Seizure medicines will not be effective for episodes that are not seizures. Therefore, patients whose presumed seizures do not respond to AEDs should undergo a diagnostic re-evaluation.

Psychogenic nonepileptic seizures

Psychogenic nonepileptic seizures (NES) represent an important alternative explanation for refractory seizures. In several clinical series of patients with possible epilepsy, the relative frequency of NES ranged from 10 to 40% [1-3]. In a recent population study from Iceland, the incidence of NES was 1.4 in 100,000 person-years of observation with maximum age–specific incidence between 15 and 24 years. There was a strong female preponderance [4]. Identifying NES and distinguishing them from epileptic events are critical to avoiding potentially grave consequences that attend errors of failing to recognize NES, a misjudgment that has far-reaching implications [5]. Antiepileptic drugs (AEDs) prescribed to NES patients have potentially serious side effects and may even exacerbate NES [6]. Failure to recognize pseudostatus epilepticus has the potential hazard of intubation and its morbidity and mortality, and failure to recognize the psychological nature of NES also delays the implementation of appropriate psychological treatment. Furthermore, the social stigma attached to a diagnosis of epilepsy is considerable. Patients who have endured such stigma for any length of time may, understandably, become hostile when informed of a diagnostic change stating that their seizures are psychogenic rather than epileptic in nature [7-9].

The diagnosis of NES as a conversion disorder ultimately rests on the clinical observation of an unambiguously nonphysiologic event that is typical of the patient's prior events. Several investigators have observed a high rate of psychiatric disorders in NES patients [10-12]. They further noted that a wide variety of psychosocial issues were associated with NES. Fliesher et al. [13] studied 32 subjects with NES. Each participant completed the Impact of Event Scale, the Davidson Trauma Scale, the Mississippi Scale for Combat-Related Posttraumatic Stress Disorder (PTSD), the Dissociative Experience Scale, and Pittsburg Sleep Quality Index measures. Subjects with NES exhibited trauma-related profiles that differed significantly from those of epileptic comparison subjects and closely resembled those of individuals with a history of traumatic experiences. Bowman et al. [10] studied 45 adult patients with NES using the DSM-III-R classification system. They found that the most common diagnosis was a dissociative disorder and concluded that subjects with NES appeared to express dissociative distress about reported trauma.

Although other studies [14] report the frequency of a history of sexual abuse during childhood in 24% of patients, in the Bowman et al. study 69% of females with NES reported childhood sexual abuse. They suggest that subjects revealed conflict over anger, sexuality, and dependency, exhibiting lifelong patterns of avoiding awareness or expression of anger such that seizures began after adult frustrations.

Prigatano et al. [15] studied prospectively 15 patients with NES who attended group therapy to explore the potential role of psychological factors in the genesis of NES. Self-reported frequency of seizures was used to determine if psychotherapy intervention reduced the frequency of NES. The majority of the patients completed most of the treatment sessions and 66% reported reduction in the frequency of NES. Dissociative phenomena were common as was the history of sexual abuse. However, they failed to report the clinical manifestations of the NES. Gates et al. [16] reported a detailed comparison of ictal manifestations of patients with NES and a control group with generalized tonic–clonic (GTC) seizures, providing bedside guidelines for distinguishing a NES from an epileptic event. Features reported to be characteristic of NES included out-of-phase limb movement, side-to-side head movement, forward pelvic thrusting, and vocalization at onset of the seizure. However, they limited the analysis of NES only to those with motor manifestations that resembled GTC seizures and excluded NES that presented with little or no motor symptoms. Several recent studies, using video-EEG monitoring, classify NES into attacks of collapse with or without prominent motor symptoms [1, 17-19].

References

1. A.A. Leis, M.A. Ross and A.K. Summers, Psychogenic seizures: ictal characteristics and diagnostic pitfalls. Neurology 42 (1992), pp. 95–99.

2. R.P. Lesser, H. Luders and D. Dinner, Evidence for epilepsy is rare in patients with psychogenic seizures. Neurology 33 (1983), pp. 502–504.

3. T. Fakhoury, B. Abou-Khalil and K. Newman, Psychogenic seizures in old age: a case report. Epilepsia 34 (1993), pp. 1049–1051.

4. K.R. Sigurdartottir and E. Olaffsson, Incidence of psychogenic seizures in adults: a population-based study in Iceland. Epilepsia 39 (1998), pp. 749–752.

