Chapter 15: epilepsy Flashcards
Epileptic seizure
When there is abnormal and excessive electrical activity in the brain that leads to changes in the functioning or behavior of the patient. Depending on the focus of the epileptic activity a temporary disturbance occurs in, for instance, consciousness, motor skills, cognitive functioning or sensory functions.
Clinical criteria for epilepsy
- At least 2 unprovoked seizures with an interval between seizures of more than 24 hours.
- One unprovoked seizure and probability of at least 60% one will have other seizures within 10 years.
- The diagnosis of an epilepsy syndrome.
Classification steps
Classification of epilepsy happens in 3 steps:
1. The seizure types: focal, generalized or unknown.
2. Type of epilepsy: focal, generalized, combination or unknown.
3. Epilepsy syndrome.
Focal onset seizure
In one area of the brain. Losing awareness that lasts seconds or minutes.
Motor onset seizure
Small shocks, fidgeting with clothes (open-mouthed chewing for example).
Non-motor onset
A lapse in awareness and activity, during a few seconds.
Tonic-clonic seizure
A generalized seizure with muscle twitching and jerking.
Generalized onset
There are epileptic discharges in both hempispheres at the same time, which always leads to a loss of consciousness.
Tonic
Stiffening of the body and muscles.
Clonic
Muscle twitching
Atonic seizure
Loss of muscle tension.
Status epilepticus
When a seizure lasts too long or does not stop on its own.
Conclusive status of a seizure
When there are continuous muscle cramps ant twitching and breathing is interrupted. This is life threatening.
Non-conclusive status of a seizure
When someone shows confused or strange bahavior, but no muscle cramps and no trouble breathing.
Etiology of epilepsy
First a MRI scan is done to determine structural brain abnomality and then there are blood tests and cerebronspinal fluid analysis to determine the cause of the epilepsy.
Structural epilepsy
As a result of malformation of cortical development or an abnormal development of the cerebral cortex during pregnancy.
Genetic epilepsy
Some people have non-functioning or reduced functioning sodium channels in their neurons that result in more epileptic charges.
Treatment
- Anti-epileptic drugs help about 70% of people to get rid of seizures.
- Polytherapy: multiple medications.
- In people with focal epilepsy a surgery can help them. In surgery the site of where the seizures start is removed.
- Deep brain stimulation: electrodes in the brian to modulate activity.
- Keto diet.
Network theory
Epilepsy should be regarded as a network disease. It is characterised by hypersynchrony of brain networks. The disruptions in their functional connectivity cause epileptic seizures. This theory states that cognitive impairment is not a consequence of epilepsy, but a comorbidity.
Cognitive consequences of epilepsy
- Only specific types of epilepsy are associated with a lower IQ.
- Temporal lobe epilepsy had been associated with impairments in episodic memory, which difficulties in encoding and retrieving new information (due to hippocampal atrophy).
- People with epilepsy show a slowed information processing speed on tasks and first-generation epilepsy medication can worsen this.
- A lot of patients also show language problems, but limited impairment in verbal function. Naming and word-finding problems mostly occur.
- They can be less able to recognize basis facial emotions and have impaired theory of mind.
- They can report mood symptoms, feeling more agitated, anxious and depressed.
- They have a 3 times higher risk of developing dementia etc.
