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Biomedical subjects

R H Mattson

Publications and source records attributed to R H Mattson.

At least 91 records · Page 5Linked to original sources
PubMed1988

Metamemory in temporal lobe epilepsy: self-monitoring of memory functions.

Temporal lobe seizure patients and control subjects participated in an investigation of metamemory. The two-part study explored the individual's perception of memory abilities for both encoding and retrieval. Experiment I addressed self-monitoring of encoding through a study of prediction of memory span. Experiment II explored self-monitoring of retrieval through a study of "Feeling of Knowing." The results indicate that left and right temporal lobe seizure patients tend to overestimate their memory capacities, in comparison with normal controls, and that self-monitoring tends to be less accurate for material (verbal or nonverbal) mediated by side of lesion. The potential impact of inaccurate memory monitoring on the memory dysfunction observed in seizure patients is discussed.

Adult↗
PubMed1988

Gist recall in temporal lobe seizure patients (a study of adaptive memory skills).

This study investigates the capacity of lateralized temporal lobe seizure patients to process and retain complex narrative information, to recall the most important elements of verbal material, and to make effective use of mnemonic strategies during a brief study period to improve performance. Compared to normal controls, both left and right temporal lobe samples recall significantly less information on both immediate and post-study trials. In addition seizure patients, particularly left temporal subjects, engaged in fewer active learning strategies and produced more instances of major distortion. However, despite their reduced efficiency in total recall, seizure patients, like control subjects, do tend to remember a higher proportion of important idea units and a smaller proportion of details. The findings are discussed in relation to previous research which documented memory monitoring failures in temporal lobe seizure patients, and in terms of the development of adaptive memory skills to circumvent memory deficits.

Adaptation, Psychological↗
PubMed1988

Corpus callosotomy for epilepsy. I. Seizure effects.

Twenty-two patients were analyzed 2 or more years after corpus callosum section (9 partial, 13 total). Forty-one percent had class 1 outcome (elimination of secondarily generalized and complex partial seizures), 32% had class 2 outcome (elimination of secondarily generalized seizures), and 27% had class 3 outcome (no appreciable change). Total section was twice as effective in abolishing secondarily generalized seizures as was partial section (77% versus 35%). Statistically significant associations were seen between focal CT lesions and class 1 outcome, and between IQ less than 45 and class 2 or 3 outcome.

Adolescent↗
PubMed1988

Corpus callosotomy for epilepsy. II. Neurologic and neuropsychological outcome.

Eighteen uncontrolled epileptic patients had neuropsychological evaluation before and after partial or total corpus callosotomy. In patients with early-onset seizures and signs of severe unilateral CNS dysfunction, callosotomy produced no deficits and several improvements. All patients whose language-dominant hemisphere did not control their dominant hand had impairments in some aspect of speech and language function after callosotomy. In some patients, unilateral deterioration of motor function was observed, and was associated with mild to moderate dysfunction in the contralateral hemisphere (ie, memory impairment or preexisting hemiparesis). Postoperative deficits occurred with partial, as well as total, section.

Adolescent↗
PubMed1988

Aspects of compliance: taking drugs and keeping clinic appointments.

Treatment of epilepsy depends on adherence to a drug regimen as prescribed and periodic assessment of progress. Typical problems of compliance to medication and adherence to follow-up in long-term epilepsy treatment in a clinical trial were analyzed. Zero drug levels, subtherapeutic levels, variable levels and delayed dose were measures of non-compliance to the drug regimen. Missed visits and non-drug-related dropouts from the study marked non-adherence. Data from 622 patients participating in a multicenter evaluation of the efficacy and toxicity of carbamazepine, phenobarbital, phenytoin and primidone, showed generally good compliance. Only 5% of patients had zero drug levels or greater than or equal to 24 h since prior dose at 2 or more visits. Good adherence to the protocol was demonstrated by 93% attendance as scheduled. The support structure of the study and the availability of a study assistant helped many patients to prevent potential problems and convert patients into excellent adherers.

Adolescent↗
PubMed1987

Results of a nationwide Veterans Administration Cooperative Study comparing the efficacy and toxicity of carbamazepine, phenobarbital, phenytoin, and primidone.

In 1985 a 5-year multicenter Veterans Administration Cooperative Study was completed that compared the efficacy and toxicity of phenobarbital, carbamazepine, phenytoin, and primidone in a double-blind prospective study design. A total of 622 patients, either previously untreated or undertreated, were entered into the study. Strict exclusion criteria limited confounding factors such as drug or alcohol abuse. Results showed that each of the four drugs used as monotherapy were similarly effective in the treatment of generalized tonic clonic seizures, but carbamazepine was significantly more effective in the treatment of complex partial seizures as measured by 100% control. When the results for all four drugs were combined, the data showed that approximately 80% of the patients were adequately managed on monotherapy. Differences in toxicity were the most significant factor that discriminated between these four drugs. Both carbamazepine and phenytoin were associated with significantly lower incidences of intolerable side effects than were primidone or phenobarbital. A behavioral toxicity battery was performed whenever possible prior to administration of any antiepileptic drug and at 1, 3, 6, and 12 months after initiation of monotherapy. Significant differences in performance on all subtests of the battery were found between patients with epilepsy and a control group matched by age, sex, and education. When the differential effects of all four drugs on behavioral toxicity were compared, few statistically significant differences emerged. However, carbamazepine consistently produced fewer adverse effects on tests of attention/concentration and motor performance than did the other three antiepileptic drugs.

