West syndrome and other infantile epileptic encephalopathies--Indian hospital experience.

Children with infantile epileptic encephalopathies comprising 3.5% of the Pediatric Neurology Clinic registrations in a tertiary care hospital were retrospectively analyzed. Data were retrieved from case records and analyzed for seizure semiology, prenatal and perinatal insults, developmental status and relevant investigations. The various therapeutic modalities and their influence on spasm frequency, long-term development and final seizure status were compared. The two primary outcome variables analyzed included final seizure status and developmental outcome. Of the 94 infantile epileptic encephalopathies, West syndrome was the commonest (55.3%), of which two thirds were symptomatic. Etiological factors were prenatal in 66.6% and perinatal in 33.3%. The initial response to ACTH was good in 54.5% with subsequent relapse in 27.8% and for prednisolone was 52.9 and 44.4%, respectively, compared to 25.3% spasms control with conventional antiepileptic drugs. Disease category of infantile epileptic encephalopathies evolved in 4, i.e. early myoclonic encephalopathy to West syndrome 1, early infantile epileptic encephalopathy to West syndrome 1, West syndrome to Lennox-Gastaut syndrome 2. Psychomotor retardation was seen in 88.2%, with 16.1% having normal development at onset of spasms. Microcephaly was associated with delayed development but did not influence final seizure outcome. Final seizure outcome was poor in children with delayed development at onset (adjusted odds ratio [OR]=4), delay in diagnosis >12 months (OR=2.27) and in children with Lennox-Gastaut syndrome (OR=4.75). ACTH/prednisolone and antiepileptic treatment versus antiepileptics alone showed a good final seizure response in 36.6% versus 20%. Development on follow up was delayed in children with initial psychomotor retardation (OR=23.4) and abnormal electroencephalogram (OR=7.46). Perinatal factors constituted one third of symptomatic West syndrome. The use of ACTH/corticosteroids resulted in good initial spasm control though final seizure outcome and development were unaffected. Prednisolone had similar response to ACTH in spasm control but higher subsequent relapse rate. Vigabatrin was useful though often unaffordable. The identification of a neurometabolic etiology, though uncommon, has significant therapy implications. Delay in diagnosis was common and negatively influenced final seizure outcome.     

Infantile spasms and Lennox-Gastaut syndrome

Infantile spasms and Lennox-Gastaut syndrome are rare but are important to child neurologists because of the intractable nature of the seizures and the serious neurologic comorbidities. New antiepileptic drugs offer more alternatives for treating both infantile spasms and Lennox-Gastaut syndrome. Selected children with infantile spasms are candidates for epilepsy surgery. Vagus nerve stimulation, corpus callosotomy, and the ketogenic diet are all options for selected children with Lennox-Gastaut syndrome. The epidemiology, clinical manifestations of the seizures, electroencephalographic characteristics, prognosis, and treatment options are reviewed for infantile spasms and Lennox-Gastaut syndrome. Additional therapies are needed for both infantile spasms and Lennox-Gastaut syndrome as many children fail to achieve adequate seizure control in spite of newer treatments.     

Thyrotropin-releasing hormone: role in the treatment of West syndrome and related epileptic encephalopathies.

Thyrotropin-releasing hormone (TRH) has been successfully used for treating children with neurologic disorders including epilepsy. The effectiveness of TRH and a TRH analog has been reported in West syndrome, Lennox-Gastaut syndrome, and early infantile epileptic encephalopathy that were intractable to anticonvulsants and adrenocorticotrophic hormone (ACTH). However, the peptide has not been widely studied as a treatment of intractable epilepsy outside Japan. TRH is safe in children and effective in some cases of West syndrome and Lennox-Gastaut syndrome. TRH is considered as a possible new strategy for treating West syndrome and Lennox-Gastaut syndrome prior to ACTH therapy, especially for the patient with an infection, immunosuppression, or severe organic lesions in the brain. The mechanisms of its antiepileptic action may differ from those of other antiepileptic drugs. One possibility is that TRH may act as an antiepileptic through a kynurenine mechanism, considering that kynurenic acid acts as an antagonist on the N-methyl-D-aspartate receptor complex.     

