GDNF plasma levels in spina bifida: correlation with severity of spinal damage and motor function

Glial-derived neurotrophic factor (GDNF) is one of several powerful survival factors for spinal motoneurons that play a key role in sprouting, synaptic plasticity, and reorganization after spinal cord damage. The aim of this study was to investigate the expression of GDNF in plasma of children with spina bifida (SB) and to determine its correlation with both the severity of spinal cord damage and the motor function of these patients. To measure the GDNF expression, we collected plasma samples from 152 children with SB and in 149 matched controls. Endogenous GDNF levels were quantified using a two-site immuno-enzymatic assay. The statistical analysis was performed using the Mann-Whitney two-tailed two-sample test. In children with SB the mean levels of GDNF (131.2 +/- 69.6 pg/mL) were significantly higher (p < 0.001) with respect to the mean levels of the control group (102.7 +/- 6.8 pg/mL). Moreover, in open SB, the GDNF levels (139.2 +/- 81.1 pg/mL) were significantly higher (p < 0.05) with respect to closed SB (117.2 +/- 41.3 pg/mL). In terms of the motor function of patients, we found that in children with poorer motor function, the GDNF levels (134.5 +/- 67.4 pg/mL) were higher, but not statistically significant (p < 0.1), than in patients with better motor outcome (122.3 +/- 72.2 pg/mL). Our study demonstrates GDNF over-expression in children with SB. This upregulation is significantly associated with the severity of spinal cord damage in SB patients and appears to correlate with poor motor function of children, representing an important biochemical marker of the severity of spine injury.

Longterm oculomotor and visual function in spina bifida cystica: a population-based study

PURPOSE

To document and describe the development from birth of visual and oculomotor functions in a group of children with spina bifida cystica (myelomeningocele and myeloschisis [MMC]). The emphasis in this study is on findings at 12-14 year follow-up.

METHODS

Twenty children aged 12-14 years with myelomeningocele and Chiari-related malformations were examined by an orthoptist and a paediatric ophthalmologist. A further child who did not wish to participate actively in the study is also reported. Visual acuity for near and distance, refractometer readings in cycloplegia, the presence of ocular motility disorders and nystagmus were recorded. Accommodation, convergence, colour vision and stereo acuity were assessed and the fundus and media were examined.

RESULTS

Six children (29%) in the study group had subnormal vision, although no child was visually impaired. Eleven (52%) showed manifest strabismus and 17 (81%) had a significant refractive error. Near visual acuity was normal in nearly all the children, but accommodation was defective in 10. Nine children had nystagmus and two had optic atrophy. No visual field defects were found.

CONCLUSIONS

The high incidence of ocular disturbances in children with spina bifida highlights the importance of regular ophthalmological investigation and follow-up.

Perineal sensation: an important predictor of long-term outcome in open spina bifida

OBJECTIVES

To see if perineal sensation in infants with open spina bifida is associated with a better long-term outcome, particularly in terms of survival, renal-related deaths and incontinence.

METHODS

We conducted a prospective cohort study on a complete cohort of 117 consecutive patients with open spina bifida, whose backs were closed non-selectively at birth between 1963 and 1971. A meticulous neurological examination in infancy showed that 33 (28%) of them had perineal sensation, defined as intact sensation to pinprick in at least one dermatome on one side in the saddle area (S2-4). Data recorded within 48 h of birth and during six reviews between 1972 and 2002 were used. Details of deaths were obtained from medical records and from the Office of National Statistics.

RESULTS

By December 2005, 57% (67/117) of the cohort had died. There were 50 survivors with a mean age 38 years (range 35-41). More of those with perineal sensation survived than those without (23/33 v 27/84, p<0.001). This difference was mainly caused by 19 renal deaths in those lacking perineal sensation. Crucially there were no renal-related deaths in those with perineal sensation (0/33 v 19/84, p = 0.003). Among the survivors, those with perineal sensation were more likely than the remainder to be continent of urine and faeces (10/23 v 1/27, p<0.001 and 18/23 v 9/27, p = 0.002 respectively). They were also more likely to be able to walk at least 50 m (11/23 v 5/27, p = 0.027) and never to have had pressure sores (15/23 v 9/27, p = 0.025).

CONCLUSIONS

A simple assessment of perineal sensation in infancy predicts long-term outcome in terms of survival, renal prognosis and incontinence in open spina bifida.

Thoracic myelocystoceles--two variants

Myelocystoceles are rare lesions. Rarer still are thoracic myelocystoceles. Two patients with thoracic myelocystoceles are being reported. The first patient presented with swelling in the thoracic region with paraplegia and incontinence. MR with MR myelography revealed the malformation to be a thoracic myelocystocele. The second patient presented with a midline cutaneous mass lesion without neurological deficit. MRI revealed a Type I split cord malformation, a CSF containing sac in the thoracic region that communicated through a stalk-like structure to the hydromyelic hemicord. Surgery in both these patients did not produce any change in the neurological status. The importance of recognizing thoracic myelocystoceles, their clinical presentation, embryology, value of MR myelography in the diagnosis and role of surgery are discussed. The differences between terminal myelocystoceles and thoracic myelocystoceles are also highlighted.