Adult↗
PubMed1987

Vigabatrin for refractory complex partial seizures: multicenter single-blind study with long-term follow-up.

The irreversible GABA transaminase inhibitor vigabatrin (VGB) was given in a single-blind fashion to 89 patients with complex partial seizures (CPS) refractory to conventional drugs. The median number of CPS per month decreased from 11.0 to 5.0 after addition of VGB, and 51% of patients had a 50% or greater decrease in CPS frequency (p less than 0.001). Side effects (principally drowsiness, ataxia, and headache) occurred mainly during the initiation of therapy and decreased during therapy. After 12 weeks on VGB, side effects significantly interfered with functioning in only 13% of patients, and the efficacy:toxicity ratio warranted continued administration in 74% of patients. Coadministration of VGB resulted in a mean decrease of 20% in phenytoin serum concentration (p less than 0.001). Sixty-six patients with a favorable response to VGB during the single-blind study have been followed for a median of 16.7 months on VGB. No serious systemic or neurologic toxicity has been detected, and most patients have retained their initial favorable CPS control.

Aminocaproates↗
PubMed1987

Intensive neurodiagnostic monitoring: strategy for optimal use.

Intensive neurodiagnostic monitoring has proven to be a valuable approach to diagnosis and management of epilepsy and related disorders. Certain specific types of problems can be answered with fairly limited outpatient methods, whereas others require exhaustive, complex, and expensive inpatient methods. With rapid advances in technical quality of cameras, videotape recorders, and utilization of computer assistance, changes in current methods can be expected in the near future.

Ambulatory Care↗
PubMed1986

Use of oral contraceptives by women with epilepsy.

Oral contraceptives have not been associated with exacerbation of epilepsy despite warnings in package inserts. No clinical study has provided scientific evidence of worsening of seizures in epileptic women who use oral contraceptives, and improvement in seizure control has occurred in some cases. The main concern about use of oral contraceptives in this population is their effectiveness in preventing conception. Failure rates are higher in groups of women taking enzyme-inducing antiepileptic drugs. The degree of increased metabolism of estrogen and progestin components is highly variable and unpredictable among individuals. Use of higher doses increases protection against conception but also increases the risk of side effects, particularly in patients in whom no enzyme induction occurs. The strength of hormones in the pill should be selected individually when initiating use. Some women may require higher doses for full contraceptive effect.

Animals↗
PubMed1986

Short term retention with lateralized temporal lobe epilepsy.

This investigation focused upon whether individuals with lateralized temporal-lobe epilepsy have impairments in short term memory and, if so, whether these impairments are of a material-specific nature. The Peterson short term memory distractor paradigm which consists of single, brief presentations of stimuli with varying decay intervals and appropriate interpolated distractors was employed. A significant deficit in both left and right temporal lobe seizure groups was documented in comparison to controls for verbal but not for non-verbal materials. The results suggest that one aspect of the memory problem observed in temporal lobe seizure patients relates to relatively early components of information processing where encoding is primarily based upon physical rather than semantic characteristics of the stimulus and material-specificity is less evident.

Adolescent↗
PubMed1986

Variable free and total valproic acid concentrations in sole- and multi-drug therapy.

Total and free valproic acid (VPA) serum concentrations differ between patients on sole therapy (SOLE Group) and those taking multiple drugs (MULTI Group). We found significantly higher total and free VPA levels and free fractions in 25 SOLE patients than in 29 MULTI patients, both at morning predose (minimum) and postdose (maximum) testing. Results in SOLE versus MULTI patients were, respectively, as follows: total minimum 70.5 vs. 50.2 micrograms/ml (p less than 0.01); total maximum 106.8 vs. 89.5 micrograms/ml (p less than 0.05); free minimum 9.8 vs. 4.4 micrograms/ml (p less than 0.001); free maximum 18.9 vs. 12.0 micrograms/ml (p less than 0.01). The wide variation in total and free levels suggests the need to monitor VPA levels carefully. Not only does use of other drugs influence VPA kinetics, but the time since last dose also affects levels. Nonlinear binding causes large increases in free levels as total VPA concentration rises. We monitor free and total VPA at minimum and maximum along with evaluation of side effects and seizures for better interpretation of dosage requirements.

Adult↗
PubMed1985

Comparison of carbamazepine, phenobarbital, phenytoin, and primidone in partial and secondarily generalized tonic-clonic seizures.