Plasma amino acids in childhood epileptic encephalopathies

Abnormalities in plasma amino acid levels have been noted in patients with various epilepsies, and sometimes also in their first degree relatives. We sought to study plasma amino acid levels in children with epileptic encephalopathies and their parents, relating findings to the pattern of cortical glucose metabolism as determined by 18fluorodeoxyglucose (FDG) positron emission tomography (PET). Twenty-eight children with cryptogenic epileptic encephalopathies were studied prospectively. Cortical glucose metabolism was evaluated by FDG PET with combined visual and semiquantitative analysis used to detect focal cortical defects. The plasma concentration of 21 amino acids in the children and their parents was measured by ion exchange chromatography and compared with control values using non-parametric statistical methods. Multivariate analysis was used to assess antiepileptic drug effects. Children were classified as: Lennox-Gastaut syndrome following infantile spasms (six patients); de-novo Lennox-Gastaut syndrome (eight); severe myoclonic epilepsy in infancy (eight) and myoclonic-astatic epilepsy (two). Four patients remained unclassified. Fourteen patients had focal/multifocal abnormalities on PET scans. The plasma level of aspartate was significantly lower in both the children with epileptic encephalopathies and in their parents (P < 0.005). The lowered aspartate levels could not be accounted for by the antiepileptic drug medication taken by the children. Further analysis showed the lowered aspartate levels to be confined to children and their parents who lacked focal PET abnormalities. These findings suggest a possible genetic abnormality in the aspartate neurotransmitter systems in the pathogenesis of seizures in the childhood epileptic encephalopathies.     

A retrospective study on aetiology based outcome of infantile spasms

PurposeThe goal of this retrospective study is to review the causes of infantile spasms and to correlate aetiology with outcome.MethodsAll children diagnosed with infantile spasms between 1990 and 2003 at our institution were included. Charts were reviewed for the presence or absence of a defined aetiology/association, response to treatment, long-term epileptic and cognitive outcome.Results80 out of 95 children are included in this review. 50 children (63%) had symptomatic spasms with disorders of cortical development being the most frequent cause followed by neonatal injury and tuberous sclerosis. Symptomatic children with developmental brain lesions responded at a rate of 54% to vigabatrin versus 62% for ACTH/prednisone, while other symptomatic aetiologies 83% responded to vigabatrin versus 63% for ACTH/prednisone. Cryptogenic spasms responded at a similar rate to both drugs. Other than children with cryptogenic spasms, very few went on to develop normally. Our results are however biased by on average more than 30 days of delay to diagnosis. None of our children developed Lennox-Gastaut syndrome but a number developed severe epilepsy with multifocal spikes.DiscussionThe aetiology and prognosis of infantile spasms is evolving. To improve outcome, we need to reduce the delay to diagnosis and develop prospective double-blind randomized clinical trials looking at not only the epileptic outcome but also cognitive outcome of these children.     

Seizure frequency and characteristics in children with Down syndrome

Seizures have not historically been considered a major component of Down syndrome. We examined the prevalence of epileptic seizures in 350 children and adolescents with Down syndrome evaluated at a regional center between 1985 and 1997. Results showed that 28 patients (8%) had epileptic seizures: 13 (47%) partial seizures; 9 (32%) infantile spasms, and 6 (21%) generalized tonic-clonic seizures. In the infantile spasm group, there was no relationship between the initial electroencephalogram (EEG) pattern and response to treatment or long-term seizure control, or between type of pharmacologic treatment (valproic acid, adrenocorticotropic hormone or both) and clinical remission, EEG normalization or long-term seizure control. Neurodevelopmental outcome was poor despite good seizure control in the infantile spasm group. This regional study reinforces the relative association of seizures and Down syndrome. A prospective study including a national/international registry with emphasis on developmental assessment and long-term follow up is warranted.     

