Long-term follow-up study of West syndrome: Differences of outcome among symptomatic etiologies

Long-term analysis of adrenocorticotropic hormone monotherapy for infantile epileptic spasms syndrome with periventricular leukomalacia

PURPOSE

Infantile epileptic spasms syndrome (IESS) with periventricular leukomalacia (PVL) has a poor neurological prognosis. Adrenocorticotropic hormone (ACTH) and vigabatrin therapies are the recommended first-line treatments for IESS. However, ACTH monotherapy for IESS with PVL has not been studied in detail. We analysed long-term outcomes of ACTH monotherapy for IESS with PVL.

METHODS

We retrospectively examined 12 patients with IESS and PVL at Saitama Children's Medical Center between January 1993 and September 2022. We evaluated seizure outcomes 3 months post-ACTH therapy and at the last visit. We also assessed electroencephalography findings and developmental outcomes. A positive response was defined as complete remission of epileptic spasms, no other seizure types, and hypsarrhythmia resolution post-ACTH therapy.

RESULTS

The median onset age of epileptic spasms was 7 (range: 3-14) months. The median age at initiation of ACTH therapy was 9 (7-17) months. Seven of 12 patients (58.3%) showed a positive response. The median age at the last visit was 5 years and 6 months (1 year and 5 months-22 years and 2 months). At the last visit, only 2 of 7 initial responders remained seizure-free who demonstrated normal electroencephalography findings within 1-month post-ACTH therapy. Patients with epileptic discharge in the parieto-occipital region within 1-month post-ACTH therapy showed relapse of epileptic spasms or other seizure types.

CONCLUSION

Patients having epileptic discharge in the parietal or occipital regions on electroencephalography within 1-month post-ACTH therapy may be at a high risk of epileptic spasm recurrence or other seizure types in the long term.

Treatment-Resistant Epilepsy and Tuberous Sclerosis Complex: Treatment, Maintenance, and Future Directions

Tuberous sclerosis complex (TSC) is a neurogenetic disorder that affects multiple organ systems, including the heart, kidneys, eyes, skin, and central nervous system. The neurologic manifestations have the highest morbidity and mortality, in particular in children. Clinically, patients with TSC often present with new-onset seizures within the first year of life. TSC-associated epilepsy is often difficult to treat and refractory to multiple antiseizure medications. Refractory TSC-associated epilepsy is associated with increased risk of neurodevelopmental comorbidities, including developmental delay, intellectual disability, autism spectrum disorder, and attention hyperactivity disorder. An increasing body of research suggests that early, effective treatment of TSC-associated epilepsy during critical neurodevelopmental periods can potentially improve cognitive outcomes. Therefore, it is important to treat TSC-associated epilepsy aggressively, whether it be with pharmacological therapy, surgical intervention, and/or neuromodulation. This review discusses current and future pharmacological treatments for TSC-associated epilepsy, as well as the importance of early surgical evaluation for refractory epilepsy in children with TSC and consideration of neuromodulatory interventions in young adults.

Adjunctive perampanel therapy for patients with epileptic spasms

BACKGROUND

Perampanel is an antiepileptic drug. Some studies have documented the efficacy of perampanel in epileptic spasms. We aimed to evaluate the efficacy and safety of adjunctive perampanel therapy (PT) in patients with epileptic spasms.

METHODS

We retrospectively surveyed the efficacy and safety of adjunctive PT in 14 patients with epileptic spasms at the Saitama Children's Medical Center between June 2016 and September 2021. Seizure outcomes and safety were evaluated 12 months after commencing PT. Response to perampanel was defined as complete remission of epileptic spasms for more than 3 months.

RESULTS

The median age at onset of epileptic spasms was 0.4 years (range, 0.1-1.3 years). The etiology was structural in 11 patients, genetic in two, and unknown in one. The median age at the commencement of PT was 3.2 years (1.5-10.3 years). The initial and maintenance doses of perampanel were administered at 0.04 (range, 0.02-0.05) mg/kg/day and 0.12 (range, 0.03-0.24) mg/kg/day, respectively. Five of the 14 patients (35.7%) showed remission of epileptic spasms for more than 3 months at 12 months after PT; these patients had a structural etiology. The median duration between commencement of perampanel and spasm remission was 2 months (range, 1-6 months). No serious adverse effects occurred.

