Non-epileptic seizures: delayed diagnosis in patients presenting with electroencephalographic (EEG) or clinical signs of epileptic seizures.

The clinical differentiation between epileptic seizures (ES) and non-epileptic seizures (NES) is often difficult and mostly based on the presence or absence of widely recognized features of ES such as tongue biting, falling, incontinence or concomitant epileptic abnormalities in the electroencephalogram (EEG). We retrospectively analysed the records of all patients referred to our Epilepsy Centre for refractory epilepsy and finally diagnosed with NES between 1980 and 1999 ( n= 103), half of them also exhibiting ES. The mean time-lapse between first attack and NES diagnosis was 8.7 +/- 1.3 years and 16.5 +/- 1.4 years for the NES and NES + ES groups respectively. At least one of the usual signs associated with generalized tonic-clonic seizures (tongue biting, falling or incontinence) was reported by 66% and 60% of patients with NES or NES + ES respectively. Interictal EEG abnormalities were recorded in 16% of NES patients vs. 80% of NES + ES patients. In the NES group, delay before establishing the correct diagnosis was significantly longer when the patients exhibited > or =1 symptom(s) of generalized seizures, or when patients exhibited interictal EEG abnormalities. Upon admission, 72% of NES patients and all NES + ES patients were being treated with antiepileptic drugs (AEDs).We conclude that EEG or clinical abnormalities suggestive of epileptic seizures are common in undiagnosed NES patients. Such diagnostic pitfalls, besides considerably delaying NES diagnosis, also considerably delay appropriate treatment implementation.     

Postictal SPECT in Epileptic Versus Nonepileptic Seizures

Despite advances in video-electroencephalogram (EEG) technology, in many patients distinguishing epileptic seizures from nonepileptic seizures (NES) remains a challenge. Reliable methods to make this distinction are needed. In a pilot study, we performed postictal and interictal single photon emission computed tomography (SPECT) in 22 patients undergoing video-EEG monitoring who had altered responsiveness during an episode. Eleven had seizures, defined as episodes associated with EEG seizure patterns or postictal prolactin (PRL) elevations greater than 1.5 times the highest interictal baseline PRL; 11 had NES. Among the 11 seizures, postictal SPECT was abnormal in seven (regions of hypoperfusion in six and hyperperfusion in one) and normal in four. In six cases (55%), the interictal and postictal SPECT changed. Among the 11 NES cases, postictal SPECT was abnormal in three cases (all hypoperfusion abnormalities) and normal in eight cases. In no case did the interictal and postictal SPECT change. This small sample revealed a trend toward greater hypometabolism (postictal versus interictal) on SPECT for epileptic seizures compared to NES (p < 0.12). There were postictal SPECT changes in two of five seizures unassociated with postictal PRL elevation. Prolactin was elevated in two cases unassociated with change on SPECT. Comparision of postictal to interictal SPECT may help distinguish epileptic seizures from NES. Results from SPECT may also help identify epileptic seizures unassociated with PRL elevation.     

A comparative study of mismatch negativity (MMN) in epilepsy and non-epileptic seizures.

This study investigated mismatch negativity (MMN) differences between subjects with non-epileptic seizures (NES), subjects with epilepsy, and healthy controls. Event-related potentials (ERPs) were obtained from 14 patients with NES, 15 patients with epilepsy and 16 healthy control subjects. A conventional MMN procedure was used with a random sequence of 12% deviant tones (922 Hz) and 88% standard tones (1000 Hz). Subjects were instructed to ignore the tones delivered through headphones whilst reading a book. Significant differences in distribution of the mismatch negativity (MMN) in patients with NES compared to controls were obtained (F3, p 相似文献   

Auditory event-related potentials (P300) in the identification of psychogenic nonepileptic seizures

