For much of epilepsy history, clinicians could describe seizures and eventually record electrical activity without being able to see the living brain in structural detail. Cross-sectional neuroimaging changed that relationship between symptoms, electrical localisation and anatomy.
Before cross-sectional imaging
Early investigation relied on examination, skull radiography, EEG and invasive procedures. Pneumoencephalography and angiography could provide indirect structural information, but many causes remained hidden until surgery or post-mortem examination.
CT changes neurology
Computed tomography was introduced in 1971. For the first time clinicians could obtain cross-sectional images of the living brain quickly and non-invasively. In epilepsy it made tumours, calcification, old injuries, haemorrhage and other structural lesions easier to recognise.
MRI reveals what CT could not
MRI entered clinical practice roughly a decade later and had an even greater impact because of superior soft-tissue contrast. It made abnormalities such as hippocampal sclerosis and subtle developmental lesions much more visible.
Epilepsy-specific MRI
Specialists learned that a routine MRI could still miss epileptogenic abnormalities. Thin slices, appropriate orientation, high-resolution sequences and expert neuroradiology review became central to epilepsy-protocol MRI.
Functional and metabolic imaging
PET, SPECT, functional MRI, MEG, source imaging and post-processing later added metabolic, perfusion and functional information to the presurgical pathway.
From cryptogenic to visible
One of MRI’s biggest effects was diagnostic: some people previously described as having apparently unexplained focal epilepsy could be shown to have a structural lesion, changing diagnosis, prognosis and surgical candidacy.
Related reading
Sources and further reading
- A history of neuroimaging in epilepsy 1909–2009
- A History of Diagnostic Investigations in Epilepsy Surgery
- The start and development of epilepsy surgery in Europe
Evidence checked: September 2026.