Review on the current long-term, limited lead electroencephalograms.

In the last century, 10-20 lead EEG recordings became the gold standard of surface EEG recordings, and the 10-20 system provided comparability between international studies. With the emergence of advanced EEG sensors, that may be able to record and process signals in much more compact units, this additional sensor technology now opens up opportunities to revisit current ambulatory EEG recording practices and specific patient populations, and even electrodes that are embedded into the head surface. Here, we aim to provide an overview of current limited sensor long-term EEG systems. We performed a literature review using Pubmed as a database and included the relevant articles. The review identified several systems for recording long-term ambulatory EEGs. In general, EEGs recorded with these modalities can be acquired in ambulatory and home settings, achieve good sensitivity with low false detection rates, are used for automatic seizure detection as well as seizure forecasting, and are well tolerated by patients, but each of them has advantages and disadvantages. Subcutaneous, subgaleal, and subscalp electrodes are minimally invasive and provide stable signals that can record ultra--long-term EEG and are in general less noisy than scalp EEG, but they have limited spatial coverage and require anesthesia, a surgical procedure and a trained surgeon to be placed. Behind and in the ear electrodes are discrete, unobtrusive with a good sensitivity mainly for temporal seizures but might miss extratemporal seizures, recordings could be obscured by muscle artifacts and bilateral ictal patterns might be difficult to register. Finally, recording systems using electrodes in a headband can be easily and quickly placed by the patient or caregiver, but have less spatial coverage and are more prone to movement because electrodes are not attached. Overall, limited EEG recording systems offer a promising opportunity to potentially record targeted EEG with focused indications for prolonged periods, but further validation work is needed.

If the Patient Does Not Take the Medication, It Will Not Work.

COGNITIVE AND BEHAVIORAL COMORBIDITIES: AN UNWANTED EFFECT OF ANTIEPILEPTIC DRUGS IN CHILDREN: Adriana Ulate-Campos, Iván Sánchez Fernández Seminars in Pediatric Neurology Volume 24, Issue 4, November 2017, Pages 320-330 Epilepsy is one of the most common neurological disorders and, despite optimally chosen and dosed antiepileptic drugs (AEDs), approximately 20%-30% of patients will continue to have seizures. Behavior and cognition are negatively impacted by seizures, but AEDs are also a major contributor to behavioral and cognitive deficits. However, the cognitive and behavioral effect of AEDs in children is insufficiently emphasized in the literature. This review summarizes the cognitive and behavioral effects of AEDs in the pediatric population with the objective of helping pediatricians and pediatric neurologists to select the AEDs with the best profile for their individual patient's needs.

First Pediatric Case of Autoimmune Encephalitis Associated With COVID-19 in Costa Rica.

Very few COVID-19-associated autoimmune encephalitis cases have been documented in children. This case report focuses on a previously healthy four-year-old girl who presented to the emergency room of the National Children's Hospital in Costa Rica in a postictal state due to a tonic-clonic seizure that progressed to status epilepticus. She had no previous history of fever or associated trauma. She was considered severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive by epidemiological linkage four weeks prior to the event, and her immunoglobulin G (IgG) levels for SARS-CoV-2 were positive. She presented with generalized decrease in muscle strength, she couldn't even walk, also dyskinetic movements in upper extremities, language impairment, frequent seizures, retrograde amnesia, and orolingual dyskinesias. An extensive diagnostic workup was performed, including bacterial and viral panel in cerebrospinal fluid, however the only positive result was the IgG for SARS-CoV-2. Electroencephalogram (EEG) and magnetic resonance imaging (MRI) findings were compatible with autoimmune encephalitis.  An antibody panel was performed, which was negative in cerebrospinal fluid and positive for anti-gamma-aminobutyric acid (GABA)/b1 in serum. She received three antiseizure drugs, plasmapheresis, intravenous gamma-globulin, methylprednisolone, and rituximab, which partially improved her condition. She currently has refractory epilepsy, memory problems, loss of language skills, and neuropsychiatric dysfunction. To our knowledge, this is the first case of autoimmune encephalitis secondary to SARS-COV-2 infection in a pediatric patient in Costa Rica.

