This document summarizes the pathophysiology of seizures. It outlines predisposing factors like family history and precipitating factors like sensory stimuli. It then describes how an epileptogenic focus becomes hyperexcitable, leading to partial depolarization and neurotransmitter release. This lowers the seizure threshold and can be activated by precipitating factors, spreading abnormal electrical discharges between hemispheres. During the tonic phase, muscles stiffen and consciousness is lost. The clonic phase involves rapid muscle contractions and jerking. Finally, the post-ictal phase involves exhaustion and impaired coordination or consciousness.

1. PATHOPHYSIOLOGY
PRECIPITATING FACTORS: PREDISPOSING FACTORS:
Etiology:
• Sensory stimuli: loud noises • Family History
Altered integrity of
or bright lights
neuron in the
• electrolyte imbalance epileptogenic focus
Hyperexcitablity state of neurons in
the epileptogenic focus
Partial depolarization
(high voltage electrical discharge)
Partial stimulation of
neurotransmitter molecules
Imbalanced release in excitatory
and inhibitory neurotransmitters
Lowered seizure threshold
Activated by
precipitating factors
Abnormal spontaneous
spread electrical
discharges

2. Hyperexcitability of neurons
in the brainstem causing
disruption in the functions of
the medulla, pons and
midbrain
Tonic Phase
Spreads to both
hemispheres
Disruption in Alteration
medullary in the
activity thus activity of
alteration in the pons. Alteration in the activity
function of in the midbrain (connects
respiratory and brain to spinal nerves)
cardiovascular
Musculature
system
stiffening( extr
emities pulled Loss of consciousness
toward body) and swallowing reflex
Clonic phase:
Cessation of
cardiovascular and • Muscles will contract
Inhibitory impulse starts
respiratory activity and relax rapidly
from the thalamus and
causing apnea and interrupts the tonic phase
cyanosis. • Violent, jerking
into discontinuous bursts movements
of electrical activity
• Upward rolling of the
eyeballs
• Bowel and urine
incontinence in some
Post-ictal phase:
Due to physical and nervous
exhaustion, the patient may
have/ will be:
• Semiconscious
• Poor coordination
• Mild impairment of fine
motor movements
• Deep sleep