Are head injury guidelines changing the outcome of head injured children? A regional investigation.

BACKGROUND: Secondary pathophysiological CPP insult is related to outcome after head injury, and improved management would be expected to reduce secondary brain insult. Paediatric head injury management guidelines have been published in recent years, by SIGN (2000), RCPCH (2001), NICE (June 2003), and jointly by Critical/Intensive Care Societies (C/ICS July 2003). We investigated whether outcome of children's head injury (and total burden of secondary CPP insult) has changed (1) annually; (2) before and after the introduction of any HI guidelines, and (3) following other service changes. METHODS: Seventy-six children (aged 1-14 years with severe HI) were admitted to the Edinburgh Regional Head Injury Service between 1989 and 2006, and dichotomised at various time points and compared in terms of: demographic factors, intracranial pressure (ICP), cerebral perfusion pressure (CPP) insults [e.g. age-banded pressure-time index (PTI)], and Glasgow Outcome Scale (GOS) score (assessed at 6 months post injury). FINDINGS: When dichotomised around the SIGN guidelines, there were no statistically significant differences between the two group's demography or in primary brain injury, but the outcomes were different (p = 0.03), with 6 vs 4 GOS1 (died), 2 vs 4 GOS3 (severely disabled), 5 vs 16 GOS4 (moderately disabled) and 23 vs 14 GOS5 (good recovery), when comparing before and after year 2000. GOS4 was significantly different (chi-square = 7.99, p < 0.007). There was a (non-significant) trend for the later years to have longer insult durations of ICP, hypertension, CPP, hypoxia, pyrexia, tachycardia and bradycardia, greater PTI for both CPP and ICP, and more CPP insults (p = 0.003). There was, however, significantly less CPP insult (p = 0.030) after the introduction of the more management-oriented C/ICS guidelines. CONCLUSIONS: The most recent paediatric HI guidelines appear to have reduced the burden of secondary insult, but more time is required to determine if this will be reflected in improved outcomes.

Effects of different methods of peripheral nerve repair on the number and distribution of muscle afferent neurons in rat dorsal root ganglion.

The effects of three methods of peripheral nerve repair and normal controls were compared with respect to the number and distribution of muscle afferent nerve cell bodies from the extensor digitorum longus muscle in the dorsal root ganglia of the rat. Nerves were repaired using one of three methods: 1) direct epineurial suture; 2) a three-strand cable graft; or 3) a coaxially aligned freeze-thawed autologous skeletal muscle graft. In all cases the number and distribution of muscle afferent nerve cells were estimated 300 days after nerve repair. Retrograde transport of horseradish peroxidase, injected into the extensor digitorum longus muscle, was used to identify muscle afferent nerve cell bodies in dorsal root ganglia exposed at laminectomy after fixation. It was found that all methods of nerve repair were associated with a change in both the number and distribution of labeled muscle afferent cell bodies. The number of labeled muscle afferent cells was significantly different from normal controls in all methods of repair, but was not significantly different among the three methods compared. On the other hand, cell size and cell distribution departed significantly more from normal after either of the grafting procedures than after direct repair. There was no significant difference between the two grafting techniques. These results are discussed with respect to their mechanistic and clinical interpretation.

The fate of motoneurons in the spinal cord after peripheral nerve repair: a quantitative study using the neural tracer horseradish peroxidase.

This study assessed the changes that occurred in the spinal motoneuron pool after the repair of a specific peripheral nerve by means of several clinically appropriate surgical techniques: nerve graft, muscle graft, and epineurial suture. The motoneuron pool relating to a single muscle was assessed at 50, 100, 200, and 300 days after repair via retrograde axonal transport of the neural tracer horseradish peroxidase. The results indicate that although a small portion of the motoneuron population dies following peripheral nerve surgery, this is not a significant number. The majority of the anterior horn cells appear to have the ability to both survive nerve transection and form new functional connections with the regenerated nerve after repair. The degree of cell loss is influenced by the nature of the injury and the method of repair implemented. Injuries involving neurotmesis result in the loss of a greater proportion of the cell population than less severe injuries involving axonotmesis. A greater proportion of the motoneuron population is preserved when the severed nerve has been repaired using a direct epineurial suture than when repair is achieved by means of a graft. The two methods of grafting produced comparable results, although the muscle graft tended to result in the preservation of a greater number of cells than the nerve graft, making it an acceptable alternative method for the surgical repair of short gaps in peripheral nerves.