The feasibility and conceivable value of postictal event-related potential (ERP) recordings were studied in patients with nonepileptic seizures (NES) admitted for long-term video/EEG monitoring. Ten patients with NES underwent preictal (on hospital admission) and postictal (< or =6 hours after seizure) ERP recordings of an auditory oddball paradigm. Additionally, 10 temporal lobe epilepsy (TLE) patients with partial seizures and secondary generalization underwent preictal, postictal (< 6 hours after seizures), and interictal (7-48 hours after seizure) ERP recordings. We recently reported that ERPs recorded in TLE patients with partial epilepsy undergo a temporary change postictally, while returning to their preictal state during interictal recordings. In the current study intraclass correlations, transformed into z scores, are used to determine test-retest validity of repeated ERP recordings. An independent sample t test with z scores for the comparison of preictal and postictal recordings showed that ERP activation differed between NES and TLE patients (P=0.009). More specifically, ERP recordings in the preictal and postictal states were similar in NES patients, but dissimilar in TLE patients. On the other hand, this dissimilarity in ERPs disappeared when comparing z scores for the preictal and postictal recordings in NES patients with z scores for the preictal and interictal recordings in TLE patients. This further supports the notion that identical waveforms during preictal and postictal recordings in NES patients reflect nonepileptic seizure activity. The current findings suggest that postictal ERP recordings are useful in the diagnosis of NES and differentiate TLE from NES.     

HMPAO SPECT in non-epileptic seizures: preliminary results

The diagnosis of non-epileptic seizures (NES) is problematic. Although diagnosis can be achieved by videotelemetry, these facilities are expensive and not widely available. HMPAO SPECT studies show focal hypoperfusion interictally in focal epilepsy. SPECT has not been studied in any detail in NES previously. Two groups (10 patients each) were studied, one with NES and one with complex partial seizures and localisation related epilepsy. SPECT scans were normal in 7 of 10 (70%) NES patients, while showing clear focal hypoperfusion in 8 of 10 patients (80%) with epilepsy. In the NES group, 1 patient showed hypoperfusion indistinguishable from that seen in epilepsy, while 2 patients in the epilepsy group showed only equivocal focal hypoperfusion. The remaining 2 patients in the NES group showed bifrontal and equivocal focal hypoperfusion. A normal HMPAO SPECT study supports the diagnosis of NES in patients with seizures of uncertain aetiology.     

儿童非癫痫性发作

目的 :探讨儿童非癫痫性发作的各种临床表现形式。方法 :对 35例非癫痫性发作患儿的临床结合脑电图监测进行分析。结果 :35例儿童非癫痫发作中 ,生理性发作占 5 1% ,且平均年龄最小 ,全部患儿经 2 4小时脑电图或录相监测脑电图检查发作间期和 /或发作期均无异常放电 ;本组误诊 2 1例 ,其中癫痫 10例。结论 :儿童的非癫痫性发作表现形式多样 ,以生理性发作最多。儿童非癫痫性发作易误诊为癫痫及其它疾病 ,应用动态脑电图监测对其诊断及鉴别诊断有重要意义。     

The experience of earthquakes by patients with epileptic and psychogenic nonepileptic seizures

PURPOSE: We sought to understand better the experience of seizures by studying differences in the subjective experience of being in an earthquake between patients with epileptic (EP) and nonepileptic (NES) seizures. METHODS: Forty-eight patients with CCTV/EEG-documented EP or NES who were in the Seattle metropolitan area during the February 28, 2001 Nisqually earthquake were randomly selected for telephone interviews on their earthquake experiences, including whether they thought they were having a seizure during the event. RESULTS: Twenty-three percent of EP patients spontaneously volunteered that they initially thought they were having a seizure during the earthquake as compared with none of the NES individuals (p = 0.03). However, 35% of EP and 23% of NES patients thought they were having a seizure during it when asked directly (p = 0.37). The most common reasons given, regardless of seizure type, were shaking and feelings of losing control. Of those responding negatively, 100% of EP and 47% of NES patients said that movement of their environment indicated that it was not a seizure (p = 0.001). EP patients took an average of 42 s to realize that the earthquake was not a seizure compared with 105 s for the NES group (p = 0.06). The earthquake precipitated seizures in both groups (11.5% EP, 9.1% NES). CONCLUSIONS: EP patients were more likely to mistake the earthquake spontaneously for a seizure. This indicates these two experiences are similar and provides a glimpse into the subjective experience of a seizure for those who have never had one but have experienced an earthquake.     

Postictal symptoms help distinguish patients with epileptic seizures from those with non-epileptic seizures.

The aim of the study was to assess whether post-ictal symptoms can help distinguish patients who have epileptic seizures from those with non-epileptic seizures (NES). We reviewed the spontaneous responses to the question 'What symptoms do you have after a seizure?' in 16 patients with epileptic seizures (predominantly focal with secondary generalization or generalized tonic-clonic) and 23 NES patients. Six of the 16 patients (38%) vs. only one of 23 NES patients (4.3%) noted post-ictal headache (P = 0.008). Nine epilepsy patients (56%) vs. three NES patients (13%) reported post-ictal fatigue (P = 0.004). Confusion or other symptoms did not distinguish epilepsy patients from those with NES. All epilepsy patients had at least one post-ictal symptom while 12 NES patients (52%) had none (P = 0.001). Therefore, patients evaluated for epileptic vs. non-epileptic seizures who have post-ictal fatigue or headache, are more likely to have epileptic seizures. Patients with a diagnosis of NES who note post-ictal fatigue or headache should be investigated further.     

