Psychiatry of epilepsy
Table of Contents
1. Overview
- increased risk for psychiatric comorbidities for epileptic patients
- depression most associated
- psychosis, anxiety, somatic symptom, personality, hyposexuality, dissociative
- may happen within and around ictal states
- intra-ictal psychic auras
- post-ictal confusion
- inter-ictal psychosis
- must distinguish epileptic seizures from e.g. somatic symptoms such as nonepilepetic seizures
2. History
- possession by demonic beings or gods and goddesses
- Hippocrates: blockage by phlegm of air-carrying vessels
3. Seizure
- sudden, involuntary, associated with electrical charges
- epilepsy is the recurrent tendency to seize
- status epilepticus is prolonged or repetitive seizures without intervening recovery
- hyperexcitable neurons with sustained postsynaptic depolarization
- changes in ionic conductance, decreased GABA inhibition of cortex
- increased glutamate-mediated cortical excitation
- antiepileptic drugs work on sodium channels to decrease firing
- ethosuximide works on calcium channels
- EEG
- alpha waves 8-13Hz
- high-freq beta waves >13Hz
- theta 4-7.5Hz
- delta slowing <3.5
- seizures are manifest as multiple spikes or spike and wave discharges
- spikes are sharp transient with a duration of 20-70ms
- inter-ictally, single spikes and other markers, often from temporal lobe
4. Classification
- focal without impairment of consciousness
- involving motor, autonomic, sensory, psychic phenomena
- focal with impairment of consciousness or awareness
- evolving to a bilateral, convulsive seizure
- generalized
- convulsive or non-convulsive
- tonic clonic
- myoclonic
- absence
- clonic
- tonic
- atonic
- unclear mode of onset
- epileptic spasms
5. Epidemiology
- 20-40m worldwide, >0.63%
- annual incidence of 0.05%
- high incidence in first year, drops in 3rd and 4th decade of life, then peaks after age 75
- 75% have first episode <18yo
- 12-20% have familiar seizures
- most common cause of new-onset: CVA
6. Psychopathology
- more than response to psychosocial stress
- pathology itself may be the source of seizures and behavioural changes
6.1. Psychosis
- most clearly associated with epilepsy
- 7-12% prevalence
- ~5-7x greater risk of psychosis for epileptic patients vs general population
- left-sided focus and hippocampal sclerosis associated with psychosis
- left temporal lesions are 2x at risk of psychosis
6.2. Depression
- 7.5-34% of patients with epilepsy
- MDD in up to 20% of patients
- more associated with left hemisphere focus
- also with focal dyscognitive seizures of temporal limbic origin
6.3. Other behaviours
- personality disorders, suicidal behaviours, anxiety disorders, hyposexuality are more prevalent, but prevalence is less well established
- Ictal
- Ictal psychic symptoms (aura): mood changes, derealization, depersonalization, forced thinking
- Nonconvulsive status: simple partial seizures, focal dyscognitive seizures and periodic lateralizing epileptiform discharges
- Catatonia
- Peri-ictal (includes prodromal, postictal, and mixed ictal)
- Prodromal symptoms: irritability, depression, headache, etc.
