Partial Seizures Evolving to Infantile Spasms

We describe the clinical and electroencephalographic (EEG) manifestations of four patients with simultaneous EEG-video-telemetry recording (VTR) documented partial seizures evolving to infantile spasms. Clinical manifestations of the partial seizures included cessation of activity, staring, automatisms, increased limb tone, and laughter. In each case, partial seizures were followed by a cluster of infantile spasms. Infantile spasms preceded by partial seizures have not been previously documented.     

Infantile spasms provoked by partial seizures

A case of infantile spasms that were persistently preceded by a partial seizure is presented. The absence of normal interhemispheric communication through the corpus callosum excludes rapid secondary generalization via this route as a possible explanation for bilateral spasms. A mechanism implicating the brainstem as the common source of infantile spasms and their characteristic hypsarrhythmic EEG pattern is discussed.     

Asymmetric and Asynchronous Infantile Spasms

Summary: Infantile spasms most commonly show symmetric behavioral and electroencephalogram (EEG) manifestations. Asymmetric and asynchronous behavioral spasms occur occasionally, but their relationship to ictal EEG and to other localizing studies has not received much attention. We reviewed 75 consecutive video-EEG recordings, done at UCLA from 1982 to 1992, that contained infantile spasms; 8,680 spasms were scored for behavioral and EEG asymmetry and asynchrony. Of the recorded spasms, 25% were asymmetric and 7% were asynchronous. Most asymmetric or asynchronous spasms were associated with an ictal EEG discharge that was contralateral to the behaviorally more involved side. In 12 of the 60 patients (20%), more than half of the recorded spasms were asymmetric or asynchronous,. Baseline EEG, magnetic resonance imaging, positron emission tomography, and neurological examination revealed structural and functional brain abnormalities that involved the contralateral central region significantly more often in the children with >50% spasm asymmetry or asynchrony than in the other children. Partial seizures with lateralized motor behavior also occurred frequently in these children. The findings suggest that asymmetric and asynchronous spasms are generated by a cortical epileptogenic region that involves the primary sensorimotor area. The combination of asymmetric and asynchronous infantile spasms, partial motor seizures involving the same side of the body, and pathology in the contralateral central region may represent a unique subset of symptomatic localization-related infantile epilepsy.     

Alexander disease with mild dorsal brainstem atrophy and infantile spasms

We present the case of a Japanese male infant with Alexander disease who developed infantile spasms at 8 months of age. The patient had a cluster of partial seizures at 4 months of age. He presented with mild general hypotonia and developmental delay. Macrocephaly was not observed. Brain magnetic resonance imaging (MRI) findings fulfilled all MRI-based criteria for the diagnosis of Alexander disease and revealed mild atrophy of the dorsal pons and medulla oblongata with abnormal intensities. DNA analysis disclosed a novel heterozygous missense mutation (c.1154 C>T, p.S385F) in the glial fibrillary acidic protein gene. At 8 months of age, tonic spasms occurred, and electroencephalography (EEG) revealed hypsarrhythmia. Lamotrigine effectively controlled the infantile spasms and improved the abnormal EEG findings. Although most patients with infantile Alexander disease have epilepsy, infantile spasms are rare. This comorbid condition may be associated with the distribution of the brain lesions and the age at onset of Alexander disease.     

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.     

Quantitative analysis and characterization of infantile spasms

An effective, time-synchronized monitoring system for the study of patients with infantile spasms has been developed. This system utilizes concurrent graphically recorded data, including EEG, body movement via triaxial accelerometry, respiration, electrocardiogram, electromyogram, electro-oculogram, and galvanic skin response. These data, when evaluated in conjunction with a closed-circuit TV recording of the patient, greatly facilitate the differentiation of seizures from nonictal activity and permit the characterization and quantification of the behavioral, motor, and autonomic phenomena intrinsically associated with infantile spasms.     

