SEARCH · PubMed Health

Results for “ECOG”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 379 records · Page 21Linked to original sources

PubMed1979

Electroencephalographic protective action of pyridoxylate during acute hypoxia and subsequent recovery in the rat.

Pyridoxylase at a concentration of 0.6 mmol/kg body weight injected intraperitoneally in rats, increased the resistance of animals to severe hypoxia (O2:3.2%; N2; 96.,%). The electrocorticogram (ECoG) was used to indicate the effectiveness of the drug in lowering the delay of electrographic silence, in 19 control rats and 12 pretreated rats. The ECoG was also recorded period under pure oxygen. In pretreated rats, the ECoG records became flat in a mean time of 551 s, compared with 269 s in the control group. The latent periods of successive steps during cerebral anoxia were significantly delayed in pyridoxylate-pretreated rats subjected to hypoxia. During the recovery period, pyridoxylate improved the recovery of the normal ECoG, particularly when values were expressed as a function of the duration of the hypoxic period. These findings are in good agreement with the significant protection afforded by pyridoxylate on the cerebral rate of energy-rich phosphate bond utilization during hypoxia studied in a separate work.

Animals↗

PubMed1992

Production of seizures and brain damage in rats by alpha-dendrotoxin, a selective K+ channel blocker.

alpha-Dendrotoxin (Dtx), a snake polypeptide, increases neuronal excitability by blocking certain fast-activating, voltage-dependent K+ channels. Thus, the behavioural, electrocortical (ECoG) and neuropathological effects of Dtx, injected into rat brain areas, were studied. A unilateral injection of 35 pmol of Dtx into the CA1 hippocampal area or the dendate gyrus (DG; upper blade) immediately produced motor and ECoG seizures, followed at 24 h by multi-focal brain damage and significant neuronal loss. Whilst brain damage was seen bilaterally, significant neuronal loss occurred only in regions (CA1, CA3, CA4 and DG) ipsilateral to the site of injection. A lower dose (3.5 pmol) of toxin elicited motor and ECoG seizures but failed to produce brain damage. Seizures were observed 50 min after injecting Dtx (35 pmol) into the amygdala, though significant neuronal loss was not evident. 4-Aminopyridine (100 nmol), given into the CA1 area elicited a similar motor and ECoG pattern to that of Dtx except no brain damage could be seen at 24 h. Systemic pretreatment with antagonists of N-methyl-D-aspartate receptors (MK-801 or CGP 37849) did not protect against the effects typically evoked by injecting Dtx into the CA1 area.

2-Amino-5-phosphonovalerate↗

PubMed1996

Sound-evoked electrocortical desynchronization is inhibited by N omega-nitro-L-arginine methyl ester microinfused into the inferior colliculi in rats.

In previous experiments we have shown that systemic or intracerebroventricular administration of N omega-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) synthase, is able to significantly reduce sound-evoked electrocortical (ECoG) desynchronization in rats. The present experiments were aimed at identifying the site(s) of the brain through which these effects are mediated. L-NAME (200 and 300 nmol), oxyhaemoglobin (200 and 300 nmol), a NO-trapping agent, and methylene blue (100 and 150 nmol), an inhibitor of guanylate cyclase and NO synthase, given bilaterally into the inferior colliculi, but not in other relay stations of the acoustic pathway, prevented the reduction in ECoG amplitude induced by sound stimulation in rats. Significant reduction of sound-evoked ECoG desynchronization has also been observed in rats receiving injection of CGP37849 (125 and 500 pmol) and LY274614 (125 pmol), two competitive N-methyl-D-aspartate receptor antagonists into the inferior colliculi. The present results show that the inferior colliculus represents the main site where sound-evoked ECoG desynchronization is prevented by L-NAME and provide further support for the hypothesis that NO may play a role at this level in the control of the measured response.

Animals↗

PubMed2004

Identification and removal of an epileptogenic lesion using Ictal-EEG, functional-neuronavigation and electrocorticography.