Multiple extradural arachnoid cysts as a cause of spinal cord compression in a child. Case report.

Symptomatic arachnoid cysts of the spine are uncommon in children and have only rarely been reported to occur extradurally. The authors report a case of multiple extradural spinal arachnoid cysts in a 9-year-old child who presented with signs of spinal cord compression. The extent of the disease, which affected the thoracic, lumbar, and sacral spine, and the number of independent cysts make this case unique and suggest an underlying defect in the dura of the spinal canal that is predisposed to the formation of cysts. The investigations of choice, surgical planning, and surgical technique are considered. The literature is reviewed and mechanisms of cyst formation discussed.

Human chorionic gonadotrophin and laparoscopy in the treatment of impalpable testes.

The object of this preliminary retrospective study was to assess the use of human chorionic gonadotrophin (HCG) in the treatment of impalpable testes. Eleven children were found to have an impalpable testis, and in two cases neither testis was palpable. After HCG injections, 10 testes were palpable (67%), two of which were in the scrotum. During laparoscopy, three testes were found to be absent (20%) and two were found to be intraabdominal (13%). During surgery, seven testes were found in the inguinal canal, close to the deep ring (47%). The other was found at the superficial ring. The authors conclude that HCG injections are valuable in the treatment of impalpable testes; the treatment resulted in palpable testes in 83% of their cases in which one testis was present.

Obstetric brachial plexus palsy: a large animal model for traction injury and its repair. Part 1: age of the recipient.

A Sunderland type IV traction injury to the C6 root of the sheep or lamb brachial plexus was used as a model for obstetric traction injury to the C5 root in humans. The injury was created and immediately repaired using interfascicular nerve autografts in a group of adult sheep and a group of newborn lambs. The animals were examined using electrophysiological and morphometric techniques 1 year after operation. It was found that the recovery of neuromuscular function was superior in the lambs. The implication is that nerves in newborn animals have a better potential for regeneration than that seen in older individuals. This is discussed with reference to the management of obstetric brachial plexus palsy.

Assessment of the method and timing of repair of a brachial plexus traction injury in an animal model for obstetric brachial plexus palsy.

A Sunderland type IV traction injury to the C6 root of adult sheep or newborn lamb brachial plexus was used as a model for obstetric traction injury to the C5 root in humans. In one experimental cohort the injury was created and repaired using interfascicular nerve autografts or coaxially aligned freeze-thawed skeletal muscle autografts in a group of adult sheep and in a group of newborn lambs. In a second cohort a similar injury was created and repaired either immediately or after a delay of 30 days, using either interfascicular nerve autografts or coaxially aligned freeze-thawed skeletal muscle autografts in four groups of six newborn lambs. In all cases both functional and morphometric indices of nerve regeneration were poorer in the injured and repaired nerves than in normal nerves. In lambs the method of repair made no difference and no significant differences were found for any of the indices of nerve function or morphology. In sheep the use of muscle grafts was associated with a poorer outcome than the use of nerve autografts. Where a delay of 30 days had elapsed between injury and repair, the results using nerve autografts were not significantly different. Where freeze-thawed muscle autografts had been used, the maturation of the regenerated nerve fibres after delay was significantly poorer than after immediate repair. The electrophysiological variables CV(max) and jitter, which may be applied clinically, were found to be good discriminators of recovery in all of the animals and in respect of all procedures.

Biodegradable controlled release glass in the repair of peripheral nerve injuries.

The experiments in this paper were concerned with the recovery of function and ease of application of an entubulation technique using a biodegradable, controlled release glass tube (CRG) for the repair of a transected peripheral nerve. The peroneal nerves of 15 New Zealand White rabbits were repaired with either a CRG tube filled with freeze-thawed muscle, or a conventional freeze thawed muscle graft (FTMG). These were compared with controls in which a CRG was used to enclose the cut ends of a nerve separated by a 1 cm gap. Electrophysiological and morphometric assessment was carried out 6 months after repair. No statistical difference was found in any test between the FTMG and the CRG tube filled with freeze thawed muscle. The CRG tube and 1 cm gap produced inferior levels of recovery of function when compared with the other two repair groups.