Validation of the rat model of cryptogenic infantile spasms

Purpose: To determine whether a new model of cryptogenic infantile spasms consisting of prenatal priming with betamethasone and postnatal trigger of spasms by N‐methyl‐d ‐aspartate (NMDA) responds to chronic adrenocorticotropic hormone (ACTH) treatment, and has electroencephalography (EEG) signature, efficacy of treatments, and behavioral impairments similar to those in human infantile spasms. Methods: Rats prenatally primed with betamethasone on gestational day 15 were used. Spasms were triggered with NMDA between postnatal days (P) 10 and 15 in a single session or in multiple sessions in one subject. The expression of spasms was compared to prenatally saline‐injected controls. Effects of relevant treatments (ACTH, vigabatrin, methylprednisolone, rapamycin) were determined in betamethasone‐primed rats. In the rats after spasms, behavioral evaluation was performed in the open field and elevated plus maze on P20–22. Key Findings: NMDA at P10–15 (the rat “infant” period) triggers the spasms significantly earlier and in greater numbers in the prenatal betamethasone‐exposed brain compared to controls. Similar to human condition, the spasms occur in clusters. Repeated trigger of spasms is associated with ictal EEG electrodecrements and interictal large‐amplitude waves, a possible rat variant of hypsarrhythmia. Chronic ACTH treatment in a randomized experiment, and chronic pretreatment with methylprednisolone significantly suppress the number of spasms similar to the human condition. Pretreatment with vigabatrin, but not rapamycin, suppressed the spasms. Significant behavioral changes occurred following multiple bouts of spasms. Significance: The model of infantile spasms has remarkable similarities with the human condition in semiology, EEG, pharmacologic response, and long‐term outcome. Therefore, the model can be used to search for novel and more effective treatments for infantile spasms.     

Can barbiturate anaesthesia cure infantile spasms?

Five patients with infantile spasms and hypsarrhythmia and one with Lennox-Gastaut syndrome were treated with brief thiopentone anaesthesia as the primary treatment of infantile spasms. Thiopentone (30 mg/kg) was given intravenously and burst suppression was reached in EEG in three patients by this dose. The results were disappointing. In three patients a transient beneficial effect on spasms and hypsarrhythmia was seen, but all patients relapsed. Three other patients had anaesthesia for surgery. The spasms ceased and hypsarrhythmia disappeared dramatically, and the effect was permanent. The possible mechanisms of the therapeutic effect are discussed. It seems advisable to give anaesthesia and surgery prior to steroid treatment in any case where the both are needed.     

Treatment of infantile spasms: emerging insights from clinical and basic science perspectives

Infantile spasms is an epileptic encephalopathy of early infancy with specific clinical and electroencephalographic (EEG) features, limited treatment options, and a poor prognosis. Efforts to develop improved treatment options have been hindered by the lack of experimental models in which to test prospective therapies. The neuropeptide adrenocorticotropic hormone (ACTH) is effective in many cases of infantile spasms, although its mechanism(s) of action is unknown. This review describes the emerging candidate mechanisms that can underlie the therapeutic effects of ACTH in infantile spasms. These mechanisms can ultimately help to improve understanding and treatment of the disease. An overview of current treatments of infantile spasms, novel conceptual and experimental approaches to infantile spasms treatment, and a perspective on remaining clinical challenges and current research questions are presented here. This summary derives from a meeting of specialists in infantile spasms clinical care and research held in New York City on June 14, 2010.     

An anatomo-clinical case of sequelae of acute encephalopathy. Infantile spasm with hypsarrhythmia

Clinico-pathological studies of West syndrome are rather rare. A case of sequelae of acute encephalopathy which involved a nine-month-old boy with post-mortem data is reported. Birth and postnatal development had been normal until the onset of illness. Laboratory examinations ruled out bacterial or viral meningo-encephalitis and metabolic disorders. After the recovery from a coma lasting several days, spastic quadriplegia, severe mental retardation and intractable epileptic attacks were present. The latter were made of tonic spasms and myoclonic seizures. EEG records showed hypsarrhythmia. Neuropathological examination revealed almost symmetrical bilateral cystic cavities in the pontine tegmentum and lateral nuclei of both thalami. The corpus callosum was very thin. No finding suggested a congenital anomaly. In a search of the pathological basis for infantile spasms, this case was compared with the published data. It would appear that the lesions of the pontine tegmentum play a significant role in the pathogenesis of hypsarrhythmia or infantile spasms.     

