ReviewNeuropsychological effects of epilepsy and antiepileptic drugs
Section snippets
Pitfalls in research methods
Although most of the following criticisms refer to studies that investigate cognitive and behavioural side-effects of antiepileptic drugs, they are equally applicable to those that explore the influence of the other factors mentioned above. Vermeulen and Aldenkamp, in reviewing 89 studies done over 25-years, concluded that no satisfactory answer could be given to the question of adverse cognitive effects of antiepileptics because most of these studies did not “pass fairly basic standards of
Cause and neuropathology
Most generally agree that there is no universal epileptic personality trait. There is, however, a diverse range of clinical changes indicating anatomical foci, patterns of seizure spread, and biological and psychological differences among patients. In localisation-related epilepsy, a range of cognitive defects have been suggested, which mainly relate to the presumed physiological function of the anatomical site of seizure focus–for example, greater memory deficit has been found in patients with
Neuronal discharges
Ictal cognitive and behavioural features are well recognised. John Hughlings Jackson first developed the concept of temporal-lobe epilepsy, correlating clinical behaviour with pathological lesions in a series of elegant case reports, toward the end of the 19th century. The introduction of electroencephalography (EEG) provided a powerful tool to delineate the characteristic ictal, as well as interictal, patterns observed in this type of epilepsy, correlating them with observable behavioural
Antiepileptic drugs
Huette first described the cognitive and behavioural sideeffects of bromide in 1850 before its suggested use as an anticonvulsant in 1857 by Sir Charles Locock. Data have since been obtained from normal volunteers, comparisons between treated and untreated patients, measurement of concentration-effect relations, and substitution and withdrawal studies. Early observations did not detect any mental effects of phenobarbital, but the investigators failed to control for the confounding factor of
Psychosocial factors
Epilepsy has long been a misunderstood and stigmatising disorder. Although in western societies it is no longer thought of as the product of demonic possession, misconception and prejudice remain. In a survey carried out in the USA in 1979, 92% of those interviewed thought epilepsy was not a form of insanity, but only 79% believed epilepsy patients should be employed, and only 89% would not object to their children playing with others who had epilepsy.66 Although there has been much improvement
Conclusion
A better appreciation of the complex cognitive and behavioural dimensions of epilepsy would allow clinicians to provide a more holistic and patient-centred approach to management. Underlying neuropathology, and ictal and subclinical neuronal discharges, can have adverse cognitive and behavioural consequences. Some of these psychosocial disabilities can be cumulative or even irreversible. Studies of surgical outcomes indicate that even when surgery is successful in eliminating seizures, patients
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