CONCLUSIONS

This is the first case series evaluating adjunctive PT for epileptic spasms. PT is worth investigating to treat epileptic spasms in patients with structural etiologies. As our study population primarily comprised children aged 2 years and older, PT may be useful for epileptic spasms beyond infancy.

Social cognition and psychopathology in childhood and adolescence

There is a substantial body of research on social cognition in adults with epilepsy, and in broad categories such as focal and generalized epilepsies, but much less has been written about social cognition in children with epilepsy (CWE), and in childhood-onset epilepsy syndromes specifically. In several of these syndromes, autism spectrum disorder (ASD) and attention-deficit hyperactivity disorder (ADHD), two disorders with social cognitive impairments, are reported. There is strong evidence for social cognitive deficits in juvenile myoclonic epilepsy (JME). There is also a considerable amount of evidence for such deficits in a number of syndromes that may be associated with ASD or ADHD, including West syndrome (WS), Dravet syndrome (DS), and the Landau-Kleffner syndrome (LKS). However, the evidence is of variable quality and incomplete across the range of childhood epilepsy syndromes. In some syndromes, childhood epilepsy substantially increases the risk of severe social cognitive impairment, which may persist after the seizures remit. This paper presents an overview of current research on social cognition in childhood epilepsy, with a particular focus on syndromes with a high prevalence of autistic and behavioral comorbidities. Social cognitive impairments represent a considerable additional challenge for patients and caregivers. Early diagnosis and intervention might significantly improve long-term social cognitive outcomes, highlighting the need for greater awareness among clinicians of this important topic. This article is part of the Special Issue "Epilepsy and social cognition across the lifespan".

Infantile Spasms and Injuries of Prematurity: Short-Term Treatment-Based Response and Long-Term Outcomes

The association of infantile spasms and periventricular leukomalacia and/or intraventricular hemorrhage is well documented. Data regarding early treatment-based and long-term outcomes are limited. A retrospective chart review identified children with infantile spasms born prematurely (<37 weeks) with diagnoses of periventricular leukomalacia and/or intraventricular hemorrhage. Thirteen children were included. Median gestational age was 30 weeks and age of onset of infantile spasms was 8 months. Nine children had intraventricular hemorrhage, 10 had periventricular leukomalacia, and 6 children had both. Twelve of 13 children had resolution of spasms. In responders, the successful medication was adrenocorticotropic hormone (ACTH) in 7, topiramate in 3, and vigabatrin in 2. Follow-up after a median of 7.1 years found that all patients had developmental delay but only 1 had refractory epilepsy. Standard therapies (ACTH and vigabatrin) appeared to be more effective than other treatments. Developmental delay is common in children with periventricular leukomalacia / intraventricular hemorrhage and infantile spasms, but refractory epilepsy might be less frequent.

White Matter Abnormality Correlates with Developmental and Seizure Outcomes in West Syndrome of Unknown Etiology

BACKGROUND AND PURPOSE

West syndrome is an epileptic encephalopathy characterized by epileptic spasms, a specific pattern on electroencephalography of hypsarrhythmia, and developmental regression. Our aim was to assess white matter abnormalities in West syndrome of unknown etiology. We hypothesized that diffusion tensor imaging reveals white matter abnormalities, especially in patients with poor seizure and developmental outcomes.

MATERIALS AND METHODS

We enrolled 23 patients with new-onset West syndrome of unknown etiology. DTI was performed at 12 and 24 months of age. Fractional anisotropy images were compared with those of controls by using tract-based spatial statistics. We compared axial, radial, and mean diffusivity between patients and controls in the fractional anisotropy skeleton. We determined correlations of these parameters with developmental quotient, electroencephalography, and seizure outcomes. We also compared DTI with hypometabolism on fluorodeoxyglucose positron-emission tomography.

