Nonepileptic Events in Normal and Neurologically Handicapped Children: A Video-EEG Study P r a s h a n t D e s a i , M B B S a n d D i n e s h Talwar, M B B S

Nonepileptic episodic phenomena are reported in 27 of 124 children (21.8%) who had video-electroencephalographic studies performed. Mean age was 7.4 years (S.D.: 6.0; range: 0.1-19). Nineteen (70%) were neurologically impaired (Group 1) and 8 (30%) neurologieally normal (Group 2). The final diagnoses included movement sequences (48%), conversion disorder (22 %), behavioral staring (18 %), sleep disorder (11% ), behavioral episodes (8%), and central apnea (8%). In Group 1, abnormal movements (58%) and staring (26%) were most common; conversion disorder (62.5%) was most common in Group 2. Unnecessary medication therapy was prevented in many children. Video-electroencephalography is valuable in preventing over-medication and misdiagnosis. Desai P, T a l w a r D. Nonepileptic events in n o r m a l and neurologically handicapped children: A v i d e o - E E G study. Pediatr Neurol 1992;8:127-9.

Introduction Studies on the role of p r o l o n g e d video-electroencephalographic (EEG) m o n i t o r i n g in the diagnosis of nonepileptic events in children are limited [ 1-5]. Nonepileptic events, often referred to as pseudoseizures, of v a r y i n g etiologies are described in neurologically n o r m a l children [ 1,3,6]. Recent studies have stressed occurrence o f nonepileptic episodic s y m p t o m s in neurologically impaired children [3,4,7]. Nonepileptic events have also been well delineated in neonates [8]. Epileptic and nonepileptic events often coexist in the same patient, a p h e n o m e n o n observed in both neurologically impaired a n d n o r m a l children [1,4]. Prolonged split-screen v i d e o - E E G m o n i t o r i n g precisely d o c u m e n t s correlation b e t w e e n a b n o r m a l behavior and simultaneous EEG, permitting accurate diagnosis of episodic events [9]. We report the value o f this technique in the recognition and d o c u m e n t a t i o n o f nonepileptic events and its role in preventing over-medication, misdiagnosis,

From the Division of Pediatric Neurology, Section of Electroencephalography; and University Pediatric Epilepsy Program; University of Minnesota Medical School; Minneapolis, Minnesota.

a n d u n d u e parental anxiety. O u r study illustrates that n o n e p i l e p t i c e v e n t s are c o m m o n , d i f f e r e n t t y p e s are observed d e p e n d i n g on age a n d neurologic status, and d o c u m e n t a t i o n and demonstration expedites subsequent management.

Methods Video-EEG recordings of 27 children with nonepileptic events were reviewed. All had prior, routine, 30-45 min 20-21-channel EEGs. Serial EEGs had also been performed on most children. In-patient video-EEG was recorded utilizing 16-channel cable telemetry (Biomedical Monitoring Systems, Inc.) on 1/2-inchvideocassette tapes for 6 hours to 3 days. Continuous surveillance was provided by parents or trained sitters who activated an event marker at times of suspected episodes. Initial recording was referential with linked ears as a reference. Digital storage permitted print out of selected portions in several bipolar or unipolar, longitudinal or transverse, montages. Technical quality of the playback was good and was not limited by artifact. Diagnosis of seizures or nonepileptic events was based on the presence or absence of paroxysmal EEG abnormality during documented episodes. Electrodes were placed according to the International 10/20 System. Children were referred to our institution by primary physicians, nurses, and caretakers, and for video-EEG studies by our pediatric neurologists. Reason for referral was obtained from the official request forms, medical charts, and from referring pediatric neurologists. Information was obtained from medical records on pre-existing neurologic problems, previous EEGs, antiepileptic drug (AED) therapy, and subsequent evaluation, often including neuropsychologic testing, diagnosis, and treatment. Fisher Exact Probability Test was used for statistical analysis.

Results F r o m January, 1988 to April, 1990, 27 of 124 children (21.8%) who had v i d e o - E E G studies at our laboratory were diagnosed as having nonepileptic events. M e a n age was 7.37 years (S.D.: 6.02; range: 0.12-19; N = 27). Age distribution is illustrated in Figure 1. Children were referred either because the nature o f the episodic s y m p t o m s was in question or if nonepileptic events were clinically suspected, for definitive d o c u m e n tation and characterization of episodes. N i n e t e e n children (70%) had some degree of neurologic i m p a i r m e n t or a w e l l - d o c u m e n t e d pre-existing seizure disorder (Group 1)

Communications should be addressed to: Dr. Talwar; Department of Pediatrics; University of Arizona Health Science Center; 1501 North Campbell Avenue; Tucson, AZ 85724. Received September 13, 1991; accepted November 13, 1991.

