The diagnosis of epileptic and non-epileptic seizures

The aim of this prospective population-based study was to systematically define a cluster of diagnostic items which can assist in the early identification and classification of epileptic and non-epileptic seizures. A cohort of patients aged > or =14 years, suspected with a first epileptic seizure, were included in this study. A team of neurologists evaluated and classified all cases. Diagnostic items for epileptic and non-epileptic seizures were identified using logistic regression analysis. Three hundred and fifty cases entered this study. Distinctive features for epileptic seizures were postictal confusion (OR 0.09), an epileptiform EEG pattern (OR 0.02), and abnormal neuroimaging findings (OR 0.07), whereas for non-epileptic seizures of organic origin there was a history of hypertension (OR 7.5), and provoking factors (OR 13.4) such as exercise and warmth. Diagnostic items for seizures of non-organic origin were a history of febrile seizures (OR 5.8), treatment by a psychologist or psychiatrist (OR 9.1), and presentiment of the seizure (OR 3.7) such as a feeling of choking and palpitations. A separate analysis for the patients who were systematically investigated provided some additional diagnostic items for the different subgroups of patients. For instance, back arching during the seizure for the patients with seizures of non-organic origin and female sex for the patients with non-epileptic seizures of organic origin.     

Autism and epilepsy: a retrospective follow-up study

So-called "idiopathic" autism, which exhibited no major complications before diagnosis is well-known as one of the risk factors for epilepsy. This retrospective follow-up study aimed to clarify the characteristics of epilepsy in the autism; onset of seizure, seizure types, EEG findings and epilepsy outcome and the differences as a group between the autism with epilepsy and those without epilepsy. One hundred thirty individuals with autistic disorder or atypical autism diagnosed in childhood were followed up over 10 years and were evaluated almost every year up to 18-35 years of age. Their medical records related to perinatal conditions, IQ, social maturity scores and several factors of epilepsy were reviewed in October 2005. Thirty-three of the follow-up group (25%) exhibited epileptic seizures. The onset of epilepsy was distributed from 8 to 26 years of age. Two types of seizure were observed; partial seizure with secondarily generalized seizure and generalized seizure. Twenty of the epileptics (61%) showed the partial seizure. Although 18% of the non-epileptic group exhibited epileptic discharges on EEG, 68% of the epileptic group revealed epileptiform EEG findings before the onset of epilepsy. No differences were observed concerning the sex ratio, autistic disorder/atypical autism and past history of febrile seizures between the epileptic and non-epileptic groups. Lower IQ, lower social maturity score and higher frequency of prescribed psychotropics were observed in the epileptic group compared to the non-epileptics. Idiopathic autism was confirmed as the high risk factor for epilepsy. Epileptiform EEG findings predict subsequent onset of epileptic seizures in adolescence. Epilepsy is one of negative factors on cognitive, adaptive and behavioral/emotional outcomes for individuals with autism.     

Newly diagnosed epileptic seizures: focus on an elderly population on the French island of Réunion in the Southern Indian Ocean

