Epilepsiu, 33(5):805-813, 1992 Raven Press, Ltd., New York 0 International League Against Epilepsy

Video-EEG Analysis of Drop Seizures in Myoclonic Astatic Epilepsy of Early Childhood (Doose Syndrome) Hirokazu Oguni, Yukio Fukuyama, Yuichi Imaizumi, and Takashi Uehara Department of Pediatrics, Tokyo Women’s Medicat Cotlege, Tokyo, Japan

Summary: We studied 36 drop seizures in 5 patients with myoclonic astatic epilepsy of early childhood (MAEE) with simultaneous split-screen video recording and polygraph. Sixteen were falling attacks and 20 were either less severe attacks exhibiting only deep head nodding or seizures equivalent to drop attacks in terms of ictal pattern but recorded in the supine position. All seizures except those that occurred in patients in the supine position showed sudden momentary head dropping or collapse of the whole body downward. Recovery to the preictal position was observed in 0.3-1 s. As a result of carefully repeated observations, the 36 seizures were classified as myoclonic flexor type in 9, myoclonic atonic type in 2 , and atonic type, with and without transient preceding symptoms in the remaining 25. The M F seizure was char-

acterized by sudden forward flexion of the head and trunk as well as both arms, which caused the patient to fall. In the myoclonic atonic seizure, patients showed brief myoclonic flexor spasms, immediately followed by atonic falling. The AT seizure showed abrupt atonic falling, with and without transient preceding facial expression change and/or twitching of extremities. The ictal EEGs of all 36 seizures exhibited generalized bilaterally synchronous single or multiple spike(s) and wave discharges. Atonic drop attacks appear to be a common cause of ictal epileptic falling in MAEE. Key Words: Seizures-Atonic seizures-Myoclonic-atonic seizures-Myoclonic astatic epilepsy-Simultaneous video-encephalographic analysis-Electroencephalography-Children.

Myoclonic astatic epilepsy of early childhood (MAEE) was nosologically delineated by Doose (1985) to be among the idiopathic or cryptogenic myoclonic epilepsies of infancy and early childhood. MAEE is characterized by myoclonic, astatic, and myoclonic-astatic seizures, often in combination with absence and generalized tonic-clonic seizures (GTCS). Of these, myoclonic, astatic, and myoclonic-astatic seizures, which cause patients to fall abruptly (drop seizures), appear to be a hallmark of this syndrome. There have been few clinical and EEG studies of drop seizures in MAEE as compared with studies of Lennox-Gastaut syndrome (Egli et al., 1985; Ikeno et al., 1985; Nolte et al., 1988). We analyzed drop seizures in 5 patients with MAEE to clarify the seizure types and possible mechanisms underlying the falling.

PATIENTS AND METHOD The clinical details of 5 patients (4 male and 1 female) whose clinicoelectrical features and evolution are compatible with the syndrome criteria (Doose, 198S), are shown in Table 1. Age at onset of first epileptic seizures, as well as drop seizures, ranged from 1 year 3 months to 3 years 1 month (mean 2 years 0 months in the former and 2 years 2 months in the latter). The age at time of seizure recording ranged from 1 year 5 months to 3 years 11 months (mean 2 years 9 months). Patients have been followed at our clinic from 10 months to 8 years 10 months with a mean of 4 years I month. During the active period, background activity during wakefulness consisted of monornorphic 4-7-Hz theta activity with parietal accentuation in all patients (Fig. l). Generalized tonic seizures and runs of rapid spikes on EEG (Niedermeyer, 1988), characteristic of Lennox-Gastaut syndrome, were not observed during their clinical course. Seizures were studied by simultaneous splitscreen video taping (patient and EEG on the same screen) and EEG-electromyogram (EMG) poly-

Received October 1991; revision accepted December 1991. Address correspondence and reprint requests to Dr. H . Oguni at Department of Pediatrics, Tokyo Women’s Medical College, 10 Kawada-cho, Shinjuku-ku, Tokyo 162, Japan.

