Sequential Prefrontal Lobe Volume Changes in Epileptic Patients with Continuous Spikes and Waves During Slow Sleep

Epilepsy with continuous spikes and waves during slow sleep (CSWS), which is one of the prototypes of electrical status epilepticus during slow wave sleep (ESES), is a rare disease that affects children and is associated with deterioration of one or more cognitive functions, behavioral disturbances, spike and spike-wave discharges increased during slow wave sleep, and epileptic seizures. The pattern of deficits characteristic of ESES occurs mainly in the first decade of life. Almost all CSWS patients present with seizures (Smith & Poley, 2008). Seizures are typically nocturnal, partial motor or generalized convulsions (Tassinari et al., 2005). Although the most prominent feature of epilepsy is seizure, the condition may also involve mental health problems, including hyperactivity, inattention, learning disabilities, other disease-related quality of life impairments, and psychopathology (Noeker et al., 2005). Nearly all investigators have reported a high prevalence of behavioral problems in children with epilepsy. Electroencephalographic monitoring can detect subclinical spike frequency, which may affect attention and other aspects of cognitive functioning in various ways, even in the absence of clinical seizures. Although any attempt to equate epileptiform activity with epilepsy is generally discouraged, the occurrence of a paroxysmal change in cerebral electrical activity simultaneously accompanied by cognitive impairment meets generally accepted definitions of an epileptic seizure. Neuropsychological impairment occurs in almost all cases of CSWS, usually being coincidental with the detection of ESES and representing one of the crucial signs of the syndrome (Tassinari et al., 2005). CSWS is characterized by an impairment of neuropsychological abilities, frequently associated with behavioral disorders (reduced attention span, hyperkinesis, aggressiveness and difficulty interacting with the environment), hyperactivity, learning disabilities and, in some instances, psychotic regressions. These manifestations strongly correlate with frontal lobe dysfunction (Jasper et al., 1995; Fuster, 1997). These mental and behavioral disorders can persist even after CSWS has ceased. Their severity and persistence seem to be correlated with the duration and severity of ESES (Billard et al., 1990; De Negri, 1994). The goal of evaluation and treatment of CSWS must not necessarily be a seizure-free state, but improvements in seizure control, alertness, mood and behavior. We have already studied and reported prefrontal lobe volumes in a patient with CSWS using three-dimensional (3D) magnetic resonance imaging (MRI) (Kanemura et al., 2009). However, the data cannot be