Benign spasms of infancy: a mimicker of infantile epileptic disorders*

Benign spasms of infancy (BSI), previously described as benign non‐epileptic infantile spasms or benign myoclonus of early infancy, are non‐epileptic movements manifesting during the first year of life and spontaneously resolving in the second year of life. BSI are characterized by spasms typically lasting 1–2 seconds, involving, to varying degrees, the head, neck, trunk, shoulders and upper extremities. Ictal and interictal EEG recordings are normal. BSI are not associated with developmental regression and do not require treatment. Distinction between BSI and infantile epileptic disorders, such as epileptic spasms or myoclonic epilepsy of infancy, can be challenging given the clinical similarities. Moreover, interictal EEGs can be normal in all conditions. Epileptic spasms and myoclonic epilepsy require timely treatment to improve neurodevelopmental outcomes. We describe a six‐month‐old infant presenting with spasm‐like movements. His paroxysms as well as a positive family history for epileptic spasms were in keeping with a likely diagnosis of West syndrome. Surprisingly, ictal video‐EEG did not reveal epileptiform activity, and suggested a diagnosis of BSI. We emphasize that ictal video‐EEG is the gold standard for classification of infantile paroxysms as epileptic or non‐epileptic, thereby avoiding over‐treatment for BSI and facilitating timely targeted treatment of infantile epilepsies. [Published with video sequences]     

Long-term prognosis of tuberous sclerosis with epilepsy in children

A follow-up study was performed on 40 children with tuberous sclerosis and epilepsy. In 68% of the patients with infantile spasms and 73% of those without them, complex partial seizures were observed. Thus, patients with tuberous sclerosis are subject to not only infantile spasms but also complex partial seizures. Patients with infantile spasms showed mental retardation more often than those without. Seizures which had evolved from infantile spasms were more difficult to control than those which had not. The prognosis of infantile spasms associated with tuberous sclerosis was better than that of prenatal group other than tuberous sclerosis. Forty percent of the 40 cases showed asymmetry on EEG, and the asymmetry tended to disappear as the patients grew up.     

Unusual variants of infantile spasms

During evaluation of video-electroencephalograms (EEGs) performed in our laboratory, we identified 11 patients who had unusual repetitive movements that appeared to be variants of infantile spasms. Movements included yawning, facial grimacing, eye movements, and transient focal motor activity. These symptoms coincided with generalized attenuation, slow-wave transients, or other EEG ictal changes characteristic of infantile spasms. The background EEGs showed true or modified hypsarrhythmia. This series of patients shows that infantile spasms may be extremely subtle and clinically atypical. Patients who have these variants may or may not also have typical infantile spasms. In some patients, the seizures appear to be time-related or medication-induced modifications of more typical infantile spasms.     

Infantile spasms in a patient with septo-optic dysplasia, partial agenesis of the corpus callosum and an interhemispheric cyst.

An uncommon association of infantile spasms, septo-optic dysplasia, partial agenesis of the corpus callosum and an interhemispheric cyst is described in a child. The combination of these findings has not, to our knowledge, been previously reported.     

Seizures in Series: Similarities Between Seizures of the West and Lennox-Gastaut Syndromes

We observed seizures resembling infantile spasms in patients with Lennox-Gastaut syndrome (LGS). Infantile spasms, the type of seizures that occurs in patients who have West syndrome, have been well characterized by video-EEG studies and typically occur as a series of sudden generalized flexor or extensor jerks. The seizure types that occur in LGS have not been as clearly delineated. Some patients with West syndrome (WS) in early infancy later develop LGS. Using intensive video-EEG monitoring, we evaluated 14 LGS patients who had seizures that occurred in series. Clinically, the seizures greatly resembled infantile spasms, and the ictal EEG changes were identical to those that occur with infantile spasms. These findings expand the number of features known to be shared by these two syndromes and strengthen the hypothesis that the two syndromes represent age-related manifestations of similar epileptogenic processes.     