- Postictal confusion
- Peri-ictal psychoses
- Concomitant with increased seizure frequency
- Concomitant with decreased seizure frequency
- Postictal psychoses
- Interictal psychosis and personality disturbances
- Interictal psychosis (schizophreniform psychosis): no known relationship with seizure activity
- often prominent paranoid delusions, relative preserved affect, normal premorbid personality, and no family history of schizophrenia
- Personality disorders
- Gastaut–Geschwind syndrome
- focal dyscognitive seizures
- heightened significance of things, serious, humorless, overinclusive with intense interest in philosophical, moral, or religious issues
- Interictal psychosis (schizophreniform psychosis): no known relationship with seizure activity
- Behavioral disturbances variably related to ictus
- Mood disorders (depression and mania)
- Anxiety disorders including panic and posttraumatic stress disorder
- Aggression and violence
- Hyposexuality
- Suicide
- Personality disorders
- high prevalence of borderline (most common), histrionic, and dependent
- psychosocial difficulties (stigma, driving, job search) can contribute dependence
- Other behaviors
6.4. Psychogenic nonepileptic seizures (PNES)
- involuntary, psychogenically induced spells that mimic many epileptic behaviours
- one type of functional neurological symptom disorder
- ICD-10: dissociative convulsions
- term pseudoseizure is discouraged (invalidating): "psychogenic nonepileptic events"
- video EEG monitoring is the gold standard
- does not rule out epileptic seizures: 10-15% of patients have true epileptic seizures as well
- most common 26-32yo with psychological stressors and poor coping skills
- characterized by unresponsiveness with motor activity that does not fit a typical focal or general seizure
- before adolescence: M=F, after F>M
- every epileptic behaviour can occasionally occur
6.4.1. features
- Absence of explanatory disease or signs
- Seizures may be induced or provoked
- Inconsistencies in clinical presentation
- Seizures may differ from attack to attack
- Only occur when others are present
- Gradual onset, prolonged duration (>2 min)
- Asymmetrical, out-of-phase movements, pelvic
- thrusts, and hyperarching
- Rare whole body rigidity
- Rare incontinence, tongue biting, self-injury
- Normal autonomic reactivity, corneal reflex, and
- pupillary responses
- Avoids noxious stimuli or eye opening
- Vocalizations may occur throughout ictus
- Normal ictal EEG
- No postictal delirium, pseudosleep
- No increase in prolactin
- Normal postictal EEG
- Subsequent recall of events during ictus
- No relationship of ictal frequency to antiepileptic medications
6.4.2. treatment
- as with functional neurological symptom disorder
6.5. Malingered seizures
- More common in men
- Less likely to obtain prior abuse history
- Less likely to obtain prior psychiatry history
- Evident secondary gain
- No clear emotional precipitants
- Seizures are not suggestible
- Seizures under volitional control
- Conscious awareness of seizures
- Cannot maintain deficits over time
- Errors in seizure behavior are likely to be major
- distortions
- Angry, anxious on confrontation, with a lack of
- evidence for epileptic seizures
- Uncooperative, including circumstantial and evasive
- answers; may leave against medical advice
6.6. Agression
- Aggression in epilepsy is usually associated with psychosis or with intermittent explosive disorder and correlates with subnormal intelligence, lower socioeconomic status (SES), childhood behavior problems, prior head injuries, and possible orbital frontal damage
- Simple violent automatisms, such as spitting, verbal profanities, or flailing the arms, can occur at the onset of focal dyscognitive seizures, and secondary violent automatisms can occur as a response to an unpleasant or emotional aura or peri-ictal sensation
6.7. Suicide
- 4-5x higher rate of completed suicide in epileptic patients
- most not related to psychosocial stressors of having epilepsy
- Contributors to successful suicides include paranoid hallucinations, agitated compunction to kill themselves, and occasional ictal command hallucinations to commit suicide
7. Dx
- not specific to epilepsy
- mental disorder due to another medical condition
- recorded alongside dx of epilepsy
8. Course and prognosis
- generally good, most can be controlled well with meds
- some, like absence seizures can disappear by adulthood
- intractable: surgery (temporal lobectomy)
- most don't have psychiatric disorders and others only if they endure long duration of poorly controlled seizures
9. Treatment
- as with guidelines
- allowing seizures under carefully controlled conditions, much like ECT, may relieve some cases of peri-ictal psychosis, depression, or other behaviors
9.1. drug interactions
- most commonly antiepileptic drugs increase metabolism of psychotropics
- conversely, removal can precipitate rebound elevation in psychotropic levels
- be careful with Lamotrigine (Lamictal) and topiramate (Topamax)
- others are generally safe