Infantile spasms--long term results of ACTH treatment

Developmental outcomes of cryptogenic West syndrome

OBJECTIVE

To elucidate factors affecting the developmental outcome of cryptogenic West syndrome.

STUDY DESIGN

Medical records of 32 patients, who were followed-up regularly for more than 1 year, were reviewed for clinical features: treatment lag, electroencephalography findings, and seizure evolution. Those features were compared between the normal outcome group (12 patients) and the delayed outcome group (20 patients). The outcomes were determined at the average age of 8.6 +/- 4.7 years.

RESULTS

The duration from onset to any treatment of the delayed group was longer than that of the normal group (P < .05). Evolution of electroencephalographic findings showed that paroxysmal discharges reappeared in frontal regions more frequently in the delayed group than in the normal group (P < .05). In the delayed group, other types of seizure except for spasms occurred more commonly than in the normal group (P < .05). More patients of the delayed group evolved to focal epilepsy than those of the normal group (P < .05).

CONCLUSIONS

Shorter treatment lag might be associated with a favorable outcome in cryptogenic West syndrome. Reappearance of paroxysmal discharges in the frontal regions and evolution to other types of seizure may be associated with undetectable lesions in the frontal regions.

Short-duration ACTH therapy for cryptogenic West syndrome with better outcome

In this study, seven patients with cryptogenic West syndrome were subjected to short-duration adrenocorticotrophic hormone (ACTH) therapy. ACTH was administered daily for 7 to 12 days (mean 10 days), and then was withdrawn. Daily single dose was 0.022 to 0.027 mg/kg/day (0.024 mg/kg/day, 0.96 IU/kg), total dose was 0.17 to 0.28 mg/kg (0.23 mg/kg, 9.0 IU/kg), and treatment lag was 12 to 105 days (median 14 days). ACTH therapy controlled tonic spasms with no serious side effects in all patients, but two patients still had electroencephalographic abnormality. The intelligence quotients or developmental quotients of six patients with short treatment lag were 79 to 110 at the age of 2 to 6 years; only one patient with long treatment lag had a developmental quotient of 60. This new short-duration ACTH therapy could yield better cognitive outcomes for cryptogenic West syndrome.

ACTH therapy for Taiwanese children with West syndrome -- efficacy and impact on long-term prognosis

To study the efficacy of adrenocorticotrophic hormone (ACTH) in treating Taiwanese children with West syndrome (WS) and the impact on long-term prognosis, 66 patients with WS (54 symptomatic and 12 cryptogenic) were collected from 1987 to 1998 in a medical center in Taiwan. A total of 53 patients were enrolled in this study and treated with ACTH at the dosage of 2.5IU/kg daily for 2 weeks with gradual tapering in subsequent 6 weeks. Immediate responses, side effects of ACTH and long-term outcomes of the patients including seizure and developmental status were evaluated during the average follow-up period of 35.6 months. The spasm-free percentage after one or two courses of ACTH treatment was 77.4%. Nine (17%) patients encountered severe side effects such as major infections, which prompted us to stop ACTH. At the end of follow-up, 22 (41.5%) patients had intractable seizures but 25 (47.2%) patients remained seizure free with or without anticonvulsants. The ACTH-responders had a better chance of remaining seizure free (P<0.05). Regarding the long-term developmental outcome, 12 (22.6%) patients had normal or borderline development; two thirds of them belonged to the crytpogenic group. Six (11.3%) patients expired and 24 (45.3%) were severely retarded; all but one of them belonged to the symptomatic group. The prognosis of WS heavily relies on whether a patient is cryptogenic or symptomatic (P<0.001). Good response to therapy or short treatment lag did not favorably affect the developmental outcomes of the symptomatic cases. We conclude that the long-term outcomes of WS in Taiwan were generally poor despite of treatment. Only cryptogenic patients had favorable prognosis. For symptomatic patients, ACTH therapy may be used to control the spasms and decrease the incidence of subsequent epilepsy, but it will not improve developmental outcome. Considering a high percentage of severe side effects in our study, a lower dosage of ACTH with adequate therapeutic efficacy but less side effects should be considered for treating Taiwanese children with WS.

Long-term cognitive outcomes of a cohort of children with cryptogenic infantile spasms treated with high-dose adrenocorticotropic hormone

PURPOSE

To evaluate the outcome of children with cryptogenic infantile spasms treated with high-dose synthetic adrenocorticotropic hormone (ACTH) and the relation between early treatment, within 1 month of onset, and outcome.