Nonepileptic seizures in children

PURPOSE: To determine if the clinical characteristics of nonepileptic seizures (NES) are different in children younger than 13 years age as compared to adolescents. METHODS: Retrospective review of medical records and video-EEGs (VEEG) of all patients with NES confirmed on VEEG monitoring was performed. RESULTS: Sixty-eight (3.5%) of 1,967 patients monitored with VEEG had a clinical diagnosis of NES. Fifty-nine of 68 patients had their habitual event recorded. Mean age at the time of the VEEG diagnosis was 13 years 4 months. Twenty-two patients were less than 13 years (group A) and 37 were 13 years and older (group B). The male to female ratio was equal in group A, with female predominance seen in group B. NES commonly manifested as subtle motor activity in group A (p < 0.01) and prominent motor activity in group B (p < 0.001). Difficulties at school, family discord, and interpersonal conflicts, were frequent stressors in both groups. Sexual abuse was the least frequent. Depression was more common in group B; cognitive dysfunction (p < 0.001) and epilepsy (p < 0.01) were more common in group A. CONCLUSIONS: Differences in clinical semiology and predisposing factors may help identify young children and adolescents who might be at risk for the development of NES.     

Non-epileptic seizures of the elderly

OBJECTIVE: To characterize non-epileptic seizures (NES) in the elderly and compare their features with NES of a younger control group. METHODS: The database of the epilepsy monitoring unit of the Cleveland Clinic Foundation (CCF) was searched for patients aged 60 years and older having undergone long-term video-/EEG monitoring between 1994 and 2002, with the subsequent diagnosis of NES. Videotapes of all events were evaluated by independent observers. NES were classified based on the clinical manifestations recorded on video, EEG and imaging data, and compared with a control group of younger adults with NES. RESULTS : Thirty-nine elderly patients were included. Seventeen of them (44%) had NES only, six (15%) had both epilepsy and NES. The control group consisted of 20 patients, two of them had NES and epilepsy. The NES were classified as physiological in 10 elderly patients (43%) and one control patient. They included TIA, syncope, movement disorders and sleep disorders. Psychogenic NES were found in 13 elderly and 19 control patients and were associated with somatoform disorders, anxiety disorders, mood disorders and reinforced behavior pattern. Psychogenic NES consisted of predominant motor activity in 8 (61%) elderly and 13 (68%) control patients, unresponsiveness in 4 (31%) elderly and 2 (11%) control patients and subjective symptoms in 1 (8%) elderly and 4 (21%) control patients. Twelve (71%) of the patients of each group without evidence for epilepsy were on anticonvulsant drugs at the time of admission. CONCLUSION: NES are a frequent problem in elderly patients referred to a comprehensive epilepsy center. In contrast to a younger control group, physiological and psychogenic NES are equally frequent in the elderly. Loss of responsiveness was seen in only 20% of patients with psychogenic NES. Although most of the patients did not have any evidence for epilepsy, more than two thirds of these patients had been placed on anticonvulsive drugs.     

EEG findings after a cerebral territorial infarct in patients who develop early- and late-onset seizures

