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Biomedical subjects

W Cote

Publications and source records attributed to W Cote.

5 recordsLinked to original sources
PubMed1998

Experimentation with a transcranial magnetic stimulation system for functional brain mapping.

We describe functional brain mapping experiments using a transcranial magnetic stimulation (TMS) device. This device, when placed on a subject's scalp, stimulates the underlying neurons by generating focused magnetic field pulses. A brain mapping is then generated by measuring responses of different motor and sensory functions to this stimulation. The key process in generating this mapping is the association of the 3-D positions and orientations of the TMS probe on the scalp to a 3-D brain reconstruction such as is feasible with a magnetic resonance image (MRI). We have developed a registration system which not only generates functional brain maps using such a device, but also provides real-time feedback to guide the technician in placing the probe at appropriate points on the head to achieve the desired map resolution. Functional areas we have mapped are the motor and visual cortex. Validation experiments focus on repeatability tests for mapping the same subjects several times. Applications of the technique include neuroanatomy research, surgical planning and guidance, treatment and disease monitoring, and therapeutic procedures.

Brain Mapping↗
PubMed1998

Visual hemifield mapping using transcranial magnetic stimulation coregistered with cortical surfaces derived from magnetic resonance images.

The perception of a visual stimulus can be inhibited by occipital transcranial magnetic stimulation. This visual suppression effect has been attributed to disruption in the cortical gray matter of primary visual cortex or in the fiber tracts leading to V1 from the thalamus. However, others have suggested that the visual suppression effect is caused by disruption in secondary visual cortex. Here the authors used a figure-eight coil, which produces a focal magnetic field, and a Quadropulse stimulator to produce visual suppression contralateral to the stimulated hemisphere in five normal volunteer subjects. The authors coregistered the stimulation sites with magnetic resonance images in these same subjects using optical digitization. The stimulation sites were mapped onto the surface of the occipital lobes in three-dimensional reconstructions of the cortical surface to show the distribution of the visual suppression effect. The results were consistent with disruption of secondary visual cortical areas.

Adult↗
PubMed1997

QEEG and neuropsychological profiles of patients after undergoing cardiopulmonary bypass surgical procedures.

One week after surgery neuropsychological (NP) deficits were quite common, occurring in 40.6% of the patients, with QEEG abnormality developing or increasing in the majority of patients. This change in the QEEG was an accurate predictor of NP performance 1 week after surgery. Two to three months after surgery evidence of continued NP performance deficits were still present in 28.1% of the patients. Preoperative versus one week postoperative QEEG change showed higher levels of sensitivity and specificity for predicting neuropsychological performance 3 months after CPB surgery than did preoperative versus one week postoperative NP performance. The mean values of specificity plus sensitivity were 74.5% for NP performance and 89.1% for the QEEG. These high levels of sensitivity and specificity for QEEG change for predicting postoperative cognitive function may justify the utility of performing these evaluations in the general CPB surgical population. In addition, this evidence supports the need to study the role of intraoperative QEEG monitoring to determine when QEEG change occurs so that possible remediational measures can be taken as soon as possible.

Cardiac Surgical Procedures↗
PubMed1983

A network approach to rural psychiatric emergency training.

The relative lack of objective data delineating rural needs has limited the development of creative training programs. The authors describe the process of developing a network approach to teaching psychiatric emergency skills. Using information collected from questionnaires, they defined the attributes of the rural setting, the emergency services, the staff, and the patients, and then tailored a program to meet these needs. The questionnaire results suggested that the extensive informal network of crisis care providers gives rural emergency services their unique character. The authors conclude that a successful training workshop should gather together members of both informal and formal networks to address group process and teaming issues. The faculty, consisting of urban and rural staff, must also overcome regional differences to build an effective working alliance.

Adolescent↗