neurological disorders Flashcards
2 forms of alzheimer’s and their onset
sporadic: after 65
familial: before 65
how does the prevalence of alzheimer’s increase
after 65, increases every 5-10 years
3 genetic mutations of alzheimer’s
- apolipoprotein E
- presenilin 1 and 2
- amyloid percursor protein
what is the enzyme that removes acetylcholine called
acetylcholinesterase
how does calcium cause acetylcholine release from the synaptic knob
when calcium enters the synaptic knob it triggers synaptic vesicles to fuse with the membrane and release acetylcholine by exocytosis
what is glutamate
a stimulatory neurotransmitter
what is myasthenia gravis a disorder of
transmission at the neuromuscular junction
True/False:
myasthenia gravis is classic autoimmunity
true
what types of immune cells are involved in myasthenia gravis
antibodies and T cells
in myasthenia gravis T cells attack receptors leading to 3 things:
- shredding of the terminals of the muscle
- a decrease in the number of terminals
- a widening of the synaptic space
what is another problem myasthenia gravis is also associated with
thymic abnormalities or hyperplasia
myasthenic crisis may result in
respiratory failure
what are the 2 forms of Alzheimer’s, % of incidence, and onset
sporadic - 90% - > 65
familial - 10% - < 65
Alzheimer’s involves ______ atrophy
cortical atrophy
Alzheimer’s brains will have prominent ____ and slender _____
prominent sulci
slender gyri
Alzheimer’s is associated with low levels of what neurotransmitter
acetylcholine
what are the 2 types of lesions called in Alzheimer’s
- neuritic plaques
- neurofibrillary tangles
Alzheimer’s lesions are due to
accumulation of proteins
neuritic plaques are caused when
the terminal ends of neurons degenerate and protein deposits (amyloid beta)
amyloid beta results from a breakdown of
amyloid precursor protein
neurofibrillary tangles are caused by
the tangling of fibers in the neuron
3 drug classes for treating Alzheimer’s
- Donepezil
- Memantine
- Risperidone
True/False:
multiple sclerosis is an example of classic autoimmunity
true
multiple sclerosis is caused by targetting/destruction of
myelin sheath in the CNS
what gene mutation causes MS
human leukocyte antigen (HLA)
what does the human leukocyte antigen gene code for
major histocompatibility complex (MHC)
what virus may trigger MS
epstein-barr virus
what types of cells produce myelin
oligodendrocytes
the necrosis of oligodendrocytes will cause
infiltration of lymphocytes and macrophages causing sclerotic patches
MS affects what 2 types of neurons
motor
sensory
periods of MS exacerbation occur when
necrosis of oligodendrocytes and demyelination furthers
periods of MS remission occur when
antibody and T cell production dwindles allowing oligodendrocytes to recover and produce myelin
elevated protein levels in the CSF indicate
- compromised BBB
- inflammation in the CNS
- autoimmunity
what type of antibodies will be present in the CSF of MS
IgG
Amyotrophic lateral sclerosis affects what type of neurons
motor
amyotrophic lateral sclerosis is caused by _____ of nerve fibres
atrophy
Trua/False:
ALS is classic autoimmunity
False
ALS is most common in ____ over __ years old
men
50
what are the 2 types of ALS and % of incidence
sporadic - 90-95%
familial - 5-10%
ALS is sometimes caused by a mutation of what gene
superoxide dismutase (SOD1)
what does the SOD1 gene code for
the superoxide dismutase enzyme which breaks down free radicals
amyotrophic lateral sclerosis is caused by degeneration of motor neurons in these 3 areas
- motor nuclei in the brain stem
- anterior horn cells in the spinal cord
- upper motor neurons in the cerebral cortex
anterior horn cells are responsible for what types of commands from the brain
somatic motor commands
where do upper motor neurons send messages between
the brain to spinal cord
what two types of functions are not affected by amyotrophic lateral sclerosis
cognition and sensory
Parkinson’s disease is a disorder of the
basal ganglia function
Parkinson’s is caused by degenerative destruction of the
nigrostriatal pathway
