Can epilepsy affect normal EEG variants? A comparative study between subjects with and without epilepsy

Objectives: To compare the prevalence of benign EEG variants (BEVs) between epileptic and non-epileptic subjects. Methods: A prospective, observational EEG study of 1,163 consecutive patients, using the 10–20 international system with systematically two additional anterior/inferior temporal electrodes. The video-EEG monitoring duration was between 24 h and eight days. Results: We identified 917 (78.9%) epileptic patients (mean age: 33.42 ± 15.5 years; females: 53.4%) and 246 (21.2%) non-epileptic patients (mean age: 35.6 ± 18.75 years; females: 54.9%). Despite a shorter mean duration of the EEG recordings, the prevalence of BEVs was higher in non-epileptic vs. epileptic patients (73.2% vs. 57.8%, p = 0.000011). This statistical difference was confirmed for lambda waves (23.6% in the non-epilepsy group vs. 14.8% in the epilepsy group, p = 0.001), POSTs (50.8% vs. 32.5%, p < 0.000001), wicket spikes (20.3% vs. 13.6%, p = 0.009) in particular in NREM and REM sleep, and 14- and 6-Hz positive bursts (13% vs. 7.1% p = 0.003). Mu rhythm was observed at the same frequency in both groups (21.1% in the non-epilepsy group vs. 22.7% in the epilepsy group). There was no difference between the two groups for rarer rhythms, such as rhythmic mid-temporal theta burst of drowsiness, small sharp spikes, and midline theta rhythm. Conclusions: There was no increase in any of the BEVs in the epilepsy group. On the contrary, BEVs were more frequent and diversified in the non-epilepsy group. Epilepsy may negatively affect the occurrence of the most common BEVs, with the exception of the mu rhythm, which is present in about one-fifth of the population with or without epilepsy

Stimulus-Induced Rhythmic or Periodic Intermittent Discharges (SIRPIDs) in patients with triphasic waves and Creutzfeldt-Jakob disease

Since the term Stimulus-Induced Rhythmic, Periodic, or Ictal Discharges (SIRPIDs) was introduced into the vocabulary of electrophysiologists/neurologists, there has been an ongoing debate about its significance, as well as its correlation with outcomes. SIRPIDs are frequently seen in patients who are critically ill from various causes. The literature reflects the findings of triphasic morphology, with the generalized periodic discharge (GPD) classification in many patients with SIRPIDs: toxic/metabolic encephalopathies, septic, and hypoxemic/hypercapnic encephalopathies, but also sharp periodic complexes in Creutzfeldt-Jakob disease and advanced Alzheimer's disease. In these settings, GPDs disappear when patients fall asleep and reappear when patients spontaneously wake up, or are awoken by an external stimulus, or sometimes because of a respiratory event, with the possibility of the appearance of GPDs with a cyclic alternating pattern. SIRPIDs may be seen as a transitional pattern between sleep and waking states, corresponding to a postarousal/awakening phenomenon. As SIRPIDs are a transient phenomenon and can usually be recorded repeatedly with each stimulation, the word “Ictal” could be replaced by “Intermittent”: Stimulus-Induced Rhythmic or Periodic Intermittent Discharges. However, considering that SIRPIDs may be “potentially ictal” or on an “ictal–interictal continuum“ in some situations, the “plus” modifier may be added: SIRPIDs-plus

