Chapter 15 - Neurological Disorders Flashcards
a mass of cells whose growth is uncontrolled and that serves no useful function
Tumor
a cancerous tumor; lacks distinct border and may metastasize. (If you cut into it, it’s gone.)
Malignant tumor
a noncancerous tumor; has a distinct border and cannot metastasize.
Benign tumor
a process by which cells break off of a tumor, travel through the vascular system, and grow elsewhere in the body.
Metastasis.
a cancerous brain tumor composed of one of several types of glial cells.
Glioma
contain initiating cells which originate from transformations of neural stem cells. Rapidly proliferate and give rise to glioma
Malignant gliomas
a benign brain tumor composed of the cells that constitude the meninges.
Meningioma
Tumors can damage brain tissues by 2 means
Compression; Directly or indirectly (blocking flow of CSF, hydrocephalus
Infiltration: more difficult to treat, hard to remove tumor once it’s infiltrated neurons and tissue.
Primary symptom is seizures. Overabundance of electrical activity in a vessel, weakening the vessel. Causes electrical activity in the brain - causing seizures
Epilepsy
Often preceded by an aura, such as a smell, hallucination or feeling.
Seizure
strong smell - somatosensory cortex.
feelings of depression - temporal lobe
Seizure that does not involve the whole brain. Has a definite source of focus/irritation. Can be removed and number of seizures can be diminished. (most common form)
2 types.
Partial seizures
Involves entire brain. Starts at one hemisphere, crosses the corpus collosum to get to the opposite hemisphere.
Generalized epilepsy
Type of seizure.
symptoms are primarily sensory, motor or both. Symptoms spread as epileptic discharge spreads. Not associated with loss of consciousness.
Simple partial seizure
Type of seizure
Often restricted to the temporal loves (temporal lobe epilepsy). Patient engages in compulsive and repetitive simple behaviors (automatisms). Leads to loss of consciousness. (Most common type)
Complex partial seizure
Patient engages in compulsive and repetitive simple behaviours.
Automatisms
Type of seizure.
Tonic-clonic convulsions. Rigidity (tonus) ~ 15 s. All muscles contract, arms are rididly outstretched.
Tremors (clonus) ~ 30s. Muscles begin trembling, jerking, quick at first but slows down, eyes rolld, face in contorted, sweating, salivation.
firing begings at focus spreads to other regions by corpus callosum.
Resulting hypoxia may cause brain damage.
Grand mal seizure (type of generalized seizure)
Type of seizure.
More common in children. Not associated with convulsions.
A disruption of consciousness associated with a cessation of ongoing behaviour. Unresponsive, usually do not notice attacks.
can occur several hundred times a day.
Absence (petite mal)
50% of patients with seizures show damage to the ____
Hippocampus
a condition in which a patient undergoes a series of seizures withouht regaining consciouness. May cause significant hippocampal damage.
Caused by excessive release of glutamate during seizure.
Status epilepticus
type of seizure where infant gets a very high fever; does not lead to epilepsy
Febrile seizures
Seizure - when sudden release of the inhibiting effects of alcohol or barbiturate leaves the brain in a hyper-excitable condition (can be fatal)
Caused by alcohol or barbiturate withdrawal.
___ genes assocaited with seizure disorders. (not common cause)
NEarly all genes identified control the production of ion channels.
70
Treatment for seizures
Anticonvulsant drugs (increase effectiveness of inhibitory synapses) Brain surgery (remove region of the brain surronding the focus, usually located in the MTL)
A series of alternating bilateral brain stimulations eventually elicits convulsions.
typicall the amygdala or hippocampus. Neural changes are permanent.
Comparable to the development of epilepsy seen following a head injury
the kindling phenomenon
development of epilepsy
epileptogenesis
third leading cause of death. most common cause of adult disability
stroke
common consequences of stoke
amnesia, aphasia, paralysis, coma
area of dead or dying tissue produced by the stroke
infarct
dysfunctional area surrounding the infarct
Penumbra
goal of treatment following a stroke
save the penumbra.
Two major causes of Cerebrovasular accidents
hemorragic
ischemic
cerebrovasular accident caused by the rupture of a cerebral blood vessel. (malformed blood vessel; weakened blood vessel from high blood pressure)
Blood seeps out and accumulates within the brain, putting pressure on the surrounding tissue.
Hemorrhagic Strokes
pathological balloon-like dilation that forms in the wall of an artery at a point where the elasticity of the artery wall is defective.
- congenital
- vascular posions or infection
- weakened blood vessel from high blood pressure
Aneurysm
cerebrovasular accident caused by occulsion of a blood vessel
Ischemic Stroke
blood clot that forms within a blood vessel, which may occlude it.
thrombus
piece of material that forms in one part of the vascular system, breaks off, carried by blood stream until it reaches a smaller artery.
embolus
interruption of the blood supply to a region of the body.
Ischemia
toxic cells that can destroy nucleus, proteins and fatty acids
Free radicals