PURPOSE: Cases with intractable epilepsy may present with multiple lesions in their brains. Ictal-EEG carries a great value in identification of the primary epileptogenic source. On the other hand, removal of low-grade tumors located around the eloquent cortex may be risky with conventional techniques. Functional-neuronavigation (f-NN) is the integration of functional magnetic resonance imaging and stereotactic technologies; and provides interactive data regarding localization of the motor cortex. This report presents a case with dysembryoplastic neuroepithelial tumor (DNET), which was removed using f-NN and electrocorticography (ECoG) techniques. METHODS: A 19-year-old patient with intractable complex partial and secondary generalized seizures is presented. MRI revealed a low-grade tumor located in right parietal region just behind the motor cortex, and a contralateral temporal arachnoid cyst. Ictal-EEG demonstrated the right parietal origin of the seizures. The patient underwent a right parietal craniotomy and tumor excision using f-NN and ECoG techniques intraoperatively. ECoG findings correlated with epileptogenicity of the parietal lesion. RESULTS: Postoperative course was uneventful. No postoperative deficit was observed. The patient was seizure free in eight months follow-up. Pathological examination reported the lesion as DNET. CONCLUSIONS: Ictal-EEG has a very important role in identification of the epileptogenic focus in cases with multiple brain lesions. Preservation of the functional cortex is the most prominent aim during lesional surgery of epilepsy. Intraoperative mapping using f-NN and ECoG supports the orientation of the neurosurgeon to the functional and epileptogenic cortical areas; and thus, increase the safety and efficacy of surgical procedures.

Electrodes, Implanted↗

PubMed2006

Prolonged mild hypoxia alters fetal sheep electrocorticogram activity.

OBJECTIVE: To assess the effects of prolonged mild hypoxemia on fetal brain electrocorticogram (ECoG) in late gestation. STUDY DESIGN: Fetal and maternal catheters were placed under general anesthesia and animals allocated at random to receive intratracheal maternal administration of either nitrogen (n = 8) or compressed air (n = 8). Five days after surgery (125 days' gestational age), nitrogen infusion was adjusted to reduce fetal brachial artery PO2 by 25%. The targeted decrease in fetal oxygenation was maintained for 5 days while fetal ECoG activity and fetal and maternal cardiovascular variables were continuously recorded. Data are presented as mean +/- SEM and were analyzed by two-way analysis of variance (ANOVA) or two-sample t test. RESULTS: Nitrogen infusion decreased fetal Po2 by 26% (20.5 +/- 1.7 versus 14.3 +/- 0.8) without changing fetal PCO2 or pH. Mild fetal hypoxemia was associated with fetal tachycardia and increased fetal blood pressure (P < .05). Fetal ECoG in hypoxic fetuses showed a significant decrease in the time spent in high voltage (HV) (P < .05) and an increase in the time spent in low voltage (LV) and in the number of low voltage events (P < .05). Also, a significant decrease in the proportion of 1-4 Hz and an increase in the proportion of 13-20 Hz frequencies was observed in LV events without a significant change in the frequency profile of HV events (P < .05). CONCLUSION: Prolonged mild hypoxemia significantly altered fetal homeostasis as reflected by the sustained tachycardia and increased blood pressure. Fetal ECoG activity was affected significantly in a qualitatively and quantitative manner by mild prolonged hypoxemia.

Animals↗

PubMed2004

Extratympanic electrocochleographic changes on noise-induced temporary threshold shift.

OBJECTIVE: Electrocochleography (ECoG) is a sensitive evoked-response test for evaluating changes in cochlear function. We investigated the extratympanic ECoG in a noise-induced temporary threshold shift (TTS) to evaluate the usefulness of ECoG in the early detection of noise-induced hearing loss (NIHL). STUDY DESIGN AND METHODS: In a prospective analysis, 15 healthy ears were exposed to 90.3- to 105.0-dB noise for 3 hours in the same computer-game arcade. Pure-tone audiometry and ECoG were performed before, immediately after, and 24 hours after the exposure. RESULTS: Before the exposure, the average hearing level was 5.8 +/- 2.7 dB, which increased significantly to 12.8 +/- 2.8 dB immediately after exposure. A marked increment in the SP/AP (summating potential/action potential) ratio was observed with the TTS. The mean ratio was 0.22 +/- 0.11 before the exposure, 0.46 +/- 0.18 in the TTS phase, and 0.20 +/- 0.11 after resolution. CONCLUSION: The results of this study suggest that the SP/AP ratio is useful for the early detection and monitoring of NIHL.

Action Potentials↗

PubMedDate not supplied

Lycopene: a novel drug therapy in hormone refractory metastatic prostate cancer.