Desai andTalwar:Nonepileptic Events in Children 127

5 4 d~

3

E 2

0

4

8

12

16

20

Age Figure 1. Age distribution of children with nonepileptic seizures. Age in years is represented on the X-axis.

and 8 (30%) were neurologically normal (Group 2). Group 1 included ! 1 children with global developmental delay (9 also had seizures), 3 with motor delay, 2 with Chiari malformation, and 3 with pre-existing seizure disorders without other neurologic deficits. Following video-EEG studies and subsequent evaluation, nonepileptic events of all children were classified (Table 1). Subsequent examination often included other investigational studies and neuropsychologic testing. In Group 2, 5 children, all 14-19 years of age, had a conversion disorder. The diagnosis was made only alter complete neuropsychologic testing. Other diagnoses in Group 2 included a non-REM parasomnia, dystonia secondary to gastro-esophageal (GEl reflux (Sandifer syndrome), and sleep myoclonus exaggerated by an infectious illness. Only 1 child in this group had an epileptiform EEG. Conversion disorder was significantly more common in Group 2 than in Group l (P < .005). In Group 1, movement sequences (or disorder) which included myoclonus, dystonic posturing, choreoathetosis, Table 1. Final diagnosis of type of nonepileptic events on the basis of video-EEG and follow-up evaluation and investigation Type of Nonepileptic Events

All Patients (N = 27)

Group 1" (N = 19)

Group 2 + (N = 8)

Movement sequences/ disorder

13 (48%)

1I

2

Conversion disorder

6 (22%)

1

5

Behavioral staring

5 (18%)

5

0

Sleep disorder

3 (11%)

2

I

Behavioral episodes

2

8%)

2

(/

Central apnea

2

8%)

2

0

* Children with neurologic impairment (N 16) or a prior well documented history of seizures (N = 3). Two children in this group had both movement sequences/disorder and staring. Children with no neurologic impairment or prior seizure disorder. =

128 PEDIATRIC NEUROLOGY Vol. 8 No. 2

and rhythmic self-stimulatory behavior were most common, usually as a manifestation of the underlying neurologic disorder; however, l child had Sandifer syndrome and another carbamazepine-induced myoclonus [ 10]. Behavioral staring, without associated EEG abnormality, movements, or automatisms, was also relatively common (5 patients, 2 of whom also had abnormal movement sequences as separate events). Staring was associated with drowsiness or observed as a manifested behavior in mentally retarded children. Although movement sequences and staring were observed more commonly in Group 1 than in Group 2, the difference was not statistically significant. Two children had apneic episodes and 2 had abnormal behaviors; 1 child with autism had episodes in which he extended and attempted to compress his neck against the edge of furniture and another mentally retarded child manifested severe temper outbursts. Additionally, in Group 1, one 19-year-old neurologically normal patient with prior seizures had a conversion disorder. Sixteen children were receiving AEDs at the time of video-EEGs. After video-EEG and subsequent evaluation, medication was discontinued/'or 4 patients. In 2 patients, symptoms responsible for referral resolved after evaluation. In the remaining 10 children some AEDs were withdrawn or doses decreased. One child was treated for GE reflux. Eleven children were not on AEDs at the time of evaluation and none received them later. Four did not require specific treatment, 4 were referred to psychiatry for conversion disorders, 2 were successfully treated for a nonREM parasomnia, and 1 for GE reflux.

Discussion

Recently, studies have emphasized appropriate diagnosis of episodic events, particularly in neurologically handicapped children [3,4,6]. Our study, with 22% of patients demonstrating nonepileptic paroxysmal phenomena, confirms that episodic nonepileptic neurologic and behavioral symptomatology is relatively common in children. It further establishes that video-EEG is very effective in appropriate diagnosis and that epileptic and nonepileptic events often co-exist in both normal and neurologically impaired children [ 1,3,4]. Video-EEG is beneficial in distinguishing epileptic from nonepileptic events when clinical distinction is difficult [11]. In many of our patients, seizures were suspected clinically, particularly in those with neurologic impairment or prior epileptic seizures. Studies were performed because of poor response to treatment and to classify seizure type. Video-EEG helped to arrive at the correct diagnosis. We recognize that there is some possibility of not recording paroxysmal EEG changes from scalp electrodes. With careful study of the EEG playback and behavioral alterations on the video screen, and subsequent evaluation to help arrive at a final diagnosis, the possibility of not correctly diagnosing "true" seizures was minimized.

