Overview
Definition:
Psychogenic nonepileptic events (PNES), now often termed functional neurological symptoms or dissociative seizures, are paroxysmal episodes that resemble epileptic seizures but do not have the characteristic underlying epileptic brain activity
In adolescents, these events are frequently triggered by psychological stress, trauma, or emotional dysregulation.
Epidemiology:
PNES account for approximately 10-20% of patients referred to specialized epilepsy centers
The prevalence in the adolescent population is not precisely known but is considered significant
They are more common in females than males, with a reported ratio of up to 3:1 in some studies
Onset typically occurs during adolescence or young adulthood.
Clinical Significance:
Accurate diagnosis and management of PNES are crucial in adolescents to prevent misdiagnosis of epilepsy, unnecessary and potentially harmful antiepileptic drug (AED) treatment, and the significant psychosocial morbidity associated with prolonged diagnostic uncertainty and untreated underlying conditions
Early and appropriate intervention can lead to improved quality of life and functional recovery.
Clinical Presentation
Symptoms:
Events can be highly variable and often mimic epileptic seizures
Common presentations include: convulsive-like movements with asynchronous thrashing, sustained dystonic posturing, side-to-side head turning, eye closure, vocalizations, amnesia for events, and absence of postictal confusion or prolonged sleep
Episodes may be triggered by witnessed trauma or stress
Significant emotional distress is often present before, during, or after events
Episodes are typically of longer duration than epileptic seizures.
Signs:
During an event, findings may include: asynchronous limb movements, opisthotonos, tongue biting (often lateral, not midline), incontinence (less common than in epilepsy, and may occur during non-convulsive events), preserved consciousness or fluctuating consciousness, intact pupillary responses, and absence of epilepticiform EEG activity during an event
Respiration may be irregular, with gasping or hyperventilation
There may be resistance to passive eye opening.
Diagnostic Criteria:
Diagnosis of PNES is primarily clinical, supported by objective evidence
Key features supporting PNES include: (1) characteristic semiology that differs from typical epileptic seizures, (2) documented events that are normal on video-EEG monitoring, and (3) exclusion of other causes
There are no formal diagnostic criteria for PNES itself, but rather a framework for establishing it based on clinical observation and investigation
Diagnosis is confirmed when events are captured on video-EEG monitoring and show no epileptiform discharges correlated with the semiology.
Diagnostic Approach
History Taking:
A detailed history is paramount
Inquire about: the exact nature and duration of events, triggers (stressors, trauma), frequency, time of day, associated symptoms (e.g., headache, fatigue, dizziness), presence of amnesia, what happens after an event (confusion, sleepiness), any prior diagnosis of epilepsy, previous AED use and response, and psychosocial stressors (family, school, peer relationships)
Red flags for epilepsy include: nocturnal seizures, postictal confusion, tongue biting (midline), and a history of febrile seizures
Red flags for PNES include: asynchronous movements, sustained dystonic posturing, prolonged duration, eye closure, vocalizations, and clear triggers.
Physical Examination:
A comprehensive neurological examination should be performed to rule out organic neurological deficits
Look for signs of underlying neurological disorders
Assess for subtle neurological signs or symptoms that might point to an epileptic etiology
A psychiatric assessment focusing on mood, anxiety, trauma history, and coping mechanisms is also essential.
Investigations:
The cornerstone of diagnosis is simultaneous video-electroencephalography (video-EEG) monitoring
Events must be captured on video and correlated with EEG findings
Absence of epileptiform discharges during a clinical event is diagnostic for PNES
Routine EEG may be normal or show non-specific abnormalities
Neuroimaging (MRI brain) is performed to rule out structural brain lesions that could cause seizures
Blood tests (CBC, electrolytes, glucose, renal and liver function) are done to exclude metabolic or toxic causes of altered consciousness or seizures
Psychiatric evaluations and psychological testing may be used to assess for comorbid mental health conditions.
Differential Diagnosis:
The primary differential diagnosis is epilepsy
Other conditions to consider include: syncope (vasovagal, cardiac), transient ischemic attacks (TIAs), movement disorders (e.g., tic disorders, myoclonus), sleep disorders (e.g., parasomnias), factitious disorder, malingering, and other functional neurological symptoms
Differentiating PNES from epilepsy requires careful observation of clinical semiology and EEG correlation
PNES events often have a more waxing and waning course and may show responsiveness to external stimuli or suggestion, which is uncharacteristic of epileptic seizures.