RESULTS

At 12 months of age, patients showed widespread fractional anisotropy reductions and higher radial diffusivity in the fractional anisotropy skeleton with a significant difference on tract-based spatial statistics. The developmental quotient at 12 months of age correlated positively with fractional anisotropy and negatively with radial and mean diffusivity. Patients with seizure and abnormal findings on electroencephalography after initial treatments had lower fractional anisotropy and higher radial diffusivity. At 24 months, although tract-based spatial statistics did not show significant differences between patients and controls, tract-based spatial statistics in the 10 patients with a developmental quotient of <70 had significant fractional anisotropy reduction. In patients with unilateral temporal lobe hypometabolism on PET, tract-based spatial statistics showed greater fractional anisotropy reduction in the temporal lobe ipsilateral to the side of PET hypometabolism.

CONCLUSIONS

Diffuse abnormal findings on DTI at 12 months of age suggest delayed myelination as a key factor underlying abnormal findings on DTI. Conversely, asymmetric abnormal findings on DTI at 24 months may reflect underlying focal pathologies.

Relationship between initial electroencephalographic characteristics and seizure outcomes in children with non-lesional West syndrome

BACKGROUND

To characterize the initial interictal electroencephalography (EEG) activities associated with seizure outcomes in children with non-lesional West syndrome (WS), and their worth in the prediction of seizure-free (SF) vs no seizure-free (No-SF) outcomes.

METHODS

We retrospectively reviewed the initial scalp EEGs for at least a 40-min duration, and the medical records of 66 children who were diagnosed as WS with normal MRI, and who were followed-up with for 4.5 ± 2.1 years. We assessed the following clinical and EEG findings: onset of seizures, development, underlying etiologies, initial interictal EEGs, and seizure evolution. These variables were compared between two groups: SF vs No-SF groups.

RESULTS

In total, 36 (54.5%) children had SF outcomes and 30 (45.5%) had No-SF outcomes during long-term follow-up (4.4 ± 2.3 vs 4.6 ± 2.0 years, p = 0.7644). The mean age at seizure onset was similar in the SF and No-SF groups (6.0 ± 3.0 vs 6.9 ± 3.2 months, p = 0.2443). Delayed development before the onset of spasms was similarly observed in both groups (13.9% vs 13.3%). Initial EEG findings significantly differed with typical hypsarrhythmia (41.7% vs 73.3%, p = 0.0098), multiple independent spike foci (MISF) (55.6% vs 83.3%, p = 0.0158), frontal-dominant MISF (0.0% vs 40.0%, p < 0.0001), and frontal-dominant generalized epileptiform discharges (EDs) (0.0% vs 16.7%, p=0.0108) being involved more infrequently in the SF group than in the No-SF group, respectively. Patients in the SF group showed no frontal-dominant MISF or frontal-dominant generalized EDs, and a more often normal to borderline sleep-spindle (83.3% vs 40.0%, p = 0.0002) than the No-SF group.

CONCLUSION

Patients with SF outcomes more frequently showed the posterior-dominant generalized EDs and normal to borderline sleep-spindle, and the No-SF group more often had typical hypsarrhythmia, frontal-dominant MISF, frontal-dominant generalized EDs, and no normal sleep-spindle. Initial interictal EEG findings may predict seizure outcomes in patients with non-lesional WS.

Quality-of-care indicators for infantile spasms

We developed a comprehensive set of quality-of-care indicators for the management of children with infantile spasms in the United States, encompassing evaluation, diagnosis, treatment, and prevention and management of side effects and comorbidities. The indicators were developed using the RAND/UCLA Modified Delphi Method. After a focused review of the literature and guidelines by the study team, an expert panel (nominated by leaders of Child Neurology Society, American Epilepsy Society, and National Institute for Neurologic Disorders) rated the draft indicators anonymously, met face-to-face to discuss each indicator, and rerated the revised indicators on validity, feasibility, and importance. The panel recommended 21 indicators, of which 8 were identified as most likely to have a large positive impact on improving quality of life and/or health outcomes for children with infantile spasms. The proposed indicators can be used to assess and document variations and gaps in quality-of-care and inform future research and quality improvement interventions.