METHODS

We assessed the long-term cognitive and seizure outcomes of 37 patients with cryptogenic infantile spasms (onset, age 3 to 9 months) receiving standardized treatment regimen of high-dose tetracosactide depot, 1 mg IM every 48 h for 2 weeks, with a subsequent 8- to 10-week slow taper and followed by oral prednisone, 10 mg/day for a month, with a subsequent slow taper for 5 months or until the infant reached the age of 1 year, whichever came later. Development was assessed before treatment. Seizure outcomes were followed up prospectively. Cognitive outcomes were determined after 6 to 21 years and analyzed in relation to treatment lag and pretreatment regression.

RESULTS

Twenty-two infants were treated within 1 month of onset of infantile spasms, and 15 after 1 to 6.5 months. Normal cognitive outcome was found in all 22 (100%) patients of the early-treatment group, and in 40% of the late-treatment group. Normal cognitive outcome was found in all 25 (100%) patients who had no or only mild mental deterioration at presentation, including four in the late-treatment group but in only three of the 12 patients who had had marked or severe deterioration before treatment.

CONCLUSIONS

Early treatment of cryptogenic infantile spasms with a high-dose ACTH protocol is associated with favorable long-term cognitive outcomes. Once major developmental regression lasts for a month or more, the prognosis for normal cognitive outcome is poor. Further studies are needed on the optimal treatment regimen for this disorder.

Infantile spasms in Down syndrome--effects of delayed anticonvulsive treatment

To investigate the impact of treatment lag in infantile spasms (IS) on treatment response, occurrence of later epilepsy, and long-term cognition and behavior in patients with one single etiological entity, we examined 18 patients with Down syndrome (DS) and earlier IS retrospectively (follow-up period of 32-180 months with a mean of 85.1 months), and determined their history and present condition, in terms of previously mentioned items. There was a statistically significant correlation between treatment lag and lag to cessation of spasms (R=0.55, P=0.02), developmental quotient (DQ) (R=-0.75, P=0.003), and score of autistic features (AF) (R=0.57, P=0.04). Moreover we found that the later the response to treatment of IS, the lower was the DQ (R=-0.86, P=0.001) and the higher was the score of autistic features (R=0.5, P=0.06). A long duration of spasms also determined a low DQ (R=-0.93, P<0.0001) and a high score of autistic features (R=0.66, P<0.01). All patients with persistent epilepsy (n=5) had had a treatment lag of over 2 months. Conversely, for all children treated within 2 months (n=8) spasms ceased within 3 months of treatment and none of them had later epilepsy. This group of patients with a treatment lag of less than 2 months had earlier treatment response (P=0.002), higher DQ (P=0.004) and lower score of autistic features (P=0.006). The data stress the importance of a short treatment lag in view of mental development and prevention of later epilepsy and autistic features, and raise the question of antiepileptogenic effect in this specific condition.

Treatment of infantile spasms: an evidence-based approach

The object of this work was to subject established empirical medical treatment regimens for infantile spasms to evidence-based medicine analysis in order to determine the current best practice for the treatment of infantile spasms in children. Clinical studies of infantile spasms reported during the presteroid era were reviewed critically to define the natural history of the disorder. Treatment trials of infantile spasms conducted since 1958 were rigorously assessed using MEDLINE and hand searches of the English language literature. Inclusion criteria were the documented presence of infantile spasms and hypsarrhythmia. Outcome measures included complete cessation of spasms, resolution of hypsarrhythmia, relapse rate, developmental outcome, the presence or absence of epilepsy, and/or an epileptiform electroencephalogram. Evidence was defined as class I, II, or III, and practice parameter recommendations were made using the framework devised by the American Academy of Neurology. Class I and III evidence support a standard of practice recommendation for the use of vigabatrin in the treatment of infantile spasms in children with tuberous sclerosis. Class I and III evidence support a guidelines recommendation for the use of either ACTH or vigabatrin in infantile spasms in nontuberous sclerosis patients. There is no strong evidence that successful treatment of infantile spasms improves the long-term prognosis for cognitive outcome or decreases the incidence of later epilepsy. A practice option recommendation for the use of oral corticosteroids in the treatment of infantile spasms is supported by limited and inconclusive class I and III data. Based on the evidence, no recommendation can be made for the use of pyridoxine, benzodiazepines, or the newer antiepileptic drugs in the treatment of infantile spasms. ACTH and vigabatrin are the most effective agents in the treatment of infantile spasms, but concerns remain about the risk/benefit profiles of these drugs.

