Respuesta eléctrica de la corteza contralateral al área de infarto en pacientes con enfermedad cerebrovascular isquémica / Electric response of the contralateral cortex to the myocardial infarction area in patients with ischemic cerebrovascular disease

Se realizó un estudio observacional, descriptivo, longitudinal y prospectivo de 28 pacientes con enfermedad cerebrovascular isquémica, ingresados en el Servicio de Enfermedades Cerebrovasculares del Hospital General Docente "Dr. Juan Bruno Zayas Alfonso" de Santiago de Cuba, desde enero hasta diciembre del 2011, con vistas a evaluar la respuesta eléctrica de la corteza cerebral contralateral al área de infarto y su papel en la recuperación motora de los afectados hemipléjicos por la lesión. La valoración de la actividad eléctrica se efectuó mediante el análisis cuantitativo del electroencefalograma digital y la de la recuperación funcional, por el índice de Barthel. En la serie la edad media fue de 67,2 años ± 2, predominó el sexo masculino y todos los pacientes presentaron alteración de la actividad eléctrica cortical, de los cuales, 39,3 % la manifestaba en el hemisferio contralateral al área de infarto, con una peor recuperación motora a los 6 meses de evolución. Por último, la afectación eléctrica de la corteza cerebral contralateral al área de infarto constituye una manifestación observada frecuentemente en pacientes con enfermedades cerebrovasculares isquémicas, lo que influye de manera negativa en su recuperación motora.

An observational, descriptive, longitudinal and prospective study of 28 patients with ischemic cerebrovascular disease, admitted in the Cerebrovascular Diseases Service of "Dr. Juan Bruno Zayas Alfonso" Teaching General Hospital in Santiago de Cuba was carried out from January to December, 2011, with the objective of evaluating the electric response from the contralateral cerebral cortex to the myocardial infarction area and its role in the motor recovery of the affected hemiplegic patients. The evaluation of the electric activity was made by means of the quantitative analysis of the digital electroencephalogram, and that of the functional recovery through the Barthel index. In the series the mean age was of 67.2 years ± 2, the male sex prevailed and all the patients presented changes of the electrical cortical activity, of which, 39.3% manifested it in the contralateral hemisphere to the myocardial infarction area, with a worse motor recovery after 6 months of the clinical course. Lastly, the electric damage of the contralateral cerebral cortex to the myocardial infarction area constitutes a frequently observed manifestation in patients with ischemic cerebrovascular diseases, what influences in a negative way in their motor recovery.

Cortical activity in tinnitus patients and its modification by phonostimulation

OBJECTIVE: The goal of this study was to observe spontaneous cortical activity and cortical activity modulated by tinnitus-matched sound in tinnitus patients and healthy subjects with no otoneurologic symptoms. METHOD: Data were prospectively collected from 50 tinnitus patients and 25 healthy subjects. Cortical activity was recorded in all subjects with eyes closed and open and during photostimulation, hyperventilation and acoustic stimulation using 19-channel quantitative electroencephalography. The sound applied in the tinnitus patients was individually matched with the ability to mask or equal the tinnitus. The maximal and mean amplitude of the delta, theta, alpha and beta waves and the type and amount of the pathologic EEG patterns were noted during each recording. Differences in cortical localization and the influence of sound stimuli on spontaneous cortical activity were evaluated between the groups. RESULTS: The tinnitus group exhibited decreased delta activity and increased alpha and beta activity. Hyperventilation increased the intensity of the differences. The tinnitus patients had more sharp-slow waves and increased slow wave amplitude. Sound stimuli modified the EEG recordings; the delta and beta wave amplitudes were increased, whereas the alpha-1 wave amplitude was decreased. Acoustic stimulation only slightly affected the temporal region. CONCLUSION: Cortical activity in the tinnitus patients clearly differed from that in healthy subjects, i.e., tinnitus is not a “phantom” sign. The changes in cortical activity included decreased delta wave amplitudes, increased alpha-1, beta-1 and beta-h wave amplitudes and pathologic patterns. Cortical activity modifications occurred predominantly in the temporal region. Acoustic stimulation affected spontaneous cortical activity only in tinnitus patients, and although the applied sound was individually matched, the pathologic changes were only slightly improved. .

