Effect of Non-Sex Hormones on Neuronal Excitability, Seizures, and the Electroencephalogram

Summary: : Several of the non-sex hormones have been found to be useful in the treatment of seizures. These hormones have an effect on seizures, and seizures have an effect on these hormones. Adrenocorticotropic hormone (ACTH) and corticosteroid drugs have been found to be useful in the treatment of infantile spasms and other seizure disorders. Unfortunately, there is no clear consensus regarding superiority of ACTH versus prednisone in regard to efficacy and long-term benefits, dosage, or duration of treatment. There is also considerable debate regarding reasons why ACTH and prednisone are useful in infantile spasms, their mechanism of action, and their long-term effects on brain development. Thyrotropin-releasing hormone also has been used in the treatment of infantile spasms and other seizure types in children, with modest success. As with ACTH and prednisone, the mechanisms of action remain unclear.     

Clinical Effects of Thyrotropin-Releasing Hormone for Severe Epilepsy in Childhood: A Comparative Study with ACTH Therapy

We investigated the effects and side effects of thyrotropin-releasing hormone (TRH) on severely epileptic children to evaluate the clinical usefulness of TRH in the treatment of epilepsy and compared them with the results of ACTH therapy. The subjects were 64 patients admitted consecutively between 1980 and 1986. Their seizures were frequent, more than one a day or more than one a week. The subjects were divided into two groups; 33 patients treated with ACTH and 31 treated with TRH. The mean follow-up periods in TRH and ACTH therapy were 8 months and 3.0 years, respectively. The daily dose of TRH-t 0.5-1 mg was administered intravenously (i.v.) or intramuscularly (i.m.) for 1-4 weeks. The follow-up periods were 3-12 months (mean 6 months). In the TRH group, complete control of seizures was achieved in 7 of 13 (53.7%) of those with infantile spasms, and marked improvement of EEGs were observed in 8 of 13 (61.5%) of them. In the ACTH group, seizure cessation was observed in 75% of infantile spasms. Of the patients who received ACTH, 66.7% had various side effects, including pneumonia, huge subcutaneous abscess, hypokalemia, cataracts, and brain shrinkage as shown on computed tomography (CT), whereas only 16.7% of the patients treated with TRH had transient reduction of urine volume without other laboratory and physical abnormalities. The results of the study indicated that some patients who received TRH had cessation of infantile spasms and improved EEG findings with no serious side effect. Because of the untoward side effects of ACTH therapy, TRH is considered a possible new treatment for children with infantile spasms.     

Adrenocorticotropic hormone controls infantile spasms independently of cortisol stimulation

Infantile spasms constitute a severe seizure disorder unresponsive to standard anticonvulsants. Both prednisone and adrenocorticotropic hormone (ACTH) have produced remission of seizures in some patients. The mechanisms of action of these hormones are not known. Eight infants with infantile spasms were treated with prednisone for 2 weeks. This controlled the seizures in two patients. In the remaining six patients, prednisone was continued and ACTH was added. This treatment produced cessation of spasms in four patients. Serum prednisone and cortisol were measured at a number of points during treatment. In infants receiving prednisone and then prednisone plus ACTH, serum cortisol was suppressed to about one-quarter of baseline levels with the initiation of prednisone, and remained suppressed during ACTH administration. We conclude that ACTH can exert its effect on infantile spasms in the setting of adrenal suppression, and can act without stimulating endogenous cortisol production. A CNS site of action is suggested and should be sought.     

Pathophysiology of massive infantile spasms: Perpective on the putative role of the brain adrenal axis

Massive infantile spasms are an age-specific seizure syndrome of infancy. Uniquely, the spasms respond to hormonal manipulation using adrenocorticotropic hormone(ACTH) or glucocorticoids. A hypothesis explaining the efficacy of hormonal therapy, age -specificity, multiple causative factors, and spontaneous resolution of infantile spasms is presented. Corticotropin-releasing hormone(CRH), an excitant neuropeptide supressed by ACTH/Steroids, is implicated. Evidence for the age-specific vonvulsant properties of CRH is presented, and a putative secenario in which a stressinduced enhancement of endogenous CRH-mediated seizures is discussed. Clinical resting of the CRH-Excess theory and its therapeutic implication are suggested.     

