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Biomedical subjects

R Rausch

Publications and source records attributed to R Rausch.

36 records · Page 2Linked to original sources

Right-hemisphere language dominance in right-handed epileptic patients.

Hemispheric language dominance, as determined by intracarotid amobarbital sodium injections, and handedness, as reflected by writing and drawing preference, were evaluated in a select group of patients with intractable seizures who had documented focal epilepsy originating from one temporal lobe. Of the patients with left temporal lobe seizure focus, an unusually high percentage of right-handed patients (4/26 [15%]) had right hemisphere language dominance. Pathologic findings of the resected temporal lobe in these patients revealed microscopic damage (hippocampal sclerosis) of the hippocampus in three of three cases; one patient also had a small hamartoma in the midtemporal gyrus. We hypothesize that crossed dominance resulted from disruption by epileptiform activity during early development of selective areas of the left hemisphere.

Adolescent↗

Resumption of behavior following intracarotid sodium amobarbital injection.

Recovery rates of selected behaviors following intracarotid sodium amobarbital injection were examined in 17 patients with unilateral focal temporal lobe epilepsy. Left hemisphere injections resulted in more prolonged disruption of naming (p less than 0.00001), reading (p less than 0.0001), matching-to-sample behaviors (p less than 0.05), and short-term recognition memory for pictures (p less than 0.0001) and words (p less than 0.0003) than did right hemisphere injections. In addition, recovery of behaviors was prolonged if the injection was administered to the hemisphere contralateral to that with the primary seizure focus (p less than 0.005). A trend toward a similar pattern was seen in the postinjection electroencephalogram with the maximum slowing found in the injected hemisphere prolonged if the epileptic focus was in the contralateral hemisphere (p = 0.06). These findings suggest a negative effect of an epileptic lesion on the contralateral hemisphere.

Amobarbital↗

Local cerebral metabolism during partial seizures.

Interictal and ictal fluorodeoxyglucose scans were obtained with positron CT from four patients with spontaneous recurrent partial seizures, one with epilepsia partialis continua, and one with a single partial seizure induced by electrical stimulation of the hippocampus. Ictal metabolic patterns were different for each patient studied. Focal and generalized increased and decreased metabolism were observed. Ictal hypermetabolism may exceed six times the interictal rate and could represent activation of excitatory or inhibitory synapses in the epileptogenic region and its projection fields. Hypometabolism seen on ictal scans most likely reflects postictal depression and may indicate projection fields of inhibited neurons. No quantitative relationship between alterations in metabolism and EEG or behavioral measurements of ictal events could be demonstrated.

Adolescent↗

Changes in intelligence following temporal lobectomy: relationship to EEG activity, seizure relief, and pathology.

Pre- and posttemporal lobectomy measures of intelligence and memory in 36 patients with medically refractory complex partial seizures were compared with (1) various aspects of presurgical ictal and interictal EEG activity derived from surface and deep electrodes, (2) postlobectomy seizure relief, and (3) pathological findings in the resected lobe. With respect to interictal EEG data, bilaterally synchronous surface spikes (accompanied or unaccompanied by simultaneous deep spikes) and sharp waves were significantly correlated with lower prelobectomy intelligence scores and a drop in these scores following lobectomy. With respect to ictal EEG data, bilaterally synchronous and multifocal onsets were significantly correlated with a postlobectomy drop in intelligence scores. Patients with poor postlobectomy seizure relief tended to have lower presurgical intelligence scores and a drop in intelligence scores following lobectomy. The patients most likely to show a postlobectomy drop in intelligence were those demonstrating some combination of poor seizure relief, an absence of pathology in the resected specimen, or EEG signs indicative of poor seizure relief. Postlobectomy changes in intellectual status are therefore not necessarily exclusively attributable to the amount of postlobectomy seizure relief experienced by these patients, but might be due to a combination of factors.

Adult↗

Psychological status related to surgical control of temporal lobe seizures.

Patients who underwent temporal lobe surgery with diagnosis aided by stereoelectroencephalography (SEEG) were evaluated psychosocially before surgery and at one month and one year after surgery. Patients who were not operated on but who also had been evaluated by SEEG served as controls. These patients were evaluated at time periods comparable to those of the operated cases. At one year after surgery, patients whose seizures had been relieved had improved in Degree of Dependency, Work Performance, and Non-Family Relationships. Patients whose seizures were not controlled by surgery and nonoperated patients did not show any significant change in psychosocial measurements one year postoperatively. Psychosocial improvements were seen regardless of the side of the brain operated. While patients whose seizure were reduced experienced memory deficits of the type associated with side of the temporal lobe resection, the data suggested that there was improvement in intellectual score and, in the case of right-sided surgery patients, memory functions associated with the contralateral, intact hemisphere.

Adolescent↗

Correlation of criteria used for localizing epileptic foci in patients considered for surgical therapy of epilepsy.

Criteria for anterior temporal lobectomy, performed on seven patients with partial complex seizures, were derived from a battery of fourteen presurgical tests. Seven tests were routine studies aimed at identifying a focus of epileptic excitability, while seven were designed to reveal areas of focal functional deficit. Conflicting information was frequently obtained from the tests of epileptic excitability, suggesting that it is probably inaccurate to view patients with partial complex seizures as having a single epileptogenic focus. Presurgical evaluation must therefore be aimed at identifying the focus most responsible for the patient's habitual seizures. Tests of focal functional deficit provided useful nonconflicting confirmatory information in each of the seven patients studied. The most reliable information was obtained from depth electrode implantation, and this procedure should be considered essential except when all evidence of surface-recorded epileptic excitability, including ictal onset, and evidence of focal functional deficit agree.

