EPILEPSY_Part 1_ PATHOPHYSIOLOGY شرح بالعربى :الصرع باثوفسيولوجى

EPILEPSY_Part 1_ PATHOPHYSIOLOGY شرح بالعربى :الصرع باثوفسيولوجى
===========================================
Link to this lecture as pdf file:
www.mediafire.com/file/sr25ir...
==============================================================
Lecture outline
1-Normal brain activity.
2-Pathophysiology of epilepsy
3-Definition of epilepsy.
4-Aetiology of Convulsions.
5-Classification of epilepsy.
Neurones
Resting membrane potential
1-normal brain activity
To function normally, the brain must maintain a continual balance between excitation and inhibition, remaining responsive to the environment while avoiding continued unrestrained spontaneous activity.
Normal neuro_transmitter balance
Gamma-aminobutyric acid(GABA)
The inhibitory transmitter gamma-aminobutyric acid(GABA) is particularly important, acting on ion channels to enhance chloride (Cl_ _) inflow and reducing the chances of action potential formation by making the resting membrane potential more negative.
Glutamate and Aspartate)
Excitatory amino acids (glutamate and aspartate) allow influx of sodium (Na+) and calcium (Ca ++), producing action potential (making the resting membrane potential less negative).
2-Pathophysiology
It is likely that many seizures result from an imbalance between this excitation and inhibition.
In vivo, epileptic cortex shows repetitive discharges involving large groups of neurons
Intracellular recordings during seizures demonstrate a paroxysmal depolarisation shift in neuronal membrane potential, an upshift of resting membrane potential predisposing to recurrent action potentials.(in response to weak stimuli eg. flickering light,watching TV)
3-Definitions
A seizure: is sudden synchronous discharge of cerebral neurones causing symptoms or signs that are apparent either to the patient or to an observer.
Epilepsy: is the tendency to have unprovoked seizures.
A recent change in definition allows the diagnosis of epilepsy to be made after a single seizure with a high risk of recurrence (e.g. a single seizure in the presence of a cortical lesion)

[@user-kh4hi3ir3e]

شكرا دكتور بارك الله فيك

[@akramkemo4075]

جزاكم الله خيرا