Chapter 15 - Epilepsy
Introduction
It’s one of the oldest described conditions Mesopotamia, dates to 2000BCE.
Clinical Features
When there is abnormal and excessive electrical activity in the brain that leads to changes in
the functioning or behavior of the patient, this is referred to as an epileptic seizure. If
epileptic seizures occur repeatedly, one speaks of epilepsy. Consider the following criteria:
- At least two unprovoked (or reflex) seizures with an interval between seizures of more
than 24 hours; or
- One unprovoked seizure (or reflex seizure) and a probability of at least 60% that one
will have other seizures within ten years; or
- The diagnosis of an epilepsy syndrome.
Epilepsy leads to cognitive, behavioral, emotional and/ or psychosocial problems in some
patients.
Classification of epilepsy is performed in three steps:
1. Seizure types: focal, generalized, unknown
2. Epilepsy type: focal, generalized, combination between generalized and focal,
unknown
3. Epilepsy syndrome
Examples of comorbid factors in epilepsy -> subtle learning difficulties, intellectual disability,
psychiatric characteristics such as autism spectrum disorders and depression and psychosocial
problems. With severe forms of epilepsy, there may also be motor disorders, movement
disorders and sleep disorders.
Seizure types
Focal seizure -> occurs because of epileptic discharges in a specific part of the brain. This
can be localized in a small area, or more widespread. A distinction can be made:
- Awareness (intact consciousness) -> a person can generally continue to act
deliberately: they are approachable and can usually even carry out an assignment.
Common seizure symptoms: twitches in arm or leg, tingling, or having a strange taste
in the mouth.
- Impaired awareness (lowered consciousness) -> inability to respond adequately to
information from one’s surroundings. There is often automatic and/ or stereotypical
action (routinely performing an action or repeating the same, aimless action) and
absent-mindedness is involved, in which patients can sometimes appear confused.
They do not remember their seizure.
There is also a difference between seizures with a motor onset (small shocks, fidgeting
with clothes, open-mouthed chewing sounds) or non-motor onset (a rising sensation from
the stomach area, smelling a strange smell).
Duration of a focal seizure ranges from a few seconds to a few minutes. If the epileptic
discharges of a focal seizure spread further through the brain, the focal seizure can
progress to a so-called tonic-clonic seizure: a generalized seizure with muscle twitching
and jerking.
Generalized seizure-> occurs because of epileptic discharges in both hemispheres of the
brain at the same time, whereby there is always loss of consciousness. It can occur in
different forms:
, - tonic: stiffening of the body
- clonic: with rhythmic jerks on one side or both sides of the body
- tonic-clonic: a combination of stiffening and jerking
- atonic seizure: loss of all muscle tension
- absence: a short absence
An epileptic seizure usually resolves on its own after a few seconds or minutes, but if it lasts
too long and does not stop on its own: status epilepticus. This can happen in all forms of
epilepsy. A distinction can be made:
- convulsive status (continuous muscle twitching or cramps in which breathing is
interrupted; this one is life threatening).
- non-convulsive status (no twitches or cramps, someone can continue to breath, and
often shows strange, confused behavior).
Epilepsy type
Focal, generalized, combination between generalized and focal, unknown
Epilepsy syndrome -> refers to a distinctive cluster of disease characteristics (a certain
seizure type, typical age at onset, the course of the disease over time, characteristic EEG
patterns, MRI findings, cognitive and psychiatric comorbidity. It is not (yet) possible to
classify an epilepsy syndrome in every patient, which means there are also many patients who
do not meet the criteria of a syndrome.
Syndrome Causes Epilepsy Age at onset Comorbidity
characteristics
West syndrome Structural Typical Mostly first Stagnation of
abnormality in generalized year of life cognitive
brain seizures, also development
called Salaam
Genetic seizures
Metabolic
disease
Lennox- Structural Mostly tonic 1-7 years Severe
Gastaut abnormality in seizures developmental
syndrome brain delay
Genetic Behavioral
problems
Metabolic
disease
Dravet Genetic Difficult to treat First year of Stagnation or
syndrome form of life decline of
epilepsy, cognitive
starting with development
febrile seizures,
later also Characteristics
myoclonias of an autism
(sudden spectrum
contractions of disorder
muscles in one
of the limbs