Multiple and high-dose AEDs are hazardous, expensive, and may cause or accentuate nonepileptic events [10]. As a direct result of our monitoring, AEDs were discontinued or the dose was reduced in several patients. In addition, unnecessary use of AEDs was prevented in the other children. On clinical criteria, some of our children were suspected of having nonepileptic events. Video-EEG was performed for documentation of the nonepileptic nature of the episode and its characterization to guide subsequent investigation and therapy. Nonepileptic events were relatively frequent and usually were captured after brief studies. Whenever possible, parents were given the opportunity to review the events on videotape to confirm that the recorded events were similar to witnessed episodes at home and to help them understand the nature of their child's episodes. Appropriate diagnosis helped to alleviate undue parental anxiety; many parents were relieved to learn that their children were not having seizures "all or most of the time." Seizures and paroxysmal EEGs are common in neurologically handicapped children. Our study demonstrates that many types of episodic events in these children are nonepileptic, often occurring in conjunction with epilepsy; abnormal movement sequences of various types and staring were most common in all age groups. In our study, the most common nonepileptic event in neurologically normal children was a conversion disorder. One child with conversion disorder in Group 1 had a prior history of seizures but was otherwise neurologically normal. Conversion disorder was only seen in adolescents (14 to 19 years of age). Many conditions may mimic seizures in children which include potentially treatable conditions, such as sleep disorders and GE reflux. Differentiating non-REM parasomnias [12] from seizures may be difficult, particularly when they are frequent or occur in children who also have seizures. All 3 patients in our study were referred with the suspicion of nocturnal seizures. GE-reflux-related dystonic posturing or myoclonus often is misinterpreted as seizures [ 13]. Clinically nonepileptic events can be very difficult to differentiate from true epileptic events; however, certain criteria that should always raise the suspicion of nonepileptic phenomena include very frequent episodes in

neurologically impaired children not responsive to or worsened by AEDs, staring not associated with any other minor motor phenomena, normal EEGs on repeated occasions despite the presence of very frequent episodes, and parents' concerns that their child is having seizures almost all of the time. Although these factors raise the suspicion for nonepileptic phenomena, true distinction may not be possible without video-EEG monitoring. Because nonepileptic episodes are often very frequent, video-EEG monitoring for a short period of time (24 hours or less) can be very beneficial. We conclude that physicians should always consider the possibility of nonepileptic events in children. Video-EEG may help in differentiating epileptic from nonepileptic events, prevent over-medication, and guide subsequent evaluation and treatment. References

[1] Holmes GL, Sackellares JC, McKiernan J, Ragland M, Dreifuss FE. Evaluation of childhood pseudoseizures using EEG telemetry and video tape monitoring. J Pediatr 1980;97:554-8. [2] Holmes GL, Russman BS. Shuddering attacks: Evaluation using electroencephalographic frequency modulation radiotelemetry and videotape monitoring. Am J Dis Child 1986;140:72-3. [3] Duehowny MS, Resnick TJ, Deray MJ, Alvarez LA. Video EEG diagnosis of repetitive behavior in early childhood and its relationship to seizures. Pediatr Neurol 1988;4:162-4. [4] Donat JF, Wright FS. Episodic symptoms mistaken for seizures in the neurologically impaired child. Neurology 1990;40:156-7. [5] BrunqueU P, McKeever M, Russman BS. Differentiation of epileptic from nonepileptic head drops in children. Epilepsia 1990;31: 401-5. [6] Wyllie E, Friedman D, Rothner AD, et al. Psychogenic seizures in children and adolescents: Outcome after diagnosis by ictal video and electroencephalographic recording. Pediatrics 1990;85:480-4. [7l Neill JC. Pseudoseizures in impaired children. Neurology 1990; 40: l 146. [8] Mizrahi EM, Kellaway E Characterization and classification on neonatal seizures. Neurology 1987;37:1837-44. [9] Duchowny MS. Intensive monitoring in the epileptic child. J Clin Neurophysiol 1985;2:203-19. [10] Dhuna A, Pascual-Leone A, Talwar D. Exacerbation of partial seizures and onset of nonepileptic myoclonus with carbamazepine. Epilepsia 1991;32:275-8. [11] Binnie CD, Rowan AJ, Overweg J, et al. EEG and video monitoring in epilepsy. Neurology 1981;31:298-303. [12] Mahowald MW, Rosen GM. Parasomnias in children. Pediatrician 1990;17:21-31. [13] Nanayakkara CS, Paton JY. Sandifer syndrome: An overlooked diagnosis? Dev Med Child Neurol 1985;27:816-9.

Desai and Talwar: Nonepileptic Events in Children

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Nonepileptic events in normal and neurologically handicapped children: a video-EEG study.

Nonepileptic episodic phenomena are reported in 27 of 124 children (21.8%) who had video-electroencephalographic studies performed. Mean age was 7.4 y...
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