A pulse rapamycin therapy for infantile spasms and associated cognitive decline

Infantile spasms are seizures manifesting within a spectrum of epileptic encephalopathies of infancy that often lead to cognitive impairment. Their current therapies, including adrenocorticotropic hormone (ACTH), high dose steroids, or vigabatrin, are not always effective and may be associated with serious side effects. Overactivation of the TORC1 complex of the mTOR pathway is implicated in the pathogenesis of certain genetic and acquired disorders that are linked with infantile spasms, like tuberous sclerosis. Here, we tested the therapeutic potential of rapamycin, a TORC1 inhibitor, as a potential treatment for infantile spasms in the multiple-hit rat model of ACTH-refractory symptomatic infantile spasms, which is not linked to tuberous sclerosis. Rapamycin or vehicle was given after spasms appeared. Their effects on spasms, other seizures, performance in Barnes maze, and expression of the phosphorylated S6 ribosomal protein (pS6: a TORC1 target) in the cortex, using immunofluorescence, were compared. Rapamycin suppressed spasms dose-dependently and improved visuospatial learning, although it did not reduce the frequency of other emerging seizures. High-dose pulse rapamycin effected acute and sustained suppression of spasms and improved cognitive outcome, without significant side effects. Therapeutically effective rapamycin doses normalized the pS6 expression, which was increased in perilesional cortical regions of pups with spasms. These findings support that pathological overactivation of TORC1 may be implicated in the pathogenesis of infantile spasms, including those that are not linked to tuberous sclerosis. Furthermore, a high-dose, pulse rapamycin treatment is a promising, well tolerated and disease-modifying new therapy for infantile spasms, including those refractory to ACTH.     

Treatment of infantile spasms by pediatric neurologists in Japan

Objective

To clarify changes in clinical practice for infantile spasms, including West syndrome, in Japan over the past two decades.

Medical treatment of patients with infantile spasms

Infantile spasms are the main feature in West syndrome, an age-related epilepsy syndrome that affects 1 in every 2,000-4,000 infants. The authors provide a comprehensive review of the literature about infantile spasms and their therapy. In the United States, the drug of choice for infantile spasms, at least the cryptogenic cases, has been adrenocorticotropic hormone (ACTH). It is generally considered to be more effective than corticosteroids. Adrenocorticotropic hormone appears to alter long-term prognosis of cryptogenic infantile spasms, and helps in some cases of symptomatic infantile spasm. Vigabatrin has been considered the drug of choice for infantile spasms secondary to tuberous sclerosis, and possibly, according to many neurologists, for all cases of infantile spasm. Recent concerns regarding retinopathy associated with vigabatrin therapy are, however, limiting the use of this drug. Valproic acid benefits 40%-70% of patients who failed a trial of ACTH. Nitrazepam is as effective as ACTH in acutely controlling infantile spasms; however, its long-term effects on prognosis have not been studied. Pyridoxine, lamotrigine, topiramate, zonisamide, ketogenic diet, immunoglobulin therapy, felbamate, and thyrotropin-releasing hormone have all been used for the treatment of infantile spasms, but are usually reserved for cases refractory to vigabatrin and/or ACTH.     

Changes in CSF neurotransmitters in infantile spasms

Cerebrospinal fluid (CSF) from 7 patients with infantile spasms (mean age: 6.7 months) was collected before and after treatment with adrenocorticotropic hormone (ACTH). The concentration of neurotransmitter metabolites was analyzed using high-performance liquid chromatography and compared to the metabolite concentration in the CSF from 7 age-matched controls (mean age: 6.1 months). Pretreatment levels of CSF 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid, 3-methoxy-4-hydroxyphenyl glycol (MHPG), and kynurenine were significantly lower in infantile spasm patients compared to controls. Following treatment, marked increases in 5-HIAA and decreases in kynurenine levels were observed in the CSF of the 5 infants whose seizures were eliminated or reduced by ACTH. In the 2 nonresponders 5-HIAA levels decreased. The level of MHPG was reduced slightly in 5 infants, including the 2 nonresponders, and was increased in 2 responders. CSF homovanillic acid levels increased in 4 infantile spasm infants and decreased in 3 following ACTH. These data demonstrate that the presence of seizures in infantile spasms is associated with a significant decrease in serotonergic activity and that elimination of seizures by ACTH is accompanied by increased serotonin turnover. The simultaneous increase of 5-HIAA and decrease of kynurenine, an alternate metabolite of tryptophan, suggests an underlying disturbance of tryptophan metabolism in infantile spasms. The possibility that elimination of seizures by ACTH may be related to decreased production of certain kynurenine metabolites, particularly quinolinic acid, is discussed.     