805

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H . OGUNZ ET AL. TABLE 1. Clinical and EEG features

Patient1 sexlage at onset of seizure (yrlmo)

Age at onset of drop seizures (yr, mo)

Family history of epilepsy

Combined seizure types

Follow-up period (yr, mo)

11M13, 1

3, 1

No

Absence, GTCS

1, 0

Normal

2IMl1, 5

2

Yes

Absence, GTCS

0, 10

Normal

3lFl1, 6

1, 6

No

Absence, GTCS

4, 6

Borderline

4lMl2, 9

2, 10

No

Absence, GTCS

5, 1

Normal

SlMl1, 3

1, 3

No

Absence, GTCS

8, 10

Normal

Development before onset

Mental prognosis (yrlmo) IQ = 92 (3, 9) DQ = 76 (23 1) DQ = 62 (3,2) IQ = 76 (2, 9) DQ = 94 (1, 5 )

Prognosis

-

Seizure-free for 6 mo

-

Seizures continued

IQ = 54 (6, 4) IQ = 85 (7, 1) IQ = 64 ( 5 , 6)

Seizure-free for 4 yr 4 mo Seizure-frce for 5 yr Seizure-free for 8 yr 8 mo

GTCS, generalized tonic-clonic seizures; IQ, intelligence quotient; DQ, development quotient

graphic recording. Because all patients showed head nodding or falling forward, surface EMGs were placed on the trapezius, sternocleidomastoideus, and paraspinal muscles unilaterally or bilaterally in 4 patients and on only the trapezius muscle in one patient. All drop seizures were analyzed using slow motion and frame-by-frame video replay mode. The EMG potentials during falling were assessed to distinguish myoclonic or tonic events from atonic events. In addition, we analyzed the temporal relationships between epileptic EEG abnormalities and clinical phenomena.

RESULTS We documented 36 drop seizures, including 16 falling attacks, and 20 less severe attacks exhibiting only deep head nodding (17 seizures) or attacks equivalent to drop seizures in terms of ictal pattern but recorded in the supine position (three seizures). All seizures, except those recorded in the supine position, showed sudden momentary head dropping or collapse of the entire body. Recovery to the preictal position was noted in 0.3-1 s. As a result of carefully repeated observations, 36 video-docu-

F7-Al F8-A2

T3-Al T4-A2

T5-Al TS-A2

F3-Al Fl-A2 C3-Al Cl-A2

P3-Al P4-A2

Ol-AI 02-A2

EC6 FIG. 1. Patient 7. Background activity during wakefulness. Continuous monomorphic 4- to 7-Hz theta activity with some parietooccipital accentuation during the period of activity.

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DROP SEIZURES mented seizures were classified into the following three seizure types according to postural change, temporal sequence of falling, and associated EMG potentials (Table 2): 1. Myoclonic flexor (nine seizures in 2 patients). Myoclonic flexor seizures were characterized by sudden flexion of the head and trunk, causing patients to fall (Fig. 2). Falling appeared to be the result of massive flexion of the trunk at the hip. On the video picture, the time spent falling appeared to be shorter than that of atonic falling and the body appeared to be hurling toward the ground rather than slumping or collapsing. In two seizures recorded in the supine position, a brief myoclonic flexor spasm of the neck and upper trunk against gravity was clearly observed. The polygraph was difficult to interpret because of contamination by many artifacts associated with falling, but the one seizure recorded in the supine

position exhibited intense EMG potentials in the sternocleidomastoideus muscles and only simultaneous minimal attenuation of EMG potentials in the trapezius and biceps muscles. 2. Myoclonic-atonic (two seizures in 1 patient). The initial change in myoclonic-atonic seizures was the same as that of the myoclonic flexor type, but subsequent falling was caused by loss of muscle tone, whereas falling in the former resulted from massive flexion of the body (Fig. 3A and B). The polygraph showed EMG potentials in the sternocleidomastoideus muscles and simultaneous interruption of potentials in the trapezius and erector spinae muscles. 3. Atonic (25 seizures in 4 patients). Atonic seizures were characterized by sudden slumping or collapsing to the floor as a result of transient loss of muscle tone. These atonic seizures might be divided into the following two

TABLE 2. Ictal, clinical, and EEG manifestations Patientlage at examination (vr, mo) 113, 11

