Epilepsy
Updates to Article Attributes
Epilepsy is a common neurological disorder that has a varied presentation and requires two or more unprovoked seizures at least 24 hours apart for diagnosis. MRI is the modality of choice for epilepsy, most often investigating for an underlying cause, especially in adults.
Epidemiology
Epilepsy is very common, with approximately 3% of the population affected at some point in their life 1,5.
Pathology
Epilepsy syndromes can be generally divided into two broad categories 1,5:
- generalised, e.g. absence epilepsy, tonic-clonic, myoclonic
- partial (localisation-related), can progress to generalised
- temporal lobe epilepsy
- extratemporal epilepsy
Aetiology
There is a wide range of causes, however, in adults with new onset of seizures ~50% will not have a determinable cause 1-5. The International League Against Epilepsy (ILAT) have proposed the following classification 6:
- idiopathic: epilepsy due to an underlying single gene condition or complex inheritance (seizures as the only manifestation)
- cryptogenic: unknown cause
- provoked epilepsy: e.g. secondary to fevers, head trauma, drug-induced
-
predominantly genetic/developmental causation
- childhood epilepsy syndromes
- progressive myoclonic epilepsies
- neurocutaneous syndromes, e.g. tuberous sclerosis
- chromosomal disorders, e.g. Down syndrome
- single gene disorders
- developmental cortical abnormalities, e.g. focal cortical dysplasia, grey matter heterotopia
-
predominantly acquired
- stroke, cerebral palsy, bacteria/viral meningitis, traumatic brain injury, vascular malformations
- mesial temporal sclerosis, meningoencephaloceles
- tumours, e.g. gangliogliomas, DNET, PXA, low-grade gliomas
Radiographic features
MRI
MRI is the modality of choice. Please see articles on specific conditions listed above for imaging features. There are a number of MRI protocols that can be used to investigate patients with seizures.
Nuclear medicine
SPECT perfusion brain
If performed during the crisis, it can be useful for localizing the epileptogenic focus 7,8.
-<a href="/articles/stroke">stroke</a>, <a href="/articles/cerebral-palsy">cerebral palsy</a>, bacteria/viral <a href="/articles/leptomeningitis">meningitis</a>, <a href="/articles/traumatic-brain-injury">traumatic brain injury</a>, <a href="/articles/cerebral-vascular-malformations">vascular malformations</a>- +<a href="/articles/stroke">stroke</a>, <a href="/articles/cerebral-palsy">cerebral palsy</a>, bacteria/viral <a href="/articles/leptomeningitis">meningitis</a>, <a href="/articles/traumatic-brain-injury">traumatic brain injury</a>, <a href="/articles/cerebrovascular-malformations">vascular malformations</a>
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