Clinical factors of drug resistance in juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy is a comparatively benign form of idiopathic generalised epilepsy. Little is known about the prevalence of difficult to treat or drug resistant patients. Among 155 consecutive patients with newly diagnosed juvenile myoclonic epilepsy evaluated between 1981 and 1998 and followed up for at least 1 year (61men, 94 women; aged 15-70 years, mean 33 (SD 10.3); onset of juvenile myoclonic epilepsy at the age of 14.5 (SD 3.7), range 6-26; follow up 1-52 years, mean 13.5 (SD 9.9)), there were 15 pseudoresistant patients (9.7%: lack of compliance (eight), insufficient treatment (three), abnormal lifestyle (four)) and 24 patients (15.5%) who had persisting seizures despite adequate therapy and lifestyle. Clinical features associated with drug resistance were (1) the presence of psychiatric problems (58.3% v 19%; χ(2) p<0.001) and (2) independently, the combination of seizure types (Fischer's exact 2 by 4, p=0.0026). Three types were present in 62.5% of resistant patients versus 23.3% in non-resistant patients (χ(2), p=0.0001). None of the resistant patients had myoclonic jerks as the only seizure type or a combination of absences and myoclonic jerks. Family history of epilepsy, age at onset of seizures, sex, presence of photoparoxysmal response, results of conventional neuroimagings (CT and MRI), and delayed diagnosis were not significantly associated with drug resistance. There is thus a significant subgroup of patients with juvenile myoclonic epilepsy who pose difficult therapeutic problems, and the prevalence of resistant cases may be increased in the experience of a referral epilepsy centre.


Psychiatric comorbidity in temporal DNET and improvement after surgery

International audienceBACKGROUND:"Alien tissue" may be responsible for a higher frequency of psychiatric disorders in patients with temporal lobe epilepsy (TLE). Also, ganglioglioma and dysembryoplastic neuroepithelial tumors (DNET) could represent a risk-factor for the development of post-surgical psychoses. Classically, severe psychiatric disorders contra-indicate epilepsy surgery.OBJECTIVES:Assessment of inter-ictal psychiatric disorders in 10 consecutive patients with temporal DNET, before and after epilepsy surgery with a minimum of a 2-year follow-up evaluation.METHODS:DNETs were confirmed on histological examination. Psychiatric disorders were classified according to the DSM-IV-TR.RESULTS:Five patients presented inter-ictal psychiatric disorders with, according to the DSM-IV-TR, undifferentiated schizophrenia (one case), "borderline" personality (two cases), intermittent explosive disorder with slight mental retardation (one case), and personality disorders not otherwise specified but with some traits of dependent personality and with mythomania (one case). The condition of these five patients dramatically improved after surgery. No psychiatric behavior or "de novo" psychosis was observed after surgery in any of the patients.CONCLUSION:The prevalence of inter-ictal psychiatric disorders appears to be high in epileptic patients with a temporal lobe DNET primarily in relation to personality and behavioral problems with some degree of impulsivity and verbal aggressiveness. The improvements after surgery suggest that this therapy could be performed in these patients and severe psychiatric disorders do not contra-indicate this procedure

Prognostic factors in epilepsy with eyelid myoclonia (Jeavons syndrome)

Purpose: To describe the prognostic factors of drug resistance in 40 patients with epilepsy with eyelid myoclonia or Jeavons syndrome. Method: Retrospective analysis from two French tertiary centers. Results: Forty patients were enrolled (31 females and 9 males; mean age at epilepsy onset: 6.2 ± 3.4 years [range: 1–15 years]). Half of the patients (20/40) achieved at least a one-year remission from all seizure types. In the responders, seizure freedom was achieved after a mean 13.85 ± 13.43 years from the onset of epilepsy (range: 1–44). The presence of intellectual disability and an earlier onset of the disease (≤ 5 years) were the most powerful predictors of poor seizure control (P = 0.003 and P = 0.005, respectively). When considering the age of onset, patients with early-onset seizures (≤ 5 years) presented more frequently with intellectual disabilities, psychiatric comorbidities, absences, and a major risk of refractoriness (70% versus 30%, P = 0.01) than patients with onset after 5 years. At the last follow-up, 15 patients (37.5%) were taking a single drug, 16 (40%) were taking two, and seven (17.5%) were taking more than two. The most frequent drugs were valproate (23/40, 57.7%), followed by levetiracetam (16/40, 40%), and lamotrigine (14/40, 35%). Conclusion: Patients with Jeavons syndrome present a high rate of pharmaco-resistance with the need for long-term treatment. Early onset of epilepsy and the presence of intellectual disability appeared to be the most relevant predictors of poor seizure control, suggesting the use of genetic tests to individualize specific etiologies and perhaps adapt the therapeutic strategy