Immunological disturbance in West and Lennox-Gastaut syndromes

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

PURPOSE

To evaluate factors influencing the efficacy and safety of intravenous immunoglobulins (IVIG) therapy for West syndrome.

METHODS

We investigated seizure outcomes in 70 patients who received IVIG treatment for West Syndrome during the first 3months after the onset of epileptic spasms. IVIG was administered for 3 consecutive days (initial IVIG treatment) at dosages ranging from 100 to 500mg/kg/day. If spasms disappeared within 2weeks of the initial treatment, maintenance IVIG treatment was commenced. We evaluated seizure outcomes at 2weeks (initial evaluation), at 2years (long-term evaluation), and the last visit (last follow-up evaluation) after the initial IVIG treatment. We analyzed dosages of IVIG, age at onset of spasms, treatment lag, and etiologies between responders and non-responders.

RESULTS

Among the patients, 7/70 (10.0%) had cessation of spasms and resolution of hypsarrhythmia at the initial evaluation. Another 6/70 patients (8.6%) were found to have cessation of spasms at the long-term evaluations. The treatment lag in responders was shorter than that in non-responders (P<0.01). There were no significant differences between responders and non-responders in IVIG dosages, age at onset of spasms, and etiologies. Two patients had relapse of partial seizures after cessation of spasms at the last follow-up evaluation. Adverse effects occurred in 2/70 patients.

CONCLUSIONS

The efficacy of IVIG was so low that it should not be considered as first-line treatment in West syndrome. IVIG therapy has a good safety profile and we would recommend it for West syndrome cases with drug resistance, severe complications associated with profound brain damage, severe brain atrophy, and in immunocompromised patients.

Generalized epilepsies: immunologic and inflammatory mechanisms

This article focuses on the inflammatory processes in patients with generalized epilepsies. We specifically review the data regarding West, Lennox-Gastaut, and Landau-Kleffner syndromes as they have generalized clinical or electroencephalogram features. There is substantial evidence for a pathogenic implication of immune mechanisms in these epilepsies. Animal models and abnormalities in both cellular and humoral immunity support this hypothesis. They also appear to be particularly responsive to immunomodulatory therapies, which has raised the speculation that an unbalanced immune system may play an important role in the pathophysiology of these epileptic syndromes. In this article, we discuss clinical and experimental data that support the potential implication of immune mediated inflammation and immune response in the mechanism of these entities.

Immunoglobulin treatment for severe childhood epilepsy

We have used intravenous immunoglobulin to treat pediatric patients with various severe epileptic conditions. This retrospective, multicenter study comprised 64 consecutive patients treated with immunoglobulins for either epileptic encephalopathy or refractory epilepsy. The rate of full or partial improvement according to specific syndrome involved three of four patients with idiopathic West syndrome, six of 12 patients with electrical status epilepticus in sleep, eight of 19 patients with an undefined syndrome, one of three patients with Landau-Kleffner syndrome, and one of two patients with Rasmussen encephalitis. Intravenous immunoglobulins were ineffective in 10 patients with symptomatic West syndrome, nine with febrile infection-related status epilepticus, three with myoclonic astatic epilepsy, and two with Lennox-Gastaut syndrome. Nine patients (14%) demonstrated complete resolution, and 10 (15.6%) exhibited partial improvement. Of these 19 responders (29.7%), eight relapsed. Although intravenous immunoglobulin is not suitable for all cases of epilepsy, it may prove efficacious for specific epileptic syndromes, mainly idiopathic West syndrome and electrical status epilepticus during sleep.

