Epilepsy surgery Flashcards
Where do complex partial seizure originate?
Temporal lobe
Which seizure is surgical? focal vs. general
Focal
In focal seizures, which has a higher change of surgical cure?
Temporal focal seizures, vs. any other lobe
How do generalized and complex partial seizures compare in terms of response to drug therapy?
Generalized: 50% 12 months remission
CPS: 22-32% 12 months remission
What is the likelihood of a patient failing first line of drug treatment to fail additional ones?
an individual with CPS with a lesion on an MRI who fails a first line anti-seizure medications will likely fail every other ASM that is tried
How long should normal treatment be tried before surgical treatment should be considered?
1-2 years.
What percentage of those eligible for surgery in Ontario actually receive the surgery?
2%
What’s the chance of a surgical cure for temporal lobe epilepsy?
80-90% chance
What are the hippocampal afferents?
Cortex contalateral hippocampus Septal area Nuclei in reticular formation Largest recipient of entorhinal area Suncortical afferents
What are the efferents for the hippocampus?
Fornix
What carries the information to the contralateral hippocampus?
Dorsal hippocampal commisure
What carries the information to the septal area?
Pre-commisural fornix
What carries the information to the mammillary bodies?
Post-commisural fornix
What are the afferents to the amygdala?
From olfactory (forms part of the lateral olfactory area) from hypothalamus
What forms the efferent bundle of the amygdala? where does it project to?
Stria terminalis forms the efferent bundle; it projects to:
1- dorsal nucleus of the vagus nerve
2- solitary nucleus
What are the Predrome (aura) of a temporal lobe seizure?
De ja vu: hippocampus
Nasty smell: uncus, corticomedial part of the amygdala
Fear and anxiety: central and basolateral nuclei of the amgydala
autonomic manifestation:
Stria-terminals-> septal area-> stria-medullaris thalami (part of epithalamus)–> habenular nuclei (part of epithalamus)–> fasciculus retrofelxus –> interpeduncular nucleus –>autonomic nuclei
What are the symptoms of a temporal lobe seizure?
blank stare automaticity of behaviour (picking, fumbling, repeating words) Orofacial automatisms Speech arrest (esp. if dominant lobe) Wandering
What are the post ictal symptoms of a temporal lobe seizure?
Disoriented Tired Psychotic headache depressed level of consciousness
What is the most common lesion associated with medically refractory TLE?
Mesial temporal sclerosis. 47-70%
Describe mesial temporal sclerosis changes
Atrophy of hippocampal formation
loss of neurons and gliosis in dentate gyrus and CA1, CA4.
What are the main functions of the temporal lobe in the dominant vs. nondominant hemispheres?
Dominant: Verbal memory, language
Nondominant: visual-spatial memory
What are the risks associated with TLE surgery?
Memory, and language esp if dominant side--> improves within a year Visual field loss Stroke--> weakness+ visual field loss Infection hemorrhage
