seizures Flashcards
what is a seizure
a temporary abnormal electro-physiological phenomena of the brain, resulting in abnormal synchronization of electrical neuronal activity
what is epilepsy
a disease of the brain characterized by an enduring predisposition to generate epileptic seizures (at least 2 in less than 24 hours)
caused by an imbalance of inhibitory and excitory activity in the brain
what is a convulsion
sudden and often violent motor activity of cerebral or brainstem origin
what are the different types of epilepsy
focal and generalised (classified by seizure type)
idiopathic, structural, unknown (classified by aetiology)
what are the clinial signs of focal epileptic seizures
- motor (lip smacking, lip pursing, chewing, licking, teeth grinding or swallowing, pedal indicates principally distal component involvement bilateral or unilateral. usually running movement)
- autonomic (dilated pupils, hypersalivation or vomiting)
- Behavioural (anxiousness, restlessness, unexplainable fear reactions or abnormal attention seeking/clinging to O)
what are the causes of focal seizures
abnormal electrical activity arises in a localised group of neurons or network within one hemisphere
(clinical signs reflect the functions of the area or areas involved)
how are generalised epileptic seizures classified
by bilateral involvement (both sides of the body/both cerebral hemispheres
- can occur alone or from a focal epileptic start
- most common in dogs
- generally present as tonic, clinic or tonic-clonic or atonic
define tonic, clonic and tonic-clonic
tonic: sudden stiffness or tension in the muscles or the arms, legs or trunk
clonic: repeated jerking movements of the arms and legs on one or both sides
tonic-clonic: both stiffness and jerking movements
how is a structural seizure classified
an intercranial/cerebral pathology (vascular, inflammatory/infectious, traumatic, anomalous/developmental, neoplastic and degenerative diseases)
what is status epilepticus
a neurological emergency!!!
continuous epileptic seizure activity lasting longer than 5 minutes or as two or more incomplete recovery of consciousness interictally
how does epilepsy treatment work
altering intrinsic membrane properties (primarily sodium channels) or increasing inhibitory transmitter function, primarily GABA system or decreasing excitatory transmitter function, primarily the glutamate system