Treatment of preterm infants with West syndrome: differences due to etiology

BACKGROUND

This study was conducted with a particular focus on preterm infants with West syndrome (WS) to evaluate differences in the first responses to oral medication based on etiology.

METHODS

Medical records of 53 patients with WS, treated at five institutions between 2005 and 2009, were reviewed retrospectively. Patients were divided into six groups based on the time of brain insult, and evaluated for short-term outcomes using oral anti-epileptic agents and synthetic adrenocorticotropic hormone.

RESULTS

The sample consisted of 15, six, 14, two, four, and 12 patients classified, on the basis of apparent time of acquisition of etiology, into the prenatal, term, preterm, postnatal, other, and no identified etiology groups, respectively. Average age of onset in the term group was 3.3 ± 1.0 months, significantly earlier than in the prenatal, preterm, postnatal and no identified etiology groups (P < 0.05). All patients in the term group had experienced seizures before the onset of WS. Only patients in the preterm group had only experienced neonatal seizures, and responded better to treatment. Patients in the preterm group had better responses to treatment, especially oral medication, compared with those in the prenatal and term groups. The prevalence of relapse of seizures in the preterm group (14%) was significantly lower than that in the prenatal group.

CONCLUSIONS

Preterm WS patients responded well to treatment. Distinguishing WS patients on the basis of different etiologies is important for evaluating the effectiveness of treatment.

Infantile spasms: review of the literature and personal experience

This epileptic disorder has become a classic topic for neuropediatricians and the interest is documented by the large number of publications on this subject.The relative frequency among the epileptic syndromes is an another reason why not only neuropediatricians but also general pediatricians must be fully informed about diagnostic, clinical, imaging and genetic aspects.Early diagnosis is of paramount importance in order to obtain even complete results in patients with so called idiopathic situations. A number of problems are still to be solved. There is no agreement on the type and the schedule of treatment. A common denominator about this problem is not jet available even if some advances in this regard have been accomplished. Of paramount importance is an accurate clinical and laboratory examination as a prerequisite regarding prognosis and results of therapy in every single case.However, even if more than 170 years have elapsed since the first communication of dr. West on the peculiar syndrome that his child was suffering of, the interest of scientists on this subject has now been enriched and rewarded.

Interictal cerebral blood flow abnormality in cryptogenic West syndrome

PURPOSE

To elucidate the abnormality of interictal regional cerebral blood flow (rCBF) of West syndrome at the onset.

METHODS

Quantitative measurement of rCBF with an autoradiography method using N-isopropyl-((123)I) p-iodoamphetamine single photon emission computed tomography (SPECT) was performed on 14 infants with cryptogenic West syndrome. Regions of interest (ROIs) for rCBF were placed automatically using an automated ROI analysis software (three-dimensional stereotactic ROI template), and were grouped into 12 segments: callosomarginal, precentral, central, parietal, angular, temporal, posterior cerebral, pericallosal, lenticular nucleus, thalamus, hippocampus, and cerebellum. We compared rCBF between the patients and seven age-matched infants with cryptogenic focal epilepsy as a control group. The patients were divided into two groups according to the duration from onset to SPECT, to compare rCBF.

RESULTS

Quantitative analysis revealed cerebral hypoperfusion in cryptogenic West syndrome with normal SPECT images under visual inspection. In bilateral central, posterior cerebral, pericallosal, lenticular nucleus, and hippocampus, and in the left parietal, temporal, and cerebellum, and in the right angular and thalamus segments there were statistical differences (p < 0.05). Compared with the duration from onset to SPECT, there were no significant differences of rCBF in all segments.

DISCUSSION

Broad cerebral hypoperfusion with posterior predominance involving the hippocampus and lenticular nucleus implies that even cryptogenic West syndrome has a widespread cerebral dysfunction at least transiently, which would correspond to clinical manifestations of hypsarrhythmia and epileptic spasms. Hippocampal hypoperfusion suggests the dysfunction of hippocampal circuitry in the brain adrenal axis, and may contribute to subsequent cognitive impairment of cryptogenic West syndrome.