Purpose: To describe seizure types and risk factors among elderly people with newly diagnosed epileptic seizures living on La Réunion, a French Island in the Southern Indian Ocean. Methods: We describe an elderly population with newly diagnosed epileptic seizures using data from the EPIREUN study conducted between July 1, 2004 and June 30, 2005. The methodology is described in detail in the EPIREUN study report ( Mignard et al., 2009 ). Key Findings: There were 153 single unprovoked seizures (84.1%); their incidence was 278.1 [95% confidence interval (CI) 237.4–325.9] per 100,000. The incidence of newly diagnosed epilepsy was 125.4 (95% CI, 99.1–158.8) per 100,000. Twenty‐eight acute symptomatic seizures occurred (15.4%); the incidence was 50.9 (95% CI 35.1–73.7) per 100,000. The annual incidence of newly diagnosed epileptic seizure in the elderly was 330.8 (95% CI 286.1–382.6) per 100,000: 403.0 (95% CI 328.5–494.3) per 100,000 in men and 279.6 (95% CI, 227.4–343.8) per 100,000 in women. Sex had a significant (p = 0.014) effect on incidence: elderly men had a risk ratio of 1.44 compared to women of developing a newly diagnosed epileptic seizure. The etiology of single unprovoked seizure was as follows: stroke, 77 cases (50.3%); cryptogenic, 36 (23.5%); alcoholism, 10 (6.6%); a combination of several causes such as polypathology, 9 (5.9%); degenerative disease, 6 (4.0%); HIV infection, 2 (2.0%), and undetermined causes (2.7%). Most patients (170; 93.4%) were hospitalized, and 110 (60.8%) were treated. Among patients treated, 49 (44.5%) were given sodium valproate, 25 (22.7%) benzodiazepines, 12 (10.9%) phenytoin, 9 (8.2%) lamotrigine, 8 (7.3%) Trileptal, and 7 (6.4%) gabapentin. Significance: Our findings show that the incidences of newly diagnosed epileptic seizures and newly diagnosed epilepsy were high in the elderly population of La Réunion. These incidences were significantly higher in men than in women. These results may be attributable to the high incidence of cerebrovascular diseases and comorbidities in this population.     

Status epilepticus and seizures induced by iopamidol myelography.

PURPOSE: To report that iopamidol myelography can induce status epilepticus (SE) in patients carrying the diagnosis of symptomatic epilepsy and to estimate the incidence of seizures in patients undergoing iopamidol myelography. METHODS: We retrospectively identified all patients with seizures/SE associated with 1350 iopamidol myelographies during the last 5 years at our institution. The impact of cervical versus lumbar myelography was analysed. RESULTS: Induced by iopamidol myelography two non-epileptic patients suffered from first generalised tonic-clonic seizures and a 67-year-old women with symptomatic epilepsy after a remote ischemic stroke developed a generalised tonic-clonic seizure evolving into a dialeptic and right nystagmus SE (i.e. complex focal status) of 5-hour duration. The incidence of seizures in non-epileptic patients was 0.15%. The incidence of seizure induction for lumbar myelography was lower than for myelographies that included the cervical subarachnoid space. CONCLUSIONS: Iopamidol myelography (especially if cervical) is associated with a risk of seizures in non-epileptic individuals and can induce SE in patients with epilepsy. Patients should be informed about the risk of seizure induction.     

Remission of Seizures and Predictors of Intractability in Long-Term Follow-Up

In an incidence cohort, remission and relapse rates and determinants were studied in 178 patients followed long-term. A comparative study of predictive factors was performed in 40 patients with histories of antiepileptic (AED)-drug-refractory epileptic seizures in the last 10 years of follow-up and compared with the other 138 cohort subjects. The two groups were cross-tabulated with 353 variables of family history, obstetric, developmental and seizure histories, and current medical and social status. Multivariate analyses were applied for control of confounding. Defined or probable remote symptomatic etiology of seizures, abnormal neurologic development/ status, high initial seizure frequency, occurrence of status epilepticus, and poor short-term effects of AED therapy were significantly associated with long-term AED refractoriness. On logistic regression analyses, poor short-term outcome of AED therapy [odds ratio (OR) 3.6; 95% confidence interval (CI) 1.2–10.4], occurrence of status epilepticus (OR 11.4; 95% CI 3.2–41.0), high initial seizure frequency (OR 4.6; 95% CI 1.1–19.3), and remote symptomatic seizure etiology (OR 2.9; 95% CI 1.1–8.2) remained the only independent predictors of seizure intractability. These factors enable early assessment of need for epilepsy surgery.     