No. of seizures recorded" Sit., 13 (6)

Types of seizures (A) Atonic seizures with and without preceding symptoms (8)

(B) Myoclonic flexor spasms causing a forward fall (3) (C) Myoclonic-atonic seizures (2)

212, 1

Sit., 3 sup., 2 Sta., l ( 4 )

313. 2

Sit. 1 1 SUP., 1 ( 3 )

412, 10

Sit., 2 (2)

Sll, 5

Sit. 3 (1)

(A) Myoclonic flexor spasms causing forward fall (B) Myoclonic flexor spasms against gravity in the supine posture (2) (A) Atonic seizures without noticeable preceding symptoms (B) Momentary subtle change of facial expression associated with brief inspiration (1) (A) Atonic seizures with preceding symptoms

(A) Atonic seizures with preceding symptoms

Ictal EEG and EMG findings Burst of GBSSW buildup in amplitude and slowing in frequency from 3 to 1.5 Hz lasting 2 4 s; sudden interruption of EMG discharges at trapezius m Burst of irregular GBSSW; brief EMG discharges at SCM but no interruption of EMG potentials at trapezius and erector spinae Burst of irregular GBSSW; brief EMG discharges at SCM associated with interruption of EMG potentials at trapezius and erector spinae Burst of GBSSW buildup in amplitude and slowing in frequency from 3 to 1.5-2 Hz lasting 2-3 s Brief EMG discharges at SCM Burst of GBSSW buildup in amplitude and slowing in frequency from 3 to 2 Hz lasting 3-5 s Sudden interruption of EMG discharges at trapezius m Burst of GBSSW buildup in amplitude and slowing in frequency from 3.5 to 2 Hz lasting 5-6 s; sudden interruption of EMG discharges at trapezius m Burst of GBSSW buildup in amplitude and slowing in frequency from 4 to 2 Hz lasting 2-6 s; sudden interruption of EMG discharges at trapezius m

Sit., sitting position; Sup., supine position; Sta., standing position; GBSSW, generalized bilaterally synchronous spike and wave complexes; EMG, electromyographic; preceding symptoms, momentary change in facial expression characterized by sudden widening of the eye fissures and mouth and/or twitching of the extremities; SCM, sternocleidomastoideus. a Numbers in parentheses are numbers of attacks of falling,

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FIG. 2. Patient 2. Simultaneous split-screen video and polygraphic findings of the myoclonic flexor seizure. Clinical seizure manifestations. Before the seizure, the patient was standing (1). Suddenly, slight flexion of his head as well as forearms, associated with opening of the mouth, was observed (2). Flexion of the upper trunk at the hip with adduction of both arms, as well as some flexion of both knees, ensued (3). His body was further bent forward, but he did not fall because his mother held him at the waist. Interpretation of the ictal polygraph was difficult because of contamination of many fall-associated artifacts. (Numbers indicate seizure sequence.)

subtypes, according to the presence or absence of transient symptoms immediately before the fall. A . Atonic seizures with transient preceding symptoms (16 seizures). The preceding symptoms in type A atonic seizures consisted of a momentary change in facial expression characterized by sudden widening of the eye fissures and mouth andlor twitching of the extremities, which could be recognized only by repeated and close inspection of the videotaped seizures (Fig. 4A and B). They were immediately followed by slumping of the head and upper trunk. EMG discharges from the trapezius muscle were interrupted suddenly, whereas those of the sternocleidomastoideus continued. B. Atonic seizures without preceding symptoms (nine seizures). Other than absence of preceding symptoms, confirmed by repeated inspection of the video pictures, type B atonic seizures were virtually identical to those with transient preceding symptoms. Epilepsia, Vol. 33, No. 5 , 1992