Human Herpesvirus 6 Associated Encephalitis with Fulminant Brain Edema in a Previously Healthy Child.

Human herpesvirus 6 (HHV-6) is an important cause of roseola and febrile seizures in children. However, it is also a rare cause of encephalitis, most common in immunosuppressed children. We describe a case of HHV-6 encephalitis with fulminant brain edema in a previously healthy child. This severe HHV-6 clinical case with lethal brain edema is the second reported in the literature in a previously healthy child.

Seizure detection devices for use in antiseizure medication clinical trials: A systematic review.

OBJECTIVE: This study characterizes the current capabilities of seizure detection device (SDD) technology and evaluates the fitness of these devices for use in anti-seizure medication (ASM) clinical trials. METHODS: Through a systematic literature review, 36 wireless SDDs featured in published device validation studies were identified. Each device's seizure detection capabilities that addressed ASM clinical trial primary endpoint measurement needs were cataloged. RESULTS: The two most common types of seizures targeted by ASMs in clinical trials are generalized tonic-clonic (GTC) seizures and focal with impaired awareness (FIA) seizures. The Brain Sentinel SPEAC achieved the highest performance for the detection of GTC seizures (F1-score = 0.95). A non-commercial wireless EEG device achieved the highest performance for the detection of FIA seizures (F1-score = 0.88). DISCUSSION: A preliminary assessment of device capabilities for measuring selected ASM clinical trial secondary endpoints was performed. The need to address key limitations in validation studies is highlighted in order to support future assessments of SDD fitness for ASM clinical trial use. In tandem, a stepwise framework to streamline device testing is put forth. These suggestions provide a starting point for establishing SDD reporting requirements before device integration into ASM clinical trials.

Timing in the treatment of status epilepticus: From basics to the clinic.

OBJECTIVE: Describe basic science, animal models and clinical data related to timing of treatment in status epilepticus (SE). METHODS: We summarized the results of 15 studies that reported time to treatment in SE, and reviewed basic and clinical literature. RESULTS: SE is a life-threatening and time-sensitive emergency that requires immediate treatment. Current guidelines recommend escalation of anti-seizure medications (ASM) within specified time frames. Prolonged seizures may lead to changes in the composition and location of gamma-aminobutyric acid A receptors (GABAAR) and N-Methyl-d-aspartic acid receptors (NMDAR), leading to loss of inhibition and increased excitation. These biochemical changes are apparent in specific animal models having progressive resistance to benzodiazepines (BZD) with longer seizures. Later treatments lead to decreased response to BZD, longer seizures, greater need of continuous infusions, potential brain injury and increased in-hospital mortality. Despite mounting evidence that early treatment of SE is more effective and safer, treatment and ASM escalation is often delayed compared to protocols. Literature review of 2212 patients with SE showed an average time to treatment of 42.4 min and time to hospital arrival of 56 min. Also, only 51.8% of patients received treatment by emergency medical services and 12.8% by their families, including patients with a previous diagnosis of epilepsy or with prior SE. CONCLUSIONS: Morbidity and mortality may be avoided with rapid, effective treatment of SE. Treatment application and escalation remains delayed especially in outpatient settings, potentially leading to suboptimal outcomes. Implementation techniques and quality improvement methodologies may provide avenues for improving outcomes in SE.

Status epilepticus prevention, ambulatory monitoring, early seizure detection and prediction in at-risk patients.

