Juan Narbona

Idiopathic Epilepsies with Seizures Precipitated by Fever and SCN1A Abnormalities

Summary:  Purpose: SCN1A is the most clinically relevant epilepsy gene, most mutations lead to severe myoclonic epilepsy of infancy (SMEI) and generalized epilepsy with febrile seizures plus (GEFS+). We studied 132 patients with epilepsy syndromes with seizures precipitated by fever, and performed phenotype–genotype correlations with SCN1A alterations.

Non‐verbal development of children with deafness with and without cochlear implants

Deprivation of sensory input affects neurological development. Our objective was to explore clinically the role of hearing in development of sensorimotor integration and non-verbal cognition. The study involved 54 children (15 males, 839 females; 5 to 9 years old) with severe or profound bilateral prelocutive deafness but without neurological or cognitive impairment. Of these, 25 had received an early cochlear implant (CIm). Patients were compared with 40 children with normal hearing. All were given a battery of non-verbal neuropsychological tests and a balance test, and were timed for simple and complex movement of limbs. Deafness, whether treated by CIm or not, resulted in a delay in development of complex motor sequences and balance. Lack of auditory input was also associated with lower, but non-pathological, scores in visual gnoso-praxic tasks and sustained attention. Such differences were not observed in children with CIm. Hearing contributes to clinical development of spatial integration, motor control, and attention. An early CIm enables good verbal development and might also improve non-verbal capacities.

Transient Posterior Encephalopathy Induced by Chemotherapy in Children

The cases of three children, 16, 12, and 12 years of age, who suffered sudden confusional state and cortical blindness lasting 12 to 30 minutes while under treatment with high-dose methotrexate, cyclophosphamide, and dactinomycin for a lower limb osteosarcoma are reported. Transient neuropsychologic deficits arose after the acute phase of treatment: left hemispatial neglect and constructive apraxia (Patient 1); constructive apraxia (Patient 2); and constructive apraxia and alexia without aphasia (Patient 3). The three patients recovered completely from all their deficits within the time frame of 3 hours to 2 weeks. Arterial hypertension and hypomagnesemia were found during the acute phase in all patients. In Patients 2 and 3, magnetic resonance imaging revealed increased parieto-occipital T(2) signal involving gray and white matter. In Patients 1 and 2, HmPAO-SPECT revealed parieto-occipital hypoperfusion that resolved a few days later. The alterations detected by neuroimaging were concurrent with the appearance and disappearance of the clinical symptoms. Such transient acute episodes have been named occipital-parietal encephalopathy. On the basis of our clinical, laboratory, and neuroimaging findings, an explanation for the origin of this syndrome, a migrainelike mechanism, triggered by chemotherapy-induced hypomagnesemia, is proposed.

AULA virtual reality test as an attention measure: Convergent validity with Conners’ Continuous Performance Test

The majority of neuropsychological tests used to evaluate attention processes in children lack ecological validity. The AULA Nesplora (AULA) is a continuous performance test, developed in a virtual setting, very similar to a school classroom. The aim of the present study is to analyze the convergent validity between the AULA and the Continuous Performance Test (CPT) of Conners. The AULA and CPT were administered correlatively to 57 children, aged 6–16 years (26.3% female) with average cognitive ability (IQ mean = 100.56, SD = 10.38) who had a diagnosis of attention deficit/hyperactivity disorder (ADHD) according to DSM-IV-TR criteria. Spearman correlations analyses were conducted among the different variables. Significant correlations were observed between both tests in all the analyzed variables (omissions, commissions, reaction time, and variability of reaction time), including for those measures of the AULA based on different sensorial modalities, presentation of distractors, and task paradigms. Hence, convergent validity between both tests was confirmed. Moreover, the AULA showed differences by gender and correlation to Perceptual Reasoning and Working Memory indexes of the WISC-IV, supporting the relevance of IQ measures in the understanding of cognitive performance in ADHD. In addition, the AULA (but not Conners’ CPT) was able to differentiate between ADHD children with and without pharmacological treatment for a wide range of measures related to inattention, impulsivity, processing speed, motor activity, and quality of attention focus. Additional measures and advantages of the AULA versus Conners’ CPT are discussed.

Chiari Type I Malformation, Glossopharyngeal Neuralgia and Central Sleep Apn'oea in a Child

We describe the case of an 8‐year‐old child who presented with sleep breathing disorders associated with glossopharyngeal neuralgia. Polysomnographic studies showed central sleep apncea lasting 10 to 18 seconds in an average frequency of 63 times for every hour of sleep. Magnetic resonance imaging (MRI) studies showed a caudal displacement of the cerebellar tonsils down to C3 level, associated with a syringomyelic cavity in the upper cervical cord and an extramedullary cystic collection at C2. Surgical decompression of the cranio‐cervical junction completely relieved the apncea and the glossopharyngeal neuralgia immediately following the procedure. MRI study performed one month later showed the complete disappearance of the syringomyelic cavity. Two years later this child remains asymptomatic. In childhood the association of Chiari type I malformation with sleep apncea and glossopharyngeal neuralgia has not been previously reported. The successful outcome after surgery suggests a compressive mechanism on the brainstem and on the IX cranial nerve to explain these two clinical features in our patient.

