Drugs to treat Epilepsy Flashcards
What is epilepsy?
A very common neurological disorder exhibiting periodic seizures
What are seizures?
Abnormal electrical activity in the brain
Burst of uncontrolled electrical activity between brain cells that causes temporary abnormalities in muscle tone (stiffness, twitching or limpness), behaviour, sensations or state of awareness
All seizures have convulsions. True or false
False; not all seizures have convulsions
What are convulsions?
This is when a persons body shakes rapidly and uncontrollably
Uncontrollable shaking that is rapid and rhythmic with muscles contracting and relaxing repeatedly
Describe the tonic phase of convulsions
Sudden loss of consciousness, skeletal muscles tense, extremities pull rigid towards or away from body, short (last for seconds)
briefly described as stiffening of muscle
Describe the clonic phase of convulsions
muscles contract/relax rapidly, violent shaking, eyes roll back, injury to tongue and jaw
characterised by jerking or twitching
What are the main types of seizures?
Partial seizures
Generalised seizures
What are the types of partial seizures?
Complex partial seizures
Simple partial seizures
What is a complex partial seizure?
Altered awareness and behaviour e.g. confusion, repetitive movements
What is a simple partial seizure?
remains alert e.g. jerking of a limb, nausea, strange taste or smells
Complex and simple partial seizures can lead to …
secondary generalised seizures
What is a partial seizure ?
this is when seizure activity is localised to one area of the brain
What is a generalised seizure?
this is where the seizure involves the whole brain and consciousness is affected
What is a secondary generalised seizure?
this is when seizure spreads from one area to the whole brain
What are the types of generalised seizures?
Tonic Clonic (Grand-Mal)
Absence (Petit-mal)
Tonic/atonic
Myoclonic
What is the main type of secondary generalised seizure?
Tonic Clonic (Grand-mal)
What is a tonic clonic (grand-mal) seizure?
convulsion with loss of consciousness, stiffing body then jerking limbs
What is a absence (petit mal) seizure?
staring or trance like state
What is a tonic or atonic seizure?
abrupt fall, either with stiffening muscles (tonic) or loss of muscle tone (atonic)
What is a myoclonic seizure?
sudden muscle jerks
What kinds of partial seizures lead to secondary generalised seizures
both complex and simple partial seizures
What does status epilepticus refer to?
Life threatening condition in which seizure activity is uninterrupted.
A seizure that lasts > 5 minutes or having >1 seizure in a 5 minute period without returning to a normal level of consciousness between seizures
Briefly describe the pathogenesis of epilepsy?
there is a pathologic imbalance between inhibitoy and excitatory transmission
Briefly state the MOA of anticonvulsant drugs
they control seizures either by either increasing inhibition or decreasing excitation
What are the main MOAs of anticonvulsant drugs?
Enhancement of GABA action
Inhibition of sodium channel function
Inhibition of calcium channel function
What are the functions of calcium ions in neurons?
Neurotransmitter release (diffuse into neurons and interact with vesicles, causing them to migrate to active sites)
Membrane excitability
Apoptosis (remember neurodegeneration)
List anticonvulsant drugs that enhance inhibition of signals
Phenobarbital
Benzodiazepines
Vigbatrin
Tiagarbine
Gabapentin
List anticonvulsant drugs that reduce excitation of neurons
Phenytoin
Carbamezapine
Lamotrigine
Felbamate
Topiramate
Ethosuximide