Prognosis for seizure control and remission in children with myelomeningocele

Frequency, Predictors, and Outcome of Seizures in Patients With Myelomeningocele: Single-Center Retrospective Cohort Study

To determine the frequency, predictors, and outcomes of seizures in patients with myelomeningocele, we retrospectively analyzed the data from patients with myelomeningocele followed longitudinally at a single center from 1975 to 2013. We identified a total of 122 patients (61% female). The mean follow-up duration was 11.1 years (minimum-maximum = 0-34.5 years, SD = 8.8, median = 9.1 years). A total of 108 (88.5%) patients had hydrocephalus, and 98 (90.7%) of those patients required a ventriculoperitoneal shunt procedure. Twenty-four (19.7%) patients manifested with seizures, 23 of whom had hydrocephalus. The average age of seizure onset was 4.8 years (median 2 years of age). Falx dysgenesis (P = .004), lumbar myelomeningocele (P = .007), and cortical atrophy (P = .028) were significantly associated with epileptic seizure development. The average seizure-free period at the last follow-up in patients with a history of myelomeningocele and seizures was 8.1 years. We conclude that myelomeningocele patients with seizures have an overall good prognosis with considerable long-term seizure freedom.

Seizure risk factors in shunted hydrocephalic patients

OBJECTIVE

There are controversies about seizure risk factors in shunted hydrocephalic patients which can be due to having merged two different types of seizure (preshunt and postshunt seizures) in previous studies. Also, it is not known whether a considerable change in ventricular size after shunting can be a risk factor of postshunt seizures.

METHODS

150 hydrocephalic patients who underwent shunting from 2006 to 2011 in the Children's Hospital Medical Center in Tehran, Iran, were visited at least 1 year after shunting to assess risk factors of preshunt and postshunt seizures. Ventricular size was assessed by using a radiologic index of bifrontal ratio (BFR).

RESULTS

Preshunt seizures were higher in patients with postinfectious hydrocephalus and intraventricular hemorrhage. Early shunting, history of shunt complications and shunt infection, and a high number of shunt revisions were significant risk factors for developing postshunt seizures. The change in BFR after shunting was not a significant risk factor of postshunt seizures.

CONCLUSION

The difference between risk factors of preshunt seizures and postshunt seizures shows that they are two different types of seizures with different natures. Preshunt seizures are hard to prevent as they are related to the underlying disease of the brain or the etiology of hydrocephalus. However, postshunt seizures are related to the shunt and might be decreased by preventing shunt complications.

Shunts vs endoscopic third ventriculostomy in infants: are there different types and/or rates of complications? A review

INTRODUCTION

The decision-making process when we compare endoscopic third ventriculostomy (ETV) with shunts as surgical options for the treatment of hydrocephalus in infants is conditioned by the incidence of specific and shared complications of the two surgical procedures.

REVIEW

Our literature review shows that the advantages of ETV in terms of complications are almost all related to two factors: (a) the avoidance of a foreign body implantation and (b) the establishment of a 'physiological' cerebrospinal fluid (CSF) circulation. Both these kinds of achievements are particularly important in infants because of the relative high rate of some intraoperative (i.e. abdominal) and late (secondary craniosynostosis, slit-ventricle syndrome) shunt complications in this specific subset of patients. On the other side, the main factor which is claimed against ETV is the relatively high risk of immediate mortality and neurological complications. Clinical manifestations of neurological structure damage seem to be more frequent in infants, probably due to the more relevant effect of parenchymal and vascular damage in this age group; however, both the immediate mortality and neurological damage risk of ETV procedures should be weighted against the long-term mortality and the late neurological damage which is not infrequently described as a consequence of shunt malfunction and proximal shunt revision procedures. Infections are possible in both ETV and extrathecal CSF procedures, especially in infants. However, the incidence of infective complications is significantly lower in case of ETV (1-5% vs 1-20%). Moreover, different from shunting procedures, infections in children with third ventriculostomy have a more benign course, being generally controlled by antibiotic treatment alone.

Myelomeningocele: a Brazilian University Hospital experience

We analyzed 31 children with myelomeningocele born between July 1990 and July 2000. Follow-up median was 24 months (6-68 months). Only 2 mothers had a known etiologic factor (diabetes mellitus). Twelve had the correct prenatal diagnosis. All children were born at term; 23 by cesarean; 13 had rupture of the membrane. Surgical correction had a 4 days median (1 to 44 days). Lumbosacral lesions were the most frequent (46%). Thirty patients were hydrocephalic, shunt was placed in 27. Meningitis was 4 times more frequent in shunted patients. Seven became epileptic (19.4%). Denver II test showed significant delay in gross motor development. Neurogenic bladder was diagnosed in 12 patients. Congenital clubfoot was the main orthopedic malformation (53%). Six infants died. Nowadays, 17 patients are being followed. A multidisciplinary approach probably helps for a better quality of life.

