Epilepsy Flashcards
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?
- individual must have had 2 or more idiopathic seizures for epilepsy diagnosis
What type of event is epilepsy?
- is the CHRONIC neurological disorder –> RECURRENT seizures
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?
- Assess Brain Electrical Activity (Electroencephalography - EEG)
- Brain Imaging
- Functional Brain Imaging
- Blood Tests
- Neurological Evaluation
Describe Assess Brain Electrical Activity (Electroencephalography - EEG)
- non-invasive recording of brain’s electrical activity by network of electrodes placed over the scalp
- can detect synchronous epileptic electrical activity
- most common diagnostic test used for epilepsy
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?
- Functional MRI (fMRI)
- Positron emission tomography (PET) Scan
- Single-photon emission computerized tomography (SPECT)
What is Functional Brain Imaging used for?
is done to identify the exact location of where:
- epileptic activity is originating from
- areas processing language, movement etc.
These are important things to know if a surgical therapeutic approach is being planned!
Describe Blood Tests
- check for infections, toxins, genetic conditions, electrolyte imbalance,
genetic markers etc. - can be diagnostic, & determine if seizure was triggered by toxin etc.
Describe Neurological Evaluation?
- assessment of broad neurological function (ex: sensory, motor, cognitive) to
- detect deficits (if present)
- determine type of seizures experienced
What is Epilepsy’s Prevalence?
- 75% diagnosed before age 30
- For 64% of ppl with epilepsy, it is their only neurological condition
- when there is another one, migraine is most common, then brain injury, stroke
- No difference in prevalence of diabetes or heart disease for those with epilepsy, but they can have increased need of health services due to other chronic issues (e.g. higher incidence of incontinence)
- Medication is primary treatment, and able to eliminate seizures in ~70% of cases.
What is Epilepsy’s Impact?
- Persons with epilepsy have a mortality rate 2‐3 times the general population.
- 39% of household residents living with epilepsy and not having another neurological persistent/repetitive seizures condition reported epilepsy did not affect their life at all.
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)