Movement analysis in neonates with spina bifida aperta

INTRODUCTION

In neonates with spina bifida aperta (SBA), leg movements by myotomes caudal to the meningomyelocele (MMC) are transiently observed. It is unclear whether these leg movements relate to functional neural conduction through the MMC. For optimal therapeutical intervention, pathophysiological insight in these transient leg movements seems relevant. If leg movements by myotomes caudal to the MMC concur with the execution of general movements (GMs), functional neural conduction through the MMC is implicated.

OBJECTIVE

In neonates with SBA, we aimed to determine whether the transiently present leg movements caudal to the MMC indicate functional neural conduction through the MMC.

METHODS

During the perinatal period, fetuses and neonates with SBA (n = 7 and n = 13, respectively) were longitudinally analysed for concurrency between leg movements caudal to the MMC and GMs. To address the integrity of the reflex arc in spinal segments (at, or) caudal to the MMC, tendon leg reflexes were assessed during the first postnatal week.

RESULTS

At postnatal day 1, leg movements caudal to the MMC concurred with GMs in 12 of 13 infants. Isolated leg movements were observed in only 3 of these 12 infants (isolated vs. concurrent; p < 0.005). Leg movements concurring with GMs lasted longer than isolated leg movements (median duration = 11 s vs. 2 s; p < 0.05). Between days 1 and 7, tendon leg reflexes (at, or) caudal to the MMC had disappeared in all but 1 neonate. However, leg movements caudal to the MMC remained concurrently present with GMs in all five neonates available for follow-up after day 7. Comparing these leg movements between days 1 and 7 indicated a decreased duration (-44%, p < 0.05).

CONCLUSIONS

In neonates with SBA, leg movements caudal to the MMC concur with GMs, indicative of functional neural conduction through the MMC. The disappearance of these leg movements is caused by lower motor neuron dysfunction at the reflex arc, whereas neural conduction through the MMC is still functional.

Dermatoglyphics of mothers of Malawian children with spina bifida cystica: a comparative study with female controls

Dermatoglyphic traits are formed under genetic control early in development and do not change thereafter, thus maintaining stability not affected by age.

METHODOLOGY

We determined the dermatoglyphic traits of mothers of children with spina bifida cystica and compared then with controls matched for number, age and parity, by counting and classifying palmar, plantar and digital ridge pattern configurations of arches, loops, whorls and ridges based on standard techniques.

RESULTS

Palmar pattern types, showed absence of arches, significantly higher frequency of whorls (P > 0.05), lower total finger ridge count (TFRC) and higher Pattern Intensity Index (PII) in these mothers than in the controls (P > 0.001). However, no significant differences were observed between both groups in atd angle and a-b ridge count (P = 130, 0.70 respectively). Plantar pattern types showed loops restricted to the first two digits and absence of arches in the first digit in these mothers compared to controls in whom there were loops in the first four digits and a 100% frequency of arches. Similarly, PII was higher and Dankmeijer's Index (DI) lower in these mothers than in controls.

CONCLUSION

Our findings demonstrate dermatoglyphic differences between both groups that suggest that mothers presenting with these traits are more predisposed to giving birth to children with spina bifida cystica.

Neonatal loss of motor function in human spina bifida aperta

OBJECTIVE

In neonates with spina bifida aperta (SBA), leg movements innervated by spinal segments located caudal to the meningomyelocele are transiently present. This study in neonates with SBA aimed to determine whether the presence of leg movements indicates functional integrity of neuronal innervation and whether these leg movements disappear as a result of dysfunction of upper motor neurons (axons originating cranial to the meningomyelocele) and/or of lower motor neurons (located caudal to the meningomyelocele).

METHODS

Leg movements were investigated in neonates with SBA at postnatal day 1 (n = 18) and day 7 (n = 10). Upper and lower motor neuron dysfunction was assessed by neurologic examination (n = 18; disinhibition or inhibition of reflexes, respectively) and by electromyography (n = 12; absence or presence of denervation potentials, respectively).

RESULTS

Movements, related to spinal segments caudal to the meningomyelocele, were present in all neonates at postnatal day 1. At day 1, leg movements were associated with signs of both upper (10 of 18) and lower (17 of 18) motor neuron dysfunction caudal to the meningomyelocele. In 7 of 10 neonates restudied after the first postnatal week, leg movements had disappeared. The absence of leg movements coincided with loss of relevant reflexes, which had been present at day 1, indicating progression of lower motor neuron dysfunction.

CONCLUSIONS

We conclude that the presence of neonatal leg movements does not indicate integrity of functional lower motor neuron innervation by spinal segments caudal to the meningomyelocele. Present observations could explain why fetal surgery at the level of the meningomyelocele does not prevent loss of leg movements.

Long-term outcome in open spina bifida

BACKGROUND

Doctors need reliable data on outcome in order to help parents faced with difficult decisions about termination of an affected pregnancy or treatment after birth.

AIM

To determine survival, health and lifestyle at the mean age of 30 years in a complete cohort of adults born with open spina bifida.

