Neuro chapter 2 Flashcards
Brain tumors are also called ___
neoplasms
What is a meningioma?
Brain tumor encased in meninges
Usually benign
What is a neuroma?
A benign encapsulated tumor growing on a nerve
What is an infiltrating brain tumor?
Malignant tumors that grow diffusely through tissue.
Difficult to remove
What are metastatic tumors?
Tumors that originate elsewhere
What is a stroke?
A sudden-onset cerebrovascular event that causes brain damage
What is the infarct?
The dead or dying tissue at the area of the stroke
What is the penumbra?
The damaged tissue surrounding the infarct (immediate damage zone) in a stroke.
Which one is savable, the infarct or the penumbra?
The penumbra, with immediate attention
A hemorrhage causes __ % of strokes
13
What is a brain hemorrhage?
Blood vessel rupturing in the brain
The aneurysm is the weakened point in the blood vessel
What causes the damage of a brain hemorrhage?
Free floating blood breaks down, forming free radicals which degrade lipid membranes and damage DNA
Free radicals from cerebral hemorrhage
______ breaks down, forming ____ which reacts with iron to make ____ radicals
Oxyhemoglobin breaks down, forming hydrogen peroxide, which reacts with iron forming hydroxyl radicals
What is ischemia?
A disruption of blood supply to the brain (causes most strokes)
What are thrombosis?
Blood clots
What are embolisms?
Blood clots that form because a “plug” moves to block a smaller vessel
What is arteriosclerosis?
Thickening artery wall, usually from fat, causing an ischemia
What are brain stents?
Metal mesh that can open up an artery, cant use them in the brain
What is the expected damage of an ischemic stroke?
Slow time to develop
Depends on the brain area
Blood deprived brain regions release glutamate
What is the glutamate cascade in a stroke?
Dying cells release glutamate
Glutamate stimulates cells causing influx of Na and Ca2+
This kills cells
Dying cells release glutamate
How do you combat ischemic stroke damage?
Thrombolysis
Endovascular therapy
NMDA antagonists
What are closed head injuries?
Injuries that don’t penetrate the skull
Direct or contrecoup
Contusions, concussions
What are contusions?
Closed head injuries that involve bruises
What are concussions?
Closed head injury with no structural damage
What is coup vs contrecoup injuries?
If I hit my head on a wall
Coup = brain hitting front of skull
Contrecoup = brain hitting back of skull after hitting front of skull
Symptoms of a concussion include:
Lack of consciousness (sometimes)
Cognitive damage
Somatic damage
Affective damage
Sleep issues
What is CTE
Chronic Traumatic Encephalopathy
Multiple concussions
“Punch Drunk Syndrome”
What is proof of chronic traumatic encephalopathy?
multiple concussions have lead to a 400% increase in neurodegenerative disorders in NFL players
What is encephalitis?
Inflammation of the brain from microorganisms.
What can cause encephalitis?
Bacteria
Viruses
Parasites
Fungi
A brain abscess is a…
pocket of pus
Meningitis is a bacterial infection resulting in
Inflammation of the meninges
Abscesses and meningitis can be treated with
antibiotics
What is an example of a viral infection that attacks neural tissue?
Rabies
What are neurotoxins?
toxins that are destructive to nerve tissue
Exogenous neurotoxins are…
toxins that enter general circulation from the outside
Endogenous neurotoxins are…
toxins that originate from inside the body
(glutamate in stroke victims is an endogenous neurotoxin
Lead, Mercury, and Venoms are examples of
exogenous neurotoxins
Toxic psychosis is
psychosis resulting from exposure to neurotoxins (lead/mercury poisoning)
What is tardive dyskinesia?
Involuntary motion caused by some antipsychotics
An example of the effects of exogenous neurotoxins
What are genetic factors of brain damage rare and usually recessive?
Our monkey ancestors with down syndrome didn’t live long or have kids
What is an example of a genetic brain damage condition?
Down syndrome
Caused by extra chromosome 21
What are characteristics of down syndrome?
Health problems
Intellectual disability
Facial and musculoskeletal features
What is epilepsy?
A condition characterized by recurring seizures of endogenous origin.
What is the rate of epilepsy in the population?
4%
What causes epilepsy?
Brain damage
Inflammation
Genetic component
How do we diagnose epilepsy?
With an EEG
Electroencephalogram
What does a seizure look like on an electroencephalogram (EEG)?
Bursts of high amplitude spikes of neuron activity
What are features of epilepsy?
There are subtle signs (mood, behavior, thoughts) and physical signs (convulsions, rigidity, or loss of consciousness
What are the 2 types of focal seizures?
Simple and complex seizures are the 2 types of focal seizures
What are the 2 types of general seizures?
Absence and Clonic-tonic seizures
What are different names for absence and clonic-tonic seizures respectively?