Infantile spasms in Down syndrome: good response to a short course of vigabatrin

PURPOSE

To evaluate the efficacy of vigabatrin (VGB) in the treatment of infantile spasms (ISs) associated with Down syndrome (DS) and to assess the feasibility of early discontinuation to reduce the possible retinal toxicity.

METHODS

Five children with ISs with DS were treated with vigabatrin as first-line monotherapy in an open prospective study. The short-term response was evaluated, and VGB was continued in responders. The treatment was stopped after 6 months in children who were still spasm free.

RESULTS

Four children of five became spasm free with VGB, three of them responding within 1 week. This response was maintained during the 6 months of VGB treatment. After VGB discontinuation, and with a follow-up ranging from 2 to 4 years, none of the responders experienced spasm recurrence or other types of seizures.

CONCLUSIONS

This study confirms the efficacy of VGB in ISs associated with DS. Moreover, it shows that the duration of VGB treatment can be reduced to 6 months without relapse of ISs. This short treatment might reduce the risk of developing visual field constriction.

Extremely low-dose ACTH therapy for West syndrome in Japan

Adrenocorticotropic hormone (ACTH) therapy is a widely used and effective treatment for West syndrome. However, serious adverse effects can occur during or shortly after ACTH therapy. Synthetic ACTH has been reported to cause more adverse effects than natural ACTH. Currently, most Japanese pediatric neurologists try other non-hormonal treatments before using ACTH therapy, but even then, they use extremely low dosages of synthetic ACTH. The extremely low-dose synthetic ACTH therapy currently used in Japan is as effective for treatment of West syndrome as the higher doses reported in previous studies from Japan and Western countries. The dosage and duration of synthetic ACTH therapy should be as low as possible to avoid serious adverse effects. Close monitoring of the adverse effects, especially subdural hematoma, is necessary even when extremely low dosages of ACTH are administered.

Risk factors associated with infantile spasms: a hospital-based case-control study in Taiwan

We investigated the risk factors associated with infantile spasms (IS) by a hospital-based case-control study in Taiwan. Twenty-five patients with IS were recruited from one medical center (National Taiwan University Hospital) between 1990 and 1997. Based on a close-structured questionnaire, standardized interviews were carried out to obtain information on risk factors associated with IS. Two comparison groups are used, including a total of 106 subjects in the Disease Control group, and 139 subjects in the Normal Control group. Unconditional logistic regression is used to calculate odds ratios (OR) and 95% confidence interval (CI). Univariate analysis revealed gestational age, congenital cerebral anomalies, tuberous sclerosis (TS), asphyxia, febrile seizure, and developmental delay (before onset of spasm) were at increased risk of IS. After adjustment of multiple risk factors through unconditional logistic regression, significant risk factors for IS include congenital cerebral anomalies, TS, asphyxia, postterm, and developmental delay were highly associated with IS. The risk factors of IS may closely relate to underlying neurological abnormalities. Our results are consistent with the previous findings.

Epilepsy in early development: the lesson from surgery for early intractable seizures

This report examines the impact on development and the problems involved in assessing development in very young children with early-onset intractable seizures, particularly infantile spasms. A review of studies on medically and surgically treated children with infantile spasms underscores the relationship between seizure control and developmental outcome. About 50% of children with markedly intractable infantile spasms attained seizure control and significant improvement in the use of nonverbal communication, a developmental measure that has been used in other populations of developmentally delayed children. With the exception of duration of illness, clinical measures of age of onset of infantile spasms, type of surgery, and side of surgery did not appear to be related to the postoperative change in nonverbal communication. The neuropathology findings of surgically treated children with infantile spasms suggest that the underlying pathology occurs early in brain development. In conclusion, the cumulative effect of uncontrolled seizures and the underlying pathology might impact the early development of children with intractable infantile spasms.

