Richard O. Robinson

Architecture of the medial gastrocnemius in children with spastic diplegia

Ultrasound images were obtained of the medial gastrocnemius at different ankle joint positions with the knee extended. Fascicle length and deep fascicle angle were measured in five normally developing adults (mean age 33 years, age range 24 to 36 years) and in five normally developing children (mean age 7.8 years, age range 7 to 11 years), and in seven children with spastic diplegia (mean age 10 years, age range 6 to 13 years). These architectural variables were similar in the groups of normally developing adults and children. Importantly, no statistical difference could be found between the normally developing children and those with diplegia for fascicle length. Deep fascicle angles were reduced significantly in the clinical group at a particular ankle joint angle but not at the resting angles. The difference in deep fascicle angles is explained as a function of resting muscle length and is not attributed any clinical importance. Our results do not explain the structural origin of muscle contracture explicitly. However, they do indicate that most of the fixed shortness in the medial gastrocnemii of ambulant children with spastic diplegia is not due to reduced muscle fascicle length. We suggest that muscle contracture may be better explained in terms of shortness of the aponeuroses of pennate muscles, such as the medial gastrocnemius, through reduced muscle fascicle diameter.

Vagal nerve stimulation in epileptic encephalopathies.

Objective. To study the effect of vagal nerve stimulation (VNS) in children with epileptic encephalopathies. Methods and Materials. All children receiving VNS during a 2-year period at our center were studied prospectively for changes in seizure frequency, electroencephalogram (EEG), adaptive behavior, quality of life, and where appropriate, verbal/nonverbal performance. Assessments were made before and for at least 1 year after implant. Results. Sixteen children were studied. One device was removed because of infection. Of the remaining 15 children, 4 had a >50% reduction and 2 had a >50% increase in seizure frequency at 1 year after implant. Median reduction in seizure frequency was 17%. There was no trend toward improvement of the EEG or adaptive behavior. Quality of life was unchanged in most areas, except in perceived treatment side effects and general behavior that were improved. In 6 children undergoing further assessment, there was a significant improvement in verbal performance; this did not correlate with reduction in seizure frequency. Conclusion. VNS did not significantly improve seizure frequency, severity, adaptive behavior, or the EEG during the first year of treatment for the group as a whole, although 4 children (27%) had a worthwhile reduction in seizure frequency. There were significant improvements in perceived treatment side effects and general behavior.

Diagnosis and management of benign intracranial hypertension

Benign intracranial hypertension (BIH) is a headache syndrome characterised by (1) raised cerebrospinal fluid (CSF) pressure in the absence of an intracranial mass lesion or ventricular dilatation; (2) normal spinal fluid composition; (3) usually normal findings on neurological examination except for papilloedema and an occasional VI nerve palsy; and (4) normal level of consciousness. The appellation “benign” means not fatal. The syndrome can, however, disrupt normal life and cause significant visual failure. It is an uncommon condition in childhood presenting about once or twice a year in a large referral hospital. Early recognition is important as timely intervention may preserve vision and enables the doctor to start the appropriate treatment to control headaches. Children as young as 4 months can be affected; sex distribution is equal.1 2 Which intracranial compartment is primarily responsible for raising CSF pressure in the absence of ventricular dilatation is still unclear. Theories of BIH pathophysiology have been based on neuroradiological studies on patients with BIH (computed tomograms, magnetic resonance imaging (MRI), magnetic resonance diffusion scans, and radioisotope cisternography) and CSF hydrodynamic studies. These include increased venous sinus pressure, decreased spinal fluid absorption, increased spinal fluid secretion, increased blood volume, and brain oedema.3 4 Since the first large report on childhood BIH in 1967, reports subsequently show a changing clinical picture over time in terms of possible aetiology and clinical presentation.5 6Diagnosis is not always simply achieved. BIH can occur in the absence of papilloedema; a “normal resting” CSF pressure does not exclude the diagnosis in the presence of suggestive symptoms and signs.7 8 Review of our cases over the past 10 years confirms the wide clinical spectrum of this condition. Of the 22 cases seen, 15 presented with the classical picture of headaches, papilloedema, and a raised CSF pressure of …

Lamotrigine as an add-on drug in typical absence seizures

Introduction ‐ Lamotrigine is licenced in many countries for use in patients with partial seizures. Evidence suggests that it may also be effective in generalised epilepsies. Material & methods ‐ We analysed retrospectively our patients with idiopathic generalised epilepsy with refractory absences. Results ‐ Fifteen patients with idiopathic generalised epilepsies were identified who had been treated with lamotrigine for 3 months or more. All patients were also treated with sodium valproate. Fourteen patients had active absences. Nine (64%) had a total or virtual cessation of absences and in a further patient they became milder and less frequent. One patient reported an increase in seizures. The effective dose of lamotrigine was 1.6‐3.0 mg/kg/day in children and 25‐50 mg/day in adults. Patients who responded did so after the first or second dose. Lamotrigine was well tolerated. Conclusion ‐ Low‐dose lamotrigine added to sodium valproate appears to be effective in typical absence seizures. A therapeutic interaction of the two drugs seems likely.

Short-term outcome of multilevel surgical intervention in spastic diplegic cerebral palsy compared with the natural history.

