Epilepsy

Contents

•       Epilepsy

•       Classification

•       Status
epilepticus

•       Pathophysiology

Objectives
 

At the end of PDF Notes, student will be able to

•      
  Define
epilepsy

•      
  Define
status epilepticus

•      
  Classify
epilepsy

•      
 Describe the
pathogenesis of epilepsy

Epilepsy

•       Chronic
brain disease of diverse etiology

•       Characterized
by recurrent paroxysmal episodes of uncontrolled excitation of brain neurons

•        Manifesting as brief episodes (seizures) of
loss of consciousness, with or without characteristic body movements
(convulsions)

Status epilepticus (SE)

Continuous
convulsion lasting longer than 30 minutes OR Occurrence of serial convulsions
between which there is no return of consciousness

Pathophysiology of 

Epilepsy

•       Normally,
a balance between excitatory and inhibitory factors – proper functioning of a
healthy human brain

•       Reduction of inhibitory synaptic
activity or enhancement of excitatory synaptic activity -trigger a seizure

•        NTs mediating the bulk of synaptic
transmission in the mammalian brain are amino acids

•       GABA – principal inhibitory

•       Glutamate – excitatory
neurotransmitters

•       Repeated
epileptic discharge can cause neuronal death (excitotoxicity).

•        A relative deficiency of inhibitory
neurotransmitters such as GABA

•        An increase in excitatory neurotransmitters
such as glutamate would promote abnormal neuronal activity

Clinical
manifestations

 of 

Epilepsy

•       Depend on the location of the focus
and the pathways involved in its spread

•       ‘Generalised’ – initial activation
of both hemispheres of the brain

•       ‘Partial’ or ‘Focal’ –  discharge starts in a localised area of the
brain