Infantile spasms following near-drowning: a report of two cases

Trends and Costs Associated With the Diagnosis and Treatment of Infantile Spasms: A 10-Year Multicenter Retrospective Review

OBJECTIVE

Early treatment of infantile spasms (IS) may be imperative for improvement of neurodevelopmental outcomes. Existing studies have led to inconclusive recommendations with variation in treatment. Our objective was to determine the national average cost, initial diagnostic workup, treatments, and hospital length of stay for patients with IS.

METHODS

This retrospective cohort study was designed to review data of patients < 2 years from 43 non-profit institutions. Data obtained included patient demographics, length of stay, admission cost, and treatments used from 2004 to 2014. Cost data were collected and adjusted to 2014 dollars, the year data were analyzed.

RESULTS

A total of 6183 patients met study criteria (n = 3382, 55% male). Three-quarters of patients (n = 4684, 76%) had an electroencephalogram, 56.4% had brain imaging (n = 3487), and 17% (n = 1050) underwent a lumbar puncture. Medication for IS was initiated during inpatient hospital stay in two-thirds of all patients (n = 4139, 67%). Most patients were initiated on corticotropin (n = 2066, 33%) or topiramate (n = 1804, 29%). Average length of stay was 5.8 days with an average adjusted cost of $18,348. Over time there was an 86.6% increase in cost from an average $12,534.54 (2004) to $23,391.20 (2014), a significant change (p < 0.01). This correlated with an increase in average length of stay.

CONCLUSIONS

Variability exists in diagnostic workup and pharmacotherapy initiated for IS, which may lead to differences in the cost of hospital stay. Further studies may help determine contributing factors to increased cost and improve health care utilization for IS patients.

Epileptic spasms in tuberous sclerosis complex

PURPOSE

To characterize epileptic spasms (ES) occurring after the age of two years in patients with tuberous sclerosis complex (TSC), particularly treatment response to vigabatrin (VGB), which is extremely effective for infantile spasms (IS) in TSC.

METHODS

The authors retrospectively reviewed 19 patients with TSC and ES. Medical records were assessed for clinical and treatment data, neurocognitive, EEG, MRI data, and genetic analyses.

RESULTS

Of 391 patients with TSC, 19 (4.8%) had ES. Of those with detailed clinical data, six had infantile spasms that persisted after 2 years old, six recurred after an initial remission of infantile spasms (range 2-24 years old), and four occurred de novo over the age of two (range 2-20 years old). All concurrently had other seizure types. One had hypsarrhythmia on EEG. All had brain MRI stigmata typical of TSC. Thirteen had a mutation in TSC2, and one in TSC1. Six patients became spasm-free with medication treatment, including four with VGB, one with VGB in combination with the low glycemic index dietary treatment, and one with felbamate. Five became spasm-free after epilepsy surgery. VGB was not effective for seven patients. The majority continued to have refractory epilepsy.

CONCLUSIONS

ES are not uncommon in patients with TSC, especially those with TSC2 mutations. ES in TSC occur in the setting of other seizure types and refractory epilepsy. Hypsarrhythmia is rare. VGB can be effective, but the success of VGB for ES in TSC is not equivalent to that of IS in TSC.

Time interval from a brain insult to the onset of infantile spasms

The temporal latency between an encephalopathic event and the onset of infantile spasms cannot be determined in the majority of symptomatic cases (e.g. genetic conditions, cerebral malformations). However, we can measure this interval when a previously normal infant sustains brain injury followed by infantile spasms. This information has implications for understanding the underlying pathophysiologic basis for infantile spasms and, also, is germane to allegations that a close temporal relationship between vaccination and the onset of this seizure disorder establishes causation. We identified 19 published cases with sufficient information. The interval between brain injury and the onset of infantile spasms ranged from 6 weeks to 11 months (mean = 5.1 months). A similar temporal latency occurs in children with perinatal cerebral infarction and infantile spasms. We conclude that infantile spasms do not occur acutely following an encephalopathic event. This interval of weeks to months is consistent with prior studies indicating temporal latency between brain injury and the onset of other types of epilepsy, as well as with the previously proposed developmental desynchronization hypothesis. The findings refute claims that a close temporal association between an immunization and the onset of infantile spasms establishes causation.