PURPOSE: Status epilepticus is an often apparently randomly occurring, life-threatening medical emergency which affects the quality of life in patients with epilepsy and their families. The purpose of this review is to summarize information on ambulatory seizure detection, seizure prediction, and status epilepticus prevention. METHOD: Narrative review. RESULTS: Seizure detection devices are currently under investigation with regards to utility and feasibility in the detection of isolated seizures, mainly in adult patients with generalized tonic-clonic seizures, in long-term epilepsy monitoring units, and occasionally in the outpatient setting. Detection modalities include accelerometry, electrocardiogram, electrodermal activity, electroencephalogram, mattress sensors, surface electromyography, video detection systems, gyroscope, peripheral temperature, photoplethysmography, and respiratory sensors, among others. Initial detection results are promising, and improve even further, when several modalities are combined. Some portable devices have already been U.S. FDA approved to detect specific seizures. Improved seizure prediction may be attainable in the future given that epileptic seizure occurrence follows complex patient-specific non-random patterns. The combination of multimodal monitoring devices, big data sets, and machine learning may enhance patient-specific detection and predictive algorithms. The integration of these technological advances and novel approaches into closed-loop warning and treatment systems in the ambulatory setting may help detect seizures sooner, and tentatively prevent status epilepticus in the future. CONCLUSIONS: Ambulatory monitoring systems are being developed to improve seizure detection and the quality of life in patients with epilepsy and their families.

Adrenoleucodistrofia ligada al X con patrón radiológico atípico / X-linked adrenoleukodystrophy with an atypical radiological pattern

Introducción. La adrenoleucodistrofia ligada al X (ALD-X) es la enfermedad peroxisómica más frecuente. Se debe a una mutación en el gen ABCD1. La pérdida de la función de ABCD1 provoca una betaoxidación inefectiva de los ácidos grasos de cadena muy larga, lo que provoca la acumulación de estos ácidos grasos. La alteración típica en la neuroimagen en la forma cerebral es la desmielinización periventricular simétrica y de localización posterior. Caso clínico. Niño de 10 años, con hemiparesia espástica derecha y deterioro cognitivo subagudo. La resonancia magnética cerebral mostró afectación asimétrica de la sustancia blanca en la región frontoparietotemporal izquierda, y en la tomografía axial computarizada se visualizaban calcificaciones. Se confirmó ALD-X mediante la elevación de los niveles de ácidos grasos de cadena muy larga, y se encontró una variante patogénica en el gen ABCD1. Conclusiones. La desmielinización asimétrica con calcificaciones raramente se ha descrito en la ALD-X, y estos hallazgos podrían retrasar el diagnóstico. Esta presentación excepcional se debería considerar siempre en niños con inicio subagudo de síntomas motores y regresión cognitiva o del comportamiento

Introduction. X-linked adrenoleukodystrophy (X-ALD) is the most frequent peroxisomal disease. It is due to a mutation in the ABCD1 gene. The loss of functioning of ABCD1 triggers ineffective beta oxidation of very long-chain fatty acids, which gives rise to an accumulation of these fatty acids. The typical alteration revealed in neuroimaging scans in the cerebral form is symmetrical periventricular demyelination with posterior location. Case report. We report the case of a 10-year-old boy with right spastic hemiparesis and subacute cognitive impairment. Magnetic resonance imaging of the brain showed symmetrical involvement of the white matter in the left frontoparietotemporal region, and calcifications were observed in the computerised axial tomography scan. X-ALD was confirmed by means of the elevated levels of very long-chain fatty acids, and a pathogenic variant was found in the ABCD1 gene. Conclusions. Symmetrical demyelination with calcifications has rarely been reported in X-ALD, and these findings could delay diagnosis. This exceptional presentation should always be taken into consideration in children with subacute onset of motor symptoms and cognitive or behavioural regression

Cognitive and Behavioral Comorbidities: An Unwanted Effect of Antiepileptic Drugs in Children.

Epilepsy is one of the most common neurological disorders and, despite optimally chosen and dosed antiepileptic drugs (AEDs), approximately 20%-30% of patients will continue to have seizures. Behavior and cognition are negatively impacted by seizures, but AEDs are also a major contributor to behavioral and cognitive deficits. However, the cognitive and behavioral effect of AEDs in children is insufficiently emphasized in the literature. This review summarizes the cognitive and behavioral effects of AEDs in the pediatric population with the objective of helping pediatricians and pediatric neurologists to select the AEDs with the best profile for their individual patient's needs.

Histopathological Findings in Brain Tissue Obtained during Epilepsy Surgery.