Medical treatment of West syndrome in Japan

Although corticotropin (ACTH) is still the most effective drug for the treatment of West syndrome, a variety of other treatment modalities have been tried because of corticotropin's frequent and sometimes serious side effects. A recent survey on the treatment of this devastating disorder by Japanese child neurologists disclosed different therapeutic approaches from those taken by American or European child neurologists. Most Japanese child neurologists use vitamin B6 as the first agent and corticotropin as the third or second drug. Moreover, the dosage of corticotropin used by them is considerably smaller. Therefore, the current status of medical treatment of West syndrome is reviewed, especially comparing Japan with other countries.

Treatment of infantile spasms

OBJECTIVE

To summarize and evaluate the literature regarding the clinical features, epidemiology, etiology, pathophysiology, and treatment of infantile spasms.

DATA SOURCES

A literature search of articles from January 1966 to July 1993 using MEDLINE, EM-Base, and Current Concepts/Life Sciences, as well as bibliographies of relevant articles.

STUDY SELECTION

All identified original and review publications regarding the clinical features, epidemiology, etiology, pathophysiology, and treatment of infantile spasms were reviewed. Emphasis was placed on original studies published since 1975.

DATA EXTRACTION

Data from published research were extracted and evaluated according to study design, sample size, dosing regimen, outcome measures, and treatment efficacy and safety.

DATA SYNTHESIS

Infantile spasms constitute a rare epileptic syndrome with a poor long-term prognosis for normal intellectual development. The spasms are characterized by a brief symmetric contraction of the muscles of the neck, trunk, and/or extremities, often occurring in a series of 2 to more than 100 spasms during a single episode. The disorder is age-specific, with the peak onset of symptoms occurring between 2 and 8 months of age. Spasms of no identifiable cause in infants with normal development prior to the onset of infantile spasms are classified as cryptogenic or idiopathic, whereas those with an identifiable cause are classified as symptomatic. Long-term prognosis is best in cryptogenic cases, with 30-70 percent attaining normal intellect compared with 5-19 percent in symptomatic cases. The etiology and pathophysiology are not well understood. Recent theory postulates that infantile spasms may be caused by an excess of corticotropin-releasing hormone activity during infancy. The suspected association between the whole-cell pertussis vaccine and infantile spasms is coincidental. Few well-designed, prospective, controlled clinical trials for the treatment of infantile spasms have been conducted.

CONCLUSIONS

Standard anticonvulsants such as phenytoin, the barbiturates, carbamazepine, and the succinimides have been ineffective. Of the anticonvulsants, only the benzodiazepines, valproic acid, and vigabatrin have shown efficacy in reducing spasm frequency and severity. Hormonal therapy with adrenocorticotropic hormone (ACTH) and/or prednisone has been the most frequently studied treatment modality and appears to be the most effective. Hormonal therapy achieves complete spasm control in 50-75 percent of infants within four weeks of initiation. Opinions differ regarding the relative efficacy between ACTH and prednisone, the need for early initiation of hormonal treatment, and the benefits of high dosages of ACTH (> 40 units/d). No treatment has been shown conclusively to improve the long-term intellectual development of these infants. Neurosurgery may be the treatment of choice in select cases when a localized central nervous system abnormality can be demonstrated. Well-designed, blind, prospective clinical trials are needed to answer definitively many lingering questions regarding the treatment of infantile spasms.

Treatment of infantile spasms: medical or surgical?

Although infantile spasms were initially described in 1841, remarkably little progress has been made in understanding the pathophysiology of this "peculiar form of infantile convulsions." Consequently, our ability to treat infantile spasms is limited. Infantile spasms are classified as a "generalized" seizure disorder in the international classification system, which suggests that the underlying brain abnormality causing the seizures also must be diffuse or generalized. As the classification suggests, there are many diffuse, or multifocal, brain disorders related to infantile spasms, e.g., inborn errors of metabolism, hypoxic-ischemic brain injury, and developmental brain defects such as tuberous sclerosis or Aicardi's syndrome. On the other hand, infantile spasms have been reported in which a localized brain abnormality was present, e.g., tumor, stroke, and trauma. On rare occasions, removal of a tumor has resulted in cessation of the generalized infantile spasms. This finding suggests that focal cortical abnormalities can cause infantile spasms and that removing the abnormality can stop the seizures. At University of California, Los Angeles, the Pediatric Epilepsy Surgery Program has developed new approaches to the treatment of infantile spasms. The principal underlying concepts are (a) children with medically refractory infantile spasms may have an area of cortical defect (called the zone of cortical abnormality) that causes the seizures and (b) infantile spasms are usually generalized seizures. Thus, the goal of the surgical assessment is not the identification of the focus of seizure onset but rather the identification of the zone of cortical abnormality.