Medida de atención sostenida y del control de la impulsividad en niños : nueva modalidad de aplicación del test de percepción de diferencias caras

Resumen El Test de Percepción de Diferencias (TPD) es una prueba de tachado con lápiz y papel. Hemos prolongado el período de aplicación de esta prueba a 6 minutos para medir la atención sostenida—número de aciertos (A)—y el control de impulsividad—inverso al número de errores (E)—. El Índice de Control de Impulsividad (ICI) ha sido calculado con la siguiente fórmula: ICI = A-E/A+E. La muestra normativa está formada por 1090 niños (72% varones) con edades entre 6 y 10 años, extraídos aleatoriamente de las escuelas locales. El TPD se ha aplicado también a una muestra clínica de 66 sujetos del mismo rango etario; 36 con trastorno por déficit de atención e hiperactividad (TDAH) y 30 con trastorno del aprendizaje de la lectura (DLX) sin TDAH, según DSM-IV/CIE-10. Todos tienen cociente intellectual >85. Se presentan los datos normativos de las variables evaluadas (Aciertos e ICI) en la muestra poblacional. El grupo clínico obtiene peor rendimiento que el grupo normativo en ambas variables (ANOVA: p<0.01), y el grupo TDAH rinde más bajo en ICI que el DLX (t de Student: p<0.01). El ICI posee buen poder discriminante: el 64% de los participantes con TDAH rinden por debajo de −1.5 s y esto solo ocurre en el 3% de la muestra normativa. Estos resultados son congruentes con la existencia de un déficit importante en el control inhibitorio en el TDAH. Esta forma de utilización del TPD puede usarse complementariamente en la identificación de niños con TDAH.

Procedural Learning in Children With Developmental Coordination, Reading, and Attention Disorders.

The aim is to assess repetition-based learning of procedures in children with developmental coordination disorder (DCD), reading disorder (RD) and attention-deficit hyperactivity disorder (ADHD). Participants included 187 children, studied in 4 groups: (a) DCD comorbid with RD and ADHD (DCD+RD+ADHD) (n = 30); (b) RD comorbid with ADHD (RD+ADHD) (n = 48); (c) ADHD (n = 19); and typically developing children (control group) (n = 90). Two procedural learning tasks were used: Assembly learning and Mirror drawing. Children were tested on 4 occasions for each task: 3 trials were consecutive and the fourth trial was performed after an interference task. Task performance by DCD+RD+ADHD children improved with training (P < .05); however, the improvement was significantly lower than that achieved by the other groups (RD+ADHD, ADHD and controls) (P < .05). In conclusion, children with DCD+RD+ADHD improve in their use of cognitive-motor procedures over a short training period. Aims of intervention in DCD+RD+ADHD should be based on individual learning abilities.

Procedural skills and neurobehavioral freedom

This work has been supported by grants from the Government of Navarra and the Fundacion Fuentes Dutor (Pamplona, Spain) for research in developmental neurology and neuropsychology (2009–2013).

Gait Epilepsy. A Case Report of Gait-Induced Seizures

Summary: Reflex epilepsy includes a group of epileptic syndromes in which seizures are induced by a stimulus, either simple (visual, somatosensory, olfactory, auditory) or more complex (e.g., eating, thinking, reading). We document a case of reflex epilepsy in which focal seizures are triggered exclusively by gait. The patient is a young boy whose walking was impaired by abnormal motor phenomena on the left side. These phenomena were elicited by gait and were accompanied by a distinctive ictal pattern with centro‐temporal discharges. After comparing this patient with others reported in the literature, we determined that he has an unusual type of reflex epilepsy for which we coined the term “gait epilepsy.” This disorder must be considered when physicians are making a differential diagnosis in patients who have symptoms that suggest paroxysmal kinesigenic dystonia (PKD) or selective epileptic gait disorder.

Acquisition of Motor and Cognitive Skills through Repetition in Typically Developing Children

Background Procedural memory allows acquisition, consolidation and use of motor skills and cognitive routines. Automation of procedures is achieved through repeated practice. In children, improvement in procedural skills is a consequence of natural neurobiological development and experience. Methods The aim of the present research was to make a preliminary evaluation and description of repetition-based improvement of procedures in typically developing children (TDC). Ninety TDC children aged 6–12 years were asked to perform two procedural learning tasks. In an assembly learning task, which requires predominantly motor skills, we measured the number of assembled pieces in 60 seconds. In a mirror drawing learning task, which requires more cognitive functions, we measured time spent and efficiency. Participants were tested four times for each task: three trials were consecutive and the fourth trial was performed after a 10-minute nonverbal interference task. The influence of repeated practice on performance was evaluated by means of the analysis of variance with repeated measures and the paired-sample test. Correlation coefficients and simple linear regression test were used to examine the relationship between age and performance. Results TDC achieved higher scores in both tasks through repetition. Older children fitted more pieces than younger ones in assembling learning and they were faster and more efficient at the mirror drawing learning task. Conclusions These findings indicate that three consecutive trials at a procedural task increased speed and efficiency, and that age affected basal performance in motor-cognitive procedures.