Management
Initial Management:
The immediate goal is to ensure patient safety during events and to avoid harm from unnecessary interventions
If PNES is strongly suspected, avoid aggressive seizure management techniques like benzodiazepines unless a concurrent epileptic seizure is highly likely
A careful and empathetic approach is crucial, acknowledging the reality of the patient's experiences while gently guiding towards a diagnosis.
Medical Management:
Pharmacological management of PNES is not indicated as there is no underlying epileptic abnormality
If AEDs have been prescribed, they should be gradually tapered off under careful medical supervision once the diagnosis is confirmed
Treatment is focused on addressing comorbid psychiatric conditions such as depression, anxiety disorders, and post-traumatic stress disorder (PTSD) with appropriate psychotropic medications as indicated.
Psychosocial Management:
This is the mainstay of PNES treatment
Cognitive Behavioral Therapy (CBT) is highly effective, focusing on identifying triggers, developing coping strategies, managing stress, and improving emotional regulation
Psychodynamic psychotherapy or trauma-informed therapy may be beneficial for patients with a history of trauma
Education about PNES and its functional nature is important for the patient and family
Rehabilitation programs focusing on return to school and social activities can also be helpful.
Supportive Care:
Ongoing psychological support and monitoring are essential
Encourage participation in school and social activities as tolerated
Family involvement and support are critical for successful outcomes
Regular follow-up appointments with the multidisciplinary team (neurologist, psychiatrist, psychologist) are necessary to monitor progress and adjust management strategies.
Complications
Early Complications:
Physical injury from events (e.g., falls, bruises), social isolation due to frequent absences from school or activities, anxiety related to misdiagnosis, and adverse effects from unnecessary AEDs
Prolonged diagnostic delay can lead to significant emotional distress and functional impairment.
Late Complications:
Chronic functional disability, persistent psychosocial morbidity, development or exacerbation of comorbid psychiatric disorders (depression, anxiety, PTSD), difficulty reintegrating into school or work, and ongoing relationship strain with family and peers
Untreated underlying psychological issues can lead to long-term sequelae.
Prevention Strategies:
Early recognition and diagnosis of PNES
Prompt initiation of evidence-based psychotherapy
Comprehensive treatment of comorbid psychiatric conditions
Strong emphasis on patient education and family support
Multidisciplinary care involving neurology, psychiatry, and psychology.
Prognosis
Factors Affecting Prognosis:
Prognosis is generally good with appropriate treatment, particularly when PNES is diagnosed early
Factors influencing a better outcome include: absence of significant comorbid psychiatric disorders, absence of childhood trauma, adequate social support, and active engagement in psychotherapy
Patients who have had epilepsy for a long time before PNES is diagnosed may have a more challenging recovery.
Outcomes:
Many adolescents with PNES can achieve significant reduction or complete resolution of events with effective psychosocial interventions
Functional recovery, including return to school and normal social activities, is a primary goal
However, relapse can occur, necessitating ongoing management and support.
Follow Up:
Long-term follow-up is recommended, typically with a multidisciplinary team
Regular monitoring for symptom recurrence, assessment of mental health status, and reinforcement of coping strategies are important
The frequency of follow-up will depend on the individual patient's progress and stability.
Key Points
Exam Focus:
PNES in adolescents is a diagnosis of exclusion, confirmed by video-EEG
Semiology is key to differentiation from epilepsy
Psychosocial factors are central to etiology and management
CBT is the primary treatment modality.
Clinical Pearls:
When suspecting PNES, gently ask the patient about their emotional state before and after events
Observe for resistance to eye opening or asynchronous movements during an event
Remember that patients with PNES are not consciously faking their symptoms
it is a real neurological and psychological manifestation.
Common Mistakes:
Mistaking PNES for epilepsy and initiating long-term AED therapy without adequate investigation
Delaying referral to psychiatric or psychological services
Focusing solely on symptom suppression rather than addressing underlying psychological triggers and coping mechanisms
Dismissing the patient's subjective experience of the events.