We conducted a 10-center, double-blind trial to compare the efficacy and toxicity of four antiepileptic drugs in the treatment of partial and secondarily generalized tonic-clonic seizures in 622 adults. Patients were randomly assigned to treatment with carbamazepine, phenobarbital, phenytoin, or primidone and were followed for two years or until the drug failed to control seizures or caused unacceptable side effects. Overall treatment success was highest with carbamazepine or phenytoin, intermediate with phenobarbital, and lowest with primidone (P less than 0.002). Differences in failure rates of the drugs were explained primarily by the fact that primidone caused more intolerable acute toxic effects, such as nausea, vomiting, dizziness, and sedation. Decreased libido and impotence were more common in patients given primidone. Phenytoin caused more dysmorphic effects and hypersensitivity. Control of tonic-clonic seizures did not differ significantly with the various drugs. Carbamazepine provided complete control of partial seizures more often than primidone or phenobarbital (P less than 0.03). Overall, carbamazepine and phenytoin are recommended drugs of first choice for single-drug therapy of adults with partial or generalized tonic-clonic seizures or with both.

Adolescent↗
PubMed1985

Complex partial seizures of frontal lobe origin.

Complex partial seizures of medial or orbital frontal origin were documented in 10 of 90 patients with intractable epilepsy who were studied with depth electrodes. The clinical features that, in part, served to distinguish these seizures from complex partial seizures originating elsewhere included brief, frequent attacks, complex motor automatisms with kicking and thrashing, sexual automatisms, vocalization, and frequent development of complex partial status epilepticus. The constellation of clinical characteristics was often bizarre, leading to the erroneous diagnosis of hysteria. Stereotyped attack patterns helped establish the diagnosis of epilepsy. Interictal and ictal scalp electroencephalograms were often not helpful and were sometimes misleading.

Adolescent↗
PubMed1985

Complex partial status epilepticus: a depth-electrode study.

Of 87 patients with complex partial epilepsy who were evaluated with depth electrodes, 8 developed complex partial status epilepticus (CPSE). Seizures originated extratemporally in all 8 patients. Frontal lobe onset was established in 4 patients and was probable in 1 more. Medial parietal onset was documented in 1 patient. Medial occipitoparietal onset occurred in another, and 1 patient had multifocal onsets. Even when seizures did not begin frontrally, the frontal lobes were prominently involved during CPSE. CPSE did not occur in 60 patients with seizures originating in the temporal lobe. Both recurrent clinical seizures and continuous altered behavior were observed. Some patients exhibited both clinical patterns at different times during the same episode. Depth recording consistently demonstrated recurrent isolated seizure discharges throughout episodes. The clinical patterns were related, in part, to electroencephalographic seizure frequency, duration, and intensity. Episodes of CPSE were not associated with intellectual deterioration.

Adult↗
PubMed1985

Epilepsy, sex hormones, and antiepileptic drugs.

Many factors associated with hormone function have an impact on the course of epilepsy. Patients with epilepsy may have disturbances in sexual function such as anovulatory cycles in women and decreased libido and potency in men. Data indicate seizures, especially those arising in the limbic system, may influence the hypothalamic pituitary axis. Antiepileptic drugs also influence sexual function through direct brain effects as well as through induced changes in pharmacokinetics of the sex steroid hormones. Pregnancy has been reported to be a time of increased seizures; however, this has often been associated with low drug levels, for reasons that include inadequate drug dose, possible changes in pharmacokinetics, and noncompliance. Some evidence suggests that hormones affect seizure frequency. Changes in seizures during the menstrual cycle (catamenial epilepsy) have been found in some women: seizures were fewer during the luteal phase but increased when progesterone levels declined. Some improvement in seizure frequency has been shown in pilot studies using medroxyprogesterone acetate, a synthetic progesterone. Current concepts of the interrelationship among epilepsy, sex hormones, and antiepileptic drugs are discussed.

Anovulation↗
PubMed1985

Reliability and accuracy of localization by scalp ictal EEG.

One hundred forty-four scalp ictal EEGs from 54 patients were analyzed independently by three electroencephalographers for side and lobe of seizure onset. Observers did not know the patients' identities. Accuracy was determined by depth EEG. We found 58 to 60% agreement between observers for lobe, and 64 to 74% for side, of seizure onset; 21 to 38% agreement with depth EEG for lobe, and 46 to 49% agreement for side, of seizure onset; best accuracy for lateralization of seizure onset in temporal lobe seizures, but erroneous in 3 to 17%. More formal criteria are needed before scalp ictal records can be used reliably or accurately for localization.

Adolescent↗
PubMed1985

Effects of corpus callosum section on secondary bilaterally synchronous interictal EEG discharges.

We studied the effect of corpus callosum section on secondary bilaterally synchronous interictal EEG discharges in 13 patients with partial and secondarily generalized seizures before and after partial or complete section of the corpus callosum. Bilaterally synchronous discharges were completely eliminated in one patient. In 12 patients, there was a distinct reduction in frequency. Our clinical experience agrees with experimental data to suggest that epileptic discharges follow pathways, both across the corpus callosum and/or down to diencephalic/mesencephalic structures, before there is bilateral spread.

Adolescent↗