OBJECTIVE: In a prospective study we evaluated the efficacy of lycopene for the treatment of patients with metastatic hormone refractory prostate cancer. MATERIAL AND METHODS: Between January 2001 and December 2002, 20 consecutive patients (median age 72; range 56-90) with metastatic HRPC were enrolled in the study. Lycopene in the dose of 10 mg/day was administered for a period of 3 months. Inclusion criteria were patients previously treated with hormonal therapy now with clinical and biochemical evidence of disease progression. A complete response (CR) was defined as a normalization of PSA (<4 ng/mL) and the disappearance of any sign of disease for at least 8 weeks. A partial response was defined as a >50% decrease in PSA level for at least 8 weeks associated with improvement (or no worsening) in ECOG PS and relief of bone pain if present. Stable disease (SD) was defined as a <50% decrease or <25% increase in the PSA level associated with no worsening of ECOG PS and/or bone pain for at least 8 weeks. RESULTS: One patient (5%) had complete response. Partial response was achieved in 6 (30%), disease remained stable in 10 (50%) and progressed in three (15%) patients. ECOG PS was Grade 0 in five, Grade I in 10 and Grade II in five of the 20 patients. It improved from Grade I to 0 in seven and Grade II to I in three patients. It deteriorated in three and remained unchanged in the rest seven patients. Bone pain was present in 16 (Grade 1 in six and Grade 2 in 10) of the 20 patients. Grade 1 changed to Grade 0 in five and Grade II changed to Grade 1 in five patients. Bone pain remained unchanged in 5 (31%) and worsened in 1 (6%). Ten (62%) patients managed to cut down the dose of analgesics on daily basis. Eighteen patients had associated LUTS, which improved (Q max > or = 12 mL/sec) in 11 (61%) patients. The median duration of response was 25 weeks (range 12-72 weeks). No drug intolerance or toxicity was encountered in any patient. CONCLUSIONS: Lycopene therapy appears to be effective and safe in the treatment of HRPC. It not only takes care of the rising PSA but also improves the ECOG performance status, bone pain and LUTS. Because of its relative innocuousness it should be tried before the use of more toxic substances.

Administration, Oral↗

PubMed2000

Prognostic indicators for renal cell carcinoma: a multivariate analysis of 643 patients using the revised 1997 TNM staging criteria.

PURPOSE: We determine independent prognostic indicators for renal cell carcinoma using the revised 1997 TNM staging criteria. MATERIALS AND METHODS: The records of 643 consecutive patients undergoing partial or radical nephrectomy at our institution between 1987 and 1998 were reviewed. Preoperative evaluation of functional status using the Eastern Cooperative Oncology Group (ECOG) criteria was performed in all cases. Renal cell carcinoma grade and stage were evaluated using the 1997 American Joint Committee on Cancer grading and TNM staging criteria, respectively. Patients were followed for a mean plus or minus standard deviation of 47+/-40 months (median 87). Kaplan-Meier survival curves were used to determine 5-year cancer specific survival for all patient groups. Univariate analysis using log rank sum tests was performed to evaluate the prognostic significance of overall TNM stage, tumor stage, disease grade and ECOG status. Multivariate analysis was performed to determine which factors had an independent impact on survival of patients with renal cell carcinoma. RESULTS: The 5-year cancer specific survival rate was 91%, 74%, 67% and 32% for TNM stages I, II, III and IV lesions, respectively (p<0.001). Analysis demonstrated a survival rate of 83% for stage T1, 57% for stage T2, 42% for stage T3 and 28% for stage T4 disease (p<0.001), and 89% for grade 1, 65% for grade 2, and 46% for grades 3 and 4 (p<0.001). Multivariate analysis revealed that overall TNM stage and grade of disease were the most important prognostic indicators for renal cell carcinoma (p<0.001). ECOG classification was a less significant predictor (p = 0.031) and tumor stage was not shown to have any independent impact on patient survival (p = 0.138). CONCLUSIONS: Better survival rates of patients with localized and advanced renal cell carcinoma can be demonstrated with recent advances in diagnosis and treatment. The revised 1997 TNM criteria manifest an appropriate adjustment in staging renal cell carcinoma based on these improvements, with overall stage correlating with cancer specific survival. In contrast, while effectively predicting survival, tumor stage did not demonstrate an independent impact on renal cell carcinoma prognosis under multivariate analysis. Instead, other factors, such as ECOG status and more importantly grade of disease, appeared to affect survival significantly as independent elements. Based on our recent experience with patients treated for renal cell carcinoma in the era of enhanced technology and improved survival, tumor grade and molecular markers may serve as useful adjuncts to TNM staging in guiding treatment and predicting survival outcomes.

Adult↗

PubMed1998

Involvement of direct and indirect pathways in electrocorticographic activation.

