Retrieval impairment in generalized tonic-clonic epilepsy and complex partial epilepsy

Many epileptic patients complain of poor memory, especially those with complex partial seizures. Memory in epilepsy is reportedly influenced by several factors like seizure type, seizure frequency, age at onset of epilepsy, anti-epileptic medication, etc. However, the available data are somewhat confiising and do not provide any clear answers. In order to evaluate retrieval in epileptic patients the Selective Reminding Test was used in 44 epilcpsy partents (30 with generalized tonic-clonic epilepsy and 14 with partial complexepilepsy)whoweretreatedintheoutpatient clinic of the DepartmentofNeurologyoftheDrCipto Mangunkusumo Hospital during one year period ( 1993-1994). AII subjects had passed elementary school, were without severe brain damage, had their last seizure more than 24 hours ago and only take one anti-epileptic drug (phenobarbital). Retrieval impairment was analyzed with respect to thefollowing vaiabLes: seizure type, seizurefrequency, age at onseî and drug dose. In subjects with impaired reffieval the ncnwryprocesswereanalyzed. Impairedretrievalwasfoundinmostsubjects(75Vo). The mean retrieval scoreswereT.TTforsubjects with generalized tonic-clonic epilepsy and 8.36 for subjects with partial complex epilepsy. There is no correlation betvveen seizure type and retrieval (t test). Mosr subjects had low frequency seizures, but mean retrieval scores were impaired both in the high frequency (717o) and the low frequency (687o) group (not significantwith chi-square test). Although it was statistically not significant there was a tendency that thegreatestretrievalimpairmentw,asinthegroap with early age at onset (lessthanl0years).Althoughmost subjects had low doses of phenobarbinl, most of them lnd impaired retrieval. There is no correlation between drug dose and retrieval (chi-square). In analyzing the impaired memory processes although there was little dffirence in the initial storage and retrieval in both types of epilepsy, the storage/retieval (S/R) ratio were belter in complex partial epilepsy (0,5 or less) than in generalized tonic-clonic epilepsy (more than 0,5). In complex partial epilepsy initial storage occured earlier. Most epilepsy patients had impaired retrieval; and it was not influenced by seizure type, seizure frequency, age at onset and anti-epileptic drug dose. Impaired retrieval in epilepsy is probably a multifactorinl disability. Also in generalized tonic-clonic epilepsy there was impaired initial storage besides retrieval, this was probably caused by disturbance of attention. Keyworils: epilcpsy, seizure type, seizurefrequency, age at onset, drug dose, selective reminding test, retieval, storage. Departmeû of Neurology, Faculty of Medicine, University of IndonesialDr. Cipn Mangtnhuwno Hospinl, lalarta, Indonesia Epilepsy is one of the most frequent neurological disease, only stroke has a higher incidence.' In several studies the incidence varies between 24-53 per Vol 5, No 4, October December 1996 100.000 and the prevalence is 4-8 per 100.000. The numbers were relatively constant in sàveral countries.2 In Indonesia epidemiological study on epilepsy is not yet performed, but it was surmised that the incidence and prevalence is the same. Traditional or conventional treatment in patients with epilepsy is directed to drug therapy adjustments based on the type, severity and frequency of seizures, and the side effects of anti-epileptic drugs. However, epileptic seizures and anti-epileptic drugs have a great impact on the life of a patient with epilepsy, i.e. psychosocial problems. Several factors influence the quality of life of the patient with epilepsy, i.e. seizure reccurency, psyhosocial adaptation, behavior disturbances, also deficit of cognitive function and behavior disturbances caused by anti-epileptic drugs. Many epileptics, even those with mild symptoms, complain of poor memory.' In clinical practice generally the patients were only treated with anti-epileptic drugs, the memory deficits went frequently unnoticed. However, this problem needs special attention as the patient requires a holistic treatment approach, including his social function. Memory deficits in epileptic patients merit special attention since they seek help for these more frequently than for any other mental impairments. Interest in this area is not new; Tissot (1170), Gowers (1881), and Reynolds (1861) had discovered that memory impairment was frequently found in epileptics.a In clinical practice memory disturbance is more frequently found in complex partial epilepsy. However, in many studies there is still disagreement whether there is a difference in the memory functions of comple"x.partial and g epilepsy.J'J'u" Most comp ed from temporal and frontal 7O-8OVo of temporal lobe epilepsy begin in the hippocu-por.8 These facts are a little perplexing as we understand the important role of the temporal lobe and especially the hippocampus in memory functions. Another problem is what other factors can influence memory. Besides seizure type, other factors like seizure frequency, seizure onset, drugs, etc, had been reported to influence memory; however, other studies could not prove it. In developing countries like Indonesia drugs are more often chosen for their availability and their low prize, so many epileptics here use phenobarbital. Reports of deleterious effects of phenobarbital on cognitive function present an important question of how far it has reduced the human resources here. Retrieval in Epilepsy 243 ln conclusion, the available data is somewhat confusing and do not give any clear answers to those questions. Probably this was caused by differences in the type of test used (many tests were not especially made for memory testing), the sampling method and usage of anti-epileptic drugs. In this study we propose to use a simple and widely used test that can show the differences in the memory process,i.e. the selective reminding test. Also the patients included in this study only used one kind of anti-epileptic drug (phenobarbital). MATERIALS AND METHODS