Diagnostic issues and treatment of cryptogenic or symptomatic generalized epilepsies

Brainstem dysfunction in patients with late-onset Lennox-Gastaut syndrome: Voxel-based morphometry and tract-based spatial statistics study

Background:

There have been a few reports of patients who developed Lennox–Gastaut syndrome (LGS) in the second decades of their life.

Objectives:

The aim of this study was to investigate electroclinical presentation in patients with late-onset LGS. In addition, we evaluated structural abnormalities of the brain, which may give some clue about the common pathogenic pathway in LGS.

Materials and Methods:

We enrolled the patients with late-onset LGS. We collected electroclinical characteristics of the patients and evaluated structural abnormalities using voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) analysis.

Results:

The three subjects were diagnosed with late-onset LGS. The patients have no mental retardation and normal background activities on electroencephalography (EEG), and they had generalized paroxysmal fast activities on EEG, especially during sleep. The TBSS analysis revealed that fractional anisotropy values in the patients were significantly reduced in the white matter of brainstem compared with normal controls. However, VBM analysis did not show any significant difference between the patients and normal controls.

Conclusions:

Patients with late-onset LGS have different clinical and EEG characteristics from those with early-onset LGS. In addition, we demonstrated that brainstem dysfunction might contribute to the pathogenesis of late-onset LGS.

Worsening of Seizures After Asparagine Supplementation in a Child with Asparagine Synthetase Deficiency

OBJECTIVE

Asparagine synthetase deficiency is an autosomal recessive neurometabolic disorder characterized clinically by severe congenital microcephaly, global developmental delay, intractable epilepsy, and motor impairment in the form of spastic quadriparesis. Diagnosis is confirmed by findings of low cerebral spinal fluid or plasma asparagine in addition to a mutation of the subsequently in ASNS gene. There is no documented trial of asparagine as a treatment for this disorder.

PATIENT DESCRIPTION

We present a child with asparagine synthetase deficiency whose mental status improved slightly from a vegetative state to a minimally conscious state after starting asparagine supplementation. He subsequently became irritable, developed sleep disturbance, and experienced worsening seizures, requiring discontinuation of the asparagine supplements.

CONCLUSIONS

Asparagine supplementation may be not effective in controlling the seizures in asparagine synthetase deficiency, and it is likely to make them worse.

An atypical case of Lennox-Gastaut syndrome not associated with mental retardation: a nosological issue

The characteristic electroclinical features of Lennox-Gastaut syndrome (LGS) have been extensively reported, but the influence of the constellation of slow spike-and-wave (SSW) complexes with multiple seizure types (including atypical absence seizures [AAS] and tonic seizures [TS]) on patients with this syndrome is still unclear. We report the case of a 28-year-old woman who developed AAS and brief asymmetric TS at the age of 14 years. Her seizure disorder met diagnostic criteria for LGS (SSW on electroencephalogram and multiple seizure types), but there was no intellectual impairment and an interictal alpha EEG. Even 14 years after the onset of her epilepsy, she maintained fairly normal cognitive function, although she was bothered by frequent brief and subtle episodes of AAS and TS.