[Bilateral idiopathic carpal tunnel syndrome in a child under 10 years of age]. / Síndrome del túnel carpiano idiopático bilateral en un niño menor de 10 años.

INTRODUCTION: The carpal tunnel syndrome is the most frequent compression neuropathy in the adult population, being very uncommon in children, particularly under the age of 10 years. The most frequent etiology is the lisosomal storage diseases, followed by anatomical disorders, trauma, intensive sports practice and some idiopathic cases among others. In this paper we are presenting a case of an idiopathic and bilateral carpal tunnel syndrome in a 9 years old boy. CASE REPORT: A 9 year-old patient suffering daily paresthaesias in both hands for a year, producing limitations in hand mobility which disappear after physical movement of the hands. He played basketball at school, he was right handed and had no history of systemic family illnesses. After the exploration, he scored 4/5 in left thumb abductor strength and no thenar muscle hypotrophy. He achieved the criteria of attention deficit and hyperactivity disorder. Electroneurography tests confirmed the diagnosis. The etiology study was normal after completed. After bilateral surgery, the patient achieved a complete recovery. CONCLUSIONS: The importance of this clinical case lies in its rare manifestation in children under the age of 10, being bilateral and not being included in the most frequent etiology group. It has a late diagnosis because it has an etiology and clinical manifestation different from adults. The diagnosis is being done through electroneurography. Open surgical release is almost ever the treatment.

[Cognitive evoked potentials in the hyperactivity attention deficit disorder]. / Potenciales evocados cognitivos en el Trastorno por d ficit de atenci n con hiperactividad.

INTRODUCTION: The Attention Deficit Hyperactivity Disorder, ADHD, is characterized by deficient attention, impulsiveness and excessive motor activity. The incidence is estimated between 5 and 9% of children of school age. The P300 wave is one of the cognitive components of the event related potential ( ERP) that is more used to investigate the attention and the cognitive processes. OBJECTIVE: The aim of this study was to investigate the information processing in children with ADHD predominantly inattentive type by means of the visual and auditory P300 component. PATIENTS AND METHODS: P300 wave using an auditory and visual oddball paradigm were recorded in 18 children with ADHD and in 18 normal children ( control group ). RESULTS: We found differences in reaction time and in the percentage of errors between children with ADHD and between controls. In the ADHD the latency of the auditory and visual P300 were significantly longer than in the control group, and the amplitude of both components were significantly smaller in the ADHD group than in controls. We didn t found differences in the cortical distribution of the P300 between the two groups. CONCLUSIONS: These data suggests that there is an abnormal processing of cognitive information in children with ADHD predominantly inattentives and a dysfunction in attentional mechanisms.

Transcranial magnetic stimulation as a prognostic tool in stroke.

Our aims were to evaluate the prognostic usefulness of magnetic motor evoked potentials (MMEPs) in ischemic stroke, to study the evolution of MMEP abnormalities and the relationships between MMEP abnormalities and infarction topography. We prospectively analyzed 50 consecutive ischemic stroke patients who were followed up to 1 year. MMEPs were recorded 1, 3, 30 and 90 days after stroke and we measured amplitudes and latencies/central motor conduction times (CMCTs) of MMEPs from hypothenar, biceps brachiallis, gastrocnemius and quadriceps. Univariate and multivariate analyses of the clinical and MMEPs data were performed. Patients with Rankin 0-3 at 1 year had had acutely MMEPs with shorter latencies and higher amplitudes than patients with Rankin 4-5 or deceased patients. Increased blood pressure correlated with increased survival, whereas increased heart rate and hyperglycemia correlated with increased mortality. The variables infarction size on second CT, age, and first day CMCT-S1 correctly classified 1 year outcome on discriminant analysis. The inclusion of MMEPs values increased the probability of correct classification from 76% to 84%. We conclude that in patients with nondisabling strokes MMEPs may have an independent value in the prediction of prognosis, increasing the accuracy of prognosis calculations made employing clinical and laboratory data. Topography of lesions should be considered when analyzing MMEP abnormalities after stroke.

[Electrophysiologic assessment in motor neuron diseases]. / Exploración electrofisiológica en las enfermedades de motoneurona.

Electrophysiologic assessment is an important diagnostic tool in motor neuron diseases, contributing on occasions to define a patient's prognosis and clinical course as well as to further our understanding of the disease itself. The advent of motor cortex stimulation techniques facilitates the study of impaired descending motor pathways in predominantly upper motor neuron forms of amyotrophic lateral sclerosis. The most important feature of this technique is the decrease in amplitude of muscle responses to cortical stimuli, as a reflection of upper and lower motor neuron death. Coaxial needle electromyography (EMG) affords data on muscle fiber denervation as well as alterations in motor unit potentials, whose amplitude and duration increase. Motor and sensory nerve conduction velocities are preserved: single fiber and macro-EMG studies reveal changes suggestive of collateral sprouting of distal axons in surviving motor units in a compensatory reinnervation process. None of these techniques, however, provides a direct measure of the number of motor units present in a muscle, information that would be an essential aid in following the natural course of such diseases as well as assessing the efficacy of experimental treatments. Several techniques for estimating the number of motor units have been put forth, although none has been widely accepted. We describe the techniques proposed, weighing the advantages and disadvantages of each. At present it is impossible to tell which technique best estimates the real number of motor units present.

Reflex epilepsy.

We report 3 cases of reflex epilepsy, 2 of them triggered by reading (reading epilepsy) and one by mathematical calculation (epilepsy arithmetics). Electroencephalographic abnormalities predominated in the dominant hemisphere. The pathophysiologic mechanisms involved in this rare form of epilepsy are commented on, particularly the role played by the association of mental concentration and emotional strain. A possible deficiency in GABA-ergic inhibitory synapses would cause a deficit in cortical inhibition. Different drugs have been used successfully in patients with reflex epilepsy. Psychotherapy relieves anxiety and has been shown to be an effective complement to medical treatment.