Non-verbal communication skills of surgically treated children with infantile spasms

The authors present preliminary findings on the effects of surgery on the development of early non-verbal social communication skills in eight children with intractable infantile spasms. After a mean follow-up of 15.2 months, there was no statistically significant change in the post-surgical non-verbal communication behavior of these children beyond the expected developmental change. Implications of these findings for the developmental impairment associated with infantile spasms are discussed.

Prospective study of outcome of infants with infantile spasms treated during controlled studies of ACTH and prednisone

We report the long-term outcome of 64 infants with infantile spasms, followed prospectively, using controlled treatment schedules and objective techniques (24-hour EEG and video monitoring) to determine response. Average age at follow-up was 50 months. Of the 64 infants, three (5%) died; of the others, 41 (67%) had developmental retardation of 50% or more or an IQ of 50 or less. Eight patients (13%) composed our cryptogenic study group and were so classified on the basis of normal CT scan, normal development prior to onset of infantile spasms, and undetermined cause. These patients had the better outcome; 38% had normal development or were only mildly retarded. Both the responders and nonresponders in our symptomatic group had a poor outcome; only 5% had normal development or mild impairment. Outcome was not significantly influenced by short versus long treatment lag or by response to therapy. Other types of seizures occurred in 34 patients (53%). In summary, the overall prognosis for long-term outcome in these 64 patients with infantile spasms was poor.

Preliminary report of a multi-center study on the West syndrome

During a 12-month period, 54 infants with the West syndrome (10 idiopathic, 44 symptomatic) referred to 10 major children's hospitals for initial treatment were evaluated to obtain comprehensive data on clinical findings and current treatment modalities. Prominent features included prevalence of prenatal and perinatal etiologies, severe neurological deficits and disturbed psychomotor development as well as patient-specific spectrum of seizure manifestations. Characteristic behavioural abnormalities before onset of spasms are an early indicator for the West syndrome. Therapeutic management varied considerably. Response to ACTH/steroid regiments was more favourable than to non-ACTH/steroid regimens. The most frequent serious adverse reactions during the initial treatment period were arterial hypertension and infections. Improved therapeutic strategies based on detailed initial patient assessment and systematic monitoring of beneficial effects and adverse reactions are necessary for future trials.

Identification of infants at risk for infantile spasms by neonatal polygraphy

Reevaluation of neonatal EEGs and polygraphic tracings of 40 infants with infantile spasms and/or hypsarrhythmia resulted in the constitution of a compound score for the identification of infants at risk for infantile spasms by neonatal EEG. The score comprises 8 distinct items: 2 concern behavioral characteristics, 6 abnormality of EEG background activity and paroxysmal events. A tracing registered at conceptional age 36 to 44 weeks (eventually up to 50 weeks) presenting at least 4 of these 8 items is scored positive for the risk of evolving hypsarrhythmia. In a prospective study the polygraphic tracings of 941 newborn infants were evaluated for risk: 18 infants suffering from perinatal distress and 7 newborns with malformations of the brain were scored positive and all 25 developed infantile spasms and/or hypsarrhythmia. One infant with later infantile spasms was missed by the scoring system. None of the remaining infants scored negative manifested infantile spasms. Thus, correct positive prognostication was 100% and false negative 0.1%. By conventional EEG 5 out of 8 patients with infantile spasms were correctly predicted. The high validity of the risk-score based on polygraphic tracing between conceptional age 36 to 44 weeks may allow pre-onset treatment preventing secondary mental deterioration due to hypsarrhythmia and infantile spasms.

The prognostic value of EEG patterns in epilepsies with infantile spasms

By scoring EEG patterns (hypsarrhythmia = 10, absence of sleeping patterns = 10, focal epileptic discharge = 5, general-treatment or in whom infantile spasms never disappeared even during ACTH. A low voltage EEG did not have any ending ACTH therapy free of seizures showed lower scores compared to those infants relapsing after the end of ACTH treatment or in whom infantile spasms never disappeared even during ACTH. A low voltage EED did not have any prognostic significance. Using EEG scores it might be possible to separate non-responders and responders after 3 weeks of ACTH therapy, thus shortening ACTH treatment in non-responding infants.