Electroencephalographic evolution of hypsarrhythmia: toward an early treatment option

PURPOSE

A retrospective study for a classification of prehypsarrhythmic elecroencephalographies (EEGs) was carried out to enable an early treatment option for West syndrome.

METHODS

Out of 39 infants with symptomatic West syndrome, 18 infants (age 3-14 months) with 61 serial non-REM sleep EEG records of the prehypsarrhythmic phase were identified. The prehypsarrhythmic phase encompassed 2 to 13 months (mean 4.5 months) after an initial insult. A classification system of three EEG types corresponding to the clinical states prior to West syndrome occurrence was developed. In addition, follow-up of all patients presenting with type 2 EEGs (n = 22) was evaluated.

RESULTS

Three clinical states and corresponding EEG types were classified. Clinical state 1 (weeks to months, silent phase) presented with (multi-)focal epileptic discharges <50% of the non-REM EEG recording time (type 1 EEG). Clinical state 2 (several weeks, beginning mental deterioration) was accompanied by type 2 EEG with bihemispheric epileptic discharges >50% of the non-REM EEG recording time within abnormal background activity (imminent hypsarrhythmia). Clinical state 3 (mental deterioration) was characterized by hypsarryhthmia. Interrater reliability of seven blinded raters was good (median weighted kappa 0.67). Out of 22 patients presenting with type 2 EEGs, two were lost for follow-up, and 16 developed West syndrome, whereas four were treated early with anti-epileptic drugs and remained stable.

CONCLUSIONS

Infants with West syndrome could be reliably identified several weeks before the occurrence of hypsarrhythmia by a typical EEG pattern (type 2), thereby opening the way for early intervention studies.

Electroencephalographic changes before the onset of symptomatic West syndrome

To clarify the characteristics of the mode of appearance and morphology of epileptiform discharges before the onset of West syndrome (WS). The subjects were 25 infants whose electroencephalograms (EEGs) were recorded before the onset of WS and whose first EEG was recorded before 6 months of corrected age (CA). We extensively analyzed the chronological and topographical changes of the epileptiform discharges before the onset of WS. The location of the initial epileptiform discharges was in the posterior areas in 14 (Group O), the multiple areas in 7 (Group M), and areas other than occipital in 4 (Group non-O). Twelve of the 14 patients in Group O were premature infants, and all but one had PVL. Most patients in Group M were full-term infants or near full-term infants who had hypoxic damage. The ages at the appearance of the initial epileptiform discharges in Group O were significantly later than those in Group M: 3.0-5.9 months of CA in Group O vs. -0.1 to 2.0 months of CA in Group M. These facts suggest that the difference of brain damage is related to both the topographical characteristics and the age at the appearance of initial epileptiform discharges, and around 3 months of CA is a critical period for the appearance of occipital hyperexcitability. Hypsarrhythmia and tonic spasms appeared almost simultaneously from 4 to 6 months of CA in most patients. To predict the occurrence of WS in high-risk infants, EEG follow-ups from early infancy are very useful.

Regional cerebral blood flow and developmental outcome in cryptogenic West syndrome

PURPOSE

To elucidate the relation between alterations of regional cerebral blood flow (rCBF) by adrenocorticotropic hormone (ACTH) therapy and developmental outcomes of cryptogenic West syndrome.

METHODS

Quantitative measurement of rCBF, with autoradiography method using N-isopropyl-((123)I) p-iodoamphetamine single photon emission computed tomography before and after ACTH therapy, was performed on 17 infants with cryptogenic West syndrome. Regions of interest for rCBF were placed bilaterally in the cerebellum, the thalamus, the caudate nucleus, and the frontal, temporal, and occipital cortices. RCBFs and the alteration ratios calculated from rCBFs before and after ACTH therapy were compared between two groups: the normal and delayed groups, which were divided by developmental outcome at 2 years old.

