Harold H. Morris

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Summarizing, we have presented evidence in humans for two "negative motor areas" which we had speculated play a significant role in the planning of voluntary motor movements. A review of the more recent experimental literature shows that histological, physiological, and electrical stimulation studies in animals reveal the existence of two frontal regions(More)
Language interference was elicited by electrical stimulation of the dominant basal temporal region in 8 out of 22 cases and in none of 7 cases with subdural electrodes implanted over the nondominant temporal lobe. Language interference was elicited by stimulation of electrodes placed over the fusiform gyrus 3-7 cm from the tip of the temporal lobe.(More)
This study examined the effect of the surgical approach used in total hip arthroplasty (THA) on gait mechanics six months following surgery. Quantitative gait analysis was performed on 29 subjects: 10 anterolateral (A-L) and 10 posterolateral (P-L) THA patients and nine able-bodied, velocity-matched subjects. Discriminant function analysis was used to(More)
To clarify the differences of movement-related potentials (MRPs) among ipsilateral, contralateral and simultaneous bilateral movements, MRPs with finger, thumb or foot movements were recorded from subdural electrodes chronically implanted on the supplementary motor area (SMA) in 3 patients, and also from the primary sensorimotor area in two of them being(More)
OBJECTIVE To evaluate the risk factors, type, and frequency of complications during video-EEG monitoring with subdural grid electrodes. METHODS The authors retrospectively reviewed the records of all patients who underwent invasive monitoring with subdural grid electrodes (n = 198 monitoring sessions on 187 patients; median age: 24 years; range: 1 to 50(More)
Functional localization prior to cortical resections for intractable seizures has usually been performed in the operating room in awake patients. Chronically placed subdural electrodes offer the possibility of performing such testing outside of the operating room and without the unavoidable stresses and time limitations of the surgical setting. The use of(More)
We have evaluated the afterdischarge thresholds and functional response thresholds in 21 patients with chronically implanted arrays of subdural electrodes. Afterdischarge thresholds varied from 2 to greater than 15 mA over the tested cortex, by as much as 12 mA in individual patients, and by as much as 12 mA between adjacent electrodes. Thresholds for(More)
Electrical stimulation studies have demonstrated that a "supplementary motor area" (SMA) exists in humans. However, its precise functional organization has not been well defined. We reviewed the extraoperative electrical stimulation studies of 15 patients with intractable epilepsy who were evaluated with chronically implanted interhemispheric subdural(More)
We studied the eye movements (EM) elicited by electrical stimulation of the frontal lobe in 19 awake patients evaluated with subdural electrodes for epilepsy surgery. All patients had only contralateral conjugated EM. They were saccadic in 16 patients (84%). Head version, always following the eye deviation, occurred in 11 patients (58%). We also determined(More)
We propose an epileptic seizure classification based exclusively on ictal semiology. In this semiological seizure classification (SSC), seizures are classified as follows: a. Auras are ictal manifestations having sensory, psychosensory, and experiential symptoms. b. Autonomic seizures are seizures in which the main ictal manifestations are objectively(More)