Neurology Flashcards
Name the three tissue layers of the cerebral cortex
[From top to bottom]
- Molecular Layer
- Purkinje Cells
- Granule Cell Layer
Describe the functions of the molecular layer, purkinje cells and granule cell layer in the cortex?
Molecular Layer = Superficial layer, mainly grey matter, slower transmission.
Purkinje Cells = Nerve cells that can fire in multiple directions. Role in controlling motor movement.
Granule Cell Layer = Deepest layer, next to white matter. Packed with neurones. Also allows quick transmission from one area to another.
How does saltatory function allow for message transfer
The propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing theconduction
velocity of action potentials.
Explain the structural parts of the neuron
Nucleus – processes the information
Soma – (body) contains organelles (all the memorised function of the particular nerve)
Dendrite – Projections of a neuron that receives signals (information) from other neurons
Axon – sends information down towards the axon terminal
Axon terminal – Makes synaptic connections with another nerve cell or with an effector cell.
Myelin Sheath – lipid-rich substance that surrounds the axon to insulate it and increase the rate at which electrical impulses are passed along it
Neurones get excited by one of the following:
Pressure, light, chemicals or sound.
The two main resources used to assess cognitive impairment
Mini Mental State Examination (MMSE)and The General Practitioner Assessment of Cognition (GPCOG)
The ‘gold standard’ to treat acute migraines is to use combination therapy, which consists of…
NSAID/paracetamol + oral triptan + anti-emetic.
What are Triptans (most commonly Sumatriptan) used to treat?
Used for treatment of migraine and cluster headaches
MOA of Triptans
Serotonin agonist – stimulates serotonin 5HT1 receptors and modulates neurotransmitters; Mediates cerebral vasoconstriction; Inhibits the release of CGRP which is involved in pain response via the trigeminal nerve; Decreases activity of the trigeminal nerve.
With regards to Migraines, when should prophylaxis be considered?
Consider prophylaxis if:
✓ Patient is suffering form 1-2 migraines per week
✓ More than 2 migraines per month
What medications are available for the prophylaxis of migraines?
1st line: Topiramate or Propranolol;
Other option: Amitriptyline (according to the person’s preference, comorbidities and risk of adverse events).
MOA of Topiramate for migraine prophylaxis…
Anti-epileptic medication; exact MOA responsible for migraine prophylaxis is unclear. Affects neuronal hyperexcitability which is one probable factor in the development of migraine.
MOA of Amitriptyline for migraine prophylaxis…
Amitriptyline: Tricyclic antidepressant inhibits reuptake of serotonin and noradrenaline from synaptic cleft, leading to increased levels of serotonin and noradrenaline available for neurotransmission.
Blocks a wide array of receptors making it a complicated/messy drug with LOTS of side effects!
Acute Management and Prophylaxis Recommendation of Cluster Headaches
Sumatriptan - S/C or nasal administration. Repeated in 1 hour or 2 hours respectively if headache recurs.
Short Burst Oxygen Therapy: 100% O2, 12-15: via non-rebreather for 15-20 minutes
Prophylaxis: Verapamil, a rate limiting calcium blocker.
How is the sensation of emesis coordinated in the brain?
Coordinated in the vomiting centre and the chemoreceptor trigger zone, found in the medulla.
The vomiting centre responds directly to stimuli from various parts of the body that may be stressed or diseased. The chemoreceptor trigger zone, by contrast, is stimulated by many toxins and drugs.
