Page 148 - ILAE_Lectures_2015

Table 1. Features of focal seizures of medial temporal lobe origin.

Clinical Features
 Past history of prolonged febrile convulsions (in those with medial temporal sclerosis)
 Seizures longer than frontal lobe seizures (typically > 2 min), with a slower evolution

and more gradual onset/offset
 Auras common. Typical of medial temporal (rather than lateral temporal origin) are

visceral, cephalic, gustatory, affective, perceptual or autonomic auras
 Partial awareness commonly preserved, especially in early stages, and slow evolution of

seizure
 Prominent motor arrest with loss of awareness (the ‘motionless stare’)
 Post-ictal confusion and dysphasia common
 Autonomic changes (e.g. pallor, redness, and tachycardia)
 Automatisms. Often less violent than in frontal lobe epilepsy, and usually oro-

alimentary (lip-smacking, chewing, swallowing), or gestural (e.g. fumbling, fidgeting,
repetitive motor actions, undressing, walking, running) and sometimes prolonged.
Vocalisation also common. Other motor automatisms can occur.

EEG
Inter-ictal:
 Epileptiform abnormalities: Anterior or mid-temporal spikes/sharp waves (best shown
on sphenoidal electrodes)
 Non-epileptiform abnormalities: regional slowing in temporal lobe regions (EEG signs
can be unilateral or bilateral)

Ictal:
 Rhythmic temporal alpha or theta activity within 30 seconds of onset (in ~80% of MTLE

seizures)

Imaging
 Hippocampal sclerosis (demonstrable by unilateral decrease in hippocampal volume and

increase in signal on T2-weighted MRI scan)
 Structural lesion (most commonly: hamartoma, other benign tumours, glioma,

cavernous angioma, malformation of cortical development)

This table includes those clinical features particularly characteristic of temporal lobe epilepsy. In many
cases, however, these features do not occur.

More complex hallucinatory or illusionary states are produced with seizure discharges in
association areas (e.g. structured visual hallucinations, complex visual patterns, musical
sounds, and speech). A cephalic aura can occur in temporal lobe seizures, but also occurs
with a frontal lobe focus.

Blank spell. Motor arrest with altered awareness (the so-called ‘motionless stare’ or
‘dialeptic’7 or ‘dyscognitive’8 seizure) is prominent, especially in the early stages of seizures
arising in medial temporal structures, and more so than in extratemporal lobe epilepsy.

Automatism. The automatisms of mediobasal temporal lobe epilepsy are typically less violent
than in frontal lobe seizures, and are usually oro-alimentary (lip-smacking, chewing,
swallowing), or gestural (e.g. fumbling, fidgeting, repetitive motor actions, undressing,