Final Flashcards
Neuroplasticity
The brain’s ability to reorganize itself by forming new neural connections. Neurons can respond to changes and adjust their activity in response to new situations or changes in the environment.
neurons that fire together
each time we think a certain way and feel a certain emotion or perform a certain task, that connection gets reinforced.
phantom limb pain
is a sensation of pain that feels like it’s coming from a body part that is no longer there.
phantom limb pain
example of a sensory experience, produced by the brain’s adaptation to its environment.
learned paralysis
signals from the motor cortex to the paralyzed limb telling it to move, are not obeyed,
cortical remapping
areas adjacent to the limb may take over, and patients may feel as though their phantom limb is touched when their cheek is touched.
long-term potentiation
increase synaptic strength due to increased activity between neurons,
phantom limb, Spinal Hyperexcitability
- decreased activity GABA in spinal cord, may be damaged by axotomy
- Increased sensitivity of NMDA receptors to glutamate, caused by inflammation.
Parkinsons
Progressive, neurodegenerative adult-onset movement disorder
substantia nigra
2 regions SNr and SNc
SNr
input from the striatum, sends signals to thalamus using GABA
SNc
sends signals to the striatum using dopamine, Nigrostriatal pathway, when neurons here die, person become hypokinetic (decreased movement)
SNc
initiate movement, fine tune it, loosing these neurons cause the motor symptoms of parkinsons.
Bradykinesia
slow movement, bc difficulty initiating movement.
parkinsons difficult to define
- heterogeneity of clinical presentation
- variability of progression rate
- different symptoms present in clinical sub-types.
Lewy bodies
- protein aggregates,
Lysosome
in cell, digest things, can clear unwanted molecules, they aren’t doing their job because lewy bodies aren’t cleared.
parkinsons, inflammation
prolonged microglial activation leads to release of neurotoxic factors, substantia nigra has high density of microglia, THUS an increased sensitivity to cytokines has been linked to oxidative stress.
ROS
can induce pro-inflammatory signalling.
L-dopa
- Ldopa, converted to DA by enzyme called dopa-decarboxlase,
- L-dopa administered with carbidopa, a decarboxylase inhibitor.
EPO
neurotrophic factor, influence microenvironment of the SNc, promote cell survival, it decreases ROS to prevent cell death.
all cells in brain
arise from neural stem cells, because they can become any cell type,
neoplasm
new abnormal growth of tissue in the body. If it is a mass, it is called tumour. And a tumour is a mass of abnormal cells that serves no purpose.
primary brain tumour
originate from cells within the brain, stay within the CNS
secondary (metastatic) brain tumour
originate from cells outside of the brain and migrate to the brain.
Malignant bt
fast growing, undefined borders, can invade surrounding tissue.
Benign
slow growing, well-defined borders, do not invade surrounding tissue.
Gliomas
most common, start in glial cells,
suffix- blastoma
tumour made up of immature cells,
glioblastomas
type of astrocytoma…
Glioblastoma multiforme,
made of astrocytes and oligodendrocytes, most aggressive and most common type of malignant tumour, (**some times look like a butterfly.)
GBM have small area of necrotizing tissue at the core
cells grow so quickly that they outgrow their blood supply, cells at core die via necrosis.
Temozolomide
common chemotherapy drug for patients with brain tumours.
migraine
not just headache, worsens with movement, pulsating headache.
migraine
highly comorbid with depression
migraine point system
factors sum to produce migraine, predisposition may add points…
migraine: vascular hypothesis
pain of migraine caused by dilation of blood vessels.
what causes headache pain in migraine
*Ophthalmic zone, innervated by the spinal nucleus.
nerve irritation
nerves in neck and head can be compressed, surgical decompression relives migraine pain.
cellular phases of migraines
- cerebral vasoconstriction, and ischemia, neurons release serotonin, may cause aura.
- cerebral vasodilation and pain, neurons release vasoactive peptides: substance P and calcitonin gene related peptide (CGRP)
CGRP
causes vasodilation and inflammation of blood vessels,
migraine treatment
triptans are sertotonin agonists,
- act on blood vessels: vasoconstriction
- act on pre-synaptic neurons to inhibit release of peptides (like CGRP)
- activate receptors In the brain stem which is believed to inhibit trigeminal neurons.
migraines: drugs
- prophylactic: prevent phase 1,
2. abortive remedy phase two.
migraine
no standardized tool for diagnosis.