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Biomedical subjects

J R Gates

Publications and source records attributed to J R Gates.

At least 37 records · Page 2Linked to original sources
PubMed1990

Mesial temporal sclerosis: pathogenesis, diagnosis, and management.

Mesial temporal sclerosis (MTS) is probably the most common symptomatic pathologic entity--alone or mixed with other pathologic features--for seizures of temporal lobe origin. The pathophysiology of MTS, including any genetic influence, needs clarification. A characteristic ictal expression for seizures of MTS origin appears not to exist. The majority of patients (78%) with postresection MTS who are seizure-free have tightly localized interictal abnormalities restricted to F7/F8, Sp1/Sp2, T3/T4, and T5/T6 more than 96% of the time. MRI abnormalities may be seen in 55% of patients with MTS if both "hard" and "soft" criteria are used or in 20% when only "hard" criteria are used. The neuropsychologic evaluation of patients with MTS, which includes intracarotid amobarbital test (IAT), may prove to be increasingly useful in identifying patterns of cognitive deficit that correlate with enhancement of both lateralizing and localizing preoperative information.

Adolescent↗
PubMed1990

Prolonged postictal encephalopathy.

Eleven patients (6 males, 5 females; ages 7.5 to 40 years, mean 27.8) had prolonged postictal confusion lasting from 4 to 10 days. During that time, the EEG showed a typical encephalopathic pattern. Comprehensive evaluation ruled out the possibility of metabolic, toxic, drug-related, or ongoing nonconvulsive status epilepticus. We have designated this syndrome as prolonged postictal encephalopathy (PPIE). Nine of 11 patients were mildly to borderline mentally retarded. Ten had previous episodes of status epilepticus. Nine of 11 had minimal structural abnormalities (mainly diffuse cortical atrophy). Nine patients had multiple recurrent episodes of PPIE. All episodes occurred following a cluster of seizures: in 8 patients after a cluster of generalized tonic-clonic seizures, in 2 after complex partial seizures, and in 1 patient after a cluster of atypical absence seizures. This series suggests that vulnerability to develop PPIE exists in patients with diffuse structural abnormalities, mild to borderline mental retardation, a history of status epilepticus, and a tendency of seizures to cluster.

Adolescent↗
PubMed1989

Malaria in Nicaragua: community-based control efforts and the impact of war.

This descriptive study of temporal trends and geographical distribution examines the effects of prolonged low-intensity warfare on the community-based malaria control efforts. Nicaragua's post-1979 malaria control programme is based on community participation in health education and in mosquito breeding site drainage, expanded case finding, and increased availability of chemotherapy. Mosquito resistance and increasing costs have forced a reduction in the use of residual pesticides. The number of reported malaria cases in the country fell from 25,465 in 1980 to 15,702 in 1984, while the ratio of blood smears to total population increased from 86 to 137 per 1000 people. Malaria incidence in the eight states of the country under heaviest military attack in the current war was compared to incidence in the eight states least affected by the war. In the war zone there was a 17% excess in cases from August 1983-April 1985 above a 1974-82 baseline average, while there was a 62% decline in the number of cases in the non-war zone.

Humans↗
PubMed1989

Supplementation patterns in marathon runners.

The purpose of the present investigation was to study the use of supplements in a large group of endurance runners (no. = 347) who had participated in the 1987 Los Angeles Marathon. Three-day dietary records were analyzed for nutrient content and supplement usage. The runners' supplementation patterns with respect to demographics, dietary quality, training habits, and race performance were investigated. In general, no significant associations were found between supplement use and the aforementioned variables. Use of supplements, especially vitamins C and E, calcium, and zinc, increased with age (p less than .05). Daily use of at least one type of supplement was reported by 29% of the runners; 48% reported use of at least one type of supplement within the 3-day period.

Adult↗
PubMed1987

Valproic acid loading during intensive monitoring.

Of 35 patients who had generalized tonic-clonic seizures during antiepileptic drug therapy withdrawal, "loading" with valproic acid was effective in limiting these seizures in 32 patients. A loading dose of approximately 12.5 mg/kg was used. This dose resulted in valproic acid levels between 284 and 458 mumol/L (41 and 66 mg/L) 1.5 hours after "loading" in six of the eight patients in whom serum concentrations were measured.

Adolescent↗
PubMed1987

Magnetic resonance imaging in the assessment and surgical management of epilepsy and functional neurological disorders.

Magnetic resonance imaging (MRI) offers significant advantages over computerized tomography (CT) and teleradiographic techniques when used for the evaluation and management of epilepsy and functional neurological disorders. Depth recording and radiofrequency electrodes can be more accurately positioned within structures such as the amygdala and hippocampus. The extent of corpus callosum section, lobectomy, topectomy, and radiofrequency stereotactic lesions can now be readily confirmed and related with seizure, neurological, and behavioral outcome. Occult, usually low grade, intraparenchymal neoplasms not visualized on CT scans can be located by MRI and biopsied or excised by MRI stereotactic techniques.

Corpus Callosum↗
PubMed1986

Magnetic resonance imaging, electroencephalogram, and selected neuropsychological testing in staged corpus callosotomy.

A 21-year-old man with medically intractable secondarily generalized atonic seizures underwent a corpus callosotomy on Nov 5, 1981. Though improved, the falling seizures persisted. In January 1984, magnetic resonance imaging (MRI) documented that the anterior quarter of the corpus callosum remained intact. In March, the patient underwent a completion of the callosotomy, at which time the MRI findings were corroborated. Since the second surgery, a further improvement in seizure control has been observed. Use of MRI can document both noninvasively and in vivo the extent of corpus callosotomy. The implications of selected neurophysiologic and neuropsychological findings are also discussed.