Adult↗

Neuropsychologic correlates of depth spike activity in epileptic patients.

The statistical properties of depth spiking in the interictal EEG were assessed in 12 patients with intractable temporal lobe epilepsy in whom electrodes had been stereotactically implanted for diagnostic purposes. Prior to the implantation surgery each patient was administered a battery of neuropsychologic tests. Correlational analyses showed that the total amount of depth spike activity (TA) negatively correlated with measures of intelligence, while the laterality of the spike activity (LAT) appeared to be positively related to a memory score and the degree of psychologic independence. The results of this study are consistent with previous findings of a significant relationship between surface EEG recordings and performance. In addition, our data suggest a relationship between specific neuropsychologic functions and the patterns of in-depth EEG epileptiform discharges.

Adult↗

Olfactory memory in patients with anterior temporal lobectomy.

Right and left temporal lobectomy patients, matched in age and intelligence, made more errors in odor recall than a control group. Patients with right temporal lobe excisions recalled significantly fewer odors correctly than patients with left temporal lobe excisions. Olfactory memory scores were not related to other memory deficits associated with left or right temporal lobe dysfunction or to intelligence or lesion size. However, in patients with right temporal lobectomy, percent of odors recalled correctly correlated positively with a general memory index. The findings presented are consistent with previous reports that the right temporal lobe is more involved with nonverbal memory than the left temporal lobe.

Acetates↗

Factors in children that predict performance on the intracarotid amobarbital procedure.

The intracarotid amobarbital procedure (IAP) is frequently used to determine hemispheric language dominance and memory competence in individuals with intractable epilepsy before surgical intervention. The present study focused on outcome results concerning use of this technique in children. The IAP was an effective tool in determining their hemispheric language dominance. Seven characteristics, including age, gender, dose level of sodium amobarbital, Full-Scale I.Q., hemispheric side of injection (left or right), language dominance of hemisphere injected, and order of injection (first or second) were examined as possible factors predictive of memory performance on the IAP. Results suggest that after injection of the hemisphere suspected of containing the primary seizure origin, children aged < 13 years who had the left language-dominant hemisphere injected were significantly less likely to pass IAP memory tasks than were older children or younger children who had the nondominant hemisphere injected. These findings suggest that the IAP is a reliable indicator of hemispheric memory competence in children aged > 13 years or younger children whose suspected seizure focus is located in the nondominant language hemisphere.

Adolescent↗

Quality of life of epilepsy surgery patients as compared with outpatients with hypertension, diabetes, heart disease, and/or depressive symptoms.

Health-related quality of life (HRQOL) of 166 adults who had previously undergone surgical treatment for intractable epilepsy was compared with that of outpatients with hypertension, diabetes, heart disease, and/or depressive symptoms. Eight self-reported HRQOL domains were evaluated and compared by the RAND 36-Item Health Survey 1.0: emotional well-being, social function, role limitations due to emotional problems, energy/fatigue, pain, role limitations due to physical problems, physical function, and general health perceptions. A pictorial item on overall QOL was also administered, for a total of 9 HRQOL domains. With adjustment made for age, gender, education, and comorbid conditions, 55 completely seizure-free patients scored higher (i.e., better health) than patients with hypertension in 6 of 9 domains, higher than diabetic patients in 8 of 9, higher than those with heart disease in all 9, and higher than those with depressive symptoms in all 9 (all p < 0.05). Sixty-seven patients still having seizures with impaired consciousness scored worse than hypertensive patients in 5 domains, worse than diabetic patients in 3, and worse than heart disease patients in 2; for all 3 conditions, these domains included emotional well-being and overall QOL (p < 0.05). These 67 patients, however, scored better than patients with depressive symptoms in all 9 domains, better than those with heart disease in 2, and better than those with diabetes in 1 (all p < 0.05). Forty-four other patients had only simple partial seizures (SPS); their scores were comparable to those of diabetic and heart disease patients on mental and social health scales but were higher ("better") than those of these patients on physical health scales. HRQOL among patients who have undergone "curative" epilepsy surgery is better than that of patients who have hypertension, diabetes, heart disease, or depressive symptoms. Patients who have continued seizures with altered consciousness are worse off in terms of emotional well-being and overall QOL than all other patients, except for those with depressive symptoms.

Ambulatory Care↗

Anatomical substrates of interictal memory deficits in temporal lobe epileptics.

Temporal lobe epileptics frequently have as their pathological substrate selective neuron loss of the hippocampus. The extent and pattern of the hippocampal cell loss vary among patients. These patients also exhibit varying degrees of memory loss. We have demonstrated a relationship between the memory loss in left temporal lobe epileptics and their hippocampal lesions. Specifically, we have identified a memory measure, delayed-recall of unrelated word-pairs, that is highly dependent upon integrity of left hippocampus. We have also shown that extensive damage throughout the hippocampus is necessary to consistently impair this measure. These findings are relevant to understanding the memory loss of temporal lobe epileptics as well as providing insight into our understanding of the anatomical basis of memory.

Brain↗