5. R.J. Brown and M.R. Trimble, Dissociative psychopathology, non-epileptic seizures, and neurology. J. Neurol. Neurosurg. Psychiatry 69 (2000), pp. 285–289.

6. M.R. Trimble, Anticonvulsant drug and hysterical seizures. In: T.R. Riley and A. Roy, Editors, Pseudoseizures, Williams & Wilkins, Baltimore/London (1982), pp. 148–158.

7. P.T. Lelliot and P. Fenwick, Cerebral pathology in pseudoseizures. Acta Neurol. Scand. 83 (1991), pp. 129–132.

8. A. Pakalnis, M.E.J. Drake and B. Phillips, Neuropsychiatric aspects of psychogenic status epilepticus. Neurology 39 (1991), pp. 1104–1106.

9. O. Devinsky, Nonepileptic seizures: quagmires of pathophysiology, diagnosis and treatment. Epilepsia 39 (1998), pp. 458–462.

10. E.S. Bowman and O.N. Markand, Psychodynamic and psychiatric diagnoses of pseudoseizure subjects.Isr. J. Psychiatry 153 (1996), pp. 57–63.

11. E.F. Pribor, H.S. Yutzy, J.T. Dean and R.D. Wetzel, Briquette's syndrome, dissociation, and abuse.Am. J. Psychiatry 150 (1993), pp. 1507–1511.

12. K. Roelofs, G.P. Keijser, K.A. Hoogduin, G.W. Naring and F.C. Moene, Childhood abuse in patients with conversion disorder. Am. J. Psychiatry 159 (2002), pp. 1908–1913.

13. W. Fleisher, D. Staley, P. Krawetz, N. Pillay, J.L. Arnett and J. Maher, Comparative study of trauma-related phenomena in subjects with pseudoseizures and subjects with epilepsy. Am. J. Psychiatry 159 (2002), pp. 660–663.

14. K. Alper, O. Devinsky, K. Perrine, B. Vazquez and D. Luciano, NES and childhood sexual and physical abuse. Neurology 43 (1993), pp. 1950–1953.

15. G.P. Prigatano, C.M. Stonnington and R.S. Fisher, Psychological factors in the genesis and management of NES: clinical observations. Epilepsy Behav. 3 (2002), pp. 343–349.

16. J.R. Gates, V. Ramani, S. Whalen and R. Loewenson, Ictal characteristics of pseudoseizures. Arch. Neurol. 42 (1985), pp. 1183–1187.

17. D. Flugel, J. Bauer, U. Kasborn and C. Elger, Closed eyes during a seizure indicate psychogenic etiology: a study with suggestive seizure provocation. J. Epilepsy 9 (1996), pp. 165–169.

18. H. Meierkord, B. Will, D. Fish and S. Shorvon, The clinical features and prognosis of pseudoseizures diagnosed using video-EEG telemetry. Neurology 41 (1991), pp. 164–306.

19. G. Groppel, C. Kapitany and C. Baumgartner, Cluster analysis of clinical seizure semiology of psychogenic nonepileptic seizures. Epilepsia 41 (2000), pp. 610–614.

Adapted from "Psychogenic seizures: clinical features and psychological analysis", by Abubakr et al, Epilepsy & Behavior, Volume 4, Issue 3, June 2003, Pages 241-245.

Syncope

Diagnosing syncope is a great challenge in clinical medicine. Since patients usually do not have symptoms and signs during the medical interview, the diagnosis is primarily based on a meticulously taken history, if possible also from bystanders, which is particularly important when the patient's recollection is incomplete.

The first step is to find out whether or not the patient transiently lost consciousness (i.e. has an amnestic gap), fell to the ground (if upright), and whether he showed convulsive manifestations. Additional features are: Predisposing factors (e.g. occurring only in upright position, drugs, sleep deprivation), prodromal sensations (stereotyped or not), eye open during onset, upward gaze, gentle or violent fall, oral and limb automatisms, tonic and/or clonic manifestations (bilateral - rhythmical or irregular), phonations (unintelligible sounds or vocalizations), color of the face (normal, pale, or cyanotic), loss of urine (but not discriminative), and the postictal behavior and recovery of orientation.

A lateral tongue bite must be searched for and is very suggestive of an epileptic seizure, while a median tongue bite is seen with non-epileptic psychogenic seizures. To distinguish between epileptic seizure and circulatory syncope is often difficult, since the latter frequently shows, contrary to common belief, a stiff backward fall and short tonic and clonic and manifestations. Conversely, epileptic falls are not always convulsive. Psychogenic 'pseudo-seizures' are identified by the typical eye closure from the beginning and the long duration of the seizure of over 5 minutes, which are both very rare in epileptic seizures or syncope.