Reduced levels of interleukin-1 receptor antagonist in the cerebrospinal fluid in patients with West syndrome

We measured the levels of pro- and anti-inflammatory cytokines in the cerebrospinal fluid (CSF) of 24 patients with West syndrome to clarify whether inflammatory cytokines were involved in the pathophysiology of West syndrome. There was no significant elevation of any of the three pro-inflammatory cytokines, interleukin (IL)-1beta, IL-6, and tumor necrosis factor-alpha, in patients with West syndrome as compared with those in controls. However, level of anti-inflammatory cytokine, IL-1 receptor antagonist was significantly decreased in the CSF of patients with West syndrome. Further study is needed to elucidate whether an immune system disturbance is involved in the pathophysiology of West syndrome.

Immunologic aspects of West syndrome and evidence of plasma inhibitory effects on T cell function

STUDY OBJECTIVE: The purpose of this study was to assess the extent of immune dysfunction in a well-defined group of epileptic patients: children with diagnosis of West syndrome (WS) or with transitions to another age-related EEG patterns, the multifocal independent spikes (MIS), and the slow spike-wave complexes (Lennox-Gastaut syndrome - LGS). Thus, WS was studied at different points of the natural evolutive history of the disease. METHOD: A group of 50 patients (33 with WS, 10 with LGS and 7 with MIS) and 20 age-matched healthy controls were submitted to enumeration of T lymphocyte subsets: CD1, CD3, CD4, CD8, CD4/CD8 ratio and lymphocyte proliferation assay to phytohaemagglutinin (PHA), in the presence of autologous and AB, homologous plasma. Dinitrochlorobenzene (DNCB) skin test sensitization was performed only in patients. Determinations of IgG, IgA, and IgM serum levels were compared to standard values for Brazilian population in different age ranges. RESULTS: Sensitization to DNCB showed absent or low skin reactions in 76% of the patients. High levels of IgG (45.7%) and IgM (61.4%), and lower levels of IgA (23.9%) were detected in the serum of the patients. Enumeration of lymphocyte subsets in peripheral blood showed: low CD3+ (p<0.05), low CD4+ (p<0.05), high CD8+ (p<0.01) and low CD4+ / CD8+ ratio (p<0.001). The proportion of CD1+ cells in the control group was less than 3%, while ranged between 6 and 11 % in 18% of the patients. The in vitro PHA-induced T cell proliferation showed significantly low blastogenic indices only when patients, cells were cultured in presence of their own plasma. No differences in blastogenic indices were observed when the cells of patients and controls were cultured with human AB plasma. CONCLUSION: The immunodeficiency in WS was mainly characterized by anergy, impaired cell-mediated immunity, altered levels of immunoglobulins, presence of immature thymocytes in peripheral blood and functional impairment of T lymphocytes induced by plasma inhibitory factors.

[Neurocysticercosis and Lennox-Gastaut syndrome: case report]

Report of a girl with the epileptic, hydrocephalic and encephalitic form of neurocysticercosis, diagnosed by cerebrospinal fluid and computed tomography exams, during her second year of life and an evolution with multiple types of seizures, prolonged periods of intracranial hypertension due to obstruction in the ventriculoperitoneal shunt, psychomotor regression and blindness until she was 10 years old, when the Lennox-Gastaut syndrome was diagnosed. Nowadays the patient is 16 years old and presents complex partial seizures with automatism not completely controlled with clobazan and oxcarbazepine, associated to left spastic hemiparesis, universal hyperreflexia, psychomotor agitation, self-mutilation, amaurosis and severe mental retardation. The association between neurocysticercosis and Lennox-Gastaut syndrome was first described in 1973 by Frochtengarten & Scarante in a Brazilian girl with a similar clinical picture.

Alterations of cell-mediated immune response in children with febrile seizures

The aim of the present investigation was to study the distribution of T-cell subsets in peripheral blood defined by monoclonal antibodies and by the lymphocyte proliferative response to phytohemagglutinin (PHA) in 30 children with febrile seizures and in 14 age-matched control subjects. Frequent respiratory, urinary and dermatologic infections were observed in 22 patients. The immunologic parameters showed that 64% of the patients presented an increased number of CD8+ cells and a low helper/suppressor ratio was observed in 60% of the patients. In addition, the proliferative response of lymphocytes to PHA was impaired in the patients. It was observed the presence of inhibitory activity on lymphocyte function in the plasma of 33% of children with febrile seizures. These results suggest that patients with febrile seizures have an impairment of cellular immunity that may be connected with this epileptic syndrome and explain the infections observed.