Outcome in 24 ambulant children with spastic diplegic cerebral palsy, in whom multilevel surgical intervention was recommended following gait analysis, is reviewed. Twelve children had surgical intervention (treatment group; eight males, four females; mean age 9 years 10 months, SD 3 years 4 months) while the other 12 did not (control group; five males, seven females; mean age 10 years 1 month, SD 2 years 11 months). All children had interval three-dimensional gait analyses (mean time between analyses: control group, 14.1 months; treatment group, 17.9 months). At follow-up the control group (mean age 11 years 9 months) showed a significant increase in minimum hip and knee flexion in stance which was not related to age, the interval between analyses, changes in the passive joint range of motion, nor changes in anthropometric measurements. The treatment group (mean age at follow-up 11 years 3 months) showed a significant improvement in minimum knee flexion and in ankle dorsiflexion in stance. Parents of nine children said their childs walking distance had increased following intervention. Of five children using posterior walkers preoperatively, two continued to use them postoperatively; two were using crutches or sticks and the remaining child walked independently. Two children who walked independently preoperatively used sticks postoperatively for community ambulation. The deterioration seen in the kinematics of the control group suggests that previous outcome studies comparing postoperative gait with preoperative gait have underestimated the immediate effects of surgery. It also raises concerns about the long-term effects of surgical intervention.

Multiple subpial transection in Landau–Kleffner syndrome

We have considered multiple subpial transection (MST) as a treatment option for Landau-Kleffner syndrome (LKS) for the past 6 years. The effect of this technique on language and cognitive ability, behaviour, seizures, and EEG abnormalities is analysed here. Five children (4 males, 1 female; aged 5.5 to 10 years) underwent MST with sufficiently detailed pre- and postoperative data for analysis. Behaviour and seizure frequency improved dramatically after surgery in all children. Improvement in language also occurred in all children, although none improved to an age-appropriate level. All five had electrical status epilepticus in sleep (ESES) before surgery, which was eliminated by the procedure. One child has had an extension of his MST due to the recurrence of ESES and accompanying clinical deterioration with good effect. An attempt is made to set the effect of MST against the natural history of the condition. MST is an important treatment modality in LKS, although the timing of this intervention and its effect on final language outcome remains to be defined.

Psychogenic non-epileptic seizures: management and prognosis

AIM To determine the outcome and identify predictive factors in children with psychogenic non-epileptic seizures (PNES). METHOD The biographies of 35 children with PNES, attending a tertiary paediatric neurology centre, were reviewed. RESULTS Thirty five children attending the department between 1987 and 1997 were evaluated at a mean follow up of 4.6 years. The age range was 6–18 years. Twenty four were girls and 11 were boys. Eleven patients had a diagnosis of epilepsy with PNES, the remainder having PNES alone. Cause fell into four categories: a history of violence, abuse, or neglect; a high level of anxiety; dysfunctional family relationships; and attention seeking or avoidance behaviour. Management in all but five cases involved assessment and follow up by a child psychologist or child psychiatrist. The outcome was encouraging, with 66% of patients becoming PNES free. A further 23% have > 50% reduction in the frequency of PNES. Only two have had no reduction. Outcome was best in the group without epilepsy. CONCLUSION These results suggest that the prognosis of PNES is better in children than in adults, perhaps because causes are more likely to be external to the child, more easily identified, and more amenable to prompt intervention. The importance of good assessment, good communication, and a treatment plan that includes both symptom management and addressing the precipitating and perpetuating factors is emphasised.

Psychotic and severe behavioural reactions with vigabatrin: a review

Behavioural disturbances and psychotic reactions are commoner in patients with epilepsy than in the general population and may be precipitated by the majority of antiepileptic drugs, including the newer ones. These reactions may be more frequent in patients with complex partial seizures, reflecting underlying temporal lobe pathology. A review of the literature on vigabatrin found an incidence of severe abnormal behaviour in controlled trials in adults of 3.4%. In children open studies gave an incidence of around 6%. This may be related to dosage and speed of introduction. Such reactions may be related to changes in seizure control, either unaccustomed good control (forced normalisation) or breakdown in control, implying non‐specific causative mechanisms. Alternatively, any relationship to control may be fortuitous and specific, unknown pharmacological mechanisms may be involved. Appropriate risk reduction measures include slow introduction, limiting the dose to that required for seizure control, slow withdrawal and increased vigilance in those on polytherapy or with psychiatric histories. Such advice is pertinent to all antiepileptic medications. Additionally, vigabatrin is probably contraindicated in idiopathic generalised epilepsies. Behavioural reactions are uncommon with vigabatrin, and have not been shown to be greater with it than with other antiepileptic agents. Therefore, it maybe inappropriate to withhold the drug from those who may benefit from it.

Inappropriate use of carbamazepine and vigabatrin in typical absence seizures

Carbamazepine and vigabatrin are contraindicated in typical absence seizures. Of 18 consecutive referrals of children with resistant typical absences only, eight were erroneously treated with carbamazepine either as monotherapy or as an add‐on. Vigabatrin was also used in the treatment of two children. Frequency of absences increased in four children treated with carbamazepine and two of these developed myoclonic jerks, which resolved on withdrawal of carbamazepine. Absences were aggravated in both cases where vigabatrin was added on to concurrent treatment. Optimal control of the absences was achieved with sodium valproate, lamotrigine, or ethosuximide alone or in combination.

Sleep electroencephalograms in young children with autism with and without regression

A link has been postulated between regressive autism and the spectrum of epileptic encephalopathic conditions including Landau-Kleffner syndrome with the suggestion that subclinical epilepsy may be causative of regression in autism. This is an audit of investigation using sleep electroencephalograms (EEG) in 64 children (56 males, 8 females; mean age 35.6mo [SD 8.2mo]; range 18-48mo) with autism. No child had a history suggestive of epilepsy. Thirty-nine of the children presented with regressive autism and 20 of the participants showed some epileptiform abnormality. There was no significant difference in epileptiform activities in those who showed regression compared with those who did not. No child showed electrical status epilepticus with continuous spike-wave discharges in slow sleep. There was no evidence that these cases of autism with and without regression were associated with epileptic encephalopathy. The significance of epileptiform discharges without epilepsy in the sleep EEG in autism remains unknown.