A special note on terminology of West syndrome and infantile spasms

Distribution of peripheral blood mononuclear cell subtypes in patients with West syndrome: Impact of synacthen treatment

BACKGROUND

West Syndrome (WS) is an epileptic encephalopathy that typically occurs in infants and is characterized by hypsarrhythmia, infantile spasms, and neurodevelopmental impairment. Demonstration of autoantibodies and cytokines in some WS patients and favorable response to immunotherapy have implicated inflammation as a putative trigger of epileptiform activity in WS. Our aim was to provide additional support for altered inflammatory responses in WS through peripheral blood immunophenotype analysis.

METHODS

Eight WS cases treated with synacthen and 11 age- and sex-matched healthy volunteers were included. Peripheral blood mononuclear cells (PBMC) were isolated and immunophenotyping was performed in pre-treatment baseline (8 patients) and 3 months post-treatment (6 patients) samples. The analysis included PBMC expressing NFκB transcription and NLRP3 inflammasome factors.

RESULTS

In pre-treatment baseline samples, switched memory B cells (CD19+IgD-CD27+) were significantly reduced, whereas plasma cells (CD19+CD38+CD138+) and cytotoxic T cells (CD3+CD8+) were significantly increased. Regulatory T and B cell ratios were not significantly altered. Synacthen treatment only marginally reduced helper T cell ratios and did not significantly change other T, B, NK and NKT cell and monocyte ratios.

CONCLUSIONS

Our findings lend further support for the involvement of inflammation-related mechanisms in WS. New-onset WS patients are inclined to display increased plasma cells in the peripheral blood. Synacthen treatment does not show a beneficial effect on most effector acquired and innate immunity subsets.

Historical Overview of Hypsarrhythmia and Its Association to Epileptic Spasms: A Review of the Medical Literature From 1952 to 1982

SUMMARY

The initial description of infantile spasms and its association to developmental abnormalities was attributed to Dr. Williams J. West in 1841 but the clinical scenario at the time had also been seen by other physicians. French physician Henry Gastaut proposed the eponym of West syndrome in the 9th Colloquium de Marseille in 1960. The description of hypsarrhythmia in 1952 by Gibbs and Gibbs added the EEG component to the triad of infantile spasms. The hypsarrhythmia discovery led to a sudden interest in understanding the etiology and developing treatments for this devastating disease affecting infants and young children. It was in the 1950s when cases of infantile spasms with absence of hypsarrhythmia were initially observed. Also, the treatment with adrenocorticotrophic hormone was initially reported as efficacious for treating infantile spasms and hypsarrhythmia in the late 1950s. Adrenocorticotrophic hormone remains the best treatment option for these epilepsy types. This article will provide a historical review of knowledge developments about hypsarrhythmia and infantile spasms, emphasizing the period 1952 to 1982. The goal of the article was to highlight clinical elements that were discovered then and remain clinically relevant today.

Inflammation in Epileptic Encephalopathies

West syndrome (WS) is an infantile epileptic encephalopathy that manifests with infantile spasms (IS), hypsarrhythmia (in ~60% of infants), and poor neurodevelopmental outcomes. The etiologies of WS can be structural-metabolic pathologies (~60%), genetic (12%-15%), or of unknown origin. The current treatment options include hormonal treatment (adrenocorticotropic hormone and high-dose steroids) and the GABA aminotransferase inhibitor vigabatrin, while ketogenic diet can be given as add-on treatment in refractory IS. There is a need to identify new therapeutic targets and more effective treatments for WS. Theories about the role of inflammatory pathways in the pathogenesis and treatment of WS have emerged, being supported by both clinical and preclinical data from animal models of WS. Ongoing advances in genetics have revealed numerous genes involved in the pathogenesis of WS, including genes directly or indirectly involved in inflammation. Inflammatory pathways also interact with other signaling pathways implicated in WS, such as the neuroendocrine pathway. Furthermore, seizures may also activate proinflammatory pathways raising the possibility that inflammation can be a consequence of seizures and epileptogenic processes. With this targeted review, we plan to discuss the evidence pro and against the following key questions. Does activation of inflammatory pathways in the brain cause epilepsy in WS and does it contribute to the associated comorbidities and progression? Can activation of certain inflammatory pathways be a compensatory or protective event? Are there interactions between inflammation and the neuroendocrine system that contribute to the pathogenesis of WS? Does activation of brain inflammatory signaling pathways contribute to the transition of WS to Lennox-Gastaut syndrome? Are there any lead candidates or unexplored targets for future therapy development for WS targeting inflammation?

