Northeast Regional Epilepsy Group Christos Lambrakis M D

Northeast Regional Epilepsy Group Christos Lambrakis M. D. 1

September 20 th, 2014 How is PNES Diagnosed with Video-EEG 2

PNES • Non-epileptic seizures are episodes that resemble epileptic seizures clinically but are not derived from electrical disturbances. 3

Psychogenic Non-epileptic Seizures • Resemble epileptic seizures but lack EEG correlate. • Very common (~25% of patients referred to Video-EEG monitoring for evaluation of intractable epilepsy). 4

Psychogenic Non-epileptic Seizures • Psychiatric manifestation – Somatoform/Conversion Disorder (most common) • Unconscious production of physical symptoms due to psychological factors – Factitious Disorder • Consciously determined symptoms driven by a powerful unconsciously determined need. – Malingering • Willful production of symptoms for a specific external incentive. 5

Psychogenic Non-epileptic Seizures • Often difficult to distinguish clinically from epileptic seizures. • Clues: – Resistance to AEDs – Emotional Triggers (stress) – Bilateral clonic movements without loss of consciousness – Absence of post-event confusion/lethargy. • Video-EEG is very helpful in diagnosis. 6

Electroencephalogram (EEG) 7

Electroencephalogram EEG • Represents a record of the small shifting brain electrical potentials from the surface of the brain recorded over the scalp. • As seizures are caused by a disturbance of electrical activity, the EEG is uniquely suited to further our understanding of a patients seizures.

Goals of Video-EEG Monitoring • Is it really an epileptic seizure? (Epilepsy vs. non-epileptic events) • What type of seizure is it? (Characterize epilepsy type) • Where does the seizure originate from? Is it focal? (i. e. does it come from one specific region? )

Electrodes 10

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Inpatient Video-EEG 14

Outpatient Ambulatory Video. EEG 15

Routine EEG • Short duration (<1 hour) • Low sensitivity. Events are seldom recorded. • Presence of inter-ictal baseline epileptogenic abnormalities does not confirm or exclude either diagnosis. – Patient with inter-ictal epileptogenic abnormalities can still have PNES. – Patient with normal inter-ictal EEG can still have epilepsy. 16

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Video-EEG Monitoring • Long term inpatient monitoring allows for recording of seizure events. • Clinical and electroencephalographic features can be reviewed aiding in seizure characterization and localization. • Baseline EEG may be helpful in determining risk of future seizures.

Video-EEG Monitoring • Gold standard for differentiating PNES from ES. • Recommended for patients with recurrent episodes despite multiple medication trials. • Goal is to record typical event and document lack of EEG correlate. 20

Video-EEG Monitoring • Video component can be helpful in documenting movements or behaviors typically incompatible with ES. • Important in verifying that event recorded is representative of events which prompted medical attention. – ** ~20% of patients with PNES also have ES. 21

Psychogenic Non-epileptic Seizures • Many clinical patterns: – Migratory motor activity (most common) – Generalized motor activity – Unilateral (less common) – Alteration of awareness (Common) ** Can be difficult to distinguish from frontal lobe seizures. 22

Non-epileptic Seizures • EEG during PNES can be difficult to interpret. • Movements during an PNES event cause rhythmic artifacts on EEG that look very similar to epileptic seizure activity. • Some epileptic seizures (partial) can be electrically silent on EEG and can be misdiagnosed as PNES. 23

EEG (Seizure) 24

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Non-epileptic Seizures • Analysis of the clinical semiology of the episodes thru video can be helpful in differentiation between PNES and ES. – ** Definitive diagnosis should not rest solely on clinical observation. Certain types of epileptic seizures (frontal and temporal) can look very similar to a PNES event. 26

Psychogenic Non-epileptic Seizures • Characteristics of PNES – Variable responsiveness or preserved awareness. – Out of phase movements of extremities. – Discontinuous motor activity – Pelvic thrusting. – Side to side head movements. – Eye closure/eye flutter 27

Psychogenic Non-epileptic Seizures • Characteristics of PNES – Varied character of events – Suggestibility – Emotional triggers – Prompt recovery (Absence of post-ictal state) – Poor response to anti-epileptic medications 28

Video-EEG Monitoring Limitations • Event may not occur (consider home ambulatory Video-EEG). • Missed PNES diagnosis (EEG over interpreted as ES due to rhythmic artifact). • Incorrect PNES diagnosis (Partial ES may not display electrical abnormalities). 29

Psychogenic Non-epileptic Seizures • ~20 % of patients with PNES will also have coexistent epileptic seizures. • Latency between manifestation of PNES and diagnosis is ~ 7 years. • Prompt diagnosis is crucial to avoid iatrogenic morbidity (Exposure to unnecessary medication ~80%, Intubation ~50%). 30