Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “ELECTROENCEPHALOGRAPHY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 991 records · Page 55Linked to original sources
PubMed1979

Value of electroencephalography (EEG) before and after surgery of intracranial aneurysms.

Electroencephalographic (EEG) investigations were done in 36 patients with intracranial aneurysms, before and after surgery. Thirty five of them suffered from subarachnoid hemorrhage (SAH). Pre-operatively, there was no correlation between patients' age or sex and localisation of the aneurysm or degree of EEG disturbances. The most frequent finding was a generalised slowing, the degree of which depended on the time from bleeding to EEG. Focal abnormalities were due to spasms of the vessels or intracerebral haematomas. There was a high correlation with neurological deficits. Post-operatively, EEG disturbances became worse in 21 cases. Generalised and focal abnormalities increased. These were due to focal oedema and the operative approach. The EEG could be correlated very well with the findings from other investigative methods (CT scanning, angiography). The EEG, as a functional method, showed very well the whole state of the brain after bleeding and after operation.

Adult↗
PubMed1980

[Electroencephalography in hepatic coma: therapy with hemoperfusion (author's transl)].

Six patients (two men and four women) aged between 15 and 60 years in hepatic coma stage IV and with very severe EEG changes were treated with hemoperfusion. The causes leading to coma were acute virus hepatitis A in two cases, hepatitis B in three cases, and Amanita intoxication in one case. Only the patient with Amanita intoxication survived. On admission to the hospital, there were very severe EEG changes of stage IV in all patients. They preceded the clinical manifestation of coma stage IV up to one day in half of the patients who were at most in coma stage II at this time. At the beginning of therapy better survival chances are reported in the lower coma stages. On the basis of the severely pathological EEG findings preceding the clinical coma in a proportion of the patients, an earlier start of therapy should thus be demanded.

Adolescent↗
PubMed1979

Computerized tomography (CT), electroencephalography (EEG), and clinical symptoms in severe cranio-cerebral injuries: A comparative study.

In the first six months of 1977 156 patients with craniocerebral injuries underwent computerized tomography. Twelve had severe deficits which led to neurosurgical interventions. Only five had space-occupying haematomas. CT was useful in detecting neurosurgical complications, whereas EEG was useful in staging the severity of the trauma. The two methods, the functional one of EEG and the morphological one of CT, are complementary, especially with regard to the posttraumatic course. The clinical symptoms are reflected by EEG better than by CT.

Adolescent↗
PubMed1993

Continuous transcranial Doppler ultrasonography and electroencephalography during carotid endarterectomy: a multimodal monitoring system to detect intraoperative ischemia.

Transcranial Doppler ultrasonography (TCD) and EEG monitoring during carotid endarterectomy provide continuous information on the electrical activity of the cerebral cortex, blood flow velocities in the ipsilateral middle cerebral artery, and the occurrence of microemboli. One hundred thirty carotid endarterectomies performed with TCD and EEG monitoring were studied prospectively. During cross-clamping of the carotid artery a high correlation was found between EEG asymmetry and reduction of blood flow velocity in the middle cerebral artery (p < 10(-6), Student's t test). Microemboli were detected in 80 patients during the operation. Although not statistically significant, this occurrence of microemboli was associated with signs and symptoms of intraoperative ischemia (p = 0.08, Fisher's exact test). In comparison with earlier studies, a tendency toward intraoperative stroke reduction was noted. Only one nondisabling intraoperative stroke occurred (0.8%). In addition to the EEG, TCD monitoring of hemodynamic changes and microemboli in the middle cerebral artery provides important information to the surgeon instantaneously. TCD monitoring of blood flow velocities and embolism during carotid endarterectomy may help to reduce the number and gravity of intraoperative stroke.

Adult↗
PubMed1987

Periodic activity in electroencephalography.

We report ana analysis of 12 cases in which periodic activity was observed in more than one EEG recording in patients with subacute sclerosing panencephalitis (4 cases), encephalitis of unknown etiology (1 case) and vascular disease (7 cases). In the patients with infective disease periodic high voltage potentials were elicited from all over the brain and the background rhythm was markedly impaired. In the patients with vascular disease the bursts were localized, reversible and sometimes recurrent. The impression gained is that a periodic EEG pattern denotes a pathological modification of behavior of the cerebral cortex rather than any particular disease.

Adolescent↗
PubMed2005

Predictive value of electroencephalography and computed tomography in childhood non-traumatic coma.

OBJECTIVES: To study value of electroencephalogram (EEG) and computed tomography (CT Scan) in predicting outcome of non-traumatic coma in children. METHODS: 100 consecutive children, between 2 months to 12 years, with non-traumatic coma, (Glasgow Coma Scale score < 8). Demographic and clinical data was recorded at admission. EEG and CT scan were done within 24 hours of admission. Etiologic diagnosis was assigned on basis of clinical data and relevant laboratory investigations. The outcome was recorded as survived and died. Among survivors it was graded as no disability, or mild, moderate, or severe disability. Odds ratio and/or relative risk (RR) with 95% confidence interval (C I) were calculated. RESULTS: EEG could be done in 60 patients (43 survived; 7 were normal, 8 had mild, 17 moderate and 11 severe disability) CT scan in 93 patients (60 survived; 11 were normal, 14 had mild, 21 moderate and 14 severe disability). A normal/borderline EEG was associated with good outcome (P = 0.001); 11 of 12 survived and of survivors 55% had no or mild disability. Electrocerebral silence on EEG was a predictor of death (OR = 44 -sub .95% Cl - 1.5-7372; P = 0.01). An abnormal EEG was associated with significant increase in risk of disability among survivors (RR = 2.6, 95% Cl = 1.2-5.4, P = 0.03). Among CT abnormalities intracranial bleed suggested increased risk of death (RR = 2.1; 95% Cl - 0.8-5.3; P = 0.058), while, hydrocephalus was associated with better survival (RR = 0.7; 95% CI - 0.5 to 0.96; P = 0.029). However, hydrocephalus when compared with other abnormal CT scan findings, was associated with higher risk of moderate and severe disability among survivors (P = 0.046) CONCLUSION: A normal CT scan and EEG, and some of the specific findings could be helpful in predicting outcome in children with non-traumatic coma. EEG and CT scan should be done at admission in all patients with non-traumatic coma if feasible.

