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C B Dodrill

Publications and source records attributed to C B Dodrill.

At least 19 recordsLinked to original sources
PubMed1996

Unilateral focal preponderance of interictal epileptiform discharges as a predictor of seizure origin.

OBJECTIVE: To test the hypothesis that seizure origin may be predicted from scalp-recorded electroencephalographic interictal epileptiform patterns that occur exclusively or preponderantly over a single focal region. PATIENTS AND METHODS: Fifty-nine of 98 patients (>=16 years old) with intractable epilepsy who underwent sphenoidal/scalp electroencephalographic video monitoring were identified as having interictal epileptiform discharges preponderantly (>=75% of all discharges) or exclusively over a single unilateral region (basal-temporal, midposterior temporal, frontopolar, superior frontal, central). Ictal recordings in 48 patients could be interpreted as demonstrating focal origins, and the ictal findings were compared with the interictal findings. Eleven patients had uninterpretable ictal recordings or no seizures during monitoring and were not further considered. RESULTS: All seizures arose from the expected region in 39 of the 48 patients (Fisher's exact test, P<.001). Interictal discharges occurred exclusively over a single region in 23 of the 48 patients, and all seizures arose from the expected region in 22 of the 23 patients (P<.001). Seventeen patients among this group of 23 had exclusively unilateral basal-temporal discharges, and all seizures arose from the expected side, with the exception of one seizure that arose from the opposite side in one patient, with her other seizure arising from the expected side (P<.001). All seizures arose from the expected region in three patients who exhibited all interictal discharges arising from a single superior frontal region, in two patients with discharges only over a single midposterior temporal region, and in one patient with exclusively unilateral frontopolar discharges. CONCLUSIONS: Interictal discharges that demonstrate a consistent unilateral focal preponderance over a single region, regardless of location, generally predict seizure origin. If the discharges are exclusive to a single region, there is a greater than 95% probability that all recorded seizures will originate from the expected region.

Adolescent↗
PubMed1996

Epilepsy.

Explore the source record for details and available documents.

Affect↗
PubMed1995

Effects of differing dosages of vigabatrin (Sabril) on cognitive abilities and quality of life in epilepsy.

Vigabatrin (VGB) prevents seizures by irreversible inhibition of gamma-aminobutyric acid (GABA) transaminase and a resulting increase in GABA levels. We evaluated the cognitive and quality-of-life (QOL) effects of VGB in a double-blinded, add-on, placebo-controlled, parallel group dose-response study of patients with focal epilepsy whose complex partial seizures (CPS) were difficult to control. In a single investigation, patients were randomly assigned to placebo (n = 40), 1 g VGB (n = 36), 3 g VGB (n = 38), or 6 g VGB (n = 32), treated for 12 weeks after a 6-week dose escalation period, and tested at the end of the baseline period and at the end of the treatment period with eight cognitive measures and three tests of mood and adjustment. The patient groups were highly similar at study entry. Results at the end of the study showed substantial relief from seizures. The Digit Cancellation Test showed decreases in performance with increasing doses of VGB. Performance on no other test showed any decrement with increasing dosage. Relief from seizures was not associated with changes on the psychological tests. VGB is a useful antiepileptic drug (AED) that has little impact on tests of either cognitive abilities or QOL, even at a high dose.

Adolescent↗
PubMed1994

Epilepsy surgery: non-invasive versus invasive focus localization. What is needed from a neuropsychological point of view.

This article discusses the neuropsychological aspects of surgery for epilepsy, and what is needed in EEG evaluation to permit the best use of neuropsychological data to help identify the most promising surgical candidates. Neuropsychological changes after surgery are first discussed, and it is noted that changes in memory are most important with less important fluctuations in intelligence and language and with other areas showing few or no changes. Emotional and psychosocial outcomes of surgery are dependent upon relief from seizures, with substantial relief being essential for improvement to be observed. Finally, it is noted that a combination of EEG and neuropsychological variables results in the best prediction of seizure relief, but reliable EEG data are critical to this effort. Obtaining such data frequently necessitates EEG monitoring, frequently with invasive electrodes. Such information often provides the clearest information and the best chance of assisting patients with epilepsy.

