epilepsy

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 .

Pathology

Epilepsy syndromes can be generally divided into two broad categories :

  • generalized, e.g. absence epilepsy, tonic-clonic, myoclonic
  • partial (localization-related), can progress to generalized
Etiology

There is a wide range of causes, however, in adults with new onset of seizures ~50% will not have a determinable cause . The International League Against Epilepsy (ILAT) have proposed the following classification :

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 .