Brain rhythms: Epilepsy Flashcards
(22 cards)
Define a seizure.
A seizure results from an excessive or synchronous neuronal discharge
How do seizures manifest?
Seizures may manifest as:
- Behavioural change
- Involuntary skeletal muscle contraction
- Altered level of awareness
Define epilepsy.
Epilepsy is the tendency to get recurrent seizures, defined as two or more seizures occurring 24 hours apart.
What are the risk factors of seizures?
Risk factors include:
- Underlying developmental or acquired CNS abnormality
- Family history
What are the different types of seizures?
Types of seizures include:
- Focal (partial) onset
- Generalized (bilateral) onset
- Unknown onset
What is focal (partial) onset seizure?
Focal onset seizures are confined to one area of the brain and may be associated with preserved awareness or impaired cognition.
What is generalized (bilateral) onset seizure?
Generalized onset seizures tend to start in both sides of the brain simultaneously.
What are absence seizures?
Absence seizures are associated with a sudden brief alteration in awareness.
E.g. a child may be noticed daydreaming or suddenly falls over and then gets back up.
What are myoclonic jerks?
Myoclonic jerks involve sudden jerking of both upper limbs, typically occurring if the patient is sleep deprived.
What are tonic spasms?
Tonic spasms involve stiffening of the body, often with the eyes and head going back.
What are tonic-clonic seizures?
Tonic-clonic seizures consist of a tonic stiffening phase followed by a jerking phase.
What are atonic seizures?
Atonic seizures may involve a head drop where the head suddenly drops and arms come up into a tonic phase, posing a risk of falling.
What type of seizures are most common in adults vs children?
In adults, focal onset seizures are more common, often due to stroke or brain tumors. In children, generalized seizures are more common, often associated with genetic syndromes.
What are some seizure symptoms?
Seizure symptoms tend to be stereotyped and may include:
- Sensory symptoms like tingling
- Prolonged jerking of affected body parts
- Todd’s paresis after jerking
Less common symptoms may include sweating, flushing, or unusual sensations.
What are some less common seizure auras?
Less common auras may involve changes in hearing or vision, often presenting as vivid disturbances.
What are ancillary investigations for seizures?
Investigations include:
- MRI, essential in adults unless there’s a strong suspicion of genetic generalized epilepsy.
- EEG, useful to establish focality.
What are structural lesions associated with seizures?
Structural lesions associated with seizures include:
- Cerebrovascular disease
- Underlying malignancy
- Hippocampal sclerosis
What is refractory epilepsy?
Refractory epilepsy is characterized by ongoing seizures (≥ 1/month) despite two adequate trials of antiepileptic drugs.
Who should be referred for surgical consideration?
Candidates for surgical consideration include:
- Patients with refractory epilepsy
- Those with a history suggesting a focal point
- Patients of reasonable age and health
What is the ideal surgical candidate for epilepsy?
An ideal surgical candidate is typically young, has a history of febrile seizures, recent seizure onset, primarily focal seizures, and may show hippocampal sclerosis on MRI.
What occurs in resective surgery?
Resective surgery involves refining localization and resection of the seizure focus.
What was used instead of EEG?
Subdural electrodes were used instead of EEG.