Spasms in clusters in epilepsies other than typical West syndrome

Although spasms in clusters are one of the major characteristics of West syndrome (WS), there are a significant number of patients who show spasms in clusters but do not fit the standard pattern of WS. It is possible to divide these atypical cases into the following three groups. Group 1: refractory epilepsies beginning in early infancy, associated with atypical electroencephalographic (EEG) features; Group 2: generalized epilepsies with spasms in clusters at ages of 2-3 years or above; and Group 3: localization-related epilepsies with spasms in clusters. Ictal clinical and EEG findings of spasms in clusters in these atypical patients and also those in WS are similar. Patients in Group 1 often suffer from Aicardi syndrome, cortical malformations, early myoclonic encephalopathy and Ohtahara syndrome. Most patients in Group 2 suffer from Lennox-Gastaut syndrome and other generalized epilepsies such as severe epilepsy with multiple independent spike foci. A significant number of them had a history of WS. Small number of patients in Group 2 can be diagnosed as having late-onset WS or long-lasting WS. In Groups 1 and 3 patients, cortical mechanisms play a critical role in their pathophysiology. The presence of older patients with spasms in clusters might indicate not only developing process of the brain but also some selective dysfunction of the brain plays an important role in the occurrence of spasms in clusters. Investigations on these atypical patients can help the understanding of pathophysiological mechanisms of WS and its related epileptic syndromes.

Evidence of late-onset infantile spasms

PURPOSE

To underline the unusual but possible occurrence of epileptic spasms (ES) in children >1 year of age.

METHODS

Cases in whom onset of spasms occurred after 1 year of age were identified through a retrospective review of the records of all patients referred for ES to the Saint-Vincent de Paul Hôpital (Paris) and American Memorial Hospital (Reims) between 1974 and 1994.

RESULTS

Eighteen cases were identified among the 734 children referred for ES, 18 cases were identified where spasm onset time ranged from 12 to 38 months of age. In 1/3 of the cases, the diagnosis was suspected from the onset of clinical manifestations; in the remaining 2/3, diagnosis was delayed by a mean 6 months (range, 2-25 months). Neurobehavioral regression affected two-thirds of the patients. Modified hypsarrhythmia was present in 11 patients; all but one exhibited major and diffuse spike- and slow-wave activity. EEG abnormalities were detected in the frontal areas in 11 patients. Spasms were cryptogenic in 9 patients. Steroids were administered to 13 patients; these controlled the spasms in 6 patients. Outcome was favorable for both seizures; cognition favorable in only 2 of the 18 patients.

CONCLUSIONS

Beginning after the first year of life, ES, or late-onset infantile spasms, are distinct from early Lennox-Gastaut syndrome, although etiology, prognosis and treatment are similar to that for the classical infantile spasms.

Putative neurotransmitter abnormalities in infantile spasms: cerebrospinal fluid neurochemistry and drug effects