Adapted from Elger CE, Schmidt D. Modern management of epilepsy. Epilepsy Behav 2008;12:501-39.

REM behavior disorder

REM sleep behavior disorders (RBD) are episodes of motor agitation arising during REM sleep due to the absence of muscular atonia and are characterized by more or less purposeful gestures enacting attack or defense reactions, sometimes associated with emotional expressions of joy, laughter or sorrow. They occur often in elderly men. RBD often herald other signs and symptoms of neurodegenerative disorders like Parkinsonian syndromes. If correctly diagnosed, they can be treated successfully.

Adapted from Elger CE, Schmidt D. Modern management of epilepsy. Epilepsy Behav 2008;12:501-39.

Wrong seizure type

Once the diagnosis of epilepsy is confirmed, the next step in evaluating a patient whose seizures are not responding as expected to an AED is to confirm the type or types of seizures the patient is experiencing. The classifications of seizure type and epilepsy syndrome are made primarily on clinical grounds and may be supported by laboratory, neurophysiologic, and radiographic studies. This determination has important implications for the selection of AEDs.

The International Classification of Epileptic Seizures published by the International League Against Epilepsy (Commission on Classification and Terminology of the International League Against Epilepsy. Proposal for revised classification of epilepsies and epileptic syndromes. Epilepsia. 1989;30:389-399; http://www.epilepsy.com/information/professionals/about-epilepsy-seizures/classifying-seizures) is a helpful framework to follow. If possible, determining the patient's epilepsy syndrome provides even more information about which therapies are most likely to succeed.

An accurate diagnosis requires a thorough history from the patient and observers, with close attention to descriptions of actual seizures. The patient may find it easier to express symptoms by referring to published seizure descriptions.

If the patient is experiencing more than one type of seizure and can describe the different symptoms of each type, that may allow the clinician to better categorize the patient's seizure types and epilepsy syndrome, as well as plan the therapeutic approach more effectively.

AEDs may be ineffective against certain seizure types. In addition, seizure aggravation is an important limitation of current AEDs. Idiopathic generalized epilepsies are particularly prone to pharmacodynamic aggravation: typical absence seizures are consistently increased by carbamazepine, vigabatrin, tiagabine, and gabapentin, whereas phenytoin is less aggravating. Myoclonus associated with juvenile myoclonic epilepsy is often aggravated by carbamazepine and, less consistently, by phenytoin and other AEDs. Nonconvulsive status epilepticus has been associated with tiagabine. Gabapentin-associated myoclonus appears to occur relatively frequently. It is usually mild and can easily be overlooked.

In symptomatic generalized epilepsies, patients often experience several types of seizures that respond differently to AEDs: myoclonic seizures are generally aggravated by the same drugs that aggravate idiopathic generalized epsilepsies; tonic seizures in the Lennox–Gastaut syndrome respond to carbamazepine, which may, however, aggravate atypical absences. In severe myoclonic epilepsy of infancy, lamotrigine has a nearly consistent aggravating effect. In some patients with benign Rolandic epilepsy, a clear aggravation may be produced by carbamazepine, with occurrence of negative myoclonus (asterixis), atypical absences, drop attacks, and, at the maximum, evolution into a state of electrical status epilepticus during sleep. Only a few medications can control idiopathic generalized epilepsies without potentially causing seizure aggravation. Broad-spectrum antiepileptic drugs such as valproate, lamotrigine, and topiramate are extremely effective at controlling a variety of seizures without causing excessive seizure aggravation. Among these drugs, valproate has the longest clinical experience history and the largest body of published data.

Adapted from Elger CE, Schmidt D. Modern management of epilepsy. Epilepsy Behav 2008;12:501-39.

Adapted from and Schachter SC. Treatment of seizures. In: Schachter SC, Schomer DL, eds. The comprehensive evaluation and treatment of epilepsy. San Diego, CA: Academic Press; 1997. p. 61-74. With permission from Elsevier (www.elsevier.com).

Adapted from Koppel BS. Contribution of drugs and drug interactions (prescribed, over the counter, and illicit) to seizures and epilepsy. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;155–173.
With permission from Elsevier (www.elsevier.com).

Reviewed by: Steven C. Schachter MD on 5/2008
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