DESIGN OF STUDY

Prospective cohort study.

PARTICIPANTS

Well-documented cohort of 117 consecutive cases of open spina bifida whose backs were closed non-selectively at birth between 1963 and 1971.

METHOD

Survivors (age range = 26 to 33 years) were surveyed by postal questionnaire and telephone interview. The main outcome measures were the health, independence and lifestyle of the survivors in terms of living in the community, driving a car and working in open employment.

RESULTS

Ascertainment was 100%. Sixty (51%) had died, mainly the most disabled. Of the 57 survivors, 84% had a cerebrospinal fluid (CSF) shunt, 70% had an IQ of 80 or more, 37% lived independently in the community, 39% drove a car, 30% could walk more than 50 metres and 26% were in open employment. However one-third (19) still needed daily care, three were on respiratory support, two were blind, two had diabetes mellitus, and one was on dialysis. Mortality, disability and achievement reflected the neurological deficit that had been recorded in infancy in terms of sensory level. Attainment and independence were reduced in those who had needed revision of CSF shunt.

CONCLUSION

The survivors in this unselected cohort showed a wide range of outcome from apparent normality to very severe disability. This reflected both the extent of their original neurological deficit and events in the history of their CSF shunt.

Assessing physical disability in children with spina bifida and scoliosis

The purpose of this study was to develop a valid and reliable questionnaire to assess physical disability related to the spine in children with spina bifida and scoliosis and their families. Eighty-eight items were generated from a review of the literature and interviews with clinicians, parents, and children with spina bifida and scoliosis. Items were reviewed by 40 children and ranked. After eliminating redundant items, the top 25 items were formatted into a self-administered questionnaire. The questionnaire, completed 2 weeks apart, demonstrated "excellent" test-retest reliability (intraclass correlation coefficient = 0.88). Construct validity was established by high correlation with a validated scale of overall disability: the Activities Scale for Kids (r = 0.86, p < 0.01) and by correlations with global assessment of function. In conclusion, the Spina Bifida Spine Questionnaire is a valid and reliable questionnaire and can be used to assess the outcomes of treatment for children with spina bifida and scoliosis.

Perinatal motor behaviour and neurological outcome in spina bifida aperta

AIM OF THE STUDY

In the present longitudinal study we investigated the relationship between prenatal motor behaviour and the postnatal neurological sequelae of infants with spina bifida aperta.

METHODS AND PATIENTS

Prenatal isolated leg movements and general movements of 13 fetuses/infants with spina bifida aperta were assessed by means of ultrasound recordings, and were compared with: 1. the spinal level of morphological defect (meningo-myelocele), 2. the postnatal motor behaviour, 3. the postnatal sensory function, and 4. the final motor outcome.

RESULTS

In all 13 cases studied, the spinal defect was either at thoracic (n = 8) or at lumbal (n = 5) level. All fetuses displayed active leg movements corresponding to the functioning of low lumbal myelum segments (L4-5 in two cases or L5-S1 in 11 cases), despite vertebral defects at high localisation. These leg movements were of normal quality (normal in appearance) and endogenously generated, since no external stimulus was exerted to elicit them. This implies that in fetuses with spina bifida aperta active leg movements can be generated at spinal segments which are located at (n = 1), or under (n = 12) the meningo-myelelocele. Postnatally, for a short period of time (mostly during the first few hours), leg movements related to myelum function at (n = 1) or lower than (n = 7) the spinal defect were detected. However, only in two infants these early leg movements were of normal quality and corresponded with the final motor outcome. In contrast to these early neonatal leg movements, early sensory function was strongly related to the spinal defect (r = 0.76; P = 0.005) and to the final motor outcome (sensory function predicted outcome in all infants of whom follow-up was performed).

CONCLUSION

These data on fetuses/infants with spina bifida aperta strongly indicate that a discrepancy exists between the occurrence of prenatal leg movements and the spinal localisation of the meningo-myelocele on the one hand, and between the occurrence of pre- and postnatal leg movements on the other hand (quantity and quality).

Does caesarean section delivery improve neurological outcome in open spina bifida?

The antenatal diagnosis of fetuses with myelomeningocele (MMC) has focused the attention of those involved in the perinatal care on caesarean section delivery as a possible method of preserving neurological function. In this paper 25 infants with MMC were studied, 10 delivered by pre-labour caesarean section (PL C/S), and 15 by other methods. No difference in motor function was observed post natally with 50% of each group having neurological levels below L3. The PL C/S group was more heterogeneous. The feasibility of selecting a group of less impaired fetuses with good in utero leg movements for PL C/S in order to preserve neurological function depends on the ability of fetal USS to predict post natal neurological function. This preliminary report leaves unanswered the question whether C/S delivery improves neurological outcome in selected cases of open spina bifida.

Growth and the tethered cord syndrome

We investigated the role of growth in relation to the tethered cord syndrome. By investigation of the growth curve in relation to the operation date we could not establish a period of increased growth preceding the operation date. Thus the operation date was not related to periods of increased length growth. Overstretching with microtraumata of the myelum may be a more important factor.