Child↗
PubMed1989

Electroencephalography, visual evoked potentials, and cerebral CAT-scan as diagnostic tools in senile dementia of Alzheimer type.

The usefulness of a cerebral computed tomogram (CAT-scan), an electro-encephalogram (EEG), and flash visual evoked responses (FVER) as diagnostic tools in dementia was studied in 36 mentally impaired and 32 unimpaired persons aged 75 yr and above, who were recruited from a random sample of elderly people living at home. The clinical diagnosis of dementia was made after a full psychogeriatric assessment supplemented by a follow-up 18 mo later. When the measures of cortical atrophy from a cerebral CAT-scan, the presence/absence of diffuse slow activity on a standard EEG, and FVER P200 and FVER P100 latencies were introduced in a logistic regression model, the clinical diagnoses being the dependent variable, an effective prediction of senile dementia of Alzheimer type (SDAT) was obtained (sensitivity 93%, specificity 86%, misclassification rate 12%). We conclude that the use of FVER, an EEG, and a cerebral CAT-scan may facilitate the diagnosis of senile dementia of Alzheimer type.

Aged↗
PubMed2000

Caffeine withdrawal increases cerebral blood flow velocity and alters quantitative electroencephalography (EEG) activity.

RATIONALE: Cessation of daily caffeine consumption produces a withdrawal syndrome comprised of subjective symptoms and functional impairment. Few controlled studies have examined the physiological effects of caffeine withdrawal. OBJECTIVE: The present study examined the effect of caffeine withdrawal on cerebral blood flow velocity and quantitative EEG. METHODS: Ten volunteers reporting moderate caffeine intake (mean 333 mg/day) participated in this double-blind study. Subjects completed several tests when maintaining their normal diet (baseline period) and during two 1-day periods during which they consumed caffeine-free diets and received capsules containing placebo (placebo test session) or caffeine (caffeine test session) in amounts equal to their baseline daily caffeine consumption. Blood flow velocity was determined for four arteries: right and left middle (MCA), and right and left anterior (ACA) cerebral arteries using pulsed transcranial Doppler sonography. EEG was recorded for 3 min from eight scalp sites while subjects sat, with eyes closed, in a sound-attenuated electronically shielded chamber. Subjective effects were assessed with questionnaires. RESULTS: Results showed an effect of the placebo (21-h withdrawal) condition compared to the caffeine condition. Placebo significantly increased the mean velocity, systolic velocity and diastolic velocity (cm/s) in all four cerebral arteries. In the MCA, the pulsatility index was significantly decreased following placebo. Placebo significantly increased EEG theta power. Placebo also produces subjective effect changes, including increases in heavy feelings in arms and legs and decreases in ability to concentrate. The caffeine and baseline conditions produced similar results on both the physiological and subjective measures. CONCLUSION: Cessation of daily caffeine consumption produced changes in cerebral blood flow velocity and quantitative EEG. These changes may be related to classic caffeine withdrawal symptoms of headache, drowsiness and decreased alertness.

Adult↗
PubMed2006

Electroencephalography in epilepsy surgery planning.

OBJECTIVE: To describe localizing value of surface EEG recording in the presurgical evaluation of medically intractable pediatric epilepsy patients. METHODS: We review the relevant concepts required for understanding the role of surface EEG in the presurgical evaluation and in identifying the epileptogenic zone. The unique features of EEG and its limitations are discussed. CONCLUSION: Despite recent technological advancements, surface EEG continues to play a crucial role in defining the epileptogenic zone, and thus in presurgical planning.

Child, Preschool↗
PubMed2006

Spherical splines and average referencing in scalp electroencephalography.

EEG analysis and interpretation are affected by the reference electrode. Average referenced potentials are used widely to approximate the potentials relative to infinity, but estimates of the average surface potential are prone to errors due to incomplete sampling of the scalp surface. Even if the electrode density is high, this arises by not sampling the inferior scalp surface. This paper shows analytically how the spherical splines represent the average surface potential. It also shows that, for spline orders m > or = 3, the interpolating function is well approximated by its large-m limit, weighting near and distant electrodes with opposite signs. Together these motivate the hypothesis that spherical splines permit a better estimate of the potentials relative to infinity than the discrete average computed over superior scalp electrodes. It tests this hypothesis using numerical simulations in a four-sphere head model with single- and many-dipole sources, and variations in spline order, electrode number and head model parameters. The results confirm that the spherical splines yield a better estimate of the potentials relative to infinity, provided the electrode sampling density is adequate.

Brain Mapping↗