What is a Seizure?
‐temporary reaction to sudden excessive electrical activity of cortical
‐loss of awareness or consciousness, movement or sensory neurons disturbances, changed mood or mental function
‐may be from known cause or of “IDIOPATHIC” (= unknown) cause
‐usually SELF‐TERMINATE within seconds to minutes
What type of an event is a seizure?
ACUTE
What is Epilepsy?
What type of event is epilepsy?
What are the diff diagnosis paths for provoked/non-provoked epilepsy?
NOT provoked:
- primary seizure
- examine patient history
- diagnostic tests
- EPILEPSY DIAGNOSIS –> determine epilepsy syndrome
- examine treatment options
Provoked:
- investigate underlying cause
What are the clinical testing options?
Describe Assess Brain Electrical Activity (Electroencephalography - EEG)
What is the disadv of EEG?
b/c seizures are sporadic, A PERSON WITH EPILEPSY MAY HAVE A NORMAL EEG
Describe Brain Imaging
‐ Computerized Tomography (CT) Scan
‐ Magnetic resonance imaging (MRI) causing the seizures (e.g.’s tumor, cyst, bleeding
‐both CT and MRI used to reveal abnormalities that might be
What are the Functional Brain Imaging types?
What is Functional Brain Imaging used for?
is done to identify the exact location of where:
These are important things to know if a surgical therapeutic approach is being planned!
Describe Blood Tests
Describe Neurological Evaluation?
What is Epilepsy’s Prevalence?
What is Epilepsy’s Impact?
What is the pathophysiology underlying Epilepsy?
Alteration of Channel Function can –> hyper-excitability of neurons
Neurons may become hyper‐excitable because of:
- Increasing their own resting excitability
- Increasing their activation by other neurons
Explain how Alteration of Channel Function can –> hyper-excitability of neurons
e.g. “channelopathy” (class of disorder caused by alterations in ion channels)
-if this change is excitatory, then spontaneous neural activity can occur and
may manifest as Epilepsy
-hereditary alteration of some type of ion channel
-may be a single mutation of a particular channel subtype
-channels might have several possible loci where mutation –> changes in ion flow
-mutation of different types of channels may be involved
______ of voltage-gated Na+ channels can cause generalized epilepsy
discreet mutation
- is a type of “channelopathy”
What are the altered Postsynaptic Ionotropic Actions?
Increasing Excitation: ↑ excitation –> more excitable cell
Decreasing inhibition: Either ↑ excitation OR ↓ inhibition –> more excitable neuron
therefore, pathophys. is increase excitability, but there are diff ways to achieve it
Neurons may become hyper‐excitable because of:
Increasing their own resting excitability:
E.g.’s
- Increased sodium channel activation/conductance
- Decreased potassium channel activation/conductance
Increasing their activation by other neurons:
‐ Increased excitatory synaptic actions (e.g. glutamatergic)
‐ Decreased inhibitory synaptic actions (e.g. GABA or glycine)
channel activation/conduction at presynaptic
2+
‐ Increased Vdep Ca synapses.
These changes would make THE NEURONS MORE EXCITABLE (i.e., facilitates their production of AP’s)
The neurons that are firing more may have __________ on their neighbours! (the activity _______)
excitatory actions
spreads
What are the 2 types of Seizures?
What are the 6 types of Generalized Seizures?
Tonic‐clonic (grand mal) seizures: