Periodic Lateralized Epileptiform Discharges in Infants and Children Rhandy PeBenito, MD, and Joan B. Cracco, M D

Clinical and electroencephalographic data on 7 infants and children with periodic lateralized epileptiform discharges (PLEDS) in their electroencephalograms were reviewed. The waveform, periodicity, and transitory nature of these discharges were similar to those reported in adults. In children, as in adults, PLEDs reflect severe underlying brain dysfunction which is often associated with metabolic and structural abnormalities. In adults, PLEDs are usually associated with altered states of consciousness and with acute unilateral cerebral lesions; in children, however, they often occur with little or no alteration in consciousness and with chronic, diffuse lesions of the central nervous system. PeBenito R, Cracco JB: Periodic lateralized epileptiform discharges in infants and children. Ann Neurol6:47-50, 1979

Periodic lateralized epileptiform discharges (PLEDs), a term coined by Chatrian et a1 in 1964 [2], refers to a characteristic pattern of sharp-wave complexes in the electroencephalogram. In adults, this pattern is usually found in patients with acute cerebral lesions which are often vascular in natureC2, 3, 5,8,9].Associated metabolic disorders are often present [ 2 , 3, 5 , 8, 11, 121. Relatively few children with PLEDs have been reported [2, 3, 5 , 8 , 101. Except for the patient with cerebral cysticercosis described by Virmani et a1 [ 101, there has been no correlation of the clinical status of children with this pattern. This report describes the clinical status of a group of 7 infants and children who had PLEDs recorded on their EEGs during a threeyear period.

Materials and Methods The children ranged in age from 2 months to 16 years with a mean of 7 years. EEG recordings were obtained on either an eight- or a sixteen-channel electroencephalograph using the International 10/20 system of electrode placement. T h e level of consciousness and the presence or absence of seizure activity were noted during the recordings. Recordings performed during sleep were obtained in 4 patients. Two or more recordings performed at intervals of one to three months were obtained in 6 patients. EEGs recorded prior to the appearance of PLEDs were available for 2 patients. The EEGs were correlated with the clinical history, neurological status, laboratory and radiological data, presence o r absence of seizures, and clinical course of the patient.

Results The Table summarizes the clinical and EEG data. From the Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, NY. Accepted for publication Jan 24, 1979.

EEG Findings The waveform of the complexes varied from patient to patient but consisted of semiperiodic discharges of biphasic or triphasic sharp waves or polyspikes and slow waves with a repetition rate of about 1 to 2 per second (Fig 1). The amplitude of the discharges was 100 to 200 pv and the duration, 200 to 500 msec. The discharges occupied 20 to 35% of the entire recording. In all 7 patients, PLEDs were localized within one hemisphere, where they underwent phase reversal on bipolar leads and were greater in amplitude in ear reference leads (Fig 2). The discharges were recorded over only one hemisphere in 5 patients and over both hemispheres in 2 patients. The background activity was slow for age in all patients except 1. Photic driving responses were present in only 1 patient (No. 7). In this child a driving response was recorded only over the hemisphere contralateral to the PLEDs. In 3 of the 4 cases in which EEG activity was obtained with the patient both awake and asleep during a single recording, the PLEDs persisted during sleep with a frequency similar to that in the awake recording. In 1 patient (No. 5 ) , PLEDs were recorded only during sleep. Associated focal delta activity in the region of the PLEDs was seen in all patients except 1 (Patient 6). O n the follow-up EEG performed one to three months later, PLEDs were not recorded in any of the patients. However, the background activity remained slow for age in all except the patient in whom the background activity had been normal at the time of the initial recording (Patient 7). The youngest patient’s subsequent recordings revealed hypsarrhythAddress reprint requests to Dr Cracco, Box 35, Department of Neurology, Downstate Medical Center, 450 Clarkson Ave, Brooklyn, N Y 11203.

0364-5134/79/070047-04$01.25 @ 1978 by Joan B. Cracco 47

Clinical and E E G Dutu i n 7 Pediatric Patients with Periodic Laterulized Epileptiform Dischurges Patient No.