Changes in Activity of Human Motor Cortex Caused by Hyperbaric Air Therapy

OBJECTIVE: To evaluate the effect of hyperbaric air therapy (HAT) on activity of cerebral motor cortex METHOD: Eighteen right-handed subjects were recruited, who had no brain lesion and did not take any medication that can affect brain function. Experimental group (n=9) underwent motor evoked potential (MEP) study by transcranial magnetic stimulation before and after 1-hour HAT. Control group (n=9) also received motor evoked potential study twice with 1 hour interval. The cortical activity was evaluated with parameters such as resting motor threshold (rMT), amplitude of MEP, intracortical inhibition (ICI) and intracortical facilitation (ICF) and recruitment curve (RC). RESULTS: There was no significant difference of rMT, MEP, ICI, ICF and RC between experimental group and control group. CONCLUSION: One -hour hyperbaric air therapy could not modulate any cortical motor activity in health human brain.

The Influence of Negative Emotion to Cortical Activity Induced by Auditory Verbal Imagery / 신경정신의학

OBJECTIVE: The concern about auditory verbal imagery has increased due to its possible relationship with auditory hallucinations. The research on auditory hallucinations was activated in accordance with the advance of neurophysiologic and functional neuroimaging studies, and the relationship between auditory verbal imagery and auditory hallucination was also investigated with neuroscientific methods. In particular, the group of neuropsychiatrists who insisted that auditory hallucination results from the abnormality of self monitoring systems has attempted to document the relationship between auditory verbal imagery and auditory hallucination using brain activation studies. Most auditory hallucinations are derogatory in content and accompany negative emotions. If auditory verbal imagery plays an important role in the pathogenesis of auditory hallucination, then it must be influenced by negative emotions. This study was aimed to examine the hypotheses that negative emotions have influence on cortical activity provoked by auditory verbal imagery and that the area which is influenced by negative emotions is where it is regarded to be related to either auditory hallucinations or self monitoring systems. METHOD: To examine these hypotheses, quantitative electroencephalography (Q-EEG) was applied during the auditory verbal imagery tasks using a two word list. The one word list accompanied negative emotion and the other accompanied neutral emotions, and they were suggested to the subject via computer monitor system. Total 18 right handed normal subjects(11 male subjects and 7 female subjects) were enrolled. RESULTS: The difference of EEG amplitude between during the baseline task and during auditory verbal imagery task using neutral word list: there were no significant difference in all electrode and all alpha, beta, theta, and delta frequency bands. The difference of EEG amplitude between during the baseline task and during auditory verbal imagery task using negative word list: In alpha frequency band, the EEG amplitude was increased in bilateral parietal, bilateral posterior temporal and bilateral occipital area. In beta frequency band, the EEG amplitude increased in bilateral parietal, bilateral occipital and left posterior temporal area. In theta frequency band, the EEG amplitude increased in TT2, T5, T6. In delta frequency band, there were no significant differences. The difference of EEG amplitude between during the two auditory verbal imagery tasks using negative word list and neutral word list: In alpha frequency band, there was an increasing trend in TT1 and a decreasing trend in frontal area including F4 during the negative auditory verbal imagery in EEG amplitude, although statistically not significant. In beta frequency band, EEG amplitude was increased in temporal area such as TCP1. In addition, there was an increasing trend in T5 in EEG amplitude, although statistically not significant. In theta frequency band, the EEG amplitude was decreased in the right hemisphere areas such as FP2, F4, C4, CP2, P4. In delta frequency band, there were no significant differences. CONCLUSION: In summarizing the above results, left temporal area was more activated during auditory verbal imagery using negative word list than using neutral word list. Left temporal area is known to play an important role in self monitoring systems and left temporal abnormality has been observed in schizophrenic patients in many studies. According to the above results, during auditory verbal imagery with negative emotion, more activation in left temporal area is necessary, but that may not achieved in schizophrenia patients. So, the possibility that the resultant disturbance of self monitoring system may be related to auditory hallucination is suggested in this study.