About epilepsy no specific seizure type

About epilepsy, no specific seizure type has been identified because GLUT1-DS is associated with a wide range of epilepsies: patients develop seizures in infancy and early childhood, which are, frequently, do not respond to anticonvulsant medication. In infants, seizures are described as brief, subtle myoclonic limb jerking with staring alternating with eye-rolling, a sudden onset of pallor, a dazed expression, or horizontal roving eye movements, unresponsiveness, and hypotonic as well as head bobbing. Later in childhood, seizures often appear to be myoclonic and generalized. Surprisingly, familial GLUT1 deficiency has recently been associated with IGE, especially EOAE.25, 30, 31, 32, 33; IGE syndromes associated with GLUT1-DS are usually, but not always, drug responsive and individual cases may be phenotypically indistinguishable from common forms of IGE. In particular, a recent family study has shown that of 15 subjects with SLC2A1 mutation, epilepsy occurred in 12; epilepsy phenotypes varied widely, including IGE with absence, myoclonic-astatic epilepsy (MAE) and focal epilepsy; furthermore, PED occurred in just under half of the family members and in 1 individual PED was present without seizures. GLUT1-deficiency, then, should be suspected where the family history suggests a bms-536924 inheritance of IGE or PED, especially where PED and IGE coexist in the same family. Previously, the same authors found that GLUT1-deficiency, due to SLC2A1 mutations, accounts for over 10% of EOAE, beginning before 4 years of age; these patients presented milder phenotypes of GLUT1 deficiency because they had normal development before seizures onset, good AED seizure control, and intellectual outcome range from normal to moderately impaired. Thus, in these patients, the seizure phenotype could not be readily distinguished from CAE, except for the earlier age of onset. More recently, Perez et al reported a child with short absences (less than 3 s) and occasional myoclonias; seizures started between 3 and 6 months of age; he was first diagnosed with an IGE. Then, the early onset of seizures and later recognized episodes of mild confusion before meals with persistent atypical EEG features (2–4 Hz discharges more polymorphic and irregular than the classical 3 Hz spike-waves) and unexpected learning difficulties led to the diagnosis of GLUT1-DS; furthermore, seizure control was obtained with KD. Probably, GLUT1 deficiency may underline a significant proportion of EOAE, in particular those with atypical features. Although seizures have been considered to be a characteristic component of the clinical features in GLUT1-DS, same patients show prominent movement disorders other than epilepsy11, 27, 35; In fact, a minority of cases of patients with movement disorder (ataxia, choreoathetosis, dystonia, paroxysmal events, PED) with a developmental delay, but without epilepsy, has been identified.1, 22, 23, 33, 34, 35, 36, 37, 38 Interestingly, Suls et al. screened four PED families with or without epilepsy and detected novel SLC2A1/GLUT1 mutations in all of them: these data indicates that both PED without epilepsy and co-occurrence of PED with epilepsy can be caused by mutations in SLC2A1, which encodes GLUT1. Then, epilepsy and movement disorders can occur either separately or in combination. Therefore, this variable association of epilepsy and movement disorders works in both directions; severe motor disorders with dyskinesia, ataxia, and spasticity associated with intellectual disability can occur without seizures (Fig. 1). Clinical severity varies from mild motor and cognitive dysfunction between epileptic attacks to severe neurological disability, with some patients never achieving language or unsupported walking. In fact, classic GLUT1-DS is not necessarily severe but there are also mild and moderate classical phenotypes. Acquired microcephaly is present in the majority of severely affected patients; GLUT1 encephalopathy lies at the severe end of the GLUT1 phenotypic spectrum. MAE, particularly with prominent absence seizures and absence status, is the next most severe phenotype. At the mild end of the spectrum, GLUT1 deficiency causes classic IGE phenotypes, EOAE and PED with or without epilepsy.