LkS was first reported in 1951 as an acquired aphasic syndrome with seizures. Children with LKS can present with multiple subtypes of generalized and/or partial seizures and their seizure frequency varies. And the results of medical treatment with the application of different drugs have been disappointing. In 1995, Morrell et al. reported a group of LKS patients treated with a new procedure, multiple subpial transection (MST), which is based on the theory that the subcortical nerve conduction fibers are selectively cut in a tangential direction with minimal damage to the radially aligned neural functional units. The result of this treatment is the removal of the nerves that have been damaged. The result of this treatment is the removal of epileptic firing areas from the treated cortex while maximizing the preservation of normal electrophysiological activity in the cortex. In the context of epilepsy surgery, the main goal of MST treatment in LKS patients is to improve the speech function of the child. However, few research centers have been able to produce enough cases to make firm conclusions. The bulk of case reports come from Chicago, where the criteria for considering the need for surgical treatment include (a) a history of acquired aphasia, including auditory verbal dysfunction. (b) Severe epileptiform EEG abnormalities with bilateral spike-wave discharges during slow-wave sleep. (c) Neuropsychological testing showed no verbal memory function. (d) Asymmetric bilateral epileptiform discharges on neurophysiological examination. Methods to determine the above four criteria also include the mechohexital suppression test and magnetoencephalography (MEG). the MEG examination localizes interictal spike-wave discharges around and behind the lateral fissure, but this alteration is bilateral in most patients with LKS. The Chicago case also showed significant improvements in receptive and expressive speech in 14 patients treated with MST. Patients who had long-standing preoperative speech dysfunction were less likely to achieve significant postoperative improvement. A series of tests showed that the children did not achieve significant improvement in speech for at least 6 months after surgery. As the authors acknowledge, the lack of controlled studies makes it difficult to distinguish the effects of surgery from the natural course of the disease. Although there are a few other case reports, much work remains to be done before the application of the MST approach to LKS can be extended. Hypothalamic hamartoma and gelastic epilepsy Hypothalamic hamartoma is sometimes detected on cranial MRI in a subset of children presenting with demented laughter seizures. This rare condition is typical in children before the age of 10 years, but has also been reported in newborns. Accompanying symptoms include precocious puberty, severe behavioral abnormalities and cognitive impairment. Initial surgical treatment is based on significant abnormalities in cortical EEG, particularly in the temporal lobe. Unfortunately, the removal of these cortical EEG abnormalities invariably did not result in satisfactory control of the epilepsy. SPECT examinations during seizures and deep EEG monitoring of the hypothalamus recorded localized spike-wave lesions confirming that the epileptic foci may be located in the subcortical gray matter structures. Subsequently, different surgical approaches have been applied to resect lesions within this relatively complex region, with widely varying surgical outcomes, among the various groups. Some recent surgical treatment reports advocate the application of microsurgical techniques and frameless stereotactic systems to reach the third ventricular lesion area using a transcallosal-interdome approach to remove the tumor. In all five patients, the tumor was completely or subtotally resected (more than 95%), and there were no long-term neurological or endocrine complications. Postoperatively, seizures disappeared in three cases and were significantly reduced in the other two patients. In addition, postoperative evaluations demonstrated significant improvements in patient behavior and overall quality of life. In addition to craniotomy, local radiotherapy and gamma knife treatment are also effective. In a multicenter study, 10 children with hypothalamic malformation tumors with severe seizures, with a mean age of 13 years, were treated with radiotherapy or gamma knife. Six of the patients who received higher doses of irradiation had complete disappearance of seizures or only a very small number of seizures. No significant side effects occurred, but the follow-up period was relatively short, only 2 years. Rasmussen encephalitis RE is a syndrome characterized by refractory partial seizures (especially partial seizure persistence), progressive hemiparesis, and inflammatory changes in one side of the cerebral cortex. Immunological evidence for this disorder includes the presence of autoimmune antibodies to glutamate receptors in serum and cerebrospinal fluid and increased IgG-dependent complement activity in brain tissue. Pharmacological treatment to suppress the inflammatory response can only reduce the frequency of attacks for a short period of time. The largest group of surgical treatment of RE cases has been reported, with 27 patients. The indications for surgical treatment are: a clear diagnosis of RE; worsening disease; exclusion of other diagnoses of disease; MRI reveals progressive unilateral hemispheric atrophy; PET and SPECT frequently reveal areas of hypometabolism that extend beyond the MRI changes. In this disease, local excision or biopsy is not necessary, and drug refractoriness is not a prerequisite for surgical options. After hemispherectomy, 89% of patients have complete disappearance of epilepsy or only very few seizures. The authors suggested that the outcome would also improve if the midline structures and the residual gray matter near the insula were carefully removed. Many children underwent surgery when they had only mild hemiparesis early in the disease, and although they were able to walk after surgery, hemianopia and varying degrees of hemiparesis were still unavoidable outcomes of this surgery. In this group of cases, the general health of the children did not deteriorate after surgery, and the main concern was the severe speech impairment that could result from hemispherectomy if RE invaded the dominant hemisphere. This aspect will be discussed in the neuropsychological section. Early infantile epileptic encephalopathy (EIEE; Ohtahara syndrome) EIEE is a rare and catastrophic epileptic syndrome. It is characterized by frequent tonic seizures in infancy and continuous alternating waveforms of eruption and suppression on the EEG. Most cases have cortical developmental and metabolic abnormalities. The long-term prognosis of this disorder is poor, with most children having severe neurodevelopmental delays and most evolving into infantile spasms (IS) and/or Lennox-Gastaut syndrome. Similar to IS, a distinctive feature of EIEE is that it is mostly associated with localized pathological abnormalities, such as localized cortical developmental abnormalities. Some cases have reported a reduction in seizures and a short period of psychobehavioral improvement after removal of the localized lesion.