*7.3.3 Ictal EEG*

EEG pattern associated with typical seizures of LGS are:


## **7.4 Etiology**

LGS is classified as genetic, structural or metabolic, or unknown. Approximately 70% of children with LGS have symptomatic. The underlying etiologies include a history of encephalitis, meningitis, tuberous sclerosis, brain malformations (e.g., cortical dysplasias), birth asphyxia, and trauma. LGS may also follow the diagnosis of West syndrome [23]. If unknown, then it can be either idiopathic or cryptogenic. Idiopathic refers to unknown etiology with the underlying cause being suspected as genetic; in contrast to cryptogenic, the underlying cause is also not known but is presumed to be structural or metabolic. The causative role of mutations in other genes (such as GABRB3, ALG13, SCN8A, STXBP1, DNM1, FOXG1, or CHD2) has been elucidated in recent exome studies or in case reports in patients with LGS without a history of infantile spasms [85].

### **7.5 Treatment and prognosis**

The long-term prognosis varies and has not improved using new AED as compared with earlier prescribed drugs [86].

Valproate is a first-choice drug, which has an effect in multiple seizure types including drop attacks; useful combinations are with clobazam, ethosuximide, lamotrigine, levetiracetam, topiramate, zonisamide, and rufinamide. We should avoid too many drugs as well as carbamazepine, oxcarbazepine, and vigabatrin, which may deteriorate some types of seizures. Felbamate carries the risk of aplastic anemia and hepatic failure and is used in exceptional cases [17].

Alternative treatment options for LGS include ketogenic diet, vagal nerve stimulation (VNS) or thalamic electrical stimulation, and corpus callosotomy (CC) [87]. VNS and CC showed more than 50% reduction in seizure frequency in patients with LGS. A study showed that CC may be more beneficial than VNS only in "drop

**95**

*Epileptic Encephalopathies in Infants and Children DOI: http://dx.doi.org/10.5772/intechopen.85378*

between the two procedures [88].

**8.2 Seizures: symptoms and semiology**

proposed: [11].

during sleeping

sudden falls

myoclonus) [11].

ESES syndrome is manifest with epilepsy and encephalopathy:

1.Epilepsy onset can fluctuate from 2 to 12 years, with a peak at about 4–5 years, and can appear before the identification of ESES pattern. Mostly, seizures are present during ESES, but in others there is no history of clinical seizures at any time. Semiology and frequency of seizures can vary; the presence of TS during sleeping excludes this diagnosis. Three groups of seizures type have been

• Motor seizures, rare and nocturnal during the evolution of the syndrome • Unilateral partial motor seizures or secondary TCGS, principally occurring

• Rare nocturnal seizures in which AA develops during the course of ESES, often associated with negative myoclonus or atonic components leading to

2.Encephalopathy manifests at the beginning or the worsening of neuropsychological troubles, which include global cognitive regression and various degrees of language impairment (acquired aphasia), behavioral disorders (hyperactivity, attention deficits, and disturbances of personality), and deterioration of motor skills (dystonia, dyspraxia, ataxia, and negative

due to seizures and falls.

**(ESES)**

**8.1 Overview**

attack" seizures [87], while another study did not show any significant difference

Prognosis is typically poor with children having seizures into adulthood and 75–95% with intellectual disability and behavioral and psychiatric disorders [82]. The risk of death is increased, compared with their peers of the same age, usually

**8. Encephalopathy with electrical status epilepticus during slow sleep** 

The term "electrical status epilepticus during sleeping" which was first described by Tassinari [1] refers to the EEG pattern (continuous spike-wave complexes exclusively during non-rapid eye movement (NREM) sleep), with a spike-wave index accounting for at least 80–85% of slow sleep. Other concept, "continuous spikes and waves during sleeping" (CSWS) are considered synonymous of ESES, but indicates both, EEG features and clinical neuropsychological characteristics, of this EE [89, 90]. Encephalopathy with ESES is an EE characterized by seizures of various types and neurological deterioration in cognitive, motor, and behavioral areas. The encephalopathy is caused by a prominent activation of epileptic abnormalities during NREM sleep [11]. Anti-seizure drugs, immune modulatory agents, and surgery [91] have been used to treat conditions associated with ESES. In spite of the long-term favorable outcome of epilepsy and ESES, the prognosis is protected because of the persistence of severe cognitive and behavioral disturbances in about a half of the patients.

### *Epileptic Encephalopathies in Infants and Children DOI: http://dx.doi.org/10.5772/intechopen.85378*

attack" seizures [87], while another study did not show any significant difference between the two procedures [88].

Prognosis is typically poor with children having seizures into adulthood and 75–95% with intellectual disability and behavioral and psychiatric disorders [82]. The risk of death is increased, compared with their peers of the same age, usually due to seizures and falls.