Three cases of benign myoclonus of early infancy

Benign myoclonus of early infancy (BMEI) is a non-epileptic paroxysmal phenomenon. Some patients with BMEI were mistakenly treated as infantile spasms, because the fits resemble to tonic spasms in infantile spasms and they occur in cluster. However, the patients have normal development and no abnormal electroencephalograms (EEG), and the fits spontaneously subside without sequelae. There are only a few reports on BMEI, and it is not widely recognized in Japan. We report three cases of BMEI. All the cases were suspected to have infantile spasms from the characteristic features of paroxysmal events, and the parents had strong anxiety because of recurrent fits. However, the fits decreased dramatically in about three months, and spontaneously disappeared within one year without any sequelae. BMEI might be included in cases of suspected infantile spasms, and such patients should be followed by monthly EEG examinations and close observation for other seizure phenomena. To avoid unnecessary treatments, such patients should be observed without any therapeutic trials including antiepileptic drugs.     

Benign familial neonatal convulsions in a family with one member with infantile spasms]

A pedigree of benign familial neonatal convulsions (BFNC) was reported. Seven members of two generations experienced convulsions in the neonatal period and/or in early infancy. All of these members except one had a good prognosis. One member who had infantile spasms was uneventfully delivered at 37 weeks of gestation, with a birth weight of 2,562 g and, without trouble during pregnancy. At the age of 20 days, she began to have adversive seizures. Later, she developed complex partial seizures and infantile spasms at 1 month and 10 days of age. Interictal EEG showed hypsarrhythmia. Biochemical investigations and MRI of the head revealed no abnormality. Treatment with sodium valproate and carbamazepine succeeded in stopping the seizures and she had no seizures after 3 months. But her psychomotor development was moderately delayed at 8 months. No case with severe epilepsy such as infantile spasms has been reported in the previous literature on BFNC. From our experience, early treatment and careful follow-up are considered to be important for BFNC.     

A proposal for case definitions and outcome measures in studies of infantile spasms and West syndrome: consensus statement of the West Delphi group

PURPOSE: To reach a broad consensus on case definitions, outcomes, and outcome measures that will ease future study design and facilitate comparison of data from different studies of infantile spasms and West syndrome. METHODS: Persons who had recently presented or published first-author original research in this field were invited to participate in an e-mail Delphi process and to invite other investigators or clinicians who they thought might participate. RESULTS: The process consisted of six rounds, anonymous except to the facilitator. In total, responses were received from 46 participants. The final statement was approved by 31 participants from 15 countries. It concluded that the primary clinical outcome, cessation of spasms, should denote absence of witnessed spasms from within 14 days of commencement of treatment, and for > or =28 consecutive days from the last witnessed spasm. Primary electroclinical outcome denotes cessation of spasms with resolution of hypsarrhythmia. West syndrome should be a defined subset of the syndrome of infantile spasms. An infantile spasms single-spasm variant should be recognized. Ways are suggested of handling subtle spasms in the context of clinical studies. It proposes a standard for reporting modifying and atypical features of hypsarrhythmia, a minimal set of baseline characteristics and outcomes that should be reported in trials of infantile spasms, and suggests a standard definition of relapse. Consensus was not reached on a definition of hypsarrhythmia. CONCLUSIONS: We reached a clear consensus on many aspects of study design for the investigation of infantile spasms, although incomplete consensus was found on how to define EEG criteria.     

Aicardi syndrome: an unusual case associated with pineal gland cyst and ventricular septal defect

Aicardi syndrome is a cerebroretinal disorder consisting of a heterogeneous spectrum of clinical findings that includes the triad of infantile spasms, agenesis of the corpus callosum, and chorioretinal lacunae. This report describes a 6-month-old girl who has all of the essential features suggestive of Aicardi syndrome, as well as a pineal gland cyst and ventricular septal defect. Although the characteristic features of Aicardi syndrome have been described, its association with pineal gland cyst and ventricular septal defect has not been reported in the literature.     

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.