The use of ciliary neurotrophic factor to promote recovery after peripheral nerve injury by delivering it at the site of the cell body.

Despite a body of evidence showing that various neurotrophic factors support the survival of nerve cells and stimulate axonal outgrowth, doubt remains about their optimal site of application as well as the more compelling question of what clinical benefit, if any, they would confer. Ciliary neurotrophic factor (CNTF) supports the survival of motorneurons in vitro and in vivo. Direct delivery of CNTF to the cell bodies may help reduce the side effects and overcome the problem of rapid systemic clearance. The aim of this study was to establish whether nerve regeneration may be improved upon by the controlled addition of a specific humoral neurotrophic substance (CNTF) at the level of the cell body. Three groups of five adult sheep were used. The first group acted as normal controls. In the second and third groups, the median nerve was divided and repaired using an epineurial suture technique. In the second group, CNTF was supplied into the CSF at the level of C6 by an implanted osmotic pump. In the third group physiological saline was placed in the osmotic pump. The animals underwent comprehensive electrophysiological and isometric tension experiments at six months. All of the animals had reduced electrophysiological, morphometric and isometric tension indices after surgery compared to normal. The CNTF group had better results than the saline group in the following; (1) area and amplitude of the muscle action potential (2) the percentage of tetanus and muscle mass preserved after repair. These differences were only statistically significant for amplitude of the muscle action potential. No statistical difference was found in the morphological indices (fibre diameter, axon diameter, myelin thickness and internodal length) between the CNTF and saline groups. CNTF does not confer a functional benefit when applied at the level of the cell body.

Ventriculo-atrial shunt insertion: pressure monitoring as an aid to accurate placement.

The objective of this paper is to describe a new method to ensure accurate placement of a ventriculo-atrial shunt distal catheter. A technique is described using pressure waveform changes within the right side of the heart. Pressure monitoring is a new method of placing atrial catheters and is easy to perform.

Cervical cord tethering due to split cord malformation at the cervico-dorsal junction presenting with self-mutilation of the fingers.

An unusual case of cervical spinal cord tethering with diplomyelia is described. A 12-month old female presented with self-mutilation of the fingers due to sensory loss in the hands, absent reflexes, poor muscle tone, and reduced distal upper-limb movements. There was a deep skin dimple overlying the T1 spinous process. Imaging showed angulation of the lower cervical cord and an operation revealed a low cervical meningocele and a split cord malformation with tethering of one half of the cord; the cord was untethered. In this report the literature is reviewed.

Intracranial hemorrhage in neonates with unrecognized hemophilia A: a persisting problem.

Hemophilia is a rare disorder, and an uncommon cause of intracranial hemorrhage in neonates. We present 2 patients with hemophilia A, who presented with massive subdural hemorrhages on day 5 and day 4 postpartum. Both were taken urgently to surgery without a diagnosis of hemophilia being established. Neither patient had a family history of hemophilia, and both were born following difficult deliveries. The activated partial thromboplastin time (APTT) was normal in patient No. 1 (subsequent factor VIII level 10%). In patient No. 2, the APTT was slightly prolonged, but initially interpreted as being within the normal range for age (subsequent factor VII level of < 1%). Patient 1 rebled, required a second operation, and had a poor outcome. Patient 2 was given prophylactic fresh frozen plasma, and made a good recovery. Factor VIII assay should be performed in all term male babies presenting with intracranial hemorrhage. In urgent circumstances, prophylactic clotting therapy should be administered during surgery to prevent postoperative bleeding in an undiagnosed hemophiliac.

Long-term risks and benefits of a separate CSF access device with ventriculoperitoneal shunting in childhood hydrocephalus.