A dysbalanced immune system in cryptogenic Lennox-Gastaut syndrome

In children with cryptogenic Lennox-Gastaut syndrome we found a functionally impaired humoral immune response to a primary antigen (haemocyanin), despite signs of a triggered immune system consisting of elevated IgG concentrations. This combination of immunological findings, considered to be the expression of a dysbalanced-triggered as well as functionally impaired-immune system, has also been described in an auto-immune disease like systemic lupus erythaematodes in humans, and in genetically epilepsy-prone rats. The interactions between the immune system and the nervous system in Lennox-Gastaut syndrome will be discussed.

Immunoglobulin treatment in human and experimental epilepsy

The relationship between human immunoglobulin administration, and human and experimental epilepsy was investigated by reviewing the literature as well as the authors' clinical and experimental studies. The focus was: 1) the possible efficacy of IVIg; 2) the possibility that IVIg significantly increases CSF IgG and could reach the brain, and 3) the interaction between the IVIg preparation and epilepsy. There is still no formal proof of efficacy of IVIg treatment in epilepsy. However, the clinical data presented suggests that IVIg is likely to be effective in a subgroup of patients with intractable and epilepsy, and may be considered as a safe add-on medication in various types of idiopathic and symptomatic intractable epilepsy. From the authors' study on cerebrospinal fluid IgG concentrations before and after IVIg treatment in patients with epilepsy, it is concluded that the main component of the IVIg preparation (the IgG molecule) crosses the blood-CSF barrier, significantly increases CSF IgG concentration, and may reach the brain and act centrally. From a review of previous reports and two immunological studies carried out by the authors it is concluded that immunogenetic mechanisms may play a role in triggering or maintaining some types of epilepsy. In view of this, IVIg could act on epilepsy by its broad immunomodulatory mechanism of action. In addition, preliminary data are reported that contribute to the hypothesis that IVIg may have a direct neuromodulating effect.

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.

Infantile spasms

Infantile spasms constitute a relatively rare disorder of infancy and early childhood; their onset is usually within the first 6 to 8 months of life. A large percentage of patients with this disorder (85-90 per cent) show various degrees of retardation. Infantile spasms typically occur in clusters immediately on arousal, or soon thereafter, but rarely occur while the infant is actually asleep. The usual interictal EEG pattern associated with infantile spasms is hypsarrhythmia, but infantile spasms may occur in the absence of this EEG pattern. The pathophysiology of infantile spasms is not known, but recent evidence suggests that certain regions in the brain stem that are associated with sleep cycling may be responsible for the clinical and EEG manifestations of this disorder. At present, the only known effective treatment for infantile spasms is ACTH or corticosteroids. The therapeutic efficacy of these two agents is relatively equal, and one drug may be effective if the other drug fails. The effectiveness of certain traditional anticonvulsants (valproic acid and the benzodiazepines) and pyridoxine in the treatment of infantile spasms has not been adequately assessed. The long-term mental and developmental outcome of patients with infantile spasms is poor. The only factor that appears to be important in terms of long-term outcome is whether the patient is initially classified as cryptogenic or symptomatic, with the cryptogenic patients having the better outcomes. Approximately half of the infantile spasm patients will continue to have other types of seizures after their spasms stop.

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

We report the occurrence of infantile spasms following near-drowning in two children with previously normal development. In both cases, the episode of near-drowning occurred well after the 1st year of life, and the age at onset of spasms (20 and 34 months, respectively) was unusually late. The possible significance of these two cases in relation to the pathophysiological mechanism underlying infantile spasms is briefly discussed.