR-Thaddeus Kurczynski refers to the occurrence of a wide variety of neurological complications in patients with cystinuria (DMCN, 20, 811). Most of the information about this derives from a few individual or sibship case reports. We would first of all like to present our own case report.

The child, a girl, was referred to this hospital when she was nearly 1 I years old because of temper tantrums at home and learning difficulties. Both she and her mother were known to be homyzygous cystinurics and her father is heterozygous for the disorder. She is a lovely child, though in many ways shy and immature. Her head is obviously large and the OFC of 57cm exceeds the 97th percentile for age by 2cm, whilst height and

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weight are around the 90th and 75th centiles respectively. There is a single small strawberry naevus but no other cutaneous stigmata. Markings in her palms are ill-defined but the triradii are normally placed. There is nothing else abnormal on general physical examination.

Although well-built, muscle power is generally depressed and there is notable weakness in the hip flexors. There is a mild intention tremor on the left, and marked hyperreflexia of the left knee-jerks but no other lateralising signs. There seems to be true variability of tone in the lower limbs. There is marked hyperextensibility of elbows and wrists and she can do quite extraordinary things with her ‘double-jointed’ fingers.

She has great difficulty with the organisation of large movements, which are cumbersome and awkward and accompanied by odd posturing of fingers and hands. She is ungainly on stairs and has difficulty in jumping, hopping and running. Fine motor performance is poor and she has difficulty in maintaining integrated motor activity when a second activity is introduced She is right handed and right footed and has no problems with right/left differentiation. Eye movements are normal and there is no problem with gaze and no nystagmus.

Skull X-rays and a CT scan revealed no abnormality. The ventricles were rather small. Her use of language seems normal, in spite of a history of severe speech delay, but her

intonation is very variable, sometimes explosive and almost dysarthric; nevertheless expressive flowing speech is often released.

She is in normal school and they report that skills such as running have had to be specifically taught over the years, as has the ability to speak in sentences and in natural conversation.

Psychological testing reveals a variable picture. On the verbal side there is a split between the findings of average vocabulary and grammatical competence and a WISC-R verbal IQ of 52. Other average skills are the immediate and delayed recall of stories and the copy of a complicated geometric design. Estimates of general non-verbal abilities have always been in the seventies, but here again another interesting split is apparent in that when attempting the delayed recall of a complicated geometrical design, although she correctly reproduces the individual components in the correct spatial location relative to one another, they are not meshed together, thus forming an ‘exploded’ design.

It seems, then, that she has a general cognitive disability concerned with the organisation and structuring of some information, alongside a disability concerned with the organisation and maintenance of integrated motor activity.

Three distinct biochemical phenotypes of cystinuria are recognised. It seems that all breed true. The prevalence of the disorder is such that whilst individual practitioners are unlikely to see many cases (hence the number of individual case reports), significant numbers could be identified on a wider basis for evaluation. As a first step toward investigating the apparent diversity of neurological dysfunction associated with this disorder, it would be useful to know whether distinct neurological phenotypes correspond to the biochemical phenotypes. The sibship data mentioned by Kurczynski lend some support to this suggestion. If, then, there were evidence for a distinct neurological component, the need for early detection and biochemical intervention would extend far beyond attempts to prevent the formation of renal calculi. Human Development Research Unit, JENNIFER DENNIS University of Oxford, DAVID C . TAYLOR Park Hospital for Children, Headington, Oxford OX3 7LQ.

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