Petit mal and grand mal
Simple seizures are characterized by…
Sensory or motor symptoms usually, sometimes both
Simple seizures ____ through _____
Simple seizures spread through different brain regions
Complex seizures are restricted to the ____
Temporal lobe
Complex seizures cause patients to engage in….
Compulsive and repetitive simple behaviors. Almost normal behavior
Grand mal seizures are characterized by…
Loss of consciousness and convulsions.
Tonic stands for..
Rigidity
Clonic stands for…
Tremors
How can tonic-clonic seizures cause brain damage?
They may result in hypoxia
Absence seizures are…
not associated with convulsions. Like spacing out for a few seconds but more serious
What are auras in epilepsy?
Peculiar subjective experiences that precede seizures (smell, feelings, hallucinations)
The nature of an epileptic seizure can suggest the…
brain region of the seizure
Parkinson’s disease is a rare disease characterized by….
Dysfunctional motor capabilities (tremors, slow movement, reduced facial expression)
there is ____ cause of parkinson’s
no single
Parkinson’s is caused by degeneration of…
dopaminergic neurons in the substantia nigra
what is the result of the loss of dopaminergic neurons in the substantia nigra?
Loss of dopamine released in the striatum of the basal ganglia
Autopsies of Parkinson’s patients reveals…
Lewy bodies in the substantia nigra
L-dopa helps with Parkinsons because it is a…
dopamine agonist
80% of cases of parkinson’s are idiopathic meaning…
there is no specific known cause
The most common gene linked to parkinson’s is…
PRKN gene
Genes that are less common causes of parkinson’s are…
Alpha-synuclein (SNCA)
Dardarin protein (LRRK2)
What is Alpha-synuclein gene?
The main component of lewy bodies, which contribute to parkinsons.
What is MPTP and what does it do?
MPTP = synthetic heroin
Causes cell loss in the substantia nigra and reduced dopamine release in the striatum
What is huntington’s disease?
Very rare progressive motor disorder, middle aged onset, caused by single dominant gene.
What makes huntington’s disease special?
Huntington’s disease is genetic and dominant, it sets in around 40 and kills within 15 years. It isn’t curable
What is multiple sclerosis?
The progressive loss of CNS myelin
Literally means multiple harending
What are symptoms of MS?
Muscle weakness, numbness, impaired motor coordination
Is there a cure to MS?
Not currently, but immunomodulators may slow progress
What are some potential causes of MS?
There is a genetic component
Environment may play a role. (Lifestyle, infections, and climate can increase risk)
Corticosteroids help in the treatment of MS by:
reducing inflammation
Alzheimers is the most common cause of…
dimentia
Alzheimers is more common…
in women and as you get older
There is a high correlation between alzheimers rates and what condition?
down syndrome
A definitive diagnosis of alzheimers can only be given..
during an autopsy
What are the 3 stages of alzheimer’s?
Preclinical phase
Prodromal phase
Dementia phase
What occurs in the preclinical phase of alzheimer’s?
Some neuropathy presents itself but no symptoms begin to show
What occurs in the prodromal phase of Alzheimer’s
Mild cognitive impairment begins to show
Confusion, memory and attention issues
What occurs in the dementia stage of alzheimers?
serious memory and attention issues
personality changes
Massive neurological impairment (bladder control, motor control)
What are the 2 proteins that are related to the onset of alzheimers?
Tau and amyloid proteins
Tau proteins clump together ___ the cell
Inside the cell
Amyloid plaques (proteins) clump together ___ the cell
outside the cell
What can reduce the symptoms of alzheimers?
Acetylcholine (ACh) agonists help but do not cure it.
Immunotherapy against amyloid proteins is promising
Is neural regeneration common in “higher” vertebrates?
No, its not observed in the CNS at all and is rarely observed in the PNS
Why is neural regeneration seen in PNS but not CNS?
PNS has schwann cells that promote neural regeneration.
CNS has oligodendroglia which inhibit regeneration.
Neural reorganization can be a result of…
experience or damage
What is an example of neural reorganization in humans?
Blind people have larger auditory and somatosensory cortices.
Recovery from CNS damage is usually a result of _____ not ____ recovery
compensation not true recovery
Neurotransplantation of embryonic cells has had ____ success in humans for curing ____
very limited success in humans with curing parkinson’s and spinal cord damage
Neurotransplantation of non-embryonic cells has shown…
Minimal success in humans, some success in axonal regeneration of rat spinal cord damage
What are 3 neuroprotective treatments?
Apoptosis inhibitor proteins
Neurotrophins
Estrogens
How do estrogens act as a neuroprotector?
They limit or delay neuron death
Rehabilitative training to treat spinal injuries often involves…
physiotherapy
What is Ramachandran’s hypothesis of phantom limb pain?
The pain perceived by phantom limb sufferers is caused by reorganization of the somato-sensory cortex
(pain comes from brain not from arm)
What does Ramachandran’s hypothesis of phantom limb pain propose as a solution to phantom pain?
Amputees can get phantom pain relief from visual feedback