Age vr )

(

1

2 mo

2

5

3

242

4

I

5

11

6

7

,

i

16

Etiological Factors

Seizure Tvw

Localization of PLXDs

Follow-up EEG

Sickle-cell trait, acute left cerebral infarct, and metabolic abnormality Uterine rhabdomyosarcoma and acute metabolic abnormality; normal CT scan Acute right subdural hematoma; previous cerebral contusion and generalized seizures Previous left cerebral laceration, contusion, and frontal lobectomy Status epilepticus in infancy, cause unknown

Right focal motor

Left frontocemporal

H ypsarrhythmia

Generalized and left focal motor

Right parietal

None

“Scaring spells”

Right midtemporal

Slow background

Mental retardation and spastic quadriparesis; no seizurcs

None at time of PLEDs

Left f r o n d

Left frontal focal delta

Gelastic

Right midtemporal

Slow background

Perinatal brain injury; normal CT scan

Myoclonic and generalized

Left central

Left central focal spikes and electrographic seizures

Sickle-cell disease; previous bacterial meningitis

Gcneralized

Left frontotemporal

Left temporal focal delta

Mental retardation and spastic quadriparesis; left focal motor seizures Mental retardation and spastic quadriparesis; gelastic seizures Mental retardation and spastic quadriparesis; myoclonic and generalized seizures Normal neurological examination; generalized seizures

I

1

I

I

I

I

Outcome

I

Mental retardation, right hemiparesis, and inhncile spasms Died

1

1 FP1- F7

48 Annals of Neurology

Vol 6 No 1 July 1979

F i g 2. (Patient 6 ) Ear reference recording obtained in an awake 7-year-old girl with seuere mental retardation, seizures, and spastic quadriparesis. The periodic discharges consist of bilateral bisynchronous sharp and slow waves, occurring at a rate of about 2 per second, lateralized t o the left hemisphere and greatest in amplitude i n the left central area (C3).

mia (Patient 1). In another patient (No. 6), electrographic seizure discharges and focal spike activity were recorded from the same site where the P E D s had previously appeared. Focal delta activity persisted in 2 patients (Nos. 4 and 7). EEGs performed prior to the appearance of PLEDs in 2 patients (Nos. 3 and 4 ) did not reveal epileptiform discharges. Clinical Findings

Three patients had acute neurological illnesses. Four patients had chronic, nonprogressive illnesses; in 2 of them the history dated from early infancy. In 2 of the 3 patients with acute illness, the level of consciousness was impaired when the EEG tracings revealed PLEDs. The 4 patients with chronic neurological disorders were alert when the EEG was performed. All F i g I . (Patient 5 ) Bipolar recording obtained in an awake 11-year-old girl with seuere mental retardation, seizures, and spastic quadriparesis. The periodic discharges consist of sharpand slow-wave complexes, occurring at a rate of about 1 per second, which undergo phase reversal in the right midtemporal area (T4).

patients except 1 (Patient 4 ) had seizures one to two days prior to the EEG in which the PLEDs were recorded. No patient with acute illness had a prior history of epilepsy. A longstanding history of seizure disorder was present in all patients with chronic illness except 1 (Patient 4). Clinical seizures were not apparent during the recording in any patient. The seizure type varied: 1 patient had focal motor seizures; 1, focal motor and generalized tonic-clonic seizures; 1, gelastic seizures; 1, “staring spells”; 1, generalized tonic-clonic seizures; and 1, myoclonic and generalized tonic-clonic seizures. Of the 3 patients with acute illness, 1 (Patient 1) had cerebral infarction secondary to sickle-cell trait and metabolic abnormality; 1 (Patient 3 ) had an acute subdural hematoma; and another (Patient 2) had a pelvic tumor with metabolic disturbance but no evidence of metastases on C T scan. Of the 4 patients with chronic illness, 2 (Nos. 5 and 6) had had injury secondary to perinatal problems, 1 (Patient 4 ) had suffered a severe head injury, and the fourth (No. 7) had had bacterial meningitis. O n e child died of a nonneurological illness during the hospitalization (Patient 2). The remaining 6 patients were followed for one to three years. One patient (No. 7) had seizures but no further evidence of neurological impairment. Five patients had severe neurological deficits. Four of these patients had recurrent seizures, and in 3 the seizures were difficult to control. PeBenito and Cracco: PLEDs in Infants and Children 49