BACKGROUND: EEG findings are generally not considered to be very helpful for the diagnosis of poststroke seizures. PURPOSE: This retrospective study investigates the EEG characteristics in patients who develop seizures after a cerebral territorial infarct. PATIENTS AND METHODS: The study population consisted of 110 patients with seizures after a cerebral territorial infarct (12 with early- and 98 with late-onset seizures) and 275 without. All 110 patients had an interictal EEG after their first seizure. The EEG patterns after the stroke were compared between those available from 69 patients who developed seizures and those from 275 who did not. Also the EEG patterns after the seizure (n = 110) were compared to those in the poststroke group without subsequent seizures. RESULTS: Periodic lateralized epileptic discharges (PLEDs) on the EEG after stroke were only found in 5.8% of the patients with early- and late-onset seizures. They were absent in the stroke group without seizures. Frontal intermittent rhythmic delta activities (FIRDAs) were observed in 24.6% of the seizure group, compared to 1.1% in the control group. Diffuse slowing occurred also significantly more often in the former (21.7%) compared to the latter group (5.1%). Normal EEG findings were seen in 53.8% of the stroke patients without seizures, compared to 8.5% in those with seizures. The incidence of focal slowing was the same in both groups. Similar findings were observed when comparing the EEG patterns of the patients after the first poststroke seizure to those of the stroke group without subsequent seizures. In patients with early-onset seizures, PLEDs or FIRDAs were present in 25% each. FIRDAs and diffuse slowing were significantly more frequently observed on the poststroke EEGs of patients who developed late-onset seizures. CONCLUSIONS: FIRDAs, PLEDs and diffuse slowing are the most frequent EEG findings in patients with early-onset seizures. Patients with FIRDAs and diffuse slowing on the poststroke EEG have a high risk to develop late-onset seizures, while the chance is reduced in those with normal EEG findings.     

Ictal Behaviors During Nonepileptic Seizures Differ in Patients with Temporal Lobe Interictal Epileptiform EEG Activity and Patients Without Interictal Epileptiform EEG Abnormalities

Summary: Purpose: Ictal behaviors during psychogenic non-epileptic seizures (NES) vary considerably among individuals, and can closely resemble common semiologies of epileptic seizures (ES). We tested the hypothesis that behaviors during NES in patients who have temporal spikes would more closely resemble behaviors during ES in patients with temporal lobe epilepsy than would behaviors during NES in patients who do not have EEG spikes.
Methods: We identified 20 patients who had interictal temporal EEG spikes and EEG-video recorded NES (Study Group), 133 patients with temporal EEG spikes and recorded ES, without NES (Epileptic Group), and 24 patients with recorded NES and no epileptiform EEG abnormalities, without ES (Nonepileptic Group).
Results: The hypothesis was supported with regard to ictal motor behaviors. Motionless staring or complex automatisms occurred mainly during NES in the Study Group and during ES in the Epileptic Group. In contrast, convulsive movements or flaccid falls were most common during NES in the Nonepileptic Group. Duration of unresponsiveness was longer, and there were fewer postictal states in NES both in the Study and Non-epileptic Groups. Unresponsiveness was briefer and postictal states were more consistent in ES in the Epileptic Group, however.
Conclusions: Stereotyped motor activities during NES presumably represent learned behaviors. Processes underlying acquisition of ictal behaviors of NES probably differ in patients with interictal epileptiform EEG abnormalities compared to those without. Prior experiences and temporal lobe dysfunctions that are associated with epilepsy, and psychological characteristics that are unrelated to interictal epileptic dysfunctions, may determine ictal behaviors during NES.     

Comparison of heart rate variability parameters during complex partial seizures and psychogenic nonepileptic seizures

Purpose: Psychogenic nonepileptic seizures (PNES) superficially resemble epileptic seizures. Little is known about ictal autonomic nervous system (ANS) activity changes in epilepsy and PNES. This study compares ictal heart rate variability (HRV) parameters as a reflection of ANS tone in epileptic seizures and PNES, and explores differences between interictal and ictal ANS tone in both patient groups. Methods: Ictal HRV parameters were extracted from single‐lead electrocardiography (ECG) data collected during video–electroencephalography (EEG) recordings of 26 patients with medically refractory temporal lobe epilepsy and 24 age‐ and sex‐matched patients with PNES. One seizure per patient in a resting, wake, supine state was analyzed. Interictal ECG data were available for comparison from 14 patients in both groups. HRV parameters in time and frequency domains were analyzed (low frequency [LF], high frequency [HF], standard deviation of all consecutive normal R wave intervals [SDNN], square root of the mean of the sum of the squares of differences between adjacent normal R wave intervals [RMSSD]). CVI (cardiovagal index), CSI (cardiosympathetic index), and ApEn (approximate entropy) were calculated from Lorenz plots. Key Findings: There were significant differences between ictal HRV measures during epileptic and nonepileptic seizures in the time and frequency domains. CSI (p < 0.001) was higher in epileptic seizures. Time interval between two consecutive R waves in the ECG (RR interval) (p = 0.002), LF (p = 0.02), HF (p = 0.003), and RMSSD (p = 0.003) were significantly lower during epileptic seizures. Binary logistic regression yielded a significant model based on the differences in CSI classifying 88% of patients with epilepsy and 73% of patients with PNES correctly. The comparison between resting and ictal states in both seizure disorders revealed significant differences in RR interval (epilepsy p < 0.001, PNES p = 0.01), CSI (epilepsy p < 0.001, PNES p = 0.02), HF (epilepsy p = 0.002, PNES p = 0.03), and RMSSD (epilepsy p = 0.004, PNES p = 0.04). In patients with epilepsy there were also significant differences in ictal versus interictal mean values of ApEn (p = 0.03) and LF (p = 0.04). Although CSI was significantly higher, the other parameters were lower during the seizures. Stepwise binary regression in the 14 patients with epilepsy produced a significant model differentiating resting state from seizures in 100% of cases. The same statistical approach did not yield a significant model in the PNES group. Significance: Our results show greater ANS activation in epileptic seizures than in PNES. The biggest ictal HRV changes associated with epileptic seizures (CSI, HF, and RMSSD) reflect high sympathetic system activation and reduced vagal tone. The reduced ApEn also reflects a high sympathetic tone. The observed ictal alterations of HRV patterns may be a more specific marker of epileptic seizures than heart rate changes alone. These altered HRV patterns could be used to detect seizures and also to differentiate epileptic seizures from PNES. Larger studies are justified with intergroup and intragroup comparisons between ictal and resting states.     