Recent evidence indicates that neocortical electrocorticographic (ECoG) activation depends critically on cholinergic (ACh) inputs from the basal forebrain and serotonergic (5-hydroxytryptamine, 5-HT) inputs from the midbrain raphe to the neocortex. It appears that ACh and 5-HT block synchronized ECoG activity and induce cortical activation by a direct, local action in the neocortex that is not mediated by secondary systems. Concurrent blockade of cholinergic and serotonergic inputs to the cortex abolishes all ECoG activation, suggesting that: (a) together, ACh and 5-HT are essential for cortical activation to occur; and (b) other systems cannot maintain cortical activation in the absence of the cholinergic and serotonergic inputs. Nevertheless, additional neural systems (amygdala, locus coeruleus-noradrenaline (-NA), superior colliculus, orbitofrontal cortex, dopamine, histamine, glutamate) also modulate the ECoG and can produce cortical activation. In contrast to ACh and 5-HT, however, none of these systems are essential for the maintenance of cortical activation. Further, rather than producing activation via direct inputs to the neocortex, these systems appear to produce cortical activation by stimulating the cholinergic or serotonergic inputs to cortex. Thus, neocortical activation is maintained by multiple, parallel systems; cholinergic and serotonergic pathways are essential for activation and produce activation directly and locally in the neocortex, whereas additional pathways are not essential and contribute to activation indirectly by acting through these two direct activating inputs to the cortex.

Animals↗

PubMed2003

Efficacy of modified regimen with attenuated doses of paclitaxel plus carboplatin combination chemotherapy in elderly and/or weak patients with advanced non-small cell lung cancer.

PURPOSE: We conducted this study to evaluate the activity and toxicity of a combination regimen of paclitaxel plus carboplatin in patients with advanced NSCLC aged 65 years or older and/or in those with an ECOG performance status (PS) 2. MATERIALS AND METHODS: Chemotherapy-naive patients with unresectable pathologically-proven NSCLC and of either age >or=65 or ECOG PS 2 were eligible. Patients received modified regimen with attenuated doses of paclitaxel (135 mg/m(2) i.v. for 3 h D1) and carboplatin (AUC=5, D1) every 3 weeks. RESULTS: Thirty-five patients were enrolled. Nineteen patients were aged 65 or older (54%) and 26 patients (74%) were ECOG PS 2. The objective response rate was 40% with 14 partial responses. The median time to progression was 22 weeks. Grade 3 leucopenia occurred in 1 cycle and one case of neutropenic fever. CONCLUSIONS: The modified regimen with attenuated doses of paclitaxel plus carboplatin combination chemotherapy was effective and well tolerated in patients with advanced NSCLC aged 65 years or older and/or in those with ECOG PS 2.

Age Factors↗

PubMed1998

Effect of pregnane steroids on electrocortical activity and somatosensory evoked potentials in fetal sheep.

The effect of infusing the neuroactive steroids pregnanolone and iso-pregnanolone on somatosensory evoked potentials (SEP) and electrocortical (ECoG) activity was studied in unanaesthetised fetal sheep, 130-135 days gestation. Intravenous infusion of pregnanolone (6 mg/kg per h) significantly increased the proportion of high voltage ECoG (56.1+/-4.8% vs. control 43.5+/-3.2%, P < 0.05), and decreased low voltage ECoG (43.9+/-4.8% vs. control 56.6+/-3.2%, P < 0.05). Pregnanolone treatment decreased the amplitude of the N25 peak of the SEP (89.9+/-2.8% of control, P < 0.05) evoked following stimulation of the skin of the upper lip. In contrast, iso-pregnanolone treatment had no effect on ECoG activities, or on the amplitude and latency of peaks in the SEP. We conclude that 3alpha-hydroxy pregnane steroids are active at GABA(A) receptors in fetal sheep and can modulate sleep/wake activity before birth.

Animals↗

PubMed2003

Integrated contributions of basal forebrain and thalamus to neocortical activation elicited by pedunculopontine tegmental stimulation in urethane-anesthetized rats.