Physically traumatic events in patients with epilepsy compared with non-epileptic subjects

To determine the incidence of traumatic events among epileptic patients compared with non-epileptic individuals, we distributed a questionnaire on physically traumatic events occurring during the preceding three months to consecutive epileptic patients and to age- and sex-matched controls. There were 145 epileptic patients, 121 with seizures (age 36 +/- 15 y, 60 males) and 24 who were seizure free during this period (age 39 +/- 17 y, 13 males), and 145 controls (age 36 +/- 15 y, 73 males). There was no significant difference in the duration of epilepsy between the two groups of patients with epilepsy. Traumatic events (n= 27, three of them unrelated to seizure) were most common in patients with seizures, followed by controls (n= 20), and absent in seizure-free patients (P< 0.001). Patients with epilepsy most commonly injured the head while the extremities were more usually involved in controls. Patients with epilepsy had significantly more traumatic events at home, whereas controls underwent most traumatic events at work and in public areas. There was no significant difference in the type and severity of trauma between the two groups. We conclude that physically traumatic events not related to seizures are fewer among patients with epilepsy with and without seizures compared with controls, probably because of increased cautiousness.     

Seizures and epilepsy in elderly patients of an urban area of Iran: clinical manifestation, differential diagnosis, etiology, and epilepsy subtypes

The incidences of seizures and epilepsy in the population show a peak after 60 years of age. Due to the lack of reported clinical aspects of seizure and epilepsy in the older patients in our region in Iran, this study was conducted to describe the clinical manifestation, etiology, differential diagnosis, and epilepsy subtypes of epilepsy and seizure. A cross-sectional retrospective study was performed on all consecutively elderly seizure and epilepsy patients, referred to the Epilepsy Association in the city of Qom, Iran over a 10-year period. A total of 466 patients aged >60 years were admitted. 31 % of the patients had epilepsy or seizure and 69 % of them had non-epileptic events. The most prevalent differential diagnoses in the beginning were syncope and cardiovascular disorders. The most frequent clinical symptom of epilepsy was generalized tonic–clonic seizures (75 %). The most common cause of seizure was systemic metabolic disorder (27 %). In epileptic elderly patients, no cause was ascertained for 38 % and the most frequently observed pathological factors were cerebrovascular diseases, which accounted for 24 %. The most common type of epileptic seizure was generalized epileptic seizures (75 %). 10 % of elderly epileptic patients suffered from status epilepticus, which was primarily caused by anoxia. Despite the rising rate and potentially profound physical and psychosocial effects of seizures and epilepsy, these disorders have received surprisingly little research focus and attention in Iran. Referring older patients to a specialist or a specialist epilepsy center allows speedy assessment, appropriate investigation and treatment, and less likely to miss the diagnosis.     

EPIMART: Prospective Incidence Study of Epileptic Seizures in Newly Referred Patients in a French Carribean Island (Martinique)

PURPOSE: To identify, in the population living in the island of Martinique, persons who had their first epileptic seizure or first came to medical attention because of an epileptic seizure. METHODS: Between May 1, 1994, and April 30, 1995, we collected all suspected cases of provoked and unprovoked epileptic seizures admitted to the hospitals or addressed to the private neurologists or pediatricians of the island. RESULTS: Three hundred nine cases were collected. Rate of initial diagnosis of provoked and nonprovoked seizures (standardized to the U.S. population): 77.7/100,000, with a bimodal distribution of the cases with age (86 in 0- to 10-year age group and 203 in patients older than 60 years). Sixty-three cases were classified as provoked seizures (incidence, 16.4/100,000). Alcohol consumption, stroke, and cranial trauma were the most frequent causes (30.1, 20.6, and 18.7%, respectively). Two hundred forty-six cases were classified as unprovoked seizures (incidence, 64.1): seizures with a stable condition, 74 cases (I, 19.3); seizures with an evolutive condition, 17 cases (I, 4.5); seizures of unknown etiology, 155 cases (I, 40.4). These figures must be considered as the minimal rate. CONCLUSIONS: The global incidence rate of newly referred persons with a diagnosis of epileptic seizures in this study is clearly higher than those observed in industrialized countries but lower than those in developing countries. The major risk factors are represented by alcohol consumption, followed by stroke, cranial trauma, and infectious diseases.     