Head growth in infants with infantile spasms may be temporarily reduced

Epileptic activity, as a component of epileptic encephalopathies, can interfere with brain growth and development. Infantile spasms as a syndrome represent such epileptic activity during the period of spasms and hypsarrhythmia. The rate of head growth in infants with infantile spasms during the period of spasms has not been studied previously. A retrospective study of head growth in 38 infants with infantile spasms and no other cause of abnormal head growth is presented. Mental outcome was assessed at follow-up. The mean head circumference of infants with infantile spasms was not significantly smaller than in the normal population, but the proportion of head circumference below the tenth percentile in the infantile spasms group was higher (27%). Head circumference below the tenth percentile in the fourth and fifth month after the onset of infantile spasms was significantly associated with later mental retardation (P = 0.004). There was no correlation with specific treatment of infantile spasms. Transiently diminished head growth in infants with infantile spasms coincides temporally with the onset of infantile spasms and "catches up" during remission of infantile spasms in favorable cases. This pattern can reflect the negative influence of epileptic activity on brain growth during the sensitive period. Head circumference can provide a reliable predictive value of mental outcome in children with infantile spasms.     

Long-term outcome of developmental and epileptic encephalopathies

Developmental and epileptic encephalopathies are conditions where there is developmental impairment related to both the underlying etiology independent of epileptiform activity and the epileptic encephalopathy. Usually they have multiple etiologies. Therefore, long-term outcome is related to both etiology-related factors and epilepsy-related factors–age at onset of epilepsy, type(s) of seizure(s), type of electroencephalographic abnormalities, duration of the epileptic disorder. This paper focuses on long-term outcome of six developmental and epileptic encephalopathies with onset from the neonatal period to childhood: early epileptic encephalopathy with suppression bursts, West syndrome, Dravet syndrome, Lennox-Gastaut syndrome, epilepsy with myoclonic atonic seizures and epileptic encephalopathy with continuous spike and waves during slow-wave sleep including Landau-Kleffner syndrome. For each syndrome, definition, main etiologies if multiple, and long-term outcome are discussed.     

Therapeutic efficacy of ACTH in symptomatic infantile spasms with hypsarrhythmia

The records of twenty-six infants with both symptomatic infantile spasms and classic hypsarrhythmia were reviewed to determine the efficacy of various ACTH dosages and time of initiation of therapy. Mean age of infantile spasm onset was 6.4 months. Most patients (13) had sustained perinatal hypoxic-ischemic insults. Seventeen patients (65%) had complete cessation of spasms. Between these responders and the 9 nonresponders there was no difference in duration of spasms prior to treatment (2.6 and 2.0 months) or mean ACTH dose (87.4 and 84.5 U/m², respectively). Infants treated with high-dose ACTH (> 100 U/m²) did not have an improved response rate. The most favorable outcomes were associated with spasm onset at > 8 months of age (all of whom were responders, regardless of dose) or when treatment was started within 1 month of onset of infantile spasms with > 80 U/m² ACTH (88% responders). Infants treated more than 2 months after onset often did not respond (57%) regardless of dose. Nonresponders with spasm onset at < 4 months of age had the worst prognoses; all had poorly controlled seizures and regressed developmentally. Although all infants in the study were neurologically abnormal, development either improved or did not deteriorate in most responder infants following spasm resolution and one-half remained seizure free. Nonresponder infants continued to have infantile spasms or other seizure types. These data suggest that ACTH is valuable in the treatment of significantly impaired infants with symptomatic infantile spasms, but the most important determinants of outcome may be age of onset and rapidity of treatment rather than dosage.     