The Chiari II malformation: cause and impact

INTRODUCTION

It is the Chiari II malformation and its effects that determine the quality of life of the individual born with spina bifida.

DISCUSSION

The cause of this malformation has been a source of debate for many years. Understanding the cause enables strategies for the management of problems created by this malformation to be developed. An open neural tube defect allows fluid to escape from the cranial vesicles, altering the intracranial environment and leads to all of the brain changes seen in the Chiari II malformation. Decompression of the intracranial vesicles causes overcrowding, decrease in the size of the third ventricle, and changes in the fetal skull. It also permanently links the intracranial ventricular system to the spinal cord central canal.

[Chiari type II malformation with brain stem paroxystic dysfunction. What can we do?]

The Chiari type II malformation is the main cause of death in children with myelomeningocele, usually due to respiratory dysfunction, and unfortunately there is no effective cure. Episodic symptoms of brain stem dysfunction are frequent. We report a child with Chiari type II malformation and brain stem dysfunction who required tracheotomy and who was fed through a nasogastric tube from the age of 1.5 months. He first presented episodic symptoms at the age of 8 months and died at 9 months due to respiratory dysfunction despite intensive care. We also report our experience in the last 12 years with four patients with Chiari type II malformation and episodic symptoms of brain stem dysfunction. Both patients who required mechanical ventilation died. Neither surgical decompression nor intensive care prevented the fatal outcome, which was unpredictable and inevitable. Prognosis may be more positive in less severe cases, because the two patients that did not require mechanical ventilation show favorable outcome to date.

Epilepsy in children with shunted hydrocephalus

OBJECT

The incidence of epilepsy among children with hydrocephalus and its relation to shunts and their complications, raised intracranial pressure (ICP), and developmental outcome are explored in a retrospective study.

METHODS

The authors studied a series of 802 children with hydrocephalus due to varying causes, who were treated by ventriculoperitoneal shunt placement between 1980 and 1990, with a mean follow-up period of 8 years. Patients who had tumoral hydrocephalus and those whose files lacked significant data were excluded. Data extracted from medical records, including history of the hydrocephalus and history of seizures, if any, were analyzed. Thirty-two percent of the children had epilepsy, the onset of which frequently occurred at approximately the same time that the diagnosis of hydrocephalus was made. The majority of the affected children had severe uncontrolled epilepsy. The incidence of epilepsy was significantly affected by the original cause of the hydrocephalus. The presence of radiological abnormalities was also found to be a significant predictor of epilepsy. Similarly, shunt complications predisposed to epilepsy. Episodes of raised ICP related to hydrocephalus or in association with shunt malfunction may also predispose to epileptic seizures. Furthermore, the presence of a shunt by itself seems able to promote an epileptogenic focus. Finally, epilepsy appears to be an important predictor of poor intellectual outcome in hydrocephalic children with shunts.

CONCLUSIONS

A prospective study is needed to identify clearly and confirm avoidable factors predisposing to seizures in these children so that we can strive to reduce the incidence of these seizures and, subsequently, improve these children's quality of life.

Epilepsy in children with shunted hydrocephalus

The incidence of epilepsy among children with hydrocephalus and its relation to shunts and their complications, raised intracranial pressure (ICP), and developmental outcome are explored in a retrospective study.

The authors studied a series of 802 children with hydrocephalus due to varying causes, who were treated by ventriculoperitoneal shunt placement between 1980 and 1990, with a mean follow-up period of 8 years. Patients who had tumoral hydrocephalus and those whose files lacked significant data were excluded. Data extracted from medical records, including history of the hydrocephalus and history of seizures, if any, were analyzed.

Thirty-two percent of the children had epilepsy, the onset of which frequently occurred at approximately the same time that the diagnosis of hydrocephalus was made. The majority of the affected children had severe uncontrolled epilepsy. The incidence of epilepsy was significantly affected by the original cause of the hydrocephalus. The presence of radiological abnormalities was also found to be a significant predictor of epilepsy. Similarly, shunt complications predisposed to epilepsy. Episodes of raised ICP related to hydrocephalus or in association with shunt malfunction may also predispose to epileptic seizures. Furthermore, the presence of a shunt by itself seems able to promote an epileptogenic focus. Finally, epilepsy appears to be an important predictor of poor intellectual outcome in hydrocephalic children with shunts.