Polymicrogyria and infantile spasms in a patient with 1p36 deletion syndrome

A 3-months-old boy presented with partial seizures that soon evolved into infantile spasms. Magnetic resonance imaging revealed bilateral perisylvian polymicrogyria with right-sided predominance. ACTH therapy successfully controlled epilepsy and electroencephalograms were normalized. Conventional G-banded chromosomal analysis was performed due to his distinctive features and a derivative chromosome 1 derived from parental balanced translocation with a karyoptype of 46,XY,der(1)t(1;4)(p36.23;q35) was detected. Fluorescent in situ hybridization analysis confirmed the deleted region of 1p36 as large as 8.6 Mb. This is the first delineation of concurrent complications of infantile spasms and polymicrogyria in patient with 1p36 deletion. 1p36 deletion syndrome should be broadly recognized as a differential diagnosis of regional polymicrogyria and/or infantile spasms.     

Continuous infantile spasms as a form of status epilepticus

An infant with congenital cytomegalovirus infection first developed seizures at six weeks of age. At 3 1/2 months of age, he developed continuous infantile spasms that lasted for more than an hour. This episode of status epilepticus was terminated by intravenous lorazepam and paraldehyde, and seizures were subsequently controlled for seven months by adrenocorticotropic hormone (ACTH), valproic acid, and phenobarbital. This case demonstrates that continuous infantile spasms may occur as a unique form of status epilepticus in young infants.     

ACTH and prednisone in childhood seizure disorders

We treated 116 children with ACTH or prednisone. Fifty-two had infantile spasms with hypsarhythmia, and 64 had other types of intractable seizures. ACTH completely controlled seizures in all patients with infantile spasms and hypsarhythmia and 74% of those with other types of seizures. Prednisone controlled 51% of patients with infantile spasms and none with other seizures. Serious side effects were minimal for both drugs, and recurrent seizures occurred in 40 to 50% of patients within 4 to 14 months after completion of therapy.     

Partial seizures during ACTH therapy in a cryptogenic West syndrome patient

Background: Partial seizures often develop during the clinical course of infantile spasms. Herein, we report a boy with cryptogenic West syndrome, who developed partial seizures that we suspected were induced by the ACTH therapy. Subject: The patient developed cryptogenic West syndrome at six months of age and ACTH therapy was started. On the tenth day of treatment, he developed frequent partial seizures, characterized by being motionless during the seizure with eye deviation to the right. The partial seizures stopped after the ACTH was discontinued, although oral carbamazepine was commenced at the same time. Thus, a definitive role for carbamazepine in the treatment of the partial seizures was unclear as the timing of the seizure cessation also corresponded to the discontinuation of the ACTH therapy. We suspected that the partial seizures were induced by the ACTH therapy for the following reasons: (1) seizures appeared only during ACTH therapy, (2) no new epileptic focus was revealed by EEG, MRI, or ^99mTcECD SPECT, and (3) the seizures were different from the epileptic spasms. Conclusion: Our results suggest that ACTH might induce partial seizures in West syndrome. Further studies are required to confirm this phenomenon.     

Carisbamate acutely suppresses spasms in a rat model of symptomatic infantile spasms

Purpose: Infantile spasms are the signature seizures of West syndrome. The conventional treatments for infantile spasms, such as adrenocorticotropic hormone (ACTH) and vigabatrin, are not always effective, especially in symptomatic infantile spasms (SIS). We tested the efficacy of carisbamate, a novel neurotherapeutic drug, to suppress spasms in the multiple‐hit rat model of SIS, and compared it with phenytoin to determine if its effect is via sodium‐channel blockade. Methods: Sprague‐Dawley rats received right intracerebral infusions of doxorubicin and lipopolysaccharide at postnatal day 3 (PN3) and intraperitoneal p‐chlorophenylalanine at PN5. A single intraperitoneal injection of carisbamate was administered at PN4, after the onset of spasms, at the following doses: 10 mg/kg (CRS‐10), 30 mg/kg (CRS‐30), and 60 mg/kg (CRS‐60), and was compared to vehicle‐injected group (VEH). Video‐monitoring of PN6‐7 CRS‐60 or VEH‐injected pups was also done. Key Findings: Carisbamate acutely reduced both behavioral spasms (CRS‐30 and CRS‐60 groups only) and electroclinical spasms during the first 2–3 postinjection hours, without detectable toxicity or mortality. In contrast, phenytoin (20 or 50 mg/kg) failed to suppress spasms. Significance: Our findings provide preclinical evidence that carisbamate displays acute anticonvulsive effect on spasms through a sodium channel–independent mechanism. Because spasms in the multiple‐hit rat model are refractory to ACTH and transiently sensitive to vigabatrin, carisbamate may constitute a candidate new therapy for SIS, including the ACTH‐refractory spasms. Further confirmation with clinical studies is needed.     