Ictal EEG findings Generalized bilaterally synchronous single or multiple spikes and wave discharges (GBSSW) corresponded to all 36 seizures. The clinical seizure manifestations occurred exactly when the burst of GBSSW exhibiting a rhythmic buildup of amplitude and slowing in frequency from 3 to 4 Hz to 1.5-2 Hz lasting for 2-6 s reached the last spike and wave complex with the largest amplitude and slowest frequency. The ictal EEG patterns were consistently alike, regardless of seizure type. Occasionally, brief arrest of motion and staring were observed simultaneously during this rhythmic burst of GBSSW in one patient (patient 1). The temporal relation between the spike and wave discharge and the clinical seizure phenomena, analyzed by simultaneous split-screen video taping as well as polygraph, showed that the EMG phenomena of both myoclonic flexor spasms and atonic seizures corresponded roughly to the period between the spike component and the ascending portion of the slow wave component of GBSSW. In-

DROP SEIZURES

809

A

B

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A

1 1 1 1 1 1 1 I 11 1 , 1 1 , 11 1 1 1 1 1 I 1 1 I 1 1 1 I I I

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,'

I

FIG. 3. Patient 7 . Simultaneous split-screen video and polygraphic findings of myoclonic-atonic seizures. A: Clinical seizure manifestations. Before the seizure, the patient was sitting (1). Suddenly, slight flexion of his head and extension of forearms and some flexion of both thighs occurred (2). Falling of the head and trunk ensued (3 and 4). Falling of the body appeared to result from atonia of the antigravity muscles. (Numbers indicate seizure sequence.) B: lctal polygraphic findings. The seizure occurred at the last spike and wave complex that had the largest amplitude and slowest frequency. Brief electromyographic (EMG) discharges were noted in the sternocleidomastoideus (SCM) muscle, and interruption of EMG potentials was observed at the trapezius and erector spinae muscles.

Ef&@a,

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H . OGUNI ET AL. A

FIG. 4. Simultaneous split-screen video and polygraphic findings of atonic seizures with transient preceding symptoms. A: Clinical seizure manifestations. Before the seizure, the patient was using both hands to play (1). Suddenly, his eyes and mouth opened wide (2), followed by immediate slumping of his head and body toward the floor ($4).(Numbers indicate the seizure sequence.) B: lctal polygraphic findings. Clinical seizure manifestations occurred exactly when the burst of generalized bilaterally synchronous single or multiple spike and wave discharges (GBSSW) exhibiting a rhythmic buildup of amplitude and slowing in frequency from 3-4-Hz to 1.5- to 2-Hz lasting 4 s reached the last spike and wave complex, which had the largest amplitude and slowest frequency. Interruption of electromyographic (EMG) discharges was noted in the trapezius and erector spinae muscles. The EMG potential from the sternocleidomastoideus (SCM) muscle was difficult to interpret because of contamination by movement artifacts.

terruption of EMG potentials in the latter lasted 300-500 ms (Fig. 5). In addition, the transient preceding symptoms observed just before the atonic falling corresponded approximately to the length of the spike component of GBSSW. Epilepsiu, V o f .33, N o . 5 , 1992

DISCUSSION MAEE (Kruse, 1968; Doose et al., 1970, 1980; Doose, 1985) has been accepted as a distinct epileptic syndrome (Commission, 1989) and is nosologi-

DROP SEIZURES

FIG. 5. Temporal relationship between EEG and clinical seizure manifestations studied with high-speed polygraphic recording. A: Patient 2. Myoclonic flexor type. The seizure was recorded when the patient was held horizontally by his mother. Clinically, he showed sudden flexion of the neck and upper trunk with only minor involvement of the arms. Polygraph exhibited intense electromyographic (EMG) potentials in the sternocleidomastoideus muscle (SCM) and only simultaneous minimal attenuation of those in the trapezius and biceps muscles. The EMG potentials of the SCM corresponded to the period between the descending portion of the first spike component and the ascending portion of the slow wave component of generalized bilaterally synchronous spike and wave discharges. B: Patient 7. Atonic type. The atonia indicated by the interruption of EMG discharges in the trapezius, SCM, and erector spinae muscles corresponded to the same period as A but lasted -300 ms. A brief EMG potential noted in the left SCM appeared -80 ms after the beginning of EMG silence and was not considered part of the seizure process.