A Pilot Study of Topiramate in the Treatment of Infantile Spasms

Summary: Purpose : West syndrome is a rare epileptic syndrome associated with infantile spasms, a specific abnormal electroencephalographic pattern (termed hypsarrhythmia). and mental retardation. Management of this disorder is difficult because current treatment regimens, including many anticonvulsants and hormones, are often ineffective. Topiramate (TPM) is a new antiepileptic drug that may be effective in pediatric epilepsies. We conducted a pilot study to test the effects of rapid TPM dosing in patients with refractory infantile spasms.
Methods: Eleven children with refractory infantile spasms were given an initial dose of 25 mg TPM per day in addition to their current therapy. Dosage was increased by 25 mg every 2–3 days until spasms were controlled, the maximal tolerated dose was reached, or the maximal dose of 24 mg/kg/day was achieved. Efficacy was primarily assessed by video EEG and secondarily by parental count of spasm frequency.
Results: Five (45%) subjects became spasm free during the study, with absence of infantile spasms and hypsarrhythmia (either classic or modified) proven by video EEG. Nine subjects, including the five spasm free, achieved a spasm reduction of 250%. Spasm frequency decreased from 25.6 f 19.3 to 6.9 r 5.9 spasmdday. Sixty-four percent of the subjects were able to achieve TPM monotherapy.
Conclusions: Results in this cohort of 11 patients with refractory disease show TPM to be a promising new agent for the treatment of infantile spasms.     

Infantile spasms in remission may reemerge as intractable epileptic spasms

BACKGROUND: West syndrome consists of infantile spasms with hypsarrhythmia and is perceived as a disorder of infants. METHODS: We describe 10 patients with West syndrome with spasms that remitted, started again, and persisted (followed up for 8-25 years). RESULTS: In all, West syndrome developed at younger than 17 months (five cryptogenic, six symptomatic). With initial treatment, spasms completely stopped for 4.5 months to 6 years, when epileptic spasms returned. Recurrent spasms were typical with brief arm extension, eye elevation, and head drop without falling. Spasms lasted 2-6 s in rhythmic strings over 20- to 60-min periods and occurred daily throughout follow-up. Persistent spasms were particularly troublesome, because of incontinence in one and postictal confusion in several. During the string of spasms, most refused to interact, and several would wander off. Up to 15 antiepileptic drugs did not render any patient spasm free. Only two had persistent spasms as the only seizure type; six also had intractable complex partial seizures, and three had occasional grand mal convulsions. Interictal EEGs showed multifocal spikes. Ictal recordings in six showed electrodecremental events. CONCLUSIONS: Recurrent spasms after remission of West syndrome represent an extremely resistant, distressing form of epilepsy. The onset of West syndrome is age related, but it does not reliably vanish.     

Predictive value of EEG findings at control of epileptic spasms for seizure relapse in patients with West syndrome

PurposeTo evaluate the prognostic importance of electroencephalography (EEG) findings at cessation of epileptic spasms for seizure outcome.MethodsWe reviewed 71 children with West syndrome (cryptogenic 14) who had obtained control of epileptic spasms with initial treatment (adrenocorticotropic hormone (ACTH) 37, high-dose vitamin B₆ 2, and antiepileptic drugs 32). According to the EEG findings at control of epileptic spasms, the subjects were divided into three groups: normal group (no epileptic activity, n = 12), abnormal group (residual epileptic activity without hypsarrhythmia, n = 53), and hypsarrhythmic group (persisting hypsarrhythmia, n = 6).ResultsOverall, 47 (66%) of the 71 patients (cryptogenic 4) had experienced relapses of seizures (epileptic spasms 23 and focal seizure 24) after initial control of epileptic spasms. Within symptomatic cases, seizure relapse rate varied widely from 0% (Down syndrome) to 100% (tuberous sclerosis), depending on underlying causes. Seizure relapse depended on the EEG findings at control of epileptic spasms. The normal group had a significantly lower seizure relapse rate (17%) in comparison with the abnormal group (75%), the hypsarrhythmic group (83%), and the epileptiform (abnormal plus hypsarrhythmic, 76%) group. No significant difference in seizure relapse rate was observed between non-hypsarrhythmic (normal plus abnormal, 65%) and hypsarrhythmic groups. At the last follow-up, normal group children also showed a favorable seizure prognosis (seizure control 100%).ConclusionsA favorable seizure prognosis is associated with the disappearance of epileptic activity, but not the resolution of hypsarrhythmic pattern on EEG at control of epileptic spasms. We suggest that effective treatment for West syndrome should produce both cessation of epileptic spasms and disappearance of epileptic activity on EEG.     