Epileptic seizures in aspartylglucosaminuria: a common disorder

Aspartylglucosaminuria (AGU) is a lysosomal storage disorder with reduced life-span. An analysis of 121 Finnish patients showed that 22 to 78 adults (28%) and one of 43 children (2%) had epileptic seizures. Twelve patients had the onset of attacks after the age of 30 years. Eleven patients had generalized, nine partial and three unclassified seizures. The response to carbamazepine was good. The major interictal EEG abnormality was the attenuation of the amplitude found in 10/27 patients. The brain CT-scans showed diffuse atrophy in 8/11 patients.     

Characteristics of patients with nonepileptic seizures

The personality features, neuropsychological data, and ictal characteristics of 23 patients with nonepileptic seizures (NES) were compared to 25 patients with EEG-confirmed epileptic seizure (ES) disorders. A distinctive pattern of seizure, behavior, and personality features was evident in NES patients. NES was characterized by later disease onset and shorter disease duration. NES tends to last significantly longer than ES and rarely results in tongue-biting or self-injury. Patients who develop NES frequently have witnessed seizures prior to developing the disorder and have greater somatic concerns than patients with ES. Neuropsychological group data failed to differentiate NES from ES. However, the absence of group differences may reflect heterogeneity within the NES population. Although many NES patients performed well within normal limits on all neuropsychological measures, most were mildly to severely impaired. Qualitative analysis of neuropsychological data also revealed inconsistencies within the NES group. These findings suggest that a more global neurobehavioral profile may be useful in the diagnosis of NES. Future studies of NES must also recognize that important individual differences may be masked within group data.     

Etiology, diagnosis, and treatment of nonepileptic seizures

Psychogenic nonepileptic seizures (NES) can be classified into five categories. This review focuses on NES associated with emotional conflict, by far the most common and important group. Etiology is speculative, but the background histories of these patients are often similar. The presence of a trauma history, depression, post-traumatic stress symptoms, and the use of dissociation plus cognitive dysfunction possibly point to an organic etiology. The presentation of NES in children and adults is discussed, along with the differential diagnosis. The diagnostic differential is lengthy, with epileptic seizures of frontal lobe origin presenting a unique challenge. Diagnostic procedures are reviewed with an emphasis on the utility of hypnosis with seizure induction. Presenting the diagnosis to the patient, the role of the neurologist, and the role of the mental health consultant are reviewed. Issues in the doctorpatient relationship are also addressed, as well as the overall prognosis.     

Psychogenic nonepileptic seizures are associated with an increased risk of obesity

Psychogenic nonepileptic seizures (NES) are somatic manifestations of psychological distress. There is some evidence that weight problems are more common in patients with psychiatric illness. We have observed that patients admitted for video-EEG monitoring who we diagnosed with NES commonly have a larger body habitus than patients with epilepsy. The goal of this study was to test our hypothesis that there was a significant difference in body mass index (BMI) in patients with nonepileptic seizures compared with their epileptic counterparts. We compared the BMIs of 46 NES patients and 46 age- and gender-matched epileptic controls and found that the NES patients had significantly higher BMIs (30.5 vs 26.1, P=0.006) than controls. This remained true after controlling for weight-gain properties of antiepileptic drugs. These results are compared with the prevalence of overweight and obesity in the general population. Possible explanations of the findings and limitations of the study are discussed.     