Brain↗
PubMed1993

Reliability of the Lateral Dominance Examination.

The reliability of the Lateral Dominance Examination over a 5-year period was evaluated in 162 normal and neurologically impaired adults. Stability of individual test items was appraised as well as that of summary measures of handedness, eyedness, and footedness. Items evaluating handedness rendered highly consistent results with the most reliable item relating to hand used for writing (100%). Eyedness and footedness items were somewhat less reliable. While the data raised the possibility that non-right-handers may be slightly less consistent over time, membership in a neurological group, extent of impairment on neuropsychological tests, and gender were unrelated to consistency in lateral preference measurement. It is concluded that the Lateral Dominance Examination is a reliable measure of lateral preference.

Adolescent↗
PubMed1993

Evaluation of the effects of vigabatrin on cognitive abilities and quality of life in epilepsy.

We evaluated the psychological effects of the antiepilepsy drug vigabatrin in a randomized multicenter double-blind placebo-controlled parallel group study that compared 3 grams oral vigabatrin with placebo as daily add-on therapy in patients with focal epilepsy whose complex partial seizures were difficult to control. Testing at baseline and after 12 weeks of vigabatrin (n = 83) or placebo (n = 85) used eight measures of cognitive abilities and three of mood and adjustment. The vigabatrin and placebo groups were highly similar at entry into the study. At the end of the study, there were no differences between the vigabatrin and placebo groups on any cognitive variable or on any measure of mood and adjustment. Analysis of the results related to relief from seizures demonstrated only chance findings. In a similar manner, there were no relationships between vigabatrin serum levels at the end of the study and changes on measures of abilities and adjustment. Vigabatrin appears to be a useful antiepilepsy drug with little impact upon tests of either cognitive abilities or quality of life.

Adaptation, Psychological↗
PubMed1992

The role of neuropsychology in the assessment and treatment of persons with epilepsy.

Several areas of current interest in the neuropsychology of epilepsy are briefly reviewed in this article. These include variables pertaining to seizures, seizure history, antiepileptic drugs, and methods of neuropsychological evaluation. It is apparent that epilepsy is a multifaceted area: Psychologists not only can be of great assistance to patients with this condition, but may also learn a great deal from this complex disorder.

Anticonvulsants↗
PubMed1992

Natural history of drug resistant seizures: clinical aspects.

In an effort to determine the long-term efficacy of surgical therapy for epilepsy, a control group of patients was identified. Both the surgically treated and non-surgical groups were evaluated before and after 5- or 10-year follow-ups for seizure frequency in the preceding 2 years. To date 39 patients have had bona fide partial seizures, with or without secondary generalization, and EEGs with focal epileptiform patterns. Prior to first evaluation, these patients had had seizures for an average of 10 years and were treated with an average of 54 AEDs with documented therapeutic serum levels in most; one-third of the patients participated in experimental studies. After treatment for another 5 years with an average of 2.5 AEDs or 10 years with an average of 4.0 AEDs, no one was seizure free. Fifteen percent had a 75% decrease in seizure frequency and 85% continued to have no significant improvement in seizure control. Thus despite vigorous treatment, these patients who might have been considered surgical candidates continued to have uncontrolled seizures.

Adolescent↗
PubMed1992

Use of psychological and neuropsychological variables in selection of patients for epilepsy surgery.

Cortical resection surgery for epilepsy is costly, involves risk, and does not result in significant seizure relief in a number of patients. Therefore, it is important to develop methods which will as accurately as possible identify in advance those persons who will or will not be helped by this procedure. From a review of the literature and from a presentation of original data, it is concluded that psychological/neuropsychological variables are valid predictors of cessation of seizures following surgery but that they are only infrequently used. A multidisciplinary, multivariate statistical approach, using EEG findings and psychological/neuropsychological variables in combination, provides the most accurate predictions which are superior to those derived from using either EEG variables or psychological/neuropsychological variables alone. This approach also avoids much of the predictive instability encountered when single variables are evaluated. Since psychological/neuropsychological variables are obtained at low cost and are non-invasive, further evaluation of their role as predictors of seizure relief following surgery is needed.