To determine the long-term risks and benefits of a separate CSF reservoir in the management of 52 children (23 males, 29 females) with shunted hydrocephalus, a retrospective study was performed comparing the use and complications after separate reservoir insertion, with a prereservoir control period. Median age at first shunt insertion was 1 month and median age at reservoir insertion was 2 years 6 months. Median follow-up for shunt with the additional reservoir was 19 years 1 month. There was no mortality due to shunt failure nor CNS infection, and there were significantly fewer episodes of ventriculitis (p < 0.01) and shunt blockage (p < 0.0001) compared with the prereservoir period. There was no hemiplegia, epilepsy, visual, nor cognitive loss from the additional reservoir. The reservoir was used for access in 344 attendances (mean 6.62 attendances per patient) for diagnosis or treatment of raised pressure or CNS infection. It was concluded that a separate CSF reservoir is useful in the long-term management of patients with shunted hydrocephalus and is without mortality or significant increased morbidity.

Obstetric brachial plexus palsy: a comparison of the degree of recovery after repair of a C6 ventral root avulsion in newborn and adult sheep.

The C6 motor rootlets were avulsed from the spinal cord in six newborn lambs to simulate a birth lesion of the upper root of the brachial plexus. Six 1-year-old sheep were used for comparison, and treated in a similar manner. The injury was repaired immediately in each group using an autologous coaxial freeze-thawed skeletal muscle graft. The animals were allowed to recover for 1 year after the surgery. The C6 root was then examined electrophysiologically and morphologically. The results were compared with those obtained from a group of untreated intact 1-year-old sheep. The fibre and axon diameters and myelin sheath thickness were significantly different in the group repaired as lambs when compared with the group repaired at the age of 1 year. There was also a significantly increased maximum conduction velocity and a greater range of conduction velocities within the nerve in the lambs. Central motor latency was significantly slower in the sheep than in the lambs. These findings would suggest a greater potential for recovery in the lambs after brachial plexus root avulsion injuries.

The repair of large peripheral nerves using skeletal muscle autografts: a comparison with cable grafts in the sheep femoral nerve.

Recovery of morphological characteristics was compared in the femoral nerves of sheep at varying times up to 10 months after nerve repair. Groups of sheep receiving coaxially aligned freeze-thawed skeletal muscle autografts were compared with those receiving three-strand cable grafts made from autogenous cutaneous nerve. At all times after implantation more nerve fibres could be counted distal to the muscle grafts than distal to cable grafts. Indices of nerve fibre maturation were indistinguishable between the two groups at 10 months. The results are discussed in relation to the possible use of the technique for repairing large mixed nerves.

The use of conventional and invaginated autologous vein grafts for nerve repair by means of entubulation.

Nerve repair by entubulation has re-emerged recently as a possible means of enhancing the microenvironment at the site of repair by inclusion within the tube of various trophic factors. To this end, a modification of the vein-graft technique has been used by turning it inside out before repair, to expose the adventitial surface to the regenerating axons. A comparative study of standard vein grafting versus the inside-out technique was carried out in two equal-sized groups of inbred Lewis rats. Jugular vein isografts were derived from litter mates. The sciatic nerve was transected and repaired by entubulation using the standard vein graft in one group and the inside-out graft in the other group. Morpho-metric and electrophysiological assessment were carried out 3 months after repair. When the animals were assessed it was found that both the standard-vein-graft group and the inside-out group exhibited a reduction in all of the morphometric and electrophysiological variables when compared to normal nerves. The mean axon diameter, fibre diameter and myelin sheath thickness were, however, found to be greater in the group that underwent the inside-out repair. The superior morphometric results seen in the inside-out group were not matched by improved electrophysiological performance. It is concluded that the use of the inside-out technique confers no functional benefit over standard vein grafting.

In vitro nerve repair--in vivo. The reconstruction of peripheral nerves by entubulation with biodegradeable glass tubes--a preliminary report.

Biodegradeable "controlled release" inorganic polymer glass tubes can be manufactured to fit the dimensions of any nerve and their rate of solubility can be adjusted to encompass the time taken for nerve regeneration. They have been used in a number of biological applications. The facial nerve was repaired in a group of five sheep by entubulation with biodegradeable glass tubes. The sheep were assessed 10 months after repair and compared with a similar sized group of normal sheep. It was found that while there was a reduction in the peak velocity of conduction in the repaired nerves and in the range of conduction velocities, the minimum conduction velocity was within normal limits. There was a diminution in all of the measured variables of nerve morphometry but in no case did this reach statistical significance. These findings are consistent with the view that regeneration of the nerves had taken place to a degree at least as effective as that seen in nerves of a similar size repaired by conventional means.