Autonomic nervous system functions in interictal and postictal periods of nonepileptic psychogenic seizures and its comparison with epileptic seizures

Purpose(1) To evaluate autonomic nervous system (ANS) functions during both interictal and postictal periods in a group of cases with nonepileptic psychogenic seizures (NEPS) and a group of epileptic patients to determine whether they have autonomic dysfunction. (2) If a significant difference can be established between epileptic and NEPS groups, to determine whether ANS tests can be used as a clinical helper in the differentiation between epileptic seizures (ES) and NEPS.MethodsANS functions (sympathetic skin response and R–R interval variation) were measured during both interictal and postictal periods in 25 patients who had NEPS and 30 patients who had primary generalized tonic–clonic seizures (GTCS) and partial seizures with secondary GTCS, as well as once in the healthy control group.ResultsWhen the patient group with NEPS both in the interictal and postictal period was compared with the control group, functions of both sympathetic and parasympathetic systems were found normal. This finding implies that patients with NEPS have normal ANS functions. A comparison of the epileptic patient group in the interictal and postictal periods with the control group revealed that the former had dysfunctions in both the sympathetic and parasympathetic systems. When patients with NEPS were compared with the ES, the measurements in sympathetic and parasympathetic nervous system functions during the interictal and postictal periods in the ES group were significantly different than those of the NEPS group.ConclusionThis finding indicates that measurements of ANS functions may be helpful in differentiating between ES and NEPS.     

The value of provocation methods in patients suspected of having non-epileptic seizures.

Non-epileptic seizures (NES) are reported in 18-23% of patients referred to comprehensive epilepsy centres. Non-epileptic seizures may also be present in 5-20% of the patients who are diagnosed as having refractory seizures. Because of their prevalence, financial and psychosocial outcomes cannot be ignored and accurate diagnosis is of the utmost importance. Various methods of seizure induction have been developed with the aim of differentiating epileptic from non-epileptic seizures. However, recording the attacks by video-EEG monitoring is the gold standard. In our outpatient EEG laboratory we try to induce seizures with verbal suggestion or IV saline infusion in patients who are referred by a clinician with the diagnosis of probable non-epileptic seizures. In this study we investigated the results of 72 patients who were referred between January 1992-June 1996. Non-epileptic seizures were observed in 52 (72.2%) patients. Thirteen of these patients still had risk factors for epilepsy. We could not decide whether all of their previous attacks were non-epileptic because 10-30% of the patients with NES also have epileptic seizures. For a more accurate diagnosis it was decided that these 13 patients, together with the 20 patients who did not have seizures with induction, needed video-EEG monitoring. Thirty-nine patients who had NES and no risk factors for epilepsy were thought to have pure non-epileptic seizures. We claim that not all patients suspected of having NES need long-term video-EEG monitoring and almost half (54.2%) of the cases can be eliminated by seizure induction with some provocative techniques.     

Acute cognitive effects of nonconvulsive difficult-to-detect epileptic seizures and epileptiform electroencephalographic discharges

This study compares the acute cognitive effects of short nonconvulsive seizures with the effects of interictal epileptiform electroencephalographic (EEG) discharges in children. The study is a prospective, standardized, nonrandomized, and open clinical comparative study. Eligible patients were included when they had (a) unclear seizures and fluctuations in cognitive performance and (b) frequent epileptiform EEG discharges in a recent EEG. All children were assessed with EEG/video (Brainlab) simultaneously with computerized neuropsychologic testing (FePsy) assessing motor speed/alertness, mental speed/attention, and memory function. Eleven patients with short nonconvulsive seizures during cognitive testing were included and compared with 11 matched patients with interictal epileptiform EEG discharges during cognitive testing but without seizures. Patients included in both groups had a reconfirmed diagnosis of epilepsy. Cognitive performance for both groups was compared. Statistical analysis showed significant correlations between the number of seizures (during cognitive testing) and impaired alertness and between the duration of the ictal period and memory impairment. Interictal epileptiform EEG discharges do not have an additional independent effect on cognitive function. The results demonstrate the accumulating cognitive effect of seizures and illustrate that frequent seizures, even when these are short in duration and with subtle symptomatology, can have a substantial impact on daily life and can lead to state-dependent learning impairment. Alertness and short-term memory appeared to be the functions that are most vulnerable for the acute effects of seizures.