Page 10 - ILAE_Lectures_2015

Table 1. 1981 International classification of seizures.

Partial seizures beginning locally
Simple (consciousness not impaired)
 With motor symptoms
 With somatosensory or special sensory symptoms
 With autonomic symptoms
 With psychic symptoms

Complex (with impairment of consciousness)
 Beginning as simple partial seizure (progressing to complex seizure)
 Impairment of consciousness at onset

a) Impairment of consciousness only
b) With automatism

Partial seizures becoming secondarily generalised

Generalised seizures
Absence seizures
 Typical
 Atypical

Myoclonic seizures

Clonic seizures

Tonic seizures

Tonic-clonic seizures

Atonic seizures

Objective support for this dichotomy of focal and generalised seizures is provided by EEG
findings in patients with generalised and focal seizures. In generalised seizures, there is
immediate (within milliseconds) EEG involvement of both hemispheres. Inter-ictal
abnormalities likewise involve both hemispheres simultaneously. In focal seizures, the ictal
discharge is initially confined to one hemisphere. Inter-ictal abnormalities are also confined
to individual areas.

An inherent limitation to this scheme is that seizures are not classified by their semiologic
features alone, but in combination with EEG findings. It has to be recognised that the
semiological features seen in the generalised seizure types described above can be seen in
focal seizures as well (e.g. clonic movements, atonic head drop, brief loss of awareness).

Generalised seizures (ILAE 2010)

Tonic-clonic seizures (in any combination)
In its classic form, this seizure is a sequence of events that often begins with bilateral
myoclonic jerks. This is then followed by a tonic contraction of the extremities and axial
trunk muscles, resulting in extension of the neck and extension of the extremities. The tonic
contraction of the diaphragm and abdominal and chest wall muscles against the contracted
glottis causes the characteristic tonic cry. The patient may become cyanotic during this phase.
The generalised tonic activation can only be sustained for a short period of time. The