Epilepsy and Mental Decline

Developmental outcome after a single episode of status epilepticus

Consequences of status epilepticus (SE) on psychomotor development and the specific impact of the convulsive event on emerging executive functions remain controversial. Infants treated for a single episode of SE, those treated for a single febrile seizure, and healthy infants were tested with respect to motor development, language, personal, and social skills and self-regulation. The children were divided into two age groups to investigate the impact of the convulsive event at different windows of brain maturation. We found that infants who had had SE were inferior to healthy controls on the development scales. Age differentiated SE impact on visuomotor development versus sociolinguistic development. Children who had been treated for SE had significantly more difficulties delaying a response to an attractive stimulus in one of the long-delay conditions. A single episode of SE can interfere with psychomotor and cognitive development in children without previous developmental delay, and it seems that the functions that are emerging at the time of insult are most vulnerable.

Intellectual impairment in patients with epilepsy in Ile-Ife, Nigeria

INTRODUCTION

Epilepsy is the most common non-infectious neurologic disease in developing countries such as Africa, including Nigeria. This study was designed to assess the intellectual performance of patients with epilepsy (PWE) in Nigeria hoping that the result will serve as the basis for educational, vocational, and social counseling.

METHODS

Forty-one PWE were studied along with 41 age-, sex- and education-matched healthy controls. A questionnaire was developed and applied to all subjects and history was taken from patients and eyewitness. The intellectual function of each subject was assessed with the aid of Wechsler Adult Intelligence Scale adapted for Nigerians. All patients subsequently had electroencephalography (EEG) performed and the EEG findings were noted. SPSS statistical package was used to analyze the data.

RESULT

The PWE performed poorly on the verbal IQ, performance IQ, and full scale IQ scores when compared with controls (P < 0.05) and 20% of PWE had mental retardation. Long duration of epilepsy, long duration of antiepileptic drug therapy, younger age at onset of epilepsy, increased frequency of seizures, and low educational status were found to have negative impacts on intellectual performance in PWE (P < 0.05) while seizure types and type of antiepileptic drugs (carbamazepine or phenytoin) did not influence intellectual performance.

CONCLUSION

This study shows that PWE had significant intellectual impairment when compared with controls. In addition, long duration of epilepsy, long duration of AED therapy, earlier age of onset, increased seizure frequency, and low educational status had a negative impact on intellectual functioning in PWE.

Role of Endogenous Neural Stem Cells in Neurological Disease and Brain Repair

These examples show that stem-cell-based therapy of neuro-psychiatric disorders will not follow a single scheme, but rather include widely different approaches. This is in accordance with the notion that the impact of stem cell biology on neurology will be fundamental, providing a shift in perspective, rather than introducing just one novel therapeutic tool. Stem cell biology, much like genomics and proteomics, offers a "view from within" with an emphasis on a theoretical or real potential and thereby the inherent openness, which is central to the concept of stem cells. Thus, stem cell biology influences many other, more traditional therapeutic approaches, rather than introducing one distinct novel form of therapy. Substantial advances have been made i n neural stemcell research during the years. With the identification of stem and progenitor cells in the adult brain and the complex interaction of different stem cell compartments in the CNS--both, under physiological and pathological conditions--new questions arise: What is the lineage relationship between t he different progenitor cells in the CNS and how much lineage plasticity exists? What are the signals controlling proliferation and differentiation of neural stem cells and can these be utilized to allow repair of the CNS? Insights in these questions will help to better understand the role of stem cells during development and aging and the possible relation of impaired or disrupted stem cell function and their impact on both the development and treatment of neurological disease. A number o f studies have indicated a limited neuronal and glial regeneration certain pathological conditions. These fundamental observations have already changed our view on understanding neurological disease and the brain's capacity for endogenous repair. The following years will have to show how we can influence andmodulate endogenous repair nisms by increasing the cellular plasticity in the young and aged CNS.

Verbal memory decline and adverse effects on cognition in adult patients with pharmacoresistant partial epilepsy: a longitudinal controlled study of 36 patients

The aim of this study was to delineate possible longitudinal cognitive changes in adult patients with a long history of pharmacoresistant partial epilepsy. Thirty-six patients and thirty healthy controls were investigated at baseline. A reassessment was conducted, with median test intervals of 4.8 years for the patients and 3.1 years for controls. A standardized battery was used for assessment of general cognitive level and memory. At baseline, patients performed at a significantly lower level on general cognition, immediate recall of pairs of associated words, and retention of learned words and visuospatial stimuli, compared with controls. Analyses of change over time in the patients disclosed significant verbal memory decline in retention of pairs of associated words. Group comparisons of change over time revealed adverse effects in the performance aspect of general cognition on the patients. Also, group comparisons indicated impaired performance across time for the patients in retention of pairs of associated words and retention of visuospatial stimuli. The adverse effect on memory and general cognition in this patient group over the period was clear-cut when compared with the longitudinal changes in an adequate control group.