Adult↗
PubMed1986

Psychogenic seizures.

Psychogenic seizures occur in a heterogeneous population and are varied in their expression and etiology. Patients with psychogenic seizures form a significant percentage of patients presenting with "epilepsy"--especially the group intractable to treatment. Intensive neurodiagnostic monitoring of ictal events and the classification of patients into clinically useful subgroups are important tools in approaching this disorder.

Behavior↗
PubMed1985

Ictal characteristics of pseudoseizures.

The spontaneous pseudoseizures resembling tonic-clonic seizures in 25 patients were recorded on simultaneous videotape and electroencephalograms and were compared with the seizures recorded from 25 patients with true tonic-clonic epileptic events. The goal of the comparison was to identify bedside clinical criteria to assist in differentiating between the two groups. The variables of age, sex, and selected physical manifestations of the events were compared for the two groups by appropriate statistical methods, including a multivariate step-wise discriminate analysis. Significant differences between the two groups of seizures were identified for several variables, and most strikingly for the character of upper and lower extremity movements, the time of vocalization during the event, the character of pelvic movements, and the nature of body tone during the events. Useful bedside criteria for distinguishing a pseudoseizure from a tonic-clonic seizure were identified.

Adolescent↗
PubMed1984

Corpus callosotomy: clinical and electroencephalographic effects.

Six persons (five male, one female), 15-41 years of age (mean, 23 years), with medically intractable epilepsy for 7-35 years (mean, 15 years) underwent total corpus callosum section (anterior commissure to posterior commissure) for treatment of seizures resulting in falls and injuries. Preoperative EEGs demonstrated two or more morphologically distinct interictal discharges, at least one of which was generalized. Generalized ictal EEG discharges were documented in all cases to account for the clinical seizures resulting in injury. A comparison of generalized epileptiform discharges in comparable states of arousal pre- and postoperatively demonstrated a statistically significant (p less than 0.05) reduction of generalized discharges after surgery. Postoperative observation periods have ranged from 10 to 30 months (mean, 17.6 months) and have documented a statistically significant (p less than 0.05) decrease in the number of falling seizures (means: preoperative, 23.2 seizures/month; postoperative, 0.7 seizures/month). A statistically significant difference in pre- and postoperative total (generalized and focal) interictal discharges was not demonstrated. Long-term, clinically apparent complications of surgery did not occur in our patients. Thus, sectioning of the corpus callosum interrupts generalized epileptiform discharges (as documented by the postoperative EEG) and usually results in a significant decrease in generalized seizures.

Adolescent↗
PubMed1983

Clinical evaluation of a depth electroencephalography electrode.

Stereo depth electroencephalography (EEG) is of proven benefit in lateralizing and localizing seizure origin in select cases of epilepsy. There are potential hazards and technical considerations inherent with depth EEG, however, that have limited the general applicability of this technique. A new depth EEG electrode with materials and design features that facilitate safe insertion and artifact-free recording has been developed. The design features and technique for inserting the electrode are described. The electrode was evaluated during 2600 hours of implantation and recording in seven patients. With the use of stereotactic techniques, the electrode could be positioned accurately within precise anatomical landmarks such as the amygdaloid nucleus and the hippocampus. After insertion, no hemorrhage or edema was detected along the electrode tracts by third generation computed tomographic scanning. There was no evidence of pyrogenicity or infection. Electrode migration was not observed. A large electrical field could be sampled because of the relatively large surface of the cylindrical depth electrode contacts.

Electrodes, Implanted↗
PubMedDate not supplied

Response of multiple seizure types to corpus callosum section.

Twenty-four patients (16 men, 8 women) underwent corpus callosum section specifically for improvement of control of atonic or tonic seizures that resulted in falls and injuries. All patients suffered from multiple seizure types, including complex partial (CP) and tonic-clonic (TC) seizures, in addition to the tonic or atonic episodes. Preoperative seizure frequency was quantified for all types for 1 year immediately before surgery and for the most recent year since the procedure; average monthly counts were obtained for each seizure type. The period of follow-up since surgery averaged 43 months (range, 23-79 months). Statistically significant improvements were documented, not only for the atonic/tonic seizures (p less than 0.0001) for all patients, but also for TC seizures (17 patients; p less than 0.001) and CP seizures (20 patients; p less than 0.02). Six patients experienced an exacerbation of CP seizures postoperatively, and three developed new simple partial (SP) seizures. In all of the CP group and all three of the SP group, ictal video and EEG features suggested that the new seizures were an aborted expression of the previously generalized seizures. From these data, we conclude that callosotomy is an effective treatment for tonic, atonic, and TC seizures intractable to anticonvulsant medications. Three patients became seizure free. The procedure may also be useful for certain specific subgroups of CP epilepsy, but further studies are required before expanding callosotomy to intractable CP seizures not amenable to focal resection.

Accidental Falls↗
PubMedDate not supplied

Adjunctive therapy for intractable epilepsy with ethotoin.

In a retrospective study, records of 46 patients (24 women and 22 men aged 17-51 years; mean 29.2 years), who had been treated with ethotoin (EHN) as adjunctive therapy for control of intractable seizures were reviewed. Overall, approximately 51% of this highly selected patient population had a reduction greater than 50% in overall seizure frequency 1 month after initiation of treatment. This was reduced to approximately 25% for the last 3 months of follow-up (mean follow-up period 10.6 months). Tonic seizure frequency was reduced most dramatically, by greater than 50%, in 60% of patients at 1 month and in 35% of patients for the last 3 months of follow-up. This study suggests that prospective controlled trials of EHN, especially for tonic seizures, are needed.

Adolescent↗