Partial seizures during ACTH therapy in a cryptogenic West syndrome patient

Background: Partial seizures often develop during the clinical course of infantile spasms. Herein, we report a boy with cryptogenic West syndrome, who developed partial seizures that we suspected were induced by the ACTH therapy. Subject: The patient developed cryptogenic West syndrome at six months of age and ACTH therapy was started. On the tenth day of treatment, he developed frequent partial seizures, characterized by being motionless during the seizure with eye deviation to the right. The partial seizures stopped after the ACTH was discontinued, although oral carbamazepine was commenced at the same time. Thus, a definitive role for carbamazepine in the treatment of the partial seizures was unclear as the timing of the seizure cessation also corresponded to the discontinuation of the ACTH therapy. We suspected that the partial seizures were induced by the ACTH therapy for the following reasons: (1) seizures appeared only during ACTH therapy, (2) no new epileptic focus was revealed by EEG, MRI, or ^99mTcECD SPECT, and (3) the seizures were different from the epileptic spasms. Conclusion: Our results suggest that ACTH might induce partial seizures in West syndrome. Further studies are required to confirm this phenomenon.     

Prognosis of patients with seizures occurring in the first 2 years

The aim of this study is to determine the prognosis of patients with seizure onset from 1 to 24 months of age in respect to epilepsy, developmental outcome, and neurological status. It also aims to determine predictive factors regarding an unfavorable prognosis. Seventy-five patients were retrospectively analyzed. Univariate analysis revealed the following findings: (1) mental retardation at initial admission, abnormal neurological finding, infantile spasm, use of more than 1 antiepileptic drug, epileptic activity on electroencephalography (EEG) of neonatal seizure, and perinatal anoxia were significant risk factors with regard to developmental outcome; (2) mental retardation at initial admission, abnormal neurological finding, infantile spasm, use of more than 1 antiepileptic drug, epileptic activity on EEG, symptomatic etiology, history of neonatal seizure, and perinatal anoxia were significant risk factors regarding neurological status; and (3) mental retardation at initial admission, neurological abnormality, infantile spasm, use of more than 1 antiepileptic drug, epileptic activity on EEG, status epilepticus, symptomatic etiology, seizure frequency of more than once per week, history of perinatal anoxia, and neonatal seizure were significant risk factors regarding epilepsy prognosis. In addition, multivariate analysis revealed that neurological abnormality and use of more than 1 antiepileptic drug were significant for developmental outcome, that epileptic activity on EEG and use of more than 1 antiepileptic drug were significant for neurological status, and that perinatal anoxia, infantile spasm, and status epilepticus were significant for epilepsy prognosis. These findings suggest that neurological abnormality, use of more than 1 antiepileptic drug, infantile spasm, status epilepticus, and perinatal anoxia are unfavorable predictive risk factors regarding the prognosis of patients with seizures that have an onset from 1 to 24 months of age.     

YouTube videos as a teaching tool and patient resource for infantile spasms

The purpose of this study was to assess YouTube videos for their efficacy as a patient resource for infantile spasms. Videos were searched using the terms infantile spasm, spasm, epileptic spasm, and West syndrome. The top 25 videos under each term were selected according to set criteria. Technical quality, diagnosis of infantile spasms, and suitability as a teaching resource were assessed by 2 neurologists using the Medical Video Rating Scale. There were 5858 videos found. Of the 100 top videos, 46% did not meet selection criteria. Mean rating for technical quality was 4.0 of 5 for rater 1 and 3.9 of 5 for rater 2. Raters found 60% and 64% of videos to accurately portray infantile spasms, respectively, with significant agreement (Cohen κ coefficient = 0.75, P < .001). Ten videos were considered excellent examples (grading of 5 of 5) by at least 1 rater. YouTube may be used as an excellent patient resource for infantile spasms if guided search practices are followed.     