Therapeutic efficacy of ACTH in symptomatic infantile spasms with hypsarrhythmia

The records of twenty-six infants with both symptomatic infantile spasms and classic hypsarrhythmia were reviewed to determine the efficacy of various ACTH dosages and time of initiation of therapy. Mean age of infantile spasm onset was 6.4 months. Most patients (13) had sustained perinatal hypoxic-ischemic insults. Seventeen patients (65%) had complete cessation of spasms. Between these responders and the 9 nonresponders there was no difference in duration of spasms prior to treatment (2.6 and 2.0 months) or mean ACTH dose (87.4 and 84.5 U/m², respectively). Infants treated with high-dose ACTH (> 100 U/m²) did not have an improved response rate. The most favorable outcomes were associated with spasm onset at > 8 months of age (all of whom were responders, regardless of dose) or when treatment was started within 1 month of onset of infantile spasms with > 80 U/m² ACTH (88% responders). Infants treated more than 2 months after onset often did not respond (57%) regardless of dose. Nonresponders with spasm onset at < 4 months of age had the worst prognoses; all had poorly controlled seizures and regressed developmentally. Although all infants in the study were neurologically abnormal, development either improved or did not deteriorate in most responder infants following spasm resolution and one-half remained seizure free. Nonresponder infants continued to have infantile spasms or other seizure types. These data suggest that ACTH is valuable in the treatment of significantly impaired infants with symptomatic infantile spasms, but the most important determinants of outcome may be age of onset and rapidity of treatment rather than dosage.     

Adrenocorticotropic hormone and vigabatrin treatment of children with infantile spasms underlying cerebral palsy

Nine infants with an underlying static encephalopathy (confirmed as cerebral palsy in a later follow-up examination) and newly diagnosed infantile spasms were entered in an open study with adrenocorticotropic hormone (ACTH) and vigabatrin as the initial therapy regimen. The ACTH was discontinued after 4–6 weeks and the infants were maintained on vigabatrin alone. Following an initial response with complete suppression of spasms in all patients, a long term response maintained for a mean of 19.2 months was confirmed in all but one child. Tolerability appeared excellent with 7 of 9 patients reporting no side effects; vigabatrin related hypotonia presented in all patients and turned out to be a ‘positive’ side-effect on the abnormally increased muscle tone of these infants. Given the very poor prognosis of infantile spasms especially in such conditions as cerebral palsy, the combination of ACTH and vigabatrin appears to be an interesting therapy advance with very few side effects.     

ACTH Does Not Control Neonatal Seizures Induced by Administration of Exogenous Corticotropin-Releasing Hormone

Summary ACTH has been used extensively for treatment of massive infantile spasms (MIS) and other intractable seizures. The mechanisms by which ACTH exerts anticonvulsant effects are unknown. ACTH is a neuropeptide with both endocrine and neuromodulatory properties; its efficacy against MIS could derive from intrinsic anticonvulsant properties or from hormonal effects, either directly or through glucocorticoids. We tested ACTH activity against exogenous corticotropin-releasing hormone (CRH)-induced seizures in the infant rat model. CRH was administered into the cerebral ventricles of 85 infant rats aged 5–13 days. ACTH was used either 20–60 min before CRH administration or "chronically" (pretreatment with four doses of ACTH every 6 h, before CRH administration). In a separate group of rat pups, we measured plasma corticosterone to ascertain ACTH availability. Administration of CRH, an age-specific endogenous convulsant, resulted in a prolonged series of seizures after 2- to 55-min latency. There was no difference in latency between controls (9.5 ± 1.2 min) and ACTH-treated rats (12.4 ± 2.8 min for combined acute and chronic groups). CRH-induced seizure duration (88.2 ± 9 vs. 74.7 ± 9.4 min) and severity of seizures was also unchanged by ACTH treatment. ACTH reached the circulation and caused significant increase in plasma glucocorticoids. ACTH does not block the convulsant action of exogenous CRH in infant rats. An alternative mechanism for the anticonvulsant effect of ACTH may be suppression of synthesis and secretion of an endogenous convulsant, i.e., CRH.     