Incidence of unprovoked seizures and epilepsy in Iceland and assessment of the epilepsy syndrome classification: a prospective study

BACKGROUND: No population-based incidence studies of epilepsy have studied syndrome classification from the outset. We prospectively studied the incidence of a single unprovoked seizure and epilepsy in the population of Iceland, and applied the syndrome classification endorsed by the International League Against Epilepsy to this population. METHODS: We used a nationwide surveillance system to prospectively identify all residents of Iceland who presented with a first diagnosis of a single unprovoked seizure or epilepsy between December 1995 and February 1999. All cases were classified by seizure type, cause or risk factors, and epilepsy syndrome. RESULTS: The mean annual incidence of first unprovoked seizures was 56.8 per 100,000 person-years, 23.5 per 100,000 person-years for single unprovoked seizures, and 33.3 per 100,000 person-years for epilepsy (recurrent unprovoked seizures). Incidence was similar in males and females. Partial seizures occurred in 40% and a putative cause was identified in 33%. Age-specific incidence was highest in the first year of life (130 per 100,000 person-years) and in those 65 years and older (110.5 per 100,000 person-years). Using strict diagnostic criteria for epilepsy syndromes, 58% of cases fell into non-informative categories. Idiopathic epilepsy syndromes were identified in 14% of all cases. INTERPRETATION: Findings are consistent with incidence studies from developed countries. Although the epilepsy syndrome classification might be useful in tertiary epilepsy centers, it has limited practicality in population studies and for use by general neurologists.     

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.     

Patients with epilepsy and psychogenic non-epileptic seizures: an inpatient video-EEG monitoring study

Seizure and EEG characteristics of patients with epilepsy and concomitant psychogenic non-epileptic seizures (PNES) were compared to age and sex matched controls with epilepsy alone in a retrospective case control study. 39 patients with clearly documented epileptic and non-epileptic events were compared to 78 age and sex matched controls, sequentially admitted for video-EEG monitoring with documentation of epilepsy alone. Frontal seizures were higher in prevalence in patients with PNES who had concomitant epilepsy (P<0.001), while temporal seizures were higher in prevalence in patients with epilepsy alone (P<0.04). On regression analysis, the odds of having a frontal seizure was found to be significantly lower in the epilepsy alone group compared to the epilepsy+PNES group (odds ratio 0.13, 95% CI, 0.033-0.51). This significant association between frontal lobe epilepsy and PNES may be related to misattribution of frontal seizures for PNES events, or may reflect frontal lobe cortical dysfunction in this subgroup.     

Etiologic and diagnostic factors of psychogenic pseudo-epileptic seizures

The term psychogenic pseudoepileptic seizures (or psychogenic non-epileptic seizures-NES) generally refers to episodes of psychological origin that resemble epilepsy but without underlying epilepsy. The diagnosis of pseudo-epileptic seizures is confirmed in 5-33% of patients that are considered to suffer from refractory epilepsies. Making a correct diagnosis in patients presenting with attack disorders is sometimes very difficult. However, the best way to establish differential diagnosis of epileptic and pseudoepileptic seizures is to apply long-term video EEG monitoring. Triggering a seizure by means of placebo administration or suggestion to start or stop seizure can be also a helpful method in differential diagnosis. Over the last decade epileptologist have been paying increasing attention to the Minnesota Multiphasic Personality Inventory (MMPI) scales in describing or distinguishing real epileptic seizures vs. non-epileptic attacks. The results of the study may have practical implications for neurological and epilepsy centres, and for improving clinical knowledge and allow to establish aetiological classification of psychogenic pseudoepileptic seizures.     

Predictors of Intractable Childhood Epilepsy

Our study sought to identify early predictive factors of medically intractable childhood epilepsy. A cohort of epileptic children from the city of Mersin was retrospectively investigated. All patients received care from the same Department of Pediatric Neurology. The epileptic cohort was divided into a drug-responsive epilepsy group and an intractable epilepsy group. Intractable epilepsy is defined as continued seizures in children despite adequate therapy with two or more antiepileptic drugs for more than 18 months. Strong univariate association was observed between intractability and several factors: age of onset, high initial seizure frequency, symptomatic etiology, mixed seizure types, previous history of status epilepticus, febrile and neonatal seizures, mental and motor developmental delay, multiple seizures in 1 day, electroencephalogram abnormalities, magnetic resonance imaging findings, and specific epileptic syndromes. Logistic regression analysis revealed that a previous history of epilepticus status, abnormal electroencephalogram results, and multiple seizures in 1 day comprise independent predictors of medically intractable childhood epilepsy. We suggest that medical intractability in childhood epilepsy can be predicted by monitoring these factors. Along with early prediction, alternative therapies may be designed to provide patients better seizure control and quality of life.     

