EEG Abnormalities in Nonepileptic Patients

Abstract: A total of 202 nonepileptic patients (120 males and 82 females) who exhibited spike abnormalities at least twice in their EEG examinations were studied. The incidence of spike abnormalities among nonepileptic patients was 8.1% (847/10,473). The majority (90%) were under age 19. Headache, dizziness and vomiting, and abdominal pain were more frequently observed compared with controls. Mild paroxysmal EEG abnormalities such as diffuse irregular slow wave bursts with spike (27%), positive spikes (25%) or small spike (8.4%) were commonly detected.
In three patients who developed epileptic seizures during the follow-up period, more specific EEG abnormalities were often exhibited. Other factors like the age at onset before 9, characteristic clinical symptoms or a positive family history of seizures were confirmed to be necessary for the manifestation of clinical seizures.     

EEG abnormalities in nonepileptic patients

A total of 202 nonepileptic patients (120 males and 82 females) who exhibited spike abnormalities at least twice in their EEG examinations were studied. The incidence of spike abnormalities among nonepileptic patients was 8.1% (847/10,473). The majority (90%) were under age 19. Headache, dizziness and vomiting, and abdominal pain were more frequently observed compared with controls. Mild paroxysmal EEG abnormalities such as diffuse irregular slow wave bursts with spike (27%), positive spikes (25%) or small spike (8.4%) were commonly detected. In three patients who developed epileptic seizures during the follow-up period, more specific EEG abnormalities were often exhibited. Other factors like the age at onset before 9, characteristic clinical symptoms or a positive family history of seizures were confirmed to be necessary for the manifestation of clinical seizures.     

Epileptic seizures difficult to differentiate from alternating hemiplegia in infants: a case report

A child with epileptic seizures had a clinical course similar to that of alternating hemiplegia of infancy (AHI). Tonic hemiplegia began at 2 months of age, and atonic alternating hemiplegia and tetraplegic attacks began at 2 years of age. Clinical findings were paroxysmal ocular movement abnormalities, choreoathetotic involuntary movements, and severe developmental retardation. An interictal EEG at 6 years of age showed multiple independent spike discharges. An ictal EEG showed diffuse irregular spike-wave and slow wave bursts following focal spikes. The present case suggests that a long-term extensive follow-up is necessary to differentiate epileptic seizures from AHI.     

Effect of corticosteroids in a twin child with idiopathic localization-related epilepsy

Corticosteroids have been used only in the treatment of special epileptic syndromes or epileptic encephalopathies, such as infantile spasms. We report an antiepileptic effect of corticosteroids that were used for treatment of nephropathy in a monozygotic twin child with idiopathic localization-related epilepsy (I-LRE). The patient and her monozygotic twin sister exhibited repeated partial seizures at two years of age and electroencephalogram (EEG) showed focal spikes in the occipital area and, on other occasions, the centro-parietal areas. After oral antiepileptic drugs were started, the twins still exhibited occasional seizures. The patient had IgA nephropathy at four years of age and intravenous methylprednisolone and oral prednisolone were administered. Her seizures and epileptiform discharges on EEG disappeared, while her sister continued to have seizures and EEG abnormalities. When the dose of oral predonisone was reduced, the seizures relapsed and EEG again revealed focal spikes. We conclude that corticosteroids exhibit efficacy towards seizures and epileptiform discharges on EEG in patients with I-LRE without epileptic encephalopathies.     

Clinical trials of carbamazepine for autonomic seizures with and without generalized epileptic seizures

Carbamazepine (CBZ) was used for the treatment of 52 children of autonomic seizures with and without generalized epileptic seizures. Their ages ranged from 4 to 17 years. Their autonomic seizures were recurrent episodic headaches and/or abdominal pains. EEG abnormalities were found in all cases in this study. The abnormal EEG findings consisted of diffuse paroxysmal slow dysrhythmia, generalized spike and wave complexes, focal spike and wave complexes with diffuse slow wave bursts, spike and wave complexes with 14 and 6 Hz positive spikes of 14 and 6 Hz positive spikes. Of the 40 patients with autonomic seizures only, 36 (90%) showed disappearance of pain, and of the remaining 4, 2 showed moderate improvement and 2 showed no change as far as their clinical symptoms were concerned. Of the 12 patients with both autonomic seizures and generalized epileptic seizures, 10 (83%) became free from headache and 2 improved moderately. The efficacy of CBZ was found to be very satisfactory. The effective dosage of CBZ ranged from 3.9 to 11.4 mg/kg/day (total dose, 100 to 400 mg/day) with the mean value of 7.0 mg/kg/day.     

Ring chromosome 20: a distinctive syndrome identifiable by electroclinical diagnosis

The ring chromosome 20 syndrome is characterized by treatment resistant non-convulsive status epilepticus, and slow waves intercalated by spikes/spike waves predominantly in the front-temporal regions. Here, we describe the case of an 18 year old patient, whose seizures began at the age of 10, these being resistant to treatment. Neurologic examination and cranial MRI were normal. Interictal EEG showed normal background activity with burst of 2-20 seconds with bilateral spike wave. Ictal EEG showed continuous paroxysmal activity with generalized spike waves discharges and slow delta waves, coinciding with nonconvulsive status epilepticus. After 1 mg of intravenous clonazepam, both clinical semiology and EEG abnormalities disappeared. A cytogenetic study showed ring chromosome 20 in 35 % of metaphases. The epilepsy associated with ring chromosome 20 constitutes a syndrome with its distinctive electroclinical characteristics.     

Comparison of epileptic and nonepileptic cases with centrotemporal spikes in view of clinical findings and electroencephalographic characteristics

The morphological features of centrotemporal spike discharges (CTSD) and relationship of them with clinical diagnosis in cases with benign epilepsy of childhood with centrotemporal spikes (BECTS) and the other epileptic syndromes of childhood as well as some nonconvulsive neurological disorders were detected in the routine patient population who referred to the authors' EEG laboratory. Thirty-six cases (21 males, 15 females; 8 months-14 years old), in which awake and/or sleep EEGs revealed CTSD were included in this study. The cases were divided into two groups as epileptic and nonepileptic. The cases with seizure were divided into BECTS and the other epilepsies. Of the epileptic cases, 14 (38.8%) patients had typical rolandic seizures. In five cases, there were partial or secondary generalized seizures. Two cases had myoclonic seizures. In the nonepileptic group, there was mental retardation/behavioral disturbances in five cases; there were periodic syndromes of childhood such as migraine and equivalents of migraine in three cases; febrile convulsion in three cases, breath-holding spells in two cases, and primary enuresis nocturna in two cases. In the nonepileptic group, the discharges were significantly fewer than the other groups (p = .014). More frequent discharges occuring for shorter periods were more significantly observed in BECTS group (64%). Typically isolated spike and slow-waves in T3/T4 and C3/C4 location were significantly more common (86%) in rolandic epilepsy group (p = .01). The EEGs of cases with BECTS had more frequency in the cluster of discharges than the other groups (p = .018). Multifocal discharges were observed in 28.5% of cases with BECTS, in 20% of nonepileptic group, and in 71.4% of other epileptics in the trial. Although these epileptic and nonepileptic conditions have some differences in view of frequency and morphology and location, CTSDs could be manifested in the group without seizure. It was concluded that the similar focal abnormalities which could be seen in rolandic epilepsy may be observed in the other epileptic or nonepileptic disorders of childhood and this condition may be originated from the involvement of similar central structures.     

伴中央-中颞棘波的儿童良性癫癎与弥漫性棘慢波综合及失神发作的关系

目的 探讨弥漫性棘慢波综合(GSWD)及失神发作(AS)在儿童良性癫痫伴中央，中颞棘波发放(BECCT)患者中的发生情况，分析BECCT与AS间的可能的相互联系。方法 回顾性分析5年来诊断为BECCT的524例患者的临床及录像脑电图(VEEG)资料。我们对GSWD的入选标准为：在正常背景活动中，突然发生和中止、频率2.5～3．5Hz、双侧对称或大致对称的棘慢波综合(棘波数≤2)。结果在524例BECCT患者中，GSWD及AS的发生率分别为5．3％和2．0％。绝大多数合并有AS的BECCT患者对单药治疗效果较好。结论 BECCT和AS可发生在同一例患者中，提示这两种常见的癫痫综合征之间可能存在某些类似的发病机制。     

Simultaneous EEG and fMRI recordings (EEG‐fMRI) in children with epilepsy

By combining electroencephalography (EEG) with functional magnetic resonance imaging (fMRI) it is possible to describe blood oxygenation level–dependent (BOLD) signal changes related to EEG patterns. This way, EEG‐pattern–associated networks of hemodynamic changes can be detected anywhere in the brain with good spatial resolution. This review summarizes EEG‐fMRI studies that have been performed in children with epilepsy. EEG‐fMRI studies in focal epilepsy (structural and nonlesional cases, benign epilepsy with centrotemporal spikes), generalized epilepsy (especially absence epilepsy), and epileptic encephalopathies (West syndrome, Lennox‐Gastaut syndrome, continuous spike and waves during slow sleep, and Dravet syndrome) are presented. Although EEG‐fMRI was applied mainly to localize the region presumably generating focal interictal discharges in focal epilepsies, EEG‐fMRI identified underlying networks in patients with generalized epilepsies and thereby contributed to a better understanding of these epilepsies. In epileptic encephalopathies a specific fingerprint of hemodynamic changes associated with the particular syndrome was detected. The value of the EEG‐fMRI technique for diagnosis and investigation of pathogenetic mechanisms of different forms of epilepsy is discussed.     

The Long-Term Prognosis of Minor Seizures in Childhood Epilepsy

The long–term clinical and electroence-phalographic follow-up studies were carried out for more than three to 13 years on 72 cases with minor seizures in childhood epilepsy at the Department of Pediatrics of Keio University from January 1963 to January 1973. Minor seizures were classified into typical absences, infantile spasms, Lennox syndrome, myoclonic seizures and atonic seizures. The results of each group were summarized as follows, but atonic seizures were excluded because there were too few cases of this group.

• 1 Some patients with typical absences were not preceded by other epileptic seizures, while some others had generalized tonic-clonic seizures, including febrile convulsions (mixed form by Fukuyama), prior to the onset of typical absences. Typical absences were not transformed into other epileptic seizures excluding generalized tonic-clonic seizures at follow-up. Twenty-one (84%) out of 25 cases with typical absences had ceased having seizures over one year at follow-up. Spontaneous, generalized spike and wave discharges including 3 c/s spike and wave complexes were recorded in about one half of all cases at the final interictal EEG recordings, but focal components were never seen. Mental retardation was very rare.
• 2 The attacks of infantile spasms had a tendency to disappear or be converted to variously other epileptic fits, excluding typical absences, with the development of age. EEG-findings were transformed into focal or Muse paroxysmal discharges and basic dysrhythmia from hyp-sarhythmia after many years, but classical 3 c/s spike and wave discharges were never seen. Moderately or severely mental retardation was found in most of these patients.
• 3 It was characteristic of Lennox syndrome that the improvements or successions of tonic seizures and atypical absences were repeated and diffuse slow spike and wave discharges were sustained in most of children during the periods of follow-up. Mental retardation was found in half of all cases.
• 4 Myoclonic seizures had ceased in most of children without transformations to other epileptic fits at follow-up, but some tendency toward relative dirsculty in control of clinical seizures was noted. Two thirds of these patients were of normal intelligence, while one third had retarded intelligence at follow-up.

Based on the above–mentioned results, the literatures concerning prognosis of various types of minor seizures in childhood epilepsy were studied.