L6 - Disorders of neural transmission Flashcards
1. Understand the pathophysiology of seizures and epilepsy 2. Learn about types of epilepsy and underlying causes - structural, genetic and autoimmune. 3. Understand disorders of the ion channel - central and peripheral, congenital or autoimmune (primary and paraneoplastic)
Define Epilepsy?
Abnormal discharge of neuron’s causing a neurological event.
Tendency for recurrent seizures (>2)
Describe the classification of seizures?
Focal seizures: discharges arise from specific cortical region. Can either remain localised or spread more generally.
Generalised: abnormal excitability of thalamo-cortical circuits.
Give an example of a disorder of neuromuscular transmission that involves post-synaptic receptors?
Myasthenia Gravis
—> Muscle weakness and fatigability caused by auto-antibody and cell mediated destruction of ACH receptors.
Example of disorder of neuromuscular transmission involving presynaptic receptors?
Botulism
- poisoning due to clostridium botulinum toxin.
- affects peripheral nerves.
What is Eaton-Lambert syndrome?
symptoms?
Immune mediated.
Pre-synaptic, impaired release of ACH from nerve terminals.
Symptoms: fatigability, weakness, pain in proximal limb muscles, peripheral paresthesias, dry mouth, erectile dysfunction, and ptosis.
What is the action of cholinergic drugs?
Organophosphate insecticides nerve gases (sarin)
- block neuromuscular transmission by excessive ACH action
- depolarises post synpatic receptors
What does hashimoto’s disease do?
Autoimmune disease - immune system creates antibodies that damage thyroid gland.
Goiter (swelling)
Briefly describe what stiff person syndrome is?
rare-autoimmune disease.
axial muscle stiffness, abnormal posture, spasms and falls.
more common in females.
What are some common types of anti-epileptic drugs?
Sodium valproate Carbamazepine Lamotrigine Levetiracetam Oxcarbazepine Ethosuximide Topiramate
What is epilepsy?
Synchronous discharge of pyramidal cells.
