Intravenous immunoglobulin therapy is rarely effective as the initial treatment in West syndrome: A retrospective study of 70 patients

Early Response, Long-Term Seizure Outcome, and Very-Low-Dose Adrenocorticotrophic Hormone Therapy for Infantile Epileptic Spasms Syndrome With Down Syndrome

BACKGROUND

Infantile epileptic spasms syndrome (IESS) with Down syndrome has good treatment response and good seizure outcomes with high-dose adrenocorticotrophic hormone (ACTH) therapy. We investigated the early treatment response of epileptic spasms (ES), long-term seizure outcome, and efficacy of very-low-dose ACTH therapy for IESS with Down syndrome.

METHODS

We retrospectively investigated patients with Down syndrome and IESS between April 1983 and January 2023. We defined response to treatment as clinical remission and electrographic resolution of hypsarrhythmia after treatment for more than one month and early treatment as any treatment for ES within three months of initiation of treatment. Long-term seizure outcomes were determined by the presence of any type of seizure within one year of the last visit. We investigated the dosage and efficacy of very-low-dose ACTH therapy.

RESULTS

Thirty patients were enrolled with a median follow-up period of 7.7 years (range: 1.3 to 19.1). The response and relapse rates in the early treatment were 83.3% and 16.0%, respectively. The seizure-free rate of long-term seizure outcomes was 80.0%. Long-term seizure outcomes correlated with early treatment response to ES. The response rate of very-low-dose ACTH therapy was 59.3%. The efficacy of ACTH therapy tended to be dose-dependent (P = 0.055).

CONCLUSIONS

Early treatment response to ES may be useful in predicting long-term seizure outcomes of IESS with Down syndrome. Very-low-dose ACTH therapy was the most effective treatment for ES and could exhibit dose-dependent efficacy. Depending on the IESS etiology, the ACTH dose could be reduced to minimize its side effects.

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.

Serum matrix metallopeptidase-9 and tissue inhibitor of metalloproteinase-1 levels may predict response to adrenocorticotropic hormone therapy in patients with infantile spasms

OBJECTIVE

To evaluate whether serum matrix metallopeptidase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels predict response to adrenocorticotropic hormone (ACTH) therapy in patients with infantile spasms.

METHODS

We prospectively evaluated patients with infantile spasms who were referred to Saitama Children's Medical Center from January 2011 to December 2020. We measured Q-albumin and serum MMP-9 and TIMP-1 levels before ACTH therapy. Patients were divided into three groups based on the etiology of their infantile spasms: those with an unknown etiology and normal development (unknown-normal group); those with a structural and acquired etiology (structural-acquired group); and those with a structural and congenital, genetic, metabolic, or unknown etiology with developmental delay (combined-congenital group). Responders were defined as those having complete cessation of spasms for more than 3 months with the resolution of hypsarrhythmia on electroencephalography during ACTH therapy.

RESULTS

We collected serum from 36 patients with West syndrome and five patients with infantile spasms without hypsarrhythmia before ACTH therapy. Twenty-three of 41 patients (56.1%) were responders, including 8/8 (100%) in the unknown-normal group, 6/9 (66.7%) in the structural-acquired group, and 9/24 (37.5%) in the combined-congenital group. The serum MMP-9 level and MMP-9/TIMP-1 ratio were significantly higher in responders than in nonresponders (P = 0.001 for both).

CONCLUSION

A therapeutic response to ACTH was associated with a higher serum MMP-9 level and higher MMP-9/TIMP-1 ratio in patients with infantile spasms. Therefore, these biomarkers may predict responses to ACTH therapy in this patient population.

Comparison of adrenocorticotropic hormone efficacy between aetiologies of infantile spasms

PURPOSE

We aimed to study the efficacy of adrenocorticotropic hormone (ACTH) treatment on infantile spasms with different aetiologies. In particular, we were interested in patients with structural-acquired aetiology.