cally different from other myoclonic epilepsies developing in infancy and early childhood (Dravet et al., 1985a,b; Aicardi, 1986). It is characterized by onset of epilepsy between the ages of 1 and 6 years; the presence of myoclonic, astatic, and myoclonicastatic seizures, often causing the patient to fall (drop seizures); normal development before onset; genetic predisposition; 4- to 7-Hz rhythm with parietal accentuation; and variable prognosis. Patients often incur facial injury as a result of drop attacks. In addition, myoclonic as well as astatic seizures are also considered to induce falling. Most of these assumptions regarding drop seizures are based entirely on clinical observations because only a few simultaneous EEG/EMG recordings of these seizures have been reported. Visual observation alone limits accurate diagnosis because the drop attacks are so brief. However, the advent of split-screen video monitoring allows more accurate analysis of drop seizures or epileptic falling attacks. Using this

811

system, Egli et al. (1985) and Ikeno et al. (1985) independently demonstrated that most drop or falling attacks were caused by brief axial tonic spasms. In both series, only a small percentage of falling attacks were of the myoclonic-atonic type (18% in the Egli series and 25% in the Ikeno series) or true atonic seizures (29% in the Egli series and 0.04%in the Ikeno series). It is unfortunate that both groups of investigators studied patients with symptomatic generalized epilepsy or Lennox-Gastaut syndrome without including patients with other epileptic syndromes such as MAEE, which apparently has a more benign course than Lennox-Gastaut syndrome. Our 5 patients had characteristic clinical and EEG features of MAEE, lacking the generalized tonic seizures and runs of rapid EEG spikes that characterize Lennox-Gastaut syndrome. On the basis of our results, the drop seizures in these 5 patients with MAEE were classified into three general types: (a) myoclonic flexor type, (b) myoclonic-atonic type, and (c) atonic type with and without transient preceding symptoms. The myoclonic flexor type is different, with respect to duration of spasms and ictal EEG pattern, from the “axial spasms” or “flexor spasms” reported in the two previous studies. The duration of the spasm in the former appeared to be much briefer than that in the latter. With regard to ictal EEG pattern, the former corresponded to GBSSW and the latter to a nonspecific EEG pattern. We recorded only two typical myoclonic-atonic seizures among the 36 seizures (6%) in our series. The atonic type was most common in this study (25 of 36 seizures or 69%) and was often preceded by minor brief symptoms. These preceding symptoms probably represent minimal myoclonic contraction appearing only in the facial muscles and/or twitching of the extremities. We do not favor inclusion of this type of seizure in the category of myoclonicatonic seizures because they were usually subtle enough to be missed by visual observation alone, whereas the myoclonic spasms of myoclonic-atonic seizures were more pronounced. Neither is it reasonable to consider that such subtle myoclonic phenomena produced the strong ensuing inhibition termed “postmyoclonic inhibition” (Gastaut, 1972a), which was believed to be responsible for genesis of “myoclonic astatic seizures.” Nevertheless, a spectrum of intensity may exist in the initial myoclonic phenomena, ranging from the slight to relatively high intensity observed in myoclonicatonic seizures and the even higher intensity observed in the myoclonic flexor type. Neither can we exclude the possibility of minimal myoclonus in this atonic type without preceding symptoms because of Epilepsia, Vol. 33, N O . 5 , 1992

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the difficulty of attaching many EMG electrodes and obtaining videos in the most appropriate positions for reviewing falling in such young subjects. Gastaut (19726) studied atonic seizures extensively and demonstrated correspondence to GBSSW lasting 1-3 s, which were quickly replaced by a succession of generalized slow wave discharges. He considered brief forms to be related to very short-acting but intense inhibitory mechanisms, suggesting the importance of participation of the motor cortex, as well as a “centrencephalic mechanism” in production of hypotonia. I n our patients, all seizures corresponded to GBSSW regardless of seizure type. In most patients, GBSSW exhibited a rhythmic buildup of amplitude and slowing in frequency and the seizures occurred at the last GBSSW that had the largest amplitude and slowest frequency. In the atonic type, the atonia itself appeared to correspond to the period between the beginning and approximately halfway through the slow wave component of GBSSW. Tassinari et al. (1968) carefully studied inhibition of sustained muscle activity and noted correspondence to the slow wave component of spike and wave discharges in absence seizures with or without a myoclonic component. They termed this phenomenon ‘‘related epileptic silent period (RESP),” implying that the muscular inhibition caused by a physiologic silent period was followed by spike discharges. Our findings and those of Tassinari et al. (1968) showed many similarities with regard to the temporal relation except that duration of inhibition was much shorter in their study. Gloor (1979,1984) stressed the importance of recurrent cortical inhibition leading to interference with cortical function during the spike and wave discharges. The combination of a brief absence state and atonic drop seizures occurring in succession in one patient may suggest that the absence state is produced by a milder “disturbance of consciousness” and that the brief atonia occurring in the last moment of this absence is caused by a stronger disturbance, sufficient to cause the patient to collapse. Comparison of our results with those of Egli et al. (1985) and Ikeno et al. (1985), showed that atonic drop seizures apparently were more common in MAEE than in Lennox-Gastaut syndrome. Because the number of the patients we studied was limited, however, further study will be necessary before a definite conclusion can be drawn.