Efferents from the pedunculopontine tegmentum (PPTg) exert widespread control over neocortical electrocorticographic (ECoG) activity and aid in maintaining high-frequency ECoG activation during waking and rapid eye movement sleep. The mechanisms and subcortical routes that allow the PPTg to influence cortical activity remain controversial. We examined the relative contributions of the thalamus and basal forebrain in ECoG activation elicited by PPTg stimulation in urethane-anesthetized rats. Stimulation (100 Hz, 2 s) of the PPTg suppressed large-amplitude, low-frequency oscillations, replacing them with high-frequency beta-gamma activity. Systemic administration of the anti-muscarinic drug scopolamine (1 mg/kg, i.p.) abolished activation elicited by PPTg stimulation, suggestive of an essential role of acetylcholine in this effect. Local infusions of lidocaine (1 microl, 1%) into the region of the cholinergic basal forebrain complex produced a strong reduction in activation elicited by PPTg stimulation. Lidocaine infusions into the reticular thalamic nucleus had no effect, but infusions into central thalamus produced a small attenuation of PPTg-evoked cortical activation. Combined basal forebrain-central thalamic infusions (1 microl/site) produced roughly additive effects, leading to a greater loss of activation than single-site infusions. These results indicate that, under the present experimental conditions, high-frequency cortical ECoG activation elicited by the PPTg involves relays in both the basal forebrain and central thalamus, with a predominant role of the basal forebrain. After concurrent central thalamic-basal forebrain inactivation, the forebrain can maintain only limited, short-lasting activation in response to PPTg stimulation. The additivity of infusion effects suggests that, rather than participating in one serial system, basal forebrain and central thalamus constitute parallel activating pathways. These findings aid in resolving previous controversies regarding the role of thalamus and basal forebrain in activation by emphasizing the importance of multiple, large-scale networks between brainstem and cortex in regulating the activation state of the mammalian neocortex.

Acetylcholine↗

PubMed1997

A retrospective cost-effectiveness analysis of interferon as adjuvant therapy in high-risk resected cutaneous melanoma.

To assess the cost per life year gained of alpha interferon (IFN) as adjuvant therapy for patients with high-risk resected melanoma, we conducted a retrospective, incremental cost-effectiveness analysis on clinical data from a previously published ECOG trial [9]. The Gompertz model was used to estimate the total lifetime values of patient-years of subjects receiving IFN in comparison with subjects given no adjuvant treatment. The ECOG trial involved 143 patients treated with high-dose IFN and 137 given no adjuvant treatment. Estimated drug expenditures were based on the assumption of a cost of $109.25 per 10 MU of IFN. Our analysis of the ECOG results showed that the adjuvant treatment of 100 subjects with high-dose IFN improved survival expectancy by 133.6 discounted life years or 308 undiscounted life years. The use of IFN (compared with no adjuvant treatment) implied an incremental cost of $16,467 per discounted life year saved (95% CI of $4752-50,000) or $7143 per undiscounted life year saved (95% CI of $3226-33,846). Sensitivity testing, in which variations were introduced in the main factors influencing cost and effectiveness, showed that this value always remained below $50,000. Our pharmacoeconomic analysis indicates that adjuvant treatment with high-dose IFN in patients with high-risk resected melanoma implies a favourable cost-effectiveness ratio. Because two other studies showed no significant survival benefit in patients receiving adjuvant IFN at lower values of total dose per patient, the controversy remains and confirmation data are needed for the ECOG trial's results. If these clinical results are confirmed, our analysis shows that the dosage of IFN given in this trial has a favourable pharmacoeconomic profile.

Antineoplastic Agents↗

PubMed2000

Intraoperative electrocorticography in temporal lobe epilepsy surgery.

Although in clinical use for many years, the validity of intraoperative electrocorticography (ECoG) in guiding resective temporal lobe epilepsy (TLE) surgery is uncertain. Advances in neuroimaging and extraoperative intracranial recordings have contributed greatly to the identification of epileptogenic lesions and cortex, clarifying the limitations of a brief intraoperative interictal recording. Studies of undifferentiated ECoG findings (which classify all interictal cortical spike discharges as equal) tend to not support this method. This article reviews ECoG and presents data from 86 TLE surgeries at the University of British Columbia suggesting that differentiation of ECoG features may enhance the contribution of this time honored method. Specifically, independent foci may be more important for epileptogenesis than synchronous foci, and postexcision activation appears to be a benign phenomenon, while residual spikes unaltered by the resection correlate with a greater proportion of seizure recurrence.

Anesthesia↗

PubMed2001

MEG predicts epileptic zone in lesional extrahippocampal epilepsy: 12 pediatric surgery cases.