Adolescent↗
PubMed1992

Problems in the assessment of cognitive effects of antiepileptic drugs.

The major problems in the study of the cognitive effects of antiepileptic drugs (AEDs) are explored. These problems include subject selection factors, statistical difficulties, matters pertaining to choice of cognitive tests, and the impacts of seizures on performance. A tendency is noted for these contaminating factors to result in attributing to AEDs adverse changes that might more accurately be related to other causes. Although all of these active central nervous system medications likely have some adverse cognitive effects, at least at high levels, the magnitude of these effects may have been exaggerated in the past. This is confirmed by more recent and better-controlled investigations.

Anticonvulsants↗
PubMed1992

Interictal cognitive aspects of epilepsy.

Common methodological problems in the assessment of interictal cognitive deficits in epilepsy include limitations in neuropsychological tests selected and subject sampling problems. Neuropsychological functioning is related to a series of seizure history variables with an emphasis on those seizure factors showing the closest relationships. However, even these relationships are limited in scope, and it has been noted that no study has used multivariate procedures to demonstrate maximal relationships with measures of mental abilities. This technique was applied to data on 487 cases, and slightly stronger relationships were produced. However, this still did not account for the vast majority of the variance in cognitive tests. Conclusions concerning neuropsychological functioning in epilepsy require careful attention to sampling problems and other factors, and seizure history variables have only limited relationships with cognitive functioning, even when they are combined in an optimal fashion.

Adolescent↗
PubMed1992

Neuropsychological aspects of epilepsy.

Brain dysfunction between seizures is common in epilepsy and a systematic assessment of it assists in planning directed programs of remediation. A battery of well-validated neuropsychological tests formulated with the needs of persons with epilepsy in mind can be of particular help in this regard. Increasing impairment in brain functions is shown to be associated with increasing emotional problems. Medical variables pertaining to seizure history include seizure type, cause, age at onset of seizures, duration of disorder, and seizure frequency. An exploration of relationships between these variables and measures of abilities and adjustment reveals a number of findings, some of which are complex. A review of the cognitive effects of antiepileptic drugs shows that the barbiturates have at least slightly greater adverse cognitive and behavioral effects than other drugs including carbamazepine, phenytoin, and sodium valproate. Whether cognitive differences exist among these latter medications is currently in question. Carbamazepine has the best-established favorable psychiatric effect.

Adult↗
PubMed1991

An investigation of the relationship between self-report of memory functioning and memory test performance.

Memory complaints are some of the most common cognitive problems presented to clinical psychologists and neuropsychologists. However, the probable validity of memory complaints presented to a psychologist rarely has been validated by objective memory tests. Using the Memory Functioning Questionnaire (MFQ; Gilewski et al., 1983), 62 relatively young adults reported the extent to which they were experiencing various types of memory problems. These data were compared with findings of memory and non-memory tests on an expanded Halstead-Reitan test battery and with the MMPI/MMPI-2. Results showed that with the exception of persons with more than one MMPI/MMPI-2 evaluation, memory complaints were not related more to memory than to non-memory tests.

Adolescent↗
PubMed1991

Neuropsychological effects of carbamazepine and phenytoin: a reanalysis.

We previously reported that carbamazepine had fewer adverse neuropsychological effects than phenytoin, but it is now clear that our patients had much higher phenytoin than carbamazepine serum levels. When persons with high initial phenytoin levels were excluded, the statistical significance of all neuropsychological differences between the drugs disappeared.

Carbamazepine↗
PubMed1990

Intellectual impairment as an outcome of status epilepticus.

Mental ability changes following status epilepticus (SE) are explored. With respect to the studies reviewed, it is noted that (1) most dealt with children, (2) few utilized any formal psychologic assessment, (3) most were retrospective, (4) earlier studies tended to disclose greater losses in mental ability than later studies, and (5) most investigators described at least a few adverse changes attributable to SE rather than to underlying neurologic disease. An original prospective study is also reported.

Adult↗