The neuropharmacologic basis of infantile spasms and the mechanism by which adrenocorticotropic hormone (ACTH) exerts its therapeutic effects are unknown. This is a critical review of cerebrospinal fluid neurotransmitters or their metabolites in infantile spasms before and during treatment with ACTH, and of clinical drug trials with drugs acting on neurotransmission. Cerebrospinal fluid studies have shown lower gamma-aminobutyric acid (GABA), ACTH, and 5-hydroxyindoleacetic acid concentrations in patients with infantile spasms compared to controls, elevated lysine and glutamate, variable or no differences in homovanillic acid, 3-methoxy-4-hydroxyphenylglycol, norepinephrine, corticotropin-releasing hormone, and beta-endorphin. Chronic treatment with ACTH in infantile spasms reduces cerebrospinal fluid GABA, beta-endorphin, and somatostatin, increases norepinephrine and tyrosine, and has variable or no effect on homovanillic acid, 3-methoxy-4-hydroxyphenylglycol, 5-hydroxyindoleacetic acid, histamine, and tryptophan. Small therapeutic trials with drugs that act through different neurotransmitters such as methysergide, alpha-methylparatyrosine, various benzodiazepine agonists, and vigabatrin lend some support to a role for GABA and monoamines in infantile spasms. These data, though promising, provide only a hint of potential neurotransmitter disturbances, and more basic and clinical data are needed.

The Lennox-Gastaut syndrome

One of the most challenging areas in nosology is in the field of severe generalized epilepsy of early childhood. This is certainly true in the case of Lennox-Gastaut syndrome (LGS), an age-related epileptogenic encephalopathy which comprises several types of generalized seizures including tonic seizures, atypical absence seizures and frequent status epilepticus. EEG shows generalized slow spike waves, and as the disease progresses, cognitive functions deteriorate. LGS is listed in the 1989 classification of the International League Against Epilepsy alongside epilepsy with myoclonic astatic seizures and West's syndrome. A number of variants or atypical forms have been proposed. As a result, differential diagnosis presents a major challenge and includes specific generalized epilepsies, i.e., metabolic or inflammatory; secondarily generalized epilepsies, i.e., those arising from the frontal lobe; and severe forms of idiopathic generalized epilepsy, i.e., Doose syndrome. Antiepileptic drug (AED) treatment of LGS has been disappointing. Results obtained from anterior callosotomy have been promising, but only a small number of patients have been evaluated. Although the syndrome is rare, the severe nature and intractability of LGS emphasizes the need for the development of specific AEDs which would completely modify the quality of life for these patients.

The epidemiology and natural history of infantile spasms

Few population-based studies of infantile spasms have been done, and most reports have not included comparison groups. In spite of these limitations, this review attempts to summarize what is known about the distribution, etiology, and natural history of infantile spasms in populations; discusses the limitations of current data; and includes suggestions for further population-based research. Most estimates of the incidence of infantile spasms are between 0.25 and 0.42 per 1000 live births per year. Among children less than 10 years of age, the annual prevalence of infantile spasms is 0.14 to 0.19 per 1000. The peak age at onset of spasms is 4 to 6 months, and there appears to be a slight excess of male cases. The etiology of infantile spasms is unknown for 40% to 50% of affected children. Selected syndromes (eg, Aicardi syndrome, Down syndrome, etc) and inherited disorders (eg, tuberous sclerosis) may account for as many as one third of cases. Other factors, such as intrauterine infection, "birth injury," and head trauma have not been systematically evaluated, and thus, their contribution to the etiology of infantile spasms is uncertain. Areas for future etiologic research include controlled studies of immunologic factors and in utero and postnatal infections and further exploration of the interrelationship between infantile spasms and Lennox-Gastaut syndrome.

Prognosis for seizure control in infantile spasms preceded by other seizures

Thirteen to 43% of patients with infantile spasms (IS) have other types of seizures, which are considered a feature of an unfavourable prognosis and, to some extent, as a contra-indication for steroid treatment. The present series comprised 43 patients treated with steroids, who suffered from other types of seizures prior to IS. The first seizures resulted from 2 different conditions, correlated to a different outcome of epilepsy. In 27 patients with prenatal encephalopathy, the first seizures were the first manifestation of the epilepsy and IS responded poorly to steroids. In the other 16 patients, the first seizures were occasional, due to acute brain damage, and the following IS responded favourably to steroid therapy. Rational therapeutic indications should take in account the etiology of seizures that precedes IS, and steroids should be administered when IS are due to acute peri- or postnatal acute brain damage.