PURPOSE: To discover whether the spatial distribution of spike sources determined by magnetoencephalography (MEG) provides reliable information for planning surgery and predicting outcomes in pediatric patients with lesional extrahippocampal epilepsy. METHODS: We retrospectively studied 12 children with extrahippocampal epilepsy secondary to cortical dysplasia (CD), tumor, or porencephalic cyst. We compared interictal MEG spike source locations and somatosensory evoked fields derived from equivalent-current dipole modeling with intraoperative or extraoperative electrocorticography (ECoG). RESULTS: MEG spike sources were found in proximity to the lesion in all patients and extended from lesions in five patients with CD. Marginal spike sources were noted in three patients with tumors, one patient with a cyst, and one with CD, and extramarginal sources in three patients with tumors. Three patients with tumors underwent lesionectomy only; two had further cortical excisions. One patient with CD underwent lesionectomy only, three had lesionectomy and cortical excisions, and two had lesionectomy and multiple subpial transection. Asymmetric MEG spike sources correlated with ECoG findings in all patients. Residual epileptiform discharges on postexcisional ECoG corresponded to spike sources in three patients with tumors and one patient with a cyst. Eleven patients have been seizure free for 1-6 years (mean, 4 years). One patient had residual seizures after incomplete excision of right temporal CD. CONCLUSIONS: MEG delineated asymmetric epileptogenicity surrounding lesions and the eloquent cortex. Complete tumor resection produced favorable outcomes despite residual postexcisional ECoG spikes and extramarginal MEG spike sources. CD characterized by clusters of MEG spike sources within and extending from lesions seen on magnetic resonance imaging (MRI) should be removed to prevent seizures.

Adolescent↗

PubMed1982

Participation of community hospitals in clinical trials: analysis of five years of experience in the Eastern Cooperative Oncology Group.

The Eastern Cooperative Oncology Group (ECOG) initiated a program in 1976 to involve community hospitals in multi-institutional clinical trials. The community hospitals can be characterized as generally having no tradition of participating in clinical trials of cancer therapy, whereas the ECOG member institutions are university hospitals or major treatment centers. More than 100 community hospitals participated in 97 randomized trials involving 4506 patients from November 1976 through February 1981. Comparisons between the community hospitals and the ECOG member institutions indicate that the quality of participation was similar, as measured by rates of ineligibility, compliance with the protocol, and submission of data. Objective measures of outcome, such as survival, response, and toxicity, were also comparable. We conclude that under the mechanism adopted by the ECOG, it is possible to include community hospitals in clinical trials of cancer therapy without reducing the quality of the data or compromising the therapeutic outcomes.

Clinical Trials as Topic↗

PubMed1998

Sensitivity and specificity of transtympanic electrocochleography in Meniere's disease.

Transtympanic electrocochleography (TT ECoG) was conducted in 61 patients (61 ears) with the clinical diagnosis of Meniere's disease and 15 patients (21 ears) with cochlear hearing loss of other aetiologies to assess the ability of the method to separate different cochlear disorders. The click-evoked summation potential/action potential (SP/AP) ratio and the 1 and 2 kHz burst-evoked SP amplitudes were evaluated. Based on the TT ECoG results from 13 normal hearing subjects (15 ears) the upper limit of each variable was determined, above which a value was considered pathological, i.e. indicative of endolymphatic hydrops. The results showed that the sensitivity of the SP/AP ratio was 62% and specificity 95%. When evaluating the combinations of TT ECoG parameters with logistic regression, SP/AP ratio and 1 kHz burst-evoked SP amplitude were shown to increase the discriminating ability of TT ECoG significantly. Inclusion of the 1 kHz burst-evoked SP amplitudes increased sensitivity to 82%, without changing specificity. Inclusion of the 2 kHz burst had no effect on sensitivity or specificity.

Adult↗

PubMed2004

A brain-computer interface using electrocorticographic signals in humans.

Brain-computer interfaces (BCIs) enable users to control devices with electroencephalographic (EEG) activity from the scalp or with single-neuron activity from within the brain. Both methods have disadvantages: EEG has limited resolution and requires extensive training, while single-neuron recording entails significant clinical risks and has limited stability. We demonstrate here for the first time that electrocorticographic (ECoG) activity recorded from the surface of the brain can enable users to control a one-dimensional computer cursor rapidly and accurately. We first identified ECoG signals that were associated with different types of motor and speech imagery. Over brief training periods of 3-24 min, four patients then used these signals to master closed-loop control and to achieve success rates of 74-100% in a one-dimensional binary task. In additional open-loop experiments, we found that ECoG signals at frequencies up to 180 Hz encoded substantial information about the direction of two-dimensional joystick movements. Our results suggest that an ECoG-based BCI could provide for people with severe motor disabilities a non-muscular communication and control option that is more powerful than EEG-based BCIs and is potentially more stable and less traumatic than BCIs that use electrodes penetrating the brain.

Adult↗