REFERENCES Aicardi J. Lennox-Gastaut syndrome and myoclonic epilepsies of infancy and early childhood. In: Aicardi J, ed. Epilepsy in Epilepsia, Vol. 33, No. 5 , 1992

children. New York: Raven Press, 1986:39-65. (International review of child neurology series.) Commission on Classification and Terminology of the International League Against Epilepsy. Proposal for revised classification of epilepsies and epileptic syndromes. Epilepsia 1989;30:389-99. Doose H, Gerken H, Leonhart R, Volzke E, Volz C. Centrencephalic myoclonic astatic petit mal. Neuropadiatrie 1970;2: 59-78. Doose H. Genetic factors in childhood epilepsy. In: Canger R, Angeleri F , Penry JK, eds. Advances in epileptology: XIth Epilepsy In International Symposium. New York: Raven Press, 1980:289-96. Doose H. Myoclonic astatic epilepsy of early childhood. In: Roger J, Dravet C, Bureau M, Dreifuss FE, Wolf P, eds. Epileptic syndromes in infancy, childhood and adolescence. London: John Libbey Eurotext, 1985:78-88. Dravet C, Bureau M, Roger J . Benign myoclonic epilepsy in infants. In: Roger J, Dravet C, Bureau M, Dreifuss FE, Wolf P, eds. Epileptic syndromes in infancy, childhood and adolescence. London: John Libbey Eurotext, 1985a:51-7. Dravet C, Bureau M, Roger J. Severe myoclonic epilepsy in infants. In: Roger J , Dravet C, Bureau M, Dreifuss FE, Wolf P, eds. Epileptic syndromes in infancy, childhood and adolescence. London: John Libbey Eurotext, 19856:5847. Egli M, Mothersill I, O’kane M, O’kane F. The axial spasm-the predominant type of drop seizure in patients with secondary generalized epilepsy. Epilepsia 1985;26:401-15. Gastaut H, Broughton R. Bilateral myoclonus. In: Gastaut H , Broughton R, eds. Epileptic seizures, clinical and electroencephalographic features, diagnosis, and treatment. Springfield: Charles C Thomas, 1972d5-63. Gastaut H, Broughton R. Atonic seizures. In: Gastaut H, Broughton R, eds. Epileptic seizures, clinical and electroencephalographic features, diagnosis, and treatment. Springfield: Charles C Thomas, 1972h:SS-89. Gloor P. Generalized epilepsy with spike and wave discharges: a reinterpretation of its electrographic and clinical manifestations. Epilepsia 1979;20:571-88. Gloor P. Electrophysiology of generalized epilepsy. In: Schwartzkroin PA, Wheel H, eds. Electrophysiology of epilepsy. New York: Academic Press, 1984:107-36. Ikeno T, Shigematsu H , Miyakoshi M, et al. An analytic study of epileptic falls. Epilepsia 1985;26:612-21. Kruse R. Das myoclonischo-astatische Petit Mul. Berlin: Springer, 1968. Niedermeyer E. The electroencephalogram in the differential diagnosis of the Lennox-Gastaut syndrome. In: Niedermeyer E , Degen R, eds. The Lennox-Gastaut syndrome. New York: Alan R. Liss, 1988:177-220. Nolte R, Wolff M, Krageloh-Mann I. The atonic(astatic) drop attacks and their differential diagnosis. In: Niedermeyer E, Degen R, eds. The Lennox-Gastaut syndrome. New York: Alan R. Liss, 1988:95-108. Tassinari CA, Regis H, Gastaut H. A particular form of muscular inhibition in epilepsy: the related epileptic silent period (R.E.S.P.). Clin Exp Neurol 1968;5:595-602.

