Differentiating psychogenic nonepileptic seizures from epileptic seizures: An observational study of patients undergoing video-electroencephalography (VEEG) in Australia

Video-electroencephalography (VEEG) is an invaluable tool for the differentiation of psychogenic nonepileptic seizures (PNES) from epileptic seizures (ES). This paper (i) evaluates the demographics of patients undergoing VEEGs at the Princess Alexandra Hospital from July 1 2017 to July 1 2019 and identifies those subsequently diagnosed with PNES, (ii) determines the delay in PNES diagnosis and proportion of PNES patients on antiepileptic drugs (AEDs) prior to a VEEG, and (iii) determines the proportion of PNES patients who subsequently ceased their AEDs. Of the 94 patients in the study group, 51 were female and 43 were male. In total, 22 (23%) of VEEGs were consistent with epilepsy (ES), 25 (26%), with PNES, 5 (5%) mixed (PNES and ES), 5 (5%) with other types of events, and 37 were nondiagnostic. Two patients with non-diagnostic VEEGs were subsequently treated as PNES at the treating clinician's discretion. Regarding AEDs, 62 of the patients were on at least one agent at the time of VEEG recording. The mean durations of AED therapy and diagnostic delay for patients subsequently diagnosed with PNES were six years and seven years, respectively. Of these, the majority had their AEDs subsequently weaned/ceased. This study highlights the value of VEEG in diagnostic differentiation of epileptic from nonepileptic events, thereby preventing unnecessary AED therapy for patients with PNES. The results are consistent with previous studies in the literature evaluating VEEG clinical outcomes.

Focal EEG abnormalities and focal ictal semiology in generalized epilepsy

In clinical practice, the diagnosis of focal vs generalized epilepsy dictates the management of the patient. The distinction between generalized and focal epilepsy is at times imperfect and some epilepsies have features that fall in between these two extremes. An example is the occurrence of focal interictal and focal ictal abnormalities in generalized epilepsies. As a part of the special issue on "The epileptogenic zone in pediatric epilepsy surgery", this focused narrative review will discuss different focal abnormalities seen in generalized epilepsy. An overlap of focal and generalized epileptiform abnormalities may support a continuum between focal and generalized epilepsy. When evaluating patients in the "gray zone", other factors such as ictal semiology, neuroimaging, genetic testing and functional deficits may need to be considered to reach an accurate diagnosis. Being aware of possible occurrence of focal clinical and EEG features in generalized epilepsy will help clinicians select more preferred AED (s), avoiding potential iatrogenic side effects and inappropriate consideration for epilepsy surgery.

Epileptic Negative Myoclonus as the First and Only Symptom in a Challenging Diagnosis of Benign Epilepsy With Centrotemporal Spikes

OBJECTIVE

To investigate the clinical and neurophysiological characteristics of epileptic negative myoclonus as the first and only ictal symptom of benign epilepsy with centrotemporal spikes.

METHODS

Electrophysiological evaluations included polygraphic recordings with simultaneous video electroencephalogram monitoring and tests performed with patient's upper limb outstretched in standing posture. Epileptic negative myoclonus manifestations, electrophysiological features, and responses to antiepileptic drugs were analyzed.

RESULTS

The authors report 2 patients with benign epilepsy with centrotemporal spikes, who had epileptic negative myoclonus as the first and only seizure type. Video electroencephalogram monitoring results showed that their negative myoclonus seizures were emanating from the contralateral central and the parietal regions. Epileptic negative myoclonus was controlled by administration of valproate and levetiracetam.

CONCLUSION

Epileptic negative myoclonus can be the first and only seizure type of benign epilepsy with centrotemporal spikes, and long-term follow-up monitoring should be the care for the recurrence and/or presence of other types of seizures.

Controllable yawning expressed as focal seizures of frontal lobe epilepsy

Excessive yawning was described in some neurological conditions as part of periictal or ictal manifestations of epilepsy, most commonly temporal lobe. We present the first case of controllable yawning as a primary seizure semiology with dominant frontal lobe involvement in a 20-year-old man. Video electroencephalography recorded 8 yawning episodes accompanied with right arm movement correlating with rhythmic diffuse theta range activity with left hemispheric predominance. Magnetoencephalography coherence source imaging was consistent with persistent neuronal networks with areas of high coherence reliably present over the left lateral orbitofrontal region. Epileptogenic areas may have widespread networks involving the dominant frontal lobe in unique symptomatogenic areas.

Diagnosis of probable psychogenic nonepileptic seizures in the outpatient clinic: does gender matter?

Psychogenic nonepileptic seizures (PNESs) are paroxysmal events of altered behavior that outwardly resemble epilepsy but are caused by psychiatric disease. The diagnosis of probable PNESs can be made in the outpatient clinic prior to video-EEG monitoring by identification of specific PNES predictors and specific elements of seizure semiology from the clinical history. Since psychiatric disease may have distinct mechanisms between women and men, the objective of this study was to determine if gender-specific differences exist in PNES predictors and PNES semiology. Such differences could be used to optimize the accuracy of outpatient diagnosis of probable PNESs. Medical records of male and female patients with video-EEG diagnosis of definite PNESs were retrospectively reviewed for occurrence of PNES predictors. In addition, PNES semiology was analyzed de novo from video-EEG records and categorized into previously established semiology clusters. Eighty-six patients were included in the analysis (59 women and 27 men). We found significantly lower rates of reported physical and sexual abuse, lower rates of previous psychiatric diagnosis, and lower rates of chronic pain in male patients with no significant differences in rates of other PNES predictors. Furthermore, we found no difference in PNES semiology between men and women, with both groups experiencing similar rates of major motor, minor motor, and nonmotor semiology. In conclusion, our results lend support to the idea that distinct risk factor criteria but similar semiology criteria should be used for the diagnosis of probable PNESs in the outpatient clinic in men and women.