Active parts of the nervous system in epilepsy. Functions of the nervous system that are apparent and/or impaired in epilepsy patients.

1. Epilepsy

2. Epilepsy is not in itself a disease
but a symptom of a disease.
It is characterized by seizures which occur
because of a temporary disturbance in a larger
or smaller group of neurons in the brain.
A seizure is a sudden disruption in the brain's
normal electrical activity accompanied by a
state of altered consciousness.

3. In most cases the cause is unknown,
although some people develop epilepsy as the
result of brain injury, stroke, brain cancer, and
drug and alcohol misuse, among others.
Epilepsy is a neurological and not a mental disorder.
Understanding of the CNS abnormalities
causing patients to have recurrent seizures
remains limited.

4. What parts of the nervous system
are active in epilepsy?
All aspects of autonomic function can be
affected, including the parasympathetic,
sympathetic, and adrenal medullary systems.
Autonomic changes are the most common
symptoms of simple partial seizures but may go
unrecognized.

5. What parts of the nervous system
are active in epilepsy?
The probable paths of propagation of the epileptic electrical
activity are as follows: The ictal impulse involves either or
both temporal and frontal areas. The insular cortex is then
involved in both temporal and frontal seizures, and the
hippocampus is involved in temporal seizures. This activity
is then spread through the limbic system with involvement
of the amygdala, hypothalamus, and thalamus. These in
turn stimulate the ANS nuclei in medulla, including the
nucleus tractus solitarius (NTS) and ambiguus nuclei.
Both sympathetic and parasympathetic efferent discharges
are then generated.

6. What parts of the nervous system
are active in epilepsy?
Ictal autonomic changes can cause
cardiovascular, respiratory, gastrointestinal,
cutaneous, pupillary, urinary, and genital
manifestations. They also can elicit visceral,
emotional, and sexual feelings. Ictal activation
of the central autonomic network often leads to
the hallucination, and less often the illusion, of
visceral or corporeal sensations.

7. What parts of the nervous system
are active in epilepsy?
Sympathetic responses predominate during
most seizures, causing tachycardia, tachypnea,
increased blood pressure, pupillary dilatation,
diaphoresis, and facial flushing.

8. Impaired functions of the nervous system
in epilepsy patients
Neuronal messages are transmitted by electrical impulses called the action
potential. This is actually a net positive inward ion flux that leads to
depolarization or voltage change in the neuronal membrane. The ions involved
include sodium, potassium, calcium, and chloride. Normally brain tissues
prevent hyper excitability by several inhibitory mechanisms involving negative
ions like chloride ions.
Disturbance in this normal excitability leads to hyper-
excitability. In this state there is increases excitatory
transmission of impulses and decreases inhibitory
transmission. In addition there is alteration in the voltage
gated ionic channels. These ion channels normally open when the
voltage difference across the neuronal membrane is changed favourably.
The hypersynchronous discharges that occur during a
seizure may begin in a very discrete region of cortex and
then spread to neighboring regions.

9. Impaired functions of the nervous system
in epilepsy patients
Mechanism of seizure formation
● Excitation of a group of nerves. This is caused by inward currents of Na,
Ca and involvement of excitatory neurotransmitters like Glutamate and
Aspartate.
● Too little inhibition.
● Epileptogenesis and hyperexcitability and hypersynchronization of neurons
that facilitates spread. There has to be abnormal synchronization – a
property of a population of neurons to discharge together independently.
Alone, a hyperexcitable neuron cannot generate a seizure.

10. How this course has allowed me to better analyze the
events and phenomena around me?
The course has helped me understand how groups of
neurons interact to generate behavior. It gave me a
opportunity to explore the complex interactions involved in
bodily function, decision making, emotion, memory,
learning, and more. The course gave me some thoughts to
dig for extra information about diseases and disorders that
occur when interactions don't happen or go wrong.
I enjoyed a lot the way prof Peggy Mason conducted the
class! It is so much fun with such a teacher.
Tell me and I forget. Teach me and I remember. Involve me
and I learn. Benjamin Franklin
Thank you!