METHODS

Patients with infantile spasms, who were treated with ACTH, were divided into three groups based on the aetiologies: unknown aetiology with normal development (unknown-normal), structural-acquired, and combined-congenital aetiologies that included genetic, metabolic, structural-congenital, or unknown aetiology with developmental delay.

RESULTS

Of the 107 patients included (58 males, 49 females), 25 patients had unknown-normal aetiology [median age at onset 5 months, standard deviation (SD) 3.12, range 2-16 months]; 20 patients had structural-acquired aetiology (median age at onset 6.5 months, SD 3.85 months, range 4-17 months); and 62 patients had combined-congenital aetiologies (median age at onset 5 months, SD 2.73 months, range 2-16 months). The efficacy of ACTH was 64.0 %, 65 %, and 30.6 % in the unknown-normal aetiology, structural-acquired aetiology, and combined-congenital aetiologies, respectively (p < 0.01). Multivariate analysis showed a statistically significant higher efficacy in the unknown-normal aetiology [Odds ratio (OR) 4.63, 95 % confidence interval (CI) 1.60-13.30] and structural-acquired aetiology (OR 3.41, 95 % CI 1.01-11.50) compared to that in the combined-congenital aetiologies.

CONCLUSION

Infantile spasms with structural-acquired aetiology had greater response to ACTH treatment than those with combined-congenital aetiologies. The efficacy of standard therapy of infantile spasms should be considered based on aetiology.

Investigation of neuronal auto-antibodies in children diagnosed with epileptic encephalopathy of unknown cause

AIM

Cryptogenic forms of epileptic encephalopathies (EE) with their well-known features of drug-resistance, mental deterioration and partial response to immunotherapies are ideal candidates for screening for neuronal autoantibodies (NAA).

METHOD

Fifty consecutive pediatric patients with a diagnosis of EE of unknown cause were included. Nine NAAs were tested by ELISA, RIA or cell-based assays. Clinical features of seronegative and seropositive patients were compared.

RESULTS

NAAs were found in 7/50 (14%) patients. They were N-methyl-d-aspartate receptor in two (4%), glycine receptor in two (4%), contactin-associated protein-like 2 in one (2%), glutamic acid decarboxylase in one (2%) and type A gamma aminobutyric acid receptor in one patient (2%). Furthermore, serum IgGs of two patients negative for well-characterized NAAs, showed strong reactivity with the uncharacterized membrane antigens of live hippocampal neurons. There were no significant differences between seropositive and seronegative patients by means of epilepsy duration, anti-epileptic drug resistance, EE type, types of seizures, seizure frequencies, EEG features or coexisting autoimmune diseases. Some seropositive patients gave good-moderate response to immunotherapy.

DISCUSSION

Potential clues for the possible role of autoimmunity in seropositive patients with EE were atypical prognosis of the classical EE type, atypical progression and unusual neurological findings like dyskinesia.

Neuroinflammatory Nexus of Pediatric Epilepsy

A rapidly growing body of evidence supports the premise that neuroinflammation plays an important role in initiating and sustaining seizures in a range of pediatric epilepsies. Clinical and experimental evidence indicate that neuroinflammation is both an outcome and a contributor to seizures. In this manner, seizures that arise from an initial insult (e.g. infection, trauma, genetic mutation) contribute to an inflammatory response that subsequently promotes recurrent seizures. This cyclical relationship between seizures and neuroinflammation has been described as a 'vicious cycle.' Studies of human tissue resected for surgical treatment of refractory epilepsy have reported activated inflammatory and immune signaling pathways, while animal models have been used to demonstrate that key inflammatory mediators lead to increased seizure susceptibility. Further characterization of the molecular mechanisms involved in this cycle may ultimately enable the development of new therapeutic approaches for the treatment of epilepsy. In this brief review we focus on key inflammatory mediators that have become prominent in recent literature of epilepsy, including newly characterized microRNAs and their potential role in neuroinflammatory signaling.