Medical treatment of patients with infantile spasms

Infantile spasms are the main feature in West syndrome, an age-related epilepsy syndrome that affects 1 in every 2,000-4,000 infants. The authors provide a comprehensive review of the literature about infantile spasms and their therapy. In the United States, the drug of choice for infantile spasms, at least the cryptogenic cases, has been adrenocorticotropic hormone (ACTH). It is generally considered to be more effective than corticosteroids. Adrenocorticotropic hormone appears to alter long-term prognosis of cryptogenic infantile spasms, and helps in some cases of symptomatic infantile spasm. Vigabatrin has been considered the drug of choice for infantile spasms secondary to tuberous sclerosis, and possibly, according to many neurologists, for all cases of infantile spasm. Recent concerns regarding retinopathy associated with vigabatrin therapy are, however, limiting the use of this drug. Valproic acid benefits 40%-70% of patients who failed a trial of ACTH. Nitrazepam is as effective as ACTH in acutely controlling infantile spasms; however, its long-term effects on prognosis have not been studied. Pyridoxine, lamotrigine, topiramate, zonisamide, ketogenic diet, immunoglobulin therapy, felbamate, and thyrotropin-releasing hormone have all been used for the treatment of infantile spasms, but are usually reserved for cases refractory to vigabatrin and/or ACTH.     

The usefulness of subtraction ictal SPECT and ictal near-infrared spectroscopic topography in patients with West syndrome

The recent findings on subtraction ictal SPECT and ictal near-infrared spectroscopic topography in patients with West syndrome were summarized and its availability for presurgical evaluation was discussed. The subtraction ictal SPECT study in patients with West syndrome demonstrated the cortical epileptic region and subcortical involvement, which may consist of epilepsy networks related to the spasms. Moreover, subtraction ictal SPECT may have predictive power for short-term seizure outcome. Patients with a symmetric hyperperfusion pattern are predicted to have a better seizure outcome, whereas patients with asymmetric hyperperfusion pattern may develop poor seizure control. Importantly, asymmetric MRI findings had no predictive power for seizure outcome. Multichannel near-infrared spectroscopic topography applied to the patients with West syndrome detected an increase in regional cerebral blood volume in multiple areas which were activated either simultaneously or sequentially during spasms. Topographic changes in cerebral blood volume were closely correlated with spasm phenotype, suggesting that the cortex is involved in the generation of spasms. In conclusion, subtraction ictal SPECT may be considered as a useful tool for presurgical evaluation of patients with West syndrome and investigation of the pathophysiology of spasms. The ictal near-infrared spectroscopic topography should be more investigated to see if this is useful tool for presurgical evaluation.     

Epileptic encephalopathies in early infancy with suppression-burst.

Early infantile epileptic encephalopathy with suppression-burst, or Ohtahara syndrome (OS), and early myoclonic encephalopathy (EME) are epileptic encephalopathies with onset of frequent seizures in the neonatal and early infancy period and with a characteristic EEG pattern, namely, suppression-burst, in which higher-voltage bursts of slow waves mixed with multifocal spikes alternate with isoelectric suppression phase. Their nosologic independence is now widely accepted, although some controversy initially occurred because of their common characteristics such as age of onset, EEG features, seizure intractability, and poor prognosis. Major differences between the two syndromes include (1) tonic spasms in OS versus partial seizures and erratic myoclonias in EME, (2) continuous suppression-burst pattern in both waking and sleeping states in OS versus this EEG pattern almost limited to sleep in EME, and (3) static structural brain damage in OS versus genetic or metabolic disorders in EME. The most important differentiating point is their evolutional pattern with age, which may reflect their pathophysiologic difference. Ohtahara syndrome evolves to West syndrome and further to Lennox-Gastaut syndrome with age, but EME demonstrates no unique evolution; namely, it continues as such for a long time or changes into partial epilepsy or severe epilepsy with multiple independent spike foci.     

EARLY INFANTILE EPILEPTIC ENCEPHALOPATHY WITH SUPPRESSION BURST: OHTAHARA SYNDROME

Eleven infants with neonatal onset of intractable epilepsy are described, who showed the clinical and electroencephalographic features of Ohtahara syndrome. With time, transition to West and Lennox-Gastaut syndromes occurred. No cause could be found in eight cases. All nine survivors are severely mentally and physically handicapped and continue to have seizures. Early infantile epileptic encephalopathy represents the earliest of the age-dependent epileptic encephalopathies.