BACKGROUND: Detailed neuropathological information on the structural brain lesions underlying seizures is valuable for understanding drug-resistant focal epilepsy. METHODS: We report the diagnoses made on the basis of resected brain specimens from 9523 patients who underwent epilepsy surgery for drug-resistant seizures in 36 centers from 12 European countries over 25 years. Histopathological diagnoses were determined through examination of the specimens in local hospitals (41%) or at the German Neuropathology Reference Center for Epilepsy Surgery (59%). RESULTS: The onset of seizures occurred before 18 years of age in 75.9% of patients overall, and 72.5% of the patients underwent surgery as adults. The mean duration of epilepsy before surgical resection was 20.1 years among adults and 5.3 years among children. The temporal lobe was involved in 71.9% of operations. There were 36 histopathological diagnoses in seven major disease categories. The most common categories were hippocampal sclerosis, found in 36.4% of the patients (88.7% of cases were in adults), tumors (mainly ganglioglioma) in 23.6%, and malformations of cortical development in 19.8% (focal cortical dysplasia was the most common type, 52.7% of cases of which were in children). No histopathological diagnosis could be established for 7.7% of the patients. CONCLUSIONS: In patients with drug-resistant focal epilepsy requiring surgery, hippocampal sclerosis was the most common histopathological diagnosis among adults, and focal cortical dysplasia was the most common diagnosis among children. Tumors were the second most common lesion in both groups. (Funded by the European Union and others.).

Devices for Ambulatory Monitoring of Sleep-Associated Disorders in Children with Neurological Diseases.

Good sleep quality is essential for a child's wellbeing. Early sleep problems have been linked to the later development of emotional and behavioral disorders and can negatively impact the quality of life of the child and his or her family. Sleep-associated conditions are frequent in the pediatric population, and even more so in children with neurological problems. Monitoring devices can help to better characterize sleep efficiency and sleep quality. They can also be helpful to better characterize paroxysmal nocturnal events and differentiate between nocturnal seizures, parasomnias, and obstructive sleep apnea, each of which has a different management. Overnight ambulatory detection devices allow for a tolerable, low cost, objective assessment of sleep quality in the patient's natural environment. They can also be used as a notification system to allow for rapid recognition and prompt intervention of events like seizures. Optimal monitoring devices will be patient- and diagnosis-specific, but may include a combination of modalities such as ambulatory electroencephalograms, actigraphy, and pulse oximetry. We will summarize the current literature on ambulatory sleep devices for detecting sleep disorders in children with neurological diseases.

Clinical profile of patients with ATP1A3 mutations in Alternating Hemiplegia of Childhood-a study of 155 patients.

BACKGROUND: Mutations in the gene ATP1A3 have recently been identified to be prevalent in patients with alternating hemiplegia of childhood (AHC2). Based on a large series of patients with AHC, we set out to identify the spectrum of different mutations within the ATP1A3 gene and further establish any correlation with phenotype. METHODS: Clinical data from an international cohort of 155 AHC patients (84 females, 71 males; between 3 months and 52 years) were gathered using a specifically formulated questionnaire and analysed relative to the mutational ATP1A3 gene data for each patient. RESULTS: In total, 34 different ATP1A3 mutations were detected in 85 % (132/155) patients, seven of which were novel. In general, mutations were found to cluster into five different regions. The most frequent mutations included: p.Asp801Asn (43 %; 57/132), p.Glu815Lys (16 %; 22/132), and p.Gly947Arg (11 %; 15/132). Of these, p.Glu815Lys was associated with a severe phenotype, with more severe intellectual and motor disability. p.Asp801Asn appeared to confer a milder phenotypic expression, and p.Gly947Arg appeared to correlate with the most favourable prognosis, compared to the other two frequent mutations. Overall, the comparison of the clinical profiles suggested a gradient of severity between the three major mutations with differences in intellectual (p = 0.029) and motor (p = 0.039) disabilities being statistically significant. For patients with epilepsy, age at onset of seizures was earlier for patients with either p.Glu815Lys or p.Gly947Arg mutation, compared to those with p.Asp801Asn mutation (p < 0.001). With regards to the five mutation clusters, some clusters appeared to correlate with certain clinical phenotypes. No statistically significant clinical correlations were found between patients with and without ATP1A3 mutations. CONCLUSIONS: Our results, demonstrate a highly variable clinical phenotype in patients with AHC2 that correlates with certain mutations and possibly clusters within the ATP1A3 gene. Our description of the clinical profile of patients with the most frequent mutations and the clinical picture of those with less common mutations confirms the results from previous studies, and further expands the spectrum of genotype-phenotype correlations. Our results may be useful to confirm diagnosis and may influence decisions to ensure appropriate early medical intervention in patients with AHC. They provide a stronger basis for the constitution of more homogeneous groups to be included in clinical trials.