Basic mechanisms of catastrophic epilepsy -- overview from animal models

Infantile spasms are age-specific seizures of infantile epileptic encephalopathies that are usually associated with poor epilepsy and neurodevelopmental outcomes. The current treatments are not always effective and may be associated with significant side effects. Various mechanisms have been proposed as pathogenic for infantile spasms, including cortical or brainstem dysfunction, disruption of normal cortical-subcortical communications, genetic defects, inflammation, stress, developmental abnormalities. Many of these have been recently tested experimentally, resulting into the emergence of several animal models of infantile spasms. The stress theory of spasms yielded the corticotropin releasing hormone (CRH)-induced model, which showed the higher proconvulsant potency of CRH in developing rats, although only limbic seizures were observed. Models of acute induction of infantile spasms in rodents include the N-methyl-d-aspartate (NMDA) model of emprosthotonic seizures, the prenatal betamethasone and prenatal stress variants of the NMDA model, and the γ-butyrolactone induced spasms in a Down's syndrome mouse model. Chronic rodent models of infantile spasms include the tetrodotoxin model and the multiple-hit models in rats, as well as two genetic mouse models of interneuronopathies with infantile spasms due to loss of function of the aristaless X-linked homeobox-related gene (ARX). This review discusses the emerging mechanisms for generation of infantile spasms and their associated chronic epileptic and dyscognitive phenotype as well as the recent progress in identifying pathways to better treat this epileptic encephalopathy.

Neuro-lmages of Patients with Infantile Spasm

With the intention of assessing the neuro-imaging, clarifying the percentages of symptomatic, idiopathic and cryptogenic cases and identifying the underlying causes, records were reviewed retrospectively of 30 children with infantile spasm admitted to Hamad Medical Corporation, Doha, Qatar. Twenty-three patients were symptomatic, four idiopathic and three cryptogenic. Brain CT and MRI scans of 13 cases detected similar neuro-imaging findings in nine cases while MRI provided more information in another four cases. Three patients had normal neuro-images despite persistently abnormal EEGs. We conclude that MRI scans are superior to CT scans in detecting areas of cortical dysgenesis, disorders of neuronal migration, or disorders of myelination although more advanced studies are required for patients with persistently abnormal EEGs but normal MRIs.

A new paradigm for West syndrome based on molecular and cell biology

Symptomatic West syndrome has heterogeneous backgrounds. Recently, two novel genes, ARX and CDKL5, have been found to be responsible for cryptogenic West syndrome or infantile spasms. Both are located in the human chromosome Xp22 region and are mainly expressed and play roles in fetal brain. Moreover, several genes responsible for brain malformations including lissencephaly, which is frequently associated with West syndrome or infantile spasms, have been found, and the mechanisms responsible for the neural network disorders in these brain malformations are rapidly being determined. Findings of animal and in vitro studies and mutation analyses in humans are delineating the molecular and cellular basis of West syndrome. Mutations of the ARX gene controlling the development of GABAergic interneurons exhibit pleiotropic effects including lissencephaly with a strong genotype-phenotype correlation. An expansion mutation of the first polyalanine tract of ARX is more strongly related to infantile spasms than is that of the second polyalanine tract. Although the phenotype of CDKL5 mutation is similar to Rett syndrome caused by MECP2 mutation, the former is characterized by early-onset seizures and association with West syndrome. Lissencephaly caused by LIS1 or DCX mutation frequently results in West syndrome, while lissencephaly due to ARX mutation is associated with the most severe form of epilepsy but never results in West syndrome nor infantile spasms. Both LIS1 and DCX participate in the development of GABAergic interneurons as well as pyramidal neurons, while ARX participates only in that of interneurons. Individuals with lissencephaly due to ARX mutation lack non-pyramidal or GABAergic interneurons. ARX is crucial for the development of GABAergic interneuron, so abnormal interneurons in patients with ARX mutation are thought to be implicated in the pathological mechanism, even though brain MRI is normal. Abnormal interneurons appear to play an essential role in the pathogenesis of West syndrome or infantile spasms, which can be considered an interneuronopathy.

West & West syndrome--a historical sketch about the eponymous doctor, his work and his family

The British surgeon William James West has not left a tremendous literary or scientific work as many of his contemporaries did. For this reason only a little has been known about him and the fate of his family for decades, even though the eponym was created in the 1960s. Only in 1990 was a first biography published and later on supplemented. If his son had not suffered from the syndrome, which later on was named after him, he would not have published the first description of the West syndrome in The Lancet in 1841. Possibly we would be talking about Newnham's syndrome, because 8 years later he published a detailed report on this subject. There is, however, a second aspect concerning the pioneering activity of West, i.e. his advocating of ovariotomy in its early days. To judge the importance of this feat correctly, it is necessary to keep in mind that his former pupil and practice-partner Gorham in 1874 obviously tried to exaggerate the role of West in ovariotomy. Nevertheless, it is worth keeping the memory of William James West and his son James Edwin alive, as happened at the International Symposium on West Syndrome and Other Infantile Epileptic Encephalopathies at Tokyo, 9-11 February in 2001, and by other occasions.