RESUMEN Los autores han estudiado un total de 36 ataques de caida (drop attacks) en 5 enfermos con epilepsia mioclonica aestatica, de comienzo en la infancia (MAEE), utilizando simulttineamente registros de video y poligrafia. Diez y seis presentaban ataques de caida y 29 tenian ataques menos severos exhibiendo solo gestos de afirmacidn con la cabeza o ataques equivalentes a ataques de caida con patrones ictales pero registrados en posicion supina. Todos 10s ataques, con exception de 10s que ocurrian en la posicion supina, mostraron repentinos y momentaneos movimientos de caida de la cabeza o colapso total del cuerpo hacia delante. La recuperation de la posicion pre-ictal se observo en 10s siguientes 0.3 a 1.0 segundos. Como resultado de observaciones repetidas cuidadosamente 10s 36 ataques se clas-

DROP SEIZIJRES ifican en mioclonias de tipo flexor en 9 casos, mioclonias de tipo atonico en 2 y de tip0 atonico, con o sin sintomas transitorios precedentes, en 25. El ataque rnioclonico flexor se caracterizo por una repentina flexion de la cabeza, tronco y brazos que causaban caidas. En el ataque rnioclonico atonico 10s enfermos muestran breves flexiones mioclonicas seguidas inmediatamente de caida atonica. Los ataques tipo atonico se caracterizan por una caida brusca con o sin precedentes cambios de expresion facial ylo convulsiones de las extrernidades. Los EEGs ictales de 10s 36 ataques mostraron descargas generalizadas sincronas de cornplejos punta-onda, unicos o multiples. Los ataques atonicos parecen ser una causa frecuente de las caidas ictales epilepticas en la MAEE.

(A. Portera-Sanchez, Mudrid)

ZUSAMMENFASSUNG Wir untersuchten insgesamt 36 Sturzanfalle von 5 Patienten rnit myoklonischastatischen-Petit rnal rnit DoppelbildMonitoring und Polygraphie. 16 davon waren Sturzanfalle und 20 entweder weniger starke Anfalle rnit Kopfnicken oder aber An-

813

falle rnit einem fur Sturzanfalle typischen Muster, bei Ableitung irn Liegen. Samtliche Anfalle, ausgenornmen die irn Liegen abgeleiteten, gingen rnit kurzem Kopfnicken oder Sturz des ganzen Korpers einher. Die Erholungszeit bis zum Wiederreichen der praiktalen Haltung betrug 0.3 bis 1.0 Sekunden. Nach mehrfachen sorgfaltigem Beobachten erfolgte die Klassifizierung in 9 myoklonische Beuge-Anfalle (Flexor), zwei rnyoklonischatonische Anfalle und 25 atonische Anfalle mit und ohne vorrubergehende Symptomatik. Die Flexoranfalle waren durch plotzliche Vorwartsbeugung von Kopf unf Rumpf sowie beider Arme charakterisiert, die zum Fall fiihrte. Bei myoklonisch-atonischen Anfallen boten die Patieten kurze myoklonische Beugezuckungen gefolgt von plotzlichern atonischern Fall. Bei atonischen Anfallen konnte nur ein abrupter Fall beobachtet werden mit und ohne vorubergehende Veranderung des Gesichtsausdrucks oder Extremitatenbewegungen. Das iktale EEG zeigte bei allen 36 Anfallen generalisierte, bilaterale, synchrone Einzel-oder Polyspike-wave-Entladungen. Atonische Anfalle scheinen eine haufige Ursache von iktalem Sturz bei MAPM zu sein.

(C. G. Lipinski, HeidelherRlNeckurRemiind)

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