Occurrence of seizures in association with work-related stress in young male army recruits

Purpose: To examine the risk of undergoing an epileptic seizure as a function of differing levels of occupational stress (physical and mental) in new military recruits with no previous history of epilepsy or with epilepsy in remission for over 2 years.
Methods: The medical records of over 300,000 18-year-old men recruited to the Israeli army between mid-eighties and mid-nineties were used to assemble a cohort, which was followed for a period of 30 months. The severity of epilepsy at recruitment was determined according to four categories, 0 (no history of seizures) and 1–3 (history of seizures with different relapse-free periods, with or without treatment). The soldiers were subdivided according to their occupational categories to: combat units (CU), maintenance units (MU), and administrative units (AU).
Results: The annual incidence rates per 100,000 in category 0 were 317, 298, and 401 in AU, MU, and CU, respectively. The incidence of seizures in category 0 was higher (relative risk [RR]= 1.29, CI = 1.03–1.62) in CU compared to AU and MU. No differences were found for seizure recurrence among various occupational groups.
Conclusion: The increased risk of seizures in CU compared to AU and MU may indicate contribution of service conditions in CU, like physical and mental stress. The equivalent rates of seizure relapse, regardless of the type of occupation, suggests the need for minimal occupational restrictions for epilepsy patients who have been free of seizures for long periods.     

Incidence of Epilepsy in Rural Iceland: A Population-Based Study

Summary: Purpose : We wished to determine the incidence of epilepsy in the population of rural Iceland.
Methods : Cases were identified through review of records of primary care facilities for the study population, supplemented by review of referrals to EEG facilities and neurologic specialists.
Results : The incidence of epilepsy (recurrent unprovoked seizures) was 47 in 100,000. Age-specific incidence was bimodal, highest in the youngest and oldest age groups. About one third of the patients had an identifiable etiology, and one third had partial seizures. Integration of imaging and neurophysiologic data did little to modify the distribution of etiology or seizure type.
Conclusions : The present study confirms findings of other recent studies of incidence in Western Countries.     

Estimating the incidence of first unprovoked seizure and newly diagnosed epilepsy in the low-income urban community of Northern Manhattan, New York City

Purpose : To estimate the incidence and mortality associated with first unprovoked seizure or newly diagnosed epilepsy in a low-income, predominantly Hispanic community in Northern Manhattan, New York City.
Methods : We performed a population-based study to determine the incidence of first unprovoked seizure or newly diagnosed epilepsy. Participants were Northern Manhattan residents seen at area hospitals and nursing homes between 2003 and 2005. Cumulative probability of mortality and standardized mortality ratios (SMRs) were also calculated.
Results : Among 209 incident cases identified, 123 (58.9%) presented with an incident single unprovoked seizure. A total of 138 (66.0%) participants were Hispanic and 94 (45.0%) had a median household income under $15,000/year. The overall age and sex-adjusted incidence of all unprovoked seizures was 41.1 (95%CI = 35.4–46.8) per 100,000 person-years. Higher incidence was observed in low-income groups. Incidence among Hispanics was similar to that of non-Hispanic whites and non-Hispanic blacks. The cumulative probability of mortality was 17% (95%CI = 12–24%) by 3 years after diagnosis and was significantly greater in females and in those with an identified etiology. SMRs were significantly increased for all groups with respect to age, Hispanic ethnicity, middle and high income, partial seizure type, and remote symptomatic etiology. Idiopathic/cryptogenic and progressive symptomatic etiologies, low income, gender, and non-Hispanic ethnicity were not associated with a significantly increased SMR.
Conclusion : Incidence of first unprovoked seizure or newly diagnosed epilepsy did not differ by race-ethnicity. Although lower income was associated with higher incidence, higher income was associated with an increased SMR. Future research should examine reasons for differential incidence by income.     

