Psychogenic non-epileptic seizures

Question 1

Epilepsy

Answer 1

Brain disorder characterised by enduring predisposition to generate epileptic seizures.

Defined by unprovoked, spontaneously occurring seizures.

In some cases caused by:

• Hippocampal sclerosis
• Malformation of cortical development
• Vascular malformations
• Postnatal acquired CNS lesions

Question 2

Epileptic seizure

Answer 2

Paroxysmal change in behavior due to synchronised rhythmic firing of populations of CNS neurons.

Question 3

Focal vs generalised seizures

Answer 3

Focal = origination of seizure activity within one hemisphere

Focal seizures can occur with preserved consciousness, impaired consciousness, or transforming into a bilateral seizure. The last form is called a focal to bilateral tonic-clonic seizure.

Generalised = origination of seizure activity within both hemispheres. Characterised by complete loss of consciousness. Different types of generalised seizures are:
absence seizures( with just a brief loss of consciousness.)
tonic (with stiffness)
clonic (with jerking)
tonic-clonic (with stiffness and jerking)
atonic (opposite of stiffness, limbness)

Question 4

Most common localisations of focal seizures:

Answer 4

Temporal lobe (65%)
10% are lateral, causing auditory symptoms, 90% are mesial causing psychic or autonomic symptoms.

Frontal lobe (25%)
Includes tonic/clonic movements. Tonic = stiffness
Clonic = Jerking

Parietal lobe (5%)
Causing vertigo and paresthesia, which is a burning or prickling sensation that is usually felt in the hands, arms, legs, or feet, but can also occur in other parts of the body.

Occipital lobe (5%)
Causing visual symptoms

Question 5

Other types of seizures:

Answer 5

Syncope
Transient ischemic attack
Migraine with aura
Psychogenic non-epileptic seizure
Parasomnia

Question 6

Syncope

Answer 6

Temporary loss of consciousness (“fainting“) related to insufficient blood flow to the brain. Underlying causes range from benign (e.g., low blood pressure due to changes in body position; vasovagal reflex) to potentially life-threatening (e.g., cardiac syncope due to arrhythmia). Can be preceded by prodromal symptoms like lightheadedness, visual disturbances (“black-out“), sweating. Commonly accompanied by myoclonic twitching and other involuntary movements

Question 7

What tells a syncope apart from a tonic-clonic seizure?

Answer 7

Firstly, the duration is shorter. Syncopes typically last less than 30 seconds, while tonic-clonic seizures last 1-2 minutes.
Similarly, people are able to reorientate themselves much quicker after a syncope (<30 s vs 4-45 mins). Additionally, tongue biting is more frequent in tonic-clonic seizures.

Question 8

Psychogenic non-epileptic seizure (PNES)

Answer 8

Convulsive events and/or alterations in behavior that resemble epileptic seizures but are not associated with epileptiform changes in cortical activity. Instead, PNES are viewed as a type of functional neurological disorder / conversion disorder at the interface of neurology and psychiatry

Question 9

Why is it hard to differentiate PNES from tonic-clonic seizures?

Answer 9

Because clinical manifestations are almost identical (the difference is primarily in the brain).
No pathognomonic clinical features to set them apart.
The same patient can suffer from both types of seizures.

pathognomonic = “specifically characteristic or indicative of a particular disease or condition.”

Question 10

What are the few differential features of PNES?

Answer 10

• Typically a longer duration of ~10 mins compared to 1-2 mins for tonic-clonic.
• They never occur out of sleep.
• Eyes are closed

The best way to tell if it is a PNES, is using a seizure monitoring unit with video-EEG