Carbamacepina como tratamiento sintomático de las mioclonías en la panencefalitis esclerosante subaguda / Carbamazepine as treatment for the symptoms of myoclonias in subacute sclerosing panencephalitis

No disponible

Hemiplejía alternante de la infancia: estudio del gen ATP1A3 en 16 pacientes / Alternating hemiplegia of childhood: ATP1A3 gene analysis in 16 patients

Fundamento y objetivo: La hemiplejía alternante de la infancia (HAI) es una enfermedad caracterizada por episodios recurrentes de hemiplejía, crisis tónicas o distónicas y movimientos oculares anormales de inicio precoz. Recientemente se han identificado mutaciones en el gen ATP1A3 como mecanismo causante de esta enfermedad. El objetivo es describir una serie de pacientes con diagnóstico clínico y genético de HAI. Pacientes y método: Se trata de un estudio descriptivo, retrospectivo y multicéntrico, de 16 pacientes con diagnóstico clínico de HAI, en quienes se documentaron mutaciones en el gen ATP1A3. Resultados: En la serie estudiada se encontraron 6 mutaciones distintas en el gen ATP1A3, todas en heterocigosis y de novo. La mutación más común fue G2401A, presente en 8 pacientes (50%), seguida por la mutación G2443A en 3 pacientes (18,75%), G2893A en 2 pacientes (12,50%), y C2781G, G2893C y C2411T en sendos pacientes (6,25% cada una). Conclusiones: En la poblacin estudiada con HAI se detectaron mutaciones de novo en el 100% de los pacientes estudiados. Las 2 mutaciones más frecuentes fueron la G2401A y la G2443A (AU)

Background and objective: Alternating hemiplegia in childhood (AHC) is a disease characterized by recurrent episodes of hemiplegia, tonic or dystonic crisis and abnormal ocular movements. Recently, mutations in the ATP1A3 gene have been identified as the causal mechanism of AHC. The objective is to describe a series of 16 patients with clinical and genetic diagnosis of AHC. Patients and method: It is a descriptive, retrospective, multicenter study of 16 patients with clinical diagnosis of AHC in whom mutations in ATP1A3 were identified. Results: Six heterozygous, de novo mutations were found in the ATP1A3 gene. The most frequent mutation was G2401A in 8 patients (50%) followed by G2443A in 3 patients (18.75%), G2893A in 2 patients (12.50%) and C2781G, G2893C and C2411T in one patient, respectively (6.25% each). Conclusions: In the studied population with AHC, de novo mutations were detected in 100% of patients. The most frequent mutations were D801N y la E815K, as reported in other series (AU)

[Alternating hemiplegia of childhood: ATP1A3 gene analysis in 16 patients]. / Hemiplejía alternante de la infancia: estudio del gen ATP1A3 en 16 pacientes.

BACKGROUND AND OBJECTIVE: Alternating hemiplegia in childhood (AHC) is a disease characterized by recurrent episodes of hemiplegia, tonic or dystonic crisis and abnormal ocular movements. Recently, mutations in the ATP1A3 gene have been identified as the causal mechanism of AHC. The objective is to describe a series of 16 patients with clinical and genetic diagnosis of AHC. PATIENTS AND METHOD: It is a descriptive, retrospective, multicenter study of 16 patients with clinical diagnosis of AHC in whom mutations in ATP1A3 were identified. RESULTS: Six heterozygous, de novo mutations were found in the ATP1A3 gene. The most frequent mutation was G2401A in 8 patients (50%) followed by G2443A in 3 patients (18.75%), G2893A in 2 patients (12.50%) and C2781G, G2893C and C2411T in one patient, respectively (6.25% each). CONCLUSIONS: In the studied population with AHC, de novo mutations were detected in 100% of patients. The most frequent mutations were D801N y la E815K, as reported in other series.