Clinical application of neuroimaging in epilepsy

OBJECTIVE: To evaluate the use of neuroimaging in clinical practice and to assess the prevalence of detected structural abnormalities in epilepsy patients in a clinical set up. METHODS: 919 outpatients were identified and the scan results reviewed. A total of 677 patients had chronic active epilepsy (88 had idiopathic generalised epilepsy (IGE), 588 had localisation related epilepsy, one had symptomatic generalised epilepsy), 57 had a single epileptic seizure, 46 were in remission, and 139 had non-epileptic attacks. RESULTS: 391 patients had no scan (53 patients in this group had IGE, 182 had localisation related epilepsy, one had generalised symptomatic epilepsy, 18 had single epileptic attacks, 21 were in remission, 116 had non-epileptic attacks). Altogether 528 patients had a scan, the results were not available in 33, 163 had x ray computed tomography (CT) only, 178 had standard magnetic resonance imaging (MRI) (slice thickness 5 mm), and 154 had high resolution MRI (including a T1 weighted sequence with 1.5 mm thick slices). Some 252 of 495 scans (51%) were abnormal. Abnormalities were hippocampal sclerosis (n=128), atrophy or non-specific white matter lesions (n=35), vascular abnormalities (n=27), tumours (n=25), brain damage (n=24), malformations of cortical development (n=13). Excluding atrophy and non-specific white matter lesions the prevalence of detected abnormalities was 54% in localisation related epilepsy, 18% in single seizure patients, 16% in epilepsy in remission, and 0% in IGE and non-epileptic attacks. CONCLUSIONS: Abnormalities were detected in more than half of all patients with localisation related epilepsy, and in about one in five patients with single seizures or epilepsy in remission. Many patients had no scan or only CT or standard MRI. The true prevalence of structural abnormalities may be have been higher. Scanning did not add any information in patients with IGE or non-epileptic attacks.     

An epidemiologic study of febrile seizures and epilepsy in children

Prevalence and annual incidence rates of febrile seizures and types of epilepsy were investigated in all children of the Altenburg district (German Democratic Republic) being 0-14 years old. The mean total population for the period 1982 through 1985 was 108,905. The proportion of children aged 0-14 years was 20,132. The average annual incidence of febrile seizures in children being 0-5 years old was 240.8/100,000. For children between 0 and 14 years the rate of epilepsy 51.1/100,000. Based on 87 epileptic patients, the exact point prevalence rate per 1000 on December 31, 1985, was 4.4.     

The tendency to have psychogenic non-epileptic attacks out of camera view during long-term video-EEG monitoring.

The aim of this study was to compare out of camera view seizure occurrence rates between psychogenic non-epileptic and epileptic seizures during long-term video-EEG monitoring. From 1996 to 2001, 208 adult patients were monitored in 212 sessions, and 196 patients were included in the study. Depending on video-EEG recordings and witnessed accounts, 18 of the patients had no seizures recorded, 160 had epileptic seizures and 18 had psychogenic non-epileptic seizures, four of whom had psychogenic non-epileptic seizures plus true epileptic seizures. Six hundred and ninety two seizures were recorded; 634 of them were epileptic seizures and 58 of them, psychogenic non-epileptic ones. Out of camera attack occurrence was significantly higher in patients with psychogenic non-epileptic attacks compared with epileptic ones (chi-square with Yates correction = 19.75, df = 1, P< 0.001).     

Natural History of Epileptic Seizures

Since 1963 a continuous registration of patients with epileptic seizures has been carried out in Greater Aarhus, Denmark. This registration has been attempted by means of medical records dating back to 1940. On the basis of the established prevalence and the calculated cumulated incidence, we have tried to describe the natural history of the different types of epilepsy. The prevalence of all types of epileptic seizures (including febrile convulsions) has been found to be 2,441/100,000, whereas for patients with the diagnosis of epilepsy the rate is 1,274/100,000. The study describes the natural history of the different types of epilepsy. In addition, the risk-increasing effect of a febrile convulsive seizure on the development of epilepsy is analyzed.