[The use of evoked potentials in the follow-up and prognosis of patients in coma following severe traumatic brain injury]. / Utilización de potenciales evocados en el seguimiento y pronóstico de pacientes en coma por traumatismo craneoencefálico grave.

INTRODUCTION: When dealing with patients in coma, it can be very useful to have early access to objective tests that provide information about their clinical status and can help to establish a prognosis for survival and functional recovery. The value of evoked potentials (EP) in such cases is already well known, although only techniques that assess the neurological status have been used. AIM: To determine the usefulness of different types of evoked potentials as a means of reaching a short and medium term prognosis for survival and functional recovery in patients in coma as a result of traumatic brain injury (TBI). PATIENTS AND METHODS: Our study involved patients with an admission Glasgow coma score of 8 or below due to severe TBI. During the first 24 hours the following tests were carried out on patients: somatosensory EP (SSEP), brainstem auditory EP, visual EP (VEP) obtained using stimulation goggles and mismatch negativity, as well as an imaging test (computerised axial tomography). The tests were repeated at one week and one month, and each patient was evaluated by means of the Glasgow scale and the Karnofsky scale. RESULTS: We studied 22 patients (mean age: 39.95 years; interval: 15-84 years), 20 of them were males. The highest number of deaths occurred during the first week. There was a strong correlation between survival and the results from the SSEP and VEP. CONCLUSIONS: SSEP and VEP performed on admission were a valuable aid for reaching a short and medium term prognosis for survival of patients in coma due to TBI, although they were not effective in evaluating a prognosis for functional recovery.

Utilización de potenciales evocados en el seguimiento y pronóstico de pacientes en coma por traumatismo craneoencefálico grave / The use of evoked potentials in the follow-up and prognosis of patients in coma following severe traumatic brain injury

Introducción. En los pacientes en coma es útil disponer desde un primer momento de pruebas objetivas que nos informen del estado clínico y nos sirvan de ayuda para establecer un pronóstico vital y funcional. El valor de los potenciales evocados (PE) en estos casos es ya conocido, aunque la mayoría de los estudios se centran sólo en algunos tipos de potenciales, valorando únicamente el estado neurológico en ese momento. Objetivo. Determinar el valor pronóstico vital y funcional a corto y medio plazo de los distintos tipos de potenciales evocados en pacientes en coma secundario a traumatismo craneoencefálico (TCE). Pacientes y métodos. Pacientes con un Glasgow de ingreso igual o inferior a 8 debido a un TCE grave. En las primeras 24 horas se les realizaron PE somatosensitivos (PESS) de nervio mediano, PE auditivos de tronco, PE visuales (PEV) obtenidos con estimulador goggles y mismatch negativity, además de una prueba de imagen (tomografía axial computarizada). Las pruebas se repitieron a la semana y al mes, y se valoró a cada paciente mediante la escala de Glasgow y la escala de Karnofsky. Resultados. Estudiamos 22 pacientes (media: 39,95 años; intervalo: 15-84 años), 20 de ellos varones. Durante la primera semana se produjo el mayor número de fallecimientos. Existió una fuerte correlación entre la supervivencia y los resultados obtenidos con PESS y PEV. Conclusión. Los PESS y PEV realizados al ingreso son de gran utilidad para la valoración pronóstica vital a corto y medio plazo del paciente en coma por TCE, sin llegar a mostrar eficacia en la valoración pronóstica funcional

Introduction. When dealing with patients in coma, it can be very useful to have early access to objective tests that provide information about their clinical status and can help to establish a prognosis for survival and functional recovery. The value of evoked potentials (EP) in such cases is already well known, although only techniques that assess the neurological status have been used. Aim. To determine the usefulness of different types of evoked potentials as a means of reaching a short and medium term prognosis for survival and functional recovery in patients in coma as a result of traumatic brain injury (TBI). Patients and methods. Our study involved patients with an admission Glasgow coma score of 8 or below due to severe TBI. During the first 24 hours the following tests were carried out on patients: somatosensory EP (SSEP), brainstem auditory EP, visual EP (VEP) obtained using stimulation goggles and mismatch negativity, as well as an imaging test (computerised axial tomography). The tests were repeated at one week and one month, and each patient was evaluated by means of the Glasgow scale and the Karnofsky scale. Results.We studied 22 patients (mean age: 39.95 years; interval: 15-84 years), 20 of them were males. The highest number of deaths occurred during the first week. There was a strong correlation between survival and the results from the SSEP and VEP. Conclusions. SSEP and VEP performed on admission were a valuable aid for reaching a short and medium term prognosis for survival of patients in coma due to TBI, although they were not effective in evaluating a prognosis for functional recovery

Recall and recognition confabulation in psychotic and bipolar disorders: evidence for two different types without unitary mechanisms.

Several forms of confabulation have been identified recently in schizophrenic patients, but it has not yet been investigated whether these forms are specific to schizophrenia. Furthermore, the origin of confabulation is unclear. The present study investigated recall and recognition confabulation and their relations with symptomatology, cognitive domains (abstraction and flexibility, verbal fluency, verbal memory, motor activity, and visual-motor processing/attention), computed tomographic (CT) measures (ventricular, cerebral, and Sylvian fissure size), and auditory event-related potentials (amplitudes and latencies of peak components in oddball paradigms) in 33 schizophrenic patients, 35 bipolar I patients, eight schizoaffective patients, and seven patients with other psychotic disorders. We found that neither type of confabulation was specific of any diagnostic group. Recall confabulation was mainly predicted by the predominance of positive symptoms, while recognition confabulation was predicted by a delay in P300 latency and the doses of antipsychotics used. Our results suggest two different mechanisms for both types of confabulation based on interference with the adequate retrieval of information and slowness in early stimulus detection.

[Neurophysiology and neuropsychology of recognition confabulation in hospitalized schizophrenic patients]. / Neuropsicología y neurofisiología de la confabulación de reconocimiento en pacientes esquizofrénicos hospitalizados.

Recognition confabulation was studied in 16 schizoprhenic patients and 16 normal controls. Half of the schizophrenics presented recognition confabulation, while the remaining 8 and 16 controls did not. This type of confabulation was associated to attentional deficiency, difficulties in perceptual follow-up and perceptive changes. These test satisfactorily discriminated confabulating schizoprhenics and both ill and healthy non-confabulating subjects. The possible mechanisms underlying this type of confabulation are discussed, in relation to the deficiences observed.

[Basis for the study of erectile dysfunction with pudendal evoked potentials]. / Bases para el estudio de las disfunciones erectiles mediante potenciales evocados de pudendo.

The evaluation of erectile dysfunction by popliteal and pudendal evoked potentials is not widely utilized in our country, although the foregoing has proved to be a useful technique in the evaluation of a possible neurological etiology. This study describes this simple, fast and low cost method of evaluation and reports the normal ranges. The study comprised 40 subjects; 15 were healthy volunteers and the remaining had consulted for impotence and referred antecedents suggesting a neurological etiology. The results show that a latency of 40.9 +/- 2.1 msec in P1 for the pudendal evoked potentials is normal. Concerning the popliteal evoked potentials, the normal latency for P1 is 38.07 +/- 2.8 msec.