Alternating hemiplegia of childhood with a de novo mutation in ATP1A3 and changes in SLC2A1 responsive to a ketogenic diet.

BACKGROUND: Alternating hemiplegia of childhood (AHC) is a rare condition characterized by an early onset of hemiplegic episodes and other paroxysmal or permanent neurological dysfunctions. Recently, mutations in the ATP1A3 gene have been identified as the causal mechanism of AHC. Regarding the differential diagnosis of AHC, glucose transporter 1 deficiency syndrome may be considered because these two disorders share some paroxystic and nonparoxystic features. PATIENT AND RESULTS: We report a typical case of AHC harboring a de novo mutation in the ATP1A3 gene, together with a duplication and insertion in the SLC2A1 gene who exhibited marked clinical improvement following ketogenic diet. CONCLUSION: Because the contribution of the SLC2A1 mutation to the clinical phenotype cannot be definitely demonstrated, the remarkable clinical response after ketogenic diet led us to the hypothesis that ketogenic diet might be effective in AHC as it provides an alternative energy source for the brain.

Caracterización de la población pediátrica costarricense con esclerosis tuberosa y descripción del comportamiento de la epilepsia asociada / Characterisation of the paediatric population of Costa Rica with tuberous sclerosis and a description of the behaviour of the associated epilepsy

Introducción. La esclerosis tuberosa (ET) es una patología autosómica dominante debida a un trastorno en la diferenciación y proliferación celular que produce hamartomas en diferentes órganos. Afecta de forma variable el sistema nervioso central, los riñones, la piel y otros órganos. No existen estudios de su prevalencia ni de su comportamiento en la población pediátrica de Costa Rica. Objetivos. Caracterizar la población pediátrica costarricense con ET y describir el comportamiento de su epilepsia. Pacientes y métodos. Estudio de prevalencias basado en la revisión de expedientes clínicos de todos los pacientes menores de 18 años con diagnóstico de ET seguidos en el Hospital Nacional de Niños durante el período 2000-2010. Resultados. Durante el período de estudio se incluyeron 37 pacientes para una prevalencia de 3,09 por 100.000 nacidos vivos (intervalo de confianza al 95% = 1,88-4,31). No se presentaron diferencias significativas por sexo. La mediana de edad al diagnóstico fue de 14 meses. Los criterios mayores más frecuentes fueron manchas hipomelanóticas (97,3%), angiofibromas faciales (56%) y tuberomas corticales (54,1%). Treinta y cinco pacientes presentaron convulsiones (95%). Los tratamientos que lograron reducción de al menos un 50% de las crisis convulsivas fueron la vigabatrina (16,2%) y la cirugía de epilepsia (16,2%). Conclusiones. En todo paciente con epilepsia debe realizarse una valoración minuciosa de la piel, ya que las lesiones en la piel son un hallazgo muy frecuente en la ET. La epilepsia en la ET es farmacorresistente en un elevado número de pacientes y la vigabatrina debe valorarse como tratamiento farmacológico de primera línea (AU)

Introduction. Tuberous sclerosis (TS) is a pathology with an autosomal dominant pattern of inheritance that is due to a disorder affecting cell differentiation and proliferation that produces hamartomas in different organs. Its variable forms affect the central nervous system, the kidneys, the skin and other organs. No studies have been conducted on its prevalence and behaviour in the paediatric population of Costa Rica. Aims. To characterise the paediatric population with TS in Costa Rica and to describe the behaviour of its epilepsy. Patients and methods. The study analyses prevalence based on a review of the clinical records of all the patients under 18 years of age diagnosed with TS treated at the National Children’s Hospital over the period 2000-2010. Results. During the period under study a total of 37 patients were included for a prevalence of 3.09 per 100,000 live births (95% confidence interval = 1.88-4.31). No significant differences were observed according to sex. The mean age at diagnosis was 14 months. The most frequent major criteria were hypomelanotic macules (97.3%), facial angiofibromas (56%) and cortical tuberomas (54.1%). Thirty-five patients presented convulsions (95%). The treatments that achieved a reduction in the number of seizures of at least 50% were vigabatrine (16.2%) and epilepsy surgery (16.2%). Conclusions. All patients with epilepsy should be submitted to a thorough examination of the skin, since skin lesions are a very frequent finding in TS. Epilepsy in TS is pharmacoresistant in a large number of patients, and vigabatrine must be considered as first-line pharmacological treatment (AU)