A prospective study is needed to identify clearly and confirm avoidable factors predisposing to seizures in these children so that we can strive to reduce the incidence of these seizures and, subsequently, improve quality of life.

Posterior fossa malformations and epilepsy

The association between posterior fossa malformations and epilepsy is rarely reported in the literature. We describe 54 cases with posterior fossa malformations, according to embryogenesis classification, divided into two groups on the basis of presence or absence of epilepsy. Epilepsy occurred in 22 cases (40.7%) and was not related to the type of posterior fossa malformation or to supratentorial cerebral lesions associated with the malformation. Familial antecedents for epilepsy and/or febrile convulsions influenced the presence of epilepsy in patients with posterior fossa malformations (P < .01). Epilepsy was mainly partial (77.3%); benign partial/generalized epilepsies and febrile convulsions occurred in 27.3% of cases. Seizures disappeared for 2 or more years at the end of follow-up in 36.4% of patients. Good epilepsy prognosis was not related to the age at onset of seizures, familial antecedents for epilepsy and/or febrile convulsions, supratentorial associated lesions, or age of patients at the last observation. Profound mental retardation prevailed in patients with epilepsy (P < .01), as did pathologic electroencephalograms (EEG) (P < .0001), with paroxysmal abnormalities (P < .001) and asymmetry (P < .01). In our 54 cases of posterior fossa malformation, we identified two risk factors for epilepsy: familial antecedents for epilepsy and/or febrile convulsions and the involvement of the cerebellum in the malformation.

Hydrocephalus and epilepsy: an actuarial analysis

OBJECTIVE

To determine the prevalence of epilepsy among patients with hydrocephalus and to identify risk factors.

METHODS

Retrospective chart review at a single institution was conducted. The definition of epilepsy used was long-term administration of antiepileptic drugs (AEDs) for suppression of seizures. Actuarial methodology was used, with initiation of AED therapy as the endpoint of the analysis.

RESULTS

Insertion or revision of cerebrospinal fluid (CSF) shunts was performed on 464 patients at the study institution from 1976 through 1989. At the time of initial CSF shunt insertion, 12% of patients had already been treated with AEDs. After the 2nd year, the hazard rate for initiation of AED treatment was a constant 2% per year, and by 10 years after initial shunt insertion the estimated prevalence of AED treatment had risen to 33%. The cause of the hydrocephalus was a strong determinant of the prevalence of AED treatment, but most of the statistical effect of the cause was already manifest at the time of initial CSF shunt insertion. Age of patient at diagnosis of hydrocephalus, burr hole site, number of CSF shunt operations during follow-up, and history of shunt infection were factors that had no detectable association with AED treatment.

CONCLUSION

Epilepsy is common among patients with hydrocephalus, and the risk of the development of epilepsy continues indefinitely for those patients. The complications of CSF shunt surgery seem to play a relatively minor role in the development of epilepsy in this patient population.

Epilepsy in children with meningomyelocele

The medical records of 89 children followed at a multidisciplinary Meningomyelocele Clinic at the Children's Clinics for Rehabilitative Services were reviewed. Almost all children in southern Arizona with meningomyelocele are followed at this clinic. Eight children (foreign nationals) were excluded because they were not eligible for neurosurgery/neurology services at the clinic. The remaining 81 children have been followed at the clinic from 0.25 to 21 years. Seventeen children (21%; age: 1.3-17 years, mean: 9.1 +/- 4.4 years; follow-up: 1.3-16 years) manifested seizures at some time during their course. All children with seizures had shunted hydrocephalus. Neonatal seizures occurred in 2 children currently not receiving medication. An additional 3 children had an acute symptomatic seizure associated with an intraventricular hemorrhage during ventriculoperitoneal shunt revision, 2 of whom later developed epilepsy. Fourteen children (17.3%) had epilepsy; 12 were taking antiepileptic drugs. Seizures were controlled on medication in 5 children. EEG abnormalities were present in 12 children (focal slowing 4, focal spikes 8, diffuse slowing 3, generalized or bilaterally synchronous spike-wave 4). Most of these children (12/14) had evidence of additional central nervous system (CNS) pathology (i.e., areas of encephalomalacia or past stroke 7, cerebral malformations 2, CNS calcifications 1, and frequent apneic spells/cardiac arrest 2). We conclude that epilepsy occurs in approximately 17% of children with meningomyelocele, and most have other CNS pathology to account for their seizures.