RESULTS

RCBFs before the therapy were not different statistically between the normal and delayed groups, and between those groups and the control group also. RCBFs after ACTH therapy of the occipital, thalamic and cerebellar regions were different between the normal and delayed groups (p < 0.05). Alteration ratios were different between the normal and delayed groups, in all of the regions but the frontal region (p < 0.05).

CONCLUSIONS

This study showed the differences of rCBF response by ACTH therapy between the normal and delayed groups of cryptogenic West syndrome. The difference of rCBF alteration might be associated with maturation of the cerebrovascular system, or influence of corticotropin-releasing hormone regarding the brain-adrenal-axis.

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.

Popliteal angle in infants with west syndrome

The aim of this study was to clarify the relationship between neurologic findings and outcome of patients with West syndrome, focusing on the popliteal angle. The complete neurologic examination, including an assessment of the popliteal angle and muscle tone, was performed on 45 patients with West syndrome. A tight popliteal angle was determined when it was 120 degrees or less. In all 45 patients, abnormal muscle tone was not correlated with any variables. A tight popliteal angle was correlated with seizure persistence, cerebral palsy, and abnormality on magnetic resonance imaging (MRI), as well as severe developmental delay. When limited to the patients with developmental delay, a tight popliteal angle was correlated with severe developmental delay, cerebral palsy, and MRI abnormality, although abnormal muscle tone was not correlated with any items. In the delay group, eight patients had a tight popliteal angle with normal muscle tone. Among them, severe developmental delay was seen in seven (88%), seizure persistence in five (63%), and MRI abnormality in five (63%). These results suggest that a tight popliteal angle might be an indicator of poor neurologic outcome in patients with West syndrome.

Tuberous sclerosis complex: a review of the management of epilepsy with emphasis on surgical aspects

OBJECTIVE

To review the management of epilepsy in patients with tuberous sclerosis complex (TSC) with an emphasis on surgical aspects, neuropathology, and pathogenesis.

METHODS

Review of the literature and presentation of the authors' experience of surgery for refractory epilepsy in patients with TSC.

RESULTS

TSC is a multisystem genetic disorder with variable phenotypic expression. TSC results from a mutation in the TSC1 gene on chromosome 9, which codes for hamartin, or in the TSC 2 gene on chromosome 16 which codes for tuberin. The majority of the patients have TSC as a result of spontaneous genetic mutations while in one-third of the patients, the disorder is inherited in an autosomal dominant manner. Epilepsy is the most common neurological complication, and up to 80-90% of individuals with TSC develop epilepsy at some point in their lifetime. The onset of epilepsy is typically in early childhood. Infantile spasms are a very common early seizure type although partial seizures may occur. Developmental delay, intellectual impairment, autism, behavioral problems, and neuropsychiatric disorders occur commonly in individuals with TSC and may be associated with poorly controlled epilepsy. Antiepileptic drugs are the first-line management for epilepsy but the ketogenic diet, resection of one or more tubers, corpus callosotomy, and vagus nerve stimulation are other therapeutic options for individuals with poorly controlled epilepsy.

Managing epilepsy in tuberous sclerosis complex

Epilepsy is very common in tuberous sclerosis complex and occurs in 80 to 90% of affected individuals during their lifetime. Onset usually occurs during childhood, and up to one third of children with tuberous sclerosis complex will develop infantile spasms. Although not completely understood, the incidence of epilepsy is thought to relate to the neuropathologic features of the disorder, including cortical tubers and other dysgenetic features. Individuals with tuberous sclerosis complex frequently have epileptiform features to their electroencephalograms. Treatment of epilepsy in tuberous sclerosis complex is similar to epilepsy resulting from other causes and includes anticonvulsant medications, the vagus nerve stimulator, and the ketogenic diet. Vigabatrin has been shown to be particularly effective in treating infantile spasms in the setting of tuberous sclerosis complex. Epilepsy surgery has a very important role in the management of children and adults with pharmacoresistant epilepsy in tuberous sclerosis complex.