Progressive cognitive decline in adolescents and adults with epilepsy

The effects of an accumulation of single seizures upon mental abilities in adolescents and adults is explored through a selective review of the world's literature. The papers reviewed were divided up into cross-sectional and longitudinal studies. Of 16 investigations meeting all requirements for inclusion, 12 produced results pointing to a relationship between seizures and adverse cognitive change. The cross-sectional studies produced stronger results than the longitudinal ones, no doubt because the effects of co-existing factors not related to seizure effects were included in measures of cognitive decline. The longitudinal investigations showed mild but definite relationships between seizures and mental decline. However, relationships could be found only with generalized tonic-clonic seizures and not with partial attacks. Results of an original investigation were reported which were consistent with the literature review. Suggestions for future research were offered.

Cognitive and behavioural concerns in epileptic children

Cognitive performance in an epileptic child has been a difficult issue to predict in day-to-day clinical practice. Several observations made in early and later part of this century do not provide uniform and convincing answer to this issue. Recent trends in research however, have identified certain variables that are shown to be associated with cognitive decline in epileptic children. Together with associated behavioural problems, the resultant school difficulty is the essence of this concern for the parents. The variables related to cognitive deterioration as identified by several studies include underlying brain pathology (symptomatic epilepsy), early age of onset of seizure, severity and intractability of seizure, repeated head trauma, an episode of status epilepticus, presence of interictal subclinical EEG discharge, adverse psychosocial factor and antiepileptic drug (AED). Association of these variables in a given case cannot only predict adverse cognition outcome but also a preventive management package can be planned aiming at avoiding or minimizing these high risk variables.

Status epilepticus in children: aetiology, treatment, and outcome

This retrospective study includes 65 children treated for status epilepticus at Tampere University Hospital in Finland. Aetiology of the condition, effectiveness of the treatment protocol, including short barbiturate anaesthesia to prevent prolonged status epilepticus episodes, and neurological outcome were evaluated. Symptomatic aetiology was present in 40% of status epilepticus episodes, and 37% of episodes were induced by fever. Neurological sequelae secondary to status epilepticus were identified in 15% of the cases and subsequent epilepsy in 23% during the mean follow-up time of 3.6 years. There were no status epilepticus-related deaths. The cut-off point of status epilepticus duration for significant risk for permanent neurological sequelae was 2 hours. Our treatment protocol, including short barbiturate anaesthesia in refractory cases, was able to abort status epilepticus in less than 2 hours in 75% of cases. We conclude that early and prompt use of barbiturate anaesthesia should be encouraged, and may explain our low morbidity figures.

The impact of posttraumatic seizures on 1-year neuropsychological and psychosocial outcome of head injury

This study examined the relationship of posttraumatic seizures and head injury severity to neuropsychological performance and psychosocial functioning in 210 adults who were prospectively followed and assessed 1 year after moderate to severe traumatic head injury. Eighteen percent (n = 38) of the patients experienced 1 or more late seizures (i.e., seizures occurring 8 or more days posttrauma) by the time of the 1-year followup. As expected, the head injured patients who experienced late posttraumatic seizures were those with the most severe head injuries, and they were significantly more impaired on the neuropsychological and psychosocial measures compared to those who remained seizure free. However, after the effects of head injury severity were controlled, there were no significant differences in neuropsychological and psychosocial outcome at 1 year as a function of having seizures. These findings suggest that worse outcomes in patients who develop posttraumatic seizures up to 1 year posttrauma largely reflect the effects of the brain injuries that cause seizures, rather than the effect of seizures.

Cognitive and behavioral effects of antiepileptic drugs

All antiepileptic drugs (AEDs) have the potential for adverse effects on cognition and behavior. Most of the major AEDs, administered in therapeutic doses, cause little or no cognitive or behavioral impairment in group studies. However, individual variability is considerable, and some patients do not tolerate low serum levels, whereas others tolerate high levels without subjective or objective effects. In the past, carbamazepine (CBZ) and valproate (VPA) have been reported to have the fewest adverse cognitive and behavioral effects in children and adults. However, several recent, well-controlled studies have not found significant differences between the effects of phenytoin (PHT) and those of CBZ or VPA. Greater adverse effects have been found for phenobarbital (PB). However, we must use environmentally relevant measures of cognitive and behavioral functioning to measure effects on daily functioning. Future studies must define cognitive and behavioral toxicity in subpopulations (e.g., post-traumatic epilepsy, mental retardation, depression) and with the new AEDs.