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Summary:Purpose: To investigate neuronal dysfunction in the thalami of patients with juvenile myoclonic epilepsy (JME) by using proton magnetic resonance spectroscopy (MRS).Methods: We performed single-voxel proton MRS over the right and the left thalami of 10 consecutive patients (five women) with JME (mean age, 31.6 years) and 10 age-matched healthy volunteers (five men). All patients had seizure onset in late childhood-teenage, normal neurologic examination, typical EEG of JME, and normal high-resolution MR imaging (MRI). We determined ratios of N-acetylaspartate (NAA) over creatinephosphocreatine (Cr). Values <2 standard deviations from controls were considered abnormal. We performed analysis of variance to evaluate group differences.Results: Group analysis showed that thalami NAA/Cr ratios were significantly decreased in JME patients (left side, 1.58 ± 0.26; right side, 1.5 ± 0.15) as compared with controls (left side, 1.98 ± 0.18; right side, 1.88 ± 0.15; p = 0.001 and p = 0.007, respectively). Individual analysis showed that nine of the 10 patients had abnormal NAA/Cr in at least one of the thalami.Conclusions: This study shows evidence of neuronal dysfunction in the thalami of patients with JME, which may have relevance for the mechanisms of seizure generation in this form of generalized epilepsy.

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Summary:Purpose: To investigate the EEG profile and its contribution for diagnosis and management in a group of patients with a clinical diagnosis of idiopathic generalized epilepsy (IGE) who were referred to a tertiary hospital.Methods: We retrospectively studied clinical and EEG features of 180 consecutive patients with IGE. Eighty patients were diagnosed with juvenile myoclonic epilepsy (JME), 35 had absence epilepsy (AE), 13 had generalized tonic-clonic seizures on awakening (GTCS-A), 28 had generalized tonicclonic seizures only (TCS), and 24 had adult-onset idiopathic generalized epilepsy (AIGE). The EEGs were classified in typical (synchronous generalized spike or polyspikes-and-wave discharges with normal background), atypical (with clear focalities or asymmetries), and normal.Results: The 493 EEG exams were analyzed. The first EEG was normal in 45% of the 180 patients, and only 33% had typical abnormalities. AE had a higher proportion of typical examinations and needed fewer sequential examinations to register a typical abnormality compared with the other groups. By contrast, the serial EEG profile of TCS and AIGE showed a higher proportion of normal and atypical EEG findings.Conclusions: These findings support previous recommendations that IGE patients should be treated with appropriate therapy based on clinical history. Waiting for a typical abnormal EEG pattern can generate an unacceptable delay in the correct diagnosis and treatment of these patients. In patients with longterm epilepsy, the diagnosis may be difficult. Furthermore, serial EEGs can help to elucidate the syndromic diagnosis, especially in patients with TCS and AIGE.

Twenty-four percent of patients with idiopathic generalized epilepsies had MRI abnormalities. However, the majority of these abnormalities were nonspecific.