Facilitation of Infantile Spasms by Partial Seizures

Summary: We report 16 patients with infantile spasms in whom onset of the clusters of spasms appeared to be triggered by close temporal association with partial seizures. Common features included the presence of focal cerebral lesions in 12 infants (3 were classifiable as cryptogenic); all had partial seizures with EEG localization, clusters of bilateral spasms always preceded by partial seizures, and response to adrenocorticotropic hormone (ACTH) and traditional antiepileptic drugs (AEDs) generally was poor. Three had complete agenesis of the corpus callosum, which argues against interhemispheric callosal spread of focal discharges resulting in the generalized spasms. Surgical cortical resections were performed in 6 of the infants, with good outcomes. This group of patients supports a model in which the spasms, although probably generated at a subcortical level, are facilitated or possibly induced by focal discharges from cortical pathology.     

Treatment of infantile spasms: emerging insights from clinical and basic science perspectives

Infantile spasms is an epileptic encephalopathy of early infancy with specific clinical and electroencephalographic (EEG) features, limited treatment options, and a poor prognosis. Efforts to develop improved treatment options have been hindered by the lack of experimental models in which to test prospective therapies. The neuropeptide adrenocorticotropic hormone (ACTH) is effective in many cases of infantile spasms, although its mechanism(s) of action is unknown. This review describes the emerging candidate mechanisms that can underlie the therapeutic effects of ACTH in infantile spasms. These mechanisms can ultimately help to improve understanding and treatment of the disease. An overview of current treatments of infantile spasms, novel conceptual and experimental approaches to infantile spasms treatment, and a perspective on remaining clinical challenges and current research questions are presented here. This summary derives from a meeting of specialists in infantile spasms clinical care and research held in New York City on June 14, 2010.     

Positron emission tomography with glucose hypermetabolism of a hypothalamic hamartoma in infantile spasms associated with Pallister–Hall syndrome

Although hypothalamic hamartomas (HHs) have been shown to be intrinsically epileptogenic and to participate in the generation of gelastic seizures, no evidence has been reported regarding its contribution to the pathogenesis of infantile spasms. We describe a male infant with Pallister–Hall syndrome who had a large HH presenting with infantile spasms without hypsarrhythmia. [¹⁸F]fluoro-deoxyglucose positron emission tomography scan performed during the period of epileptic spasms demonstrated glucose hypermetabolism of the HH, which resolved after cessation of the spasms with adrenocorticotropin hormone treatment. No concurrent increased metabolic activity in the lenticular nuclei or brainstem was observed in the ictal or interictal states. The present case suggests that HHs may be involved in the pathogenesis of infantile spasms, possibly with propagation of epileptic discharges from the hamartoma to the descending spinal pathway.     

ACTH-induced seizures in an infant with West syndrome

We report seizures induced by adrenocorticotropic hormone (ACTH), which were demonstrated clinically and electro-encephalographically, in a severely handicapped 7-month-old infant with West syndrome due to perinatal hypoxicischemic encephalopathy. Although tonic spasms (original seizures) decreased soon after starting ACTH treatment, new brief tonic seizures, somewhat more slowly motioned than the original tonic spasms, frequently appeared only during sleep after consecutive ACTH injections for 11 days, in place of the tonic spasms seen in the waking state. After discontinuation of ACTH therapy with the last injection on the 16th day, the brief tonic seizures began to decrease and finally disappeared in 8 days. Ictal EEG of new brief tonic seizures revealed diffuse fast spiky wave bursts, 50-150 microV and 10-20 c/s, with a duration of 0.5-4 seconds, which were different from attenuation associated with low voltage rhythmic fast activity corresponding to tonic spasms, the original seizures. Therefore, we considered that the new brief tonic seizures, which appeared only during sleep in the course of ACTH therapy, were ACTH-induced seizures.