what 2 degenerative disorders typically affect men > 50
Amyotrophic lateral sclerosis (ALS)
Parkinson’s disease
what 2 degenerative disorders typically affect young women and are types of classic autoimmunity
Multiple sclerosis (MS) Myasthenia Gravis
what 2 environmental exposures can cause Parkinson’s
manganese exposure
severe carbon monoxide poisoning
In Parkinson’s, the destruction of _____ neuronal cells in the ____ _____ cause degeneration of _______ pathways and a decrease in dopamine stores
dopaminergic
substantia nigra
nigrostriatal
Parkinson’s is an imbalance of what neurotransmitters
decreased dopamine levels
normal acetylcholine levels
what are the 4 cardinal manifestations of Parkinson’s
tremor
rigidity
bradykinesia
postural instability
Parkinson’s medications (and actions)
- levodopa (dopamine precursor)
- dopamine agonists (stimulates dopamine receptors)
- monoamine oxidase (inhibits dopamine breakdown)
- anticholinergic agents (inhibits ACh - restores balance)
- Amantadine (antiviral that increases dopamine)
what are the 3 layers of the meninges
dura mater
arachnoid mater
pia mater
CSF is between what layers of the meninges
the arachnoid mater and the pia mater
subarachnoid space
what are 2 bacterias that cause bacterial meningitis and who do they affect
Neisseria meningitides (youth) streptococcus pneumonia (adults)
bacterial meningitis is usually seen following these 4:
- head trauma
- neurosurgery
- immunocompromised
- congruent infection (ex. sinusitis)
when the meninges swell and adhere to each other and the brain, this causes these 3 things
- CSF flow obstruction
- hydrocephalus (CSF accumulation in the brain)
- increased intracranial pressure
2 tests for meningeal irritation
positive brudzinski’s sign
positive kernig’s sign
Budzinski’s sign involves
hip and knee flexion when the neck is flexed
kernig’s sign is when
the knee cannot be extended when the hip is at 90 degree
the CSF of bacterial meningitis will have
- proteins
- low glucose
- leukocytes (neutrophils)
- pus
the CSF of viral meningitis will have
- proteins (lower than bacterial)
- normal glucose levels
- lymphocytes
- monocytes
encephalitis is inflammation of the
parenchyma
encephalitis is usually caused by these 2 viruses
herpes simplex type 1
arbovirus
during encephalitis, degeneration and necrosis leads to these 5 things
- inflammation
- exudate
- hemorrhaging
- edema
- IICP
encephalitis caused by arbovirus is generally ________ and lasts for _ weeks
self-limiting
2
a seizure is a ______ not a disease
manifestation
seizures are caused by changes to the ________ causing unregulated _____ ______
neurilemma
neural discharge
epilepsy is a disease characterized by
chronic seizures
2 causes of seizures
provoked (secondary)
unprovoked (primary)
5 causes of secondary (provoked) seizures
- electrolyte imbalance
- hypoxia
- CNS injury
- febrile
- hypoglycemia
seizures in one hemisphere of the brain are called
partial seizures
seizures in both hemispheres of the brain are called
generalized seizures
a seizure in one hemisphere of the brain and no loss of consciousness is called a
simple partial seizure
a seizure in one hemisphere of the brain and loss of consciousness is called a
complex partial seizure
cells with a lower stimulation threshold that are hyperresponsive are called the
epileptogenic focus
the period after a seizure subsides is called the
post-ictal phase
huntington’s is a hereditary ______ disorder
neurodegenerative
huntington’s is characterized by
- chronic progressive chorea
- psychological changes
- dementia
huntington’s is caused by what type of genetic disorder
autosomal dominant disorder of chromosome 4
what are the 2 most affected areas of Huntington’s
caudate nucleus and putamen of the basal ganglia
what are the 2 changes to neurotransmitters in Huntington’s
- decreased GABA
- decreased acetylcholine
Huntington’s is an imbalance of what
low levels of acetylcholine and uninhibited dopamine
what is preserved in Huntington’s
the dopaminergic pathway
what are the 3 types of manifestations in Huntington’s’
psychological
behavioural
postural