[Characterisation of the paediatric population of Costa Rica with tuberous sclerosis and a description of the behaviour of the associated epilepsy]. / Caracterizacion de la población pediátrica costarricense con esclerosis tuberosa y descripcion del comportamiento de la epilepsia asociada.

INTRODUCTION: Tuberous sclerosis (TS) is a pathology with an autosomal dominant pattern of inheritance that is due to a disorder affecting cell differentiation and proliferation that produces hamartomas in different organs. Its variable forms affect the central nervous system, the kidneys, the skin and other organs. No studies have been conducted on its prevalence and behaviour in the paediatric population of Costa Rica. AIMS: To characterise the paediatric population with TS in Costa Rica and to describe the behaviour of its epilepsy. PATIENTS AND METHODS: The study analyses prevalence based on a review of the clinical records of all the patients under 18 years of age diagnosed with TS treated at the National Children's Hospital over the period 2000-2010. RESULTS; During the period under study a total of 37 patients were included for a prevalence of 3.09 per 100,000 live births (95% confidence interval = 1.88-4.31). No significant differences were observed according to sex. The mean age at diagnosis was 14 months. The most frequent major criteria were hypomelanotic macules (97.3%), facial angiofibromas (56%) and cortical tuberomas (54.1%). Thirty-five patients presented convulsions (95%). The treatments that achieved a reduction in the number of seizures of at least 50% were vigabatrine (16.2%) and epilepsy surgery (16.2%). CONCLUSIONS; All patients with epilepsy should be submitted to a thorough examination of the skin, since skin lesions are a very frequent finding in TS. Epilepsy in TS is pharmacoresistant in a large number of patients, and vigabatrine must be considered as first-line pharmacological treatment.

TITLE: Caracterizacion de la poblacion pediatrica costarricense con esclerosis tuberosa y descripcion del comportamiento de la epilepsia asociada.Introduccion. La esclerosis tuberosa (ET) es una patologia autosomica dominante debida a un trastorno en la diferenciacion y proliferacion celular que produce hamartomas en diferentes organos. Afecta de forma variable el sistema nervioso central, los riñones, la piel y otros organos. No existen estudios de su prevalencia ni de su comportamiento en la poblacion pediatrica de Costa Rica. Objetivos. Caracterizar la poblacion pediatrica costarricense con ET y describir el comportamiento de su epilepsia. Pacientes y metodos. Estudio de prevalencias basado en la revision de expedientes clinicos de todos los pacientes menores de 18 años con diagnostico de ET seguidos en el Hospital Nacional de Niños durante el periodo 2000-2010. Resultados. Durante el periodo de estudio se incluyeron 37 pacientes para una prevalencia de 3,09 por 100.000 nacidos vivos (intervalo de confianza al 95% = 1,88-4,31). No se presentaron diferencias significativas por sexo. La mediana de edad al diagnostico fue de 14 meses. Los criterios mayores mas frecuentes fueron manchas hipomelanoticas (97,3%), angiofibromas faciales (56%) y tuberomas corticales (54,1%). Treinta y cinco pacientes presentaron convulsiones (95%). Los tratamientos que lograron reduccion de al menos un 50% de las crisis convulsivas fueron la vigabatrina (16,2%) y la cirugia de epilepsia (16,2%). Conclusiones. En todo paciente con epilepsia debe realizarse una valoracion minuciosa de la piel, ya que las lesiones en la piel son un hallazgo muy frecuente en la ET. La epilepsia en la ET es farmacorresistente en un elevado numero de pacientes y la vigabatrina debe valorarse como tratamiento farmacologico de primera linea.