Discussion These observations indicate that PLEDs occur during infancy and childhood and that they arc associated with both acute and chronic conditions in the pediatric age group. T h e waveform and periodicity of the PLEDs were similar to those described in previous reports [2, 3, 5 , 81. As in adults, PLEDs in o u r patients were transitory and were usually replaced by focal spikes o r slowing. I n adults, PLEDs are frequently associated with depressed levels of consciousness [ 2 , 5 , 81 and with focal motor seizures involving the side of the body contralateral to the PLEDs. In contrast, a depressed level of consciousness was present in only 2 of o u r patients. Like adult patients, most of o u r patients had seizures at the time PLEDs were first recorded in the EEG. I n adults, the disappearance of PLEDs is usually associated with cessation o f seizures [8]. However, most of o u r patients had recurrent seizures after the PLEDs disappeared. About half of o u r patients had a longstanding history of recurrent seizures prior to the time the PLEDs were recorded, whereas most adult patients have no history of epilepsy. Metabolic abnormalities are frequently found in adult patients with PLEDs [a, 3,5 , 8 , 11, 121 and may play a role in the genesis of the discharges. T w o of o u r patients had severe metabolic abnormalities, which suggests that metabolic derangements may be a contributing factor to t h e occurrence of PLEDs in children also. PLEDs have been associated with intracranial neoplasms [2, 81, infections 12, 4 , 81, subdural hematoma [GI, and, infrequently, chronic neurological disorders [2, 3 , 8, 101. They usually occur with unilateral cerebral lesions in adults, and acute infarctions have accounted for most o f t h e cases[2, 3, 5 , 8 , 9 ] . Surviving adults generally have a relatively benign course with good recovery [2, 51. Most of o u r pediatric patients had evidence of bilateral o r diffuse (or both) cerebral disease of various causes and exhibited severe neurological deficits. Therefore, in both children and adults, PLEDs reflect severe underlying brain dysfunction. I n many instances structural abnormalities are compounded by metabolic derangements. T h e association of PLEDs in childhood with chronic diffuse cerebral lesions may reflect the nature of pediatric neurological illnesses. Most neurological disor-

50 Annals of Neurology

Vol 6

N o 1 July 1979

ders in childhood are associated with chronic diffuse cerebral disease rather than with acute focal insults. T h e origin and mechanism of these periodic discharges are not known. Various hypotheses have been advanced 12, 5 , 8, 101. Periodic phenomena have been described in the acurely isolated neocortex of mature animals [ 11. In the immature animal, however, periodic bursts occur in chronically isolated cortex b u t not in the acute preparation [7].This suggests that in response to an acute insult, immature cortex may not develop periodic activity as readily as mature cortex. Therefore, brain maturational factors may also contribute t o the association o f childhood PLEDs with chronic cerebral disorders. T h e authors express their appreciation r o Dr Roger Q. Cracco tor his advice and assistance.

References 1. Burns BD: Some properties o f isolated cerebr;iI cortex in the iinanesthetized cat. J Physiol (Lond! I 12:lj6-17j,1961

2. Chatrian GE, Shaw CH, Leffman H . The significance of periodic Iateralized epiieptiform discharges in EEG: an electrographic, clinical and patho1ogic;il study. Elei troencephalogr Clin Neurophysiol I -: I ” - 1 9 3 , 1 9 6 4 3 . Hughes JR, Schlagenhauff R E . The periodicnlly rccurring focal discharge. Epilepsia 6:150- 106. 1065 4. lllis LS. Taylor FM: T h e elecrrc~cnii.phalo~ramin herpes simplex encephalitis. Lanccr I:’ 18--2 I, 19-2 5 . iMarkand ON, Daly DD: Pseudoperiodic lateralized paroxysmal discharges in electroencephalogram. Neurology (Minneap) 21:075-980, lY71 6. Merhyar GR, McIntyre HB: Periodic lateralized epilepritorm discharges associated with suhciiiral tiematoma. HiuII Los Angeles Neurol Soc 40:8-12. 1 9 7 5 7 . Purpura DP. Housepian E M : Morphological and physiological properties of chronically isolared immarure cortex. Exp Neurol 4 : 3 T 7 - 4 0 l , 1961 8. Schwartz MS, Prior PF. S c o t t DF: T h e occwrcncc and evolut i o n of ;I lateralized pcriodic phenomenon. Brain %:(,I 3 622, 1971 9. Surer C, Creveling JG: Periodic iaternlii.ing ep~iepriforindischarges (acute spikes] (abstract,. Electrociiceptialor Clin Neurophysiol 20:624, 1960 10. Virmaiii V, R o y 5, Kamaga G . Periociic 1ateral1,ed epileptiform discharges in a case o i ciiffusc icrebral cysticercosis. N e 11 ropediat rie 8.190 2 0 3. 19-1 I . Yarnell PR, C h u NS:: Focal sciziircs and aminophrilinc. N e u rology (Minneap) 25:819-822. I O ’ S 12. Young GB, Brown JL3. Bolton CF. et al: Perioclic I‘itrriilizeil epileptiform diwhargrs (PLED?) an(l nvstagmus retr;ictorius. Ann Neurol 2:61-62, -

Periodic lateralized epileptiform discharges in infants and children.

Periodic Lateralized Epileptiform Discharges in Infants and Children Rhandy PeBenito, MD, and Joan B. Cracco, M D Clinical and electroencephalographi...
330KB Sizes 0 Downloads 0 Views