Neurological Disorders Flashcards
what are neurological disorders associated with?
an abnormality of or injury to the brain
what is involved in the process of neurological examination?
neurologist asks about history of patient/family history
-neurologist observes behaviours while taking history to assess mental status, motor control, speech abnormalities
-neurologist performs basic cognitive tests (memory and attention)
-assess function of cranial nerves
-follow up testing using imaging (EEG, CT, MRI)
what are common causes of TBI?
-car accidents, combat, sports
why is the incidence of TBI hard to determine?
many go unreported
who is at higher risk of TBI?
males between ages 15 and 30
sports account for what % of all TBI?
20
what sports are most dangerous for TBI?
football, hockey, rugby, lacrosse, soccer
there is a long term decrease in ______ ______ following TBI
glucose metabolism
what are open head injuries?
TBI where skull is penetrated by an object (bullet, shrapnel)
what are closed head injuries
any blow to the head that does not penetrate the skull
what is a coup?
damage to the brain at the site of the blow caused by the brain impacting with the skull
what is a contrecoup?
damage to the brain at the opposite side of the skill from the site of injury (coup) caused by the brain rebounding from the initial injury and impacting the skull
what is shearing?
twisting/breaking of nerve fibers caused by the rapid movement of the brain inside the skull
what is a hematoma?
mass of blood trapped in the skull
what is an edema?
swelling that can result in pressure on the delicate cranial nervous tissue
boxers and football players may suffer from _____ _______, which is another form of chronic traumatic encephalopathy, also known as ‘punch drunk syndrome’
dementia pugilistica
what is true about the correlation between duration of unconsciousness (coma) and severity of head injury?
longer the coma, the greater the possibility of impairment or death, correlates with mortality, intellectual impairment and deficits in social skills
injuries can also result from ____ _____ throughout the brain and are associated with…
widespread trauma, loss of complex cognitive functions and efficiency
how can behavioural changes from head injuries impact a patient?
may make them more susceptible to further head injuries
which type of assessment is most valuable in gaining information about TBI?
behavioural assessment
what is the scale used to quantify unconsciousness and recovery of consciousness?
Glasgow Coma Scales
what 3 scales does the Glasgow Coma Scale employ?
1) eye opening
2) motor response
3) verbal resopnse
on the Glasgow coma scale, a score of what is associated with severe head injury?
8 or less
in recovering from a TBI, when does most recovery occur?
first 6-9 months
which cognitive function recovers the slowest after TBI?
memory
if the damage involves this structure, the prognosis for recovery is not as good…
brainstem
what are seizures?
spontaneous, abnormal discharges of neurons that result from injury, infection, or tumors
when is epilepsy diagnosed?
after at least 1 seizure, but typically after multiple
what is the prevalence of seizures?
about 1 in 20 individuals
what are symptomatic seizures?
seizures associated with a known cause, such as infection, trauma, fever, or another disorder
what are idiopathic seizures?
spontaneous seizures without any known or obvious causes
is there a genetic aspect to seizures?
yes, likely a genetic predisposition influenced by numerous genes
what are some common symptoms related to many types of epilepsy?
-aura, loss of consciousness, movement
what are precipitating factors in individuals susceptible to seizures?
-drugs
-emotional stress
-fever
-hormonal changes
-hyperventilation
-sensory stimuli
-sleep/sleep deprivation
-trauma
what are focal seizures?
begin in one location in the brain and the electrical activity spreads to involve other brain regions
what are the 2 types of focal seizures?
-focal aware
-focal impaired
what is a focal aware seizure?
person is conscious
what is a focal impaired seizure?
person generally aware that seizure is beginning, performs automatic behaviours, has a fixed posture, loses conscious awareness of the condition
what is another name for a focal impaired seizure?
complex partial seizure
what are generalized seizures?
when seizure activity takes place in both hemispheres without a clear focus
what are generalized seizures characterized by?
loss of consciousness and breathing stops (Tonic phase) and stereotypical motor behaviour (clonic phase)
what are akinetic seizures?
typically only seen in children, collapse suddenly and without warning
what are myoclonic seizures?
large seizures characterized by flexion or extension of whole body
what are dissociative seizures?
like focal seizures, but no EEG change
-pts report feeling cut off from body and surroundings
-not usually treated with drugs
2/3 in every 10,000 people
what pharmaceuticals can be used to end seizures?
GABA agonists or glutamate antagonists
what sort of drugs are used to inhibit the development of seizures on their propagation?
-GABA agonists
-sodium channel blockers
-anesthetics and anticonvulsants
what other treatment do 30-40% ofthe population rely on to control their seizures?
-DBS or surgery to remove areas where seizures start
what are the main types of seizures
-focal
-generalized
-akinetic
-myoclonic
-dissociative
what are tumors?
mass of new tissues that grows independent of cells and does not have physiological purpose
tumors can also be called….
neuroplasms
what do brain tumors originate from
glia or other supporting cells, as the neurons cannot grow and divide
what type of tumors generally do not reoccur after removal?
benign
what type of tumors are progressive?
malignant tumors
what are encapsulated tumors?
tumors that are localized to a distinct location but put pressure on surrounding tissue
what are infiltrating tumors?
tumors that interact with surrounding cells and either destroy them or interfere with their function
what do tumor symptoms result from?
increased pressure inside the skull as the mass is competing for more space normally occupied by healthy brain tissue
what are symptoms of a tumor?
-headache
-vomiting
-slowing of HR
-double vision
-convulsion
what are the 3 types of brain tumor?
Glioma
Meningioma
Metastatic tumor
what are glioma?
-arise from glial cells and infiltrate surrounding brain
what % of brain tumors is made up of glioma?
45
what are meningioma?
tumors associated with the protective meninges that surround the brain. they are benign and encapsulated
how do meningioma cause symptoms?
by compressing adjacent brain tissue
what are metastatic tumors?
tumor cells from elsewhere in the body that start to grow in the brain. usually more than one, making prognosis poor and treatment difficult
why does radiation therapy work better for brain tumors?
chemo drugs too large to pass through BBB
where does the pain of a headache occur?
dura mater, arteries and veins of the brain, cranial and cervical nerves
what does headache pain result from?
pressure, displacement, or inflammation
what does the World Federation of Neurology define migraine as?
” a familial disorder characterized by recurrent attacks of headache”
migraine impacts _____% of the population at some point in their lives?
5-20
migraines are often ______ and preceded by _______
unilateral, aura or mood disturbance
explain the occurrence of a classic migraine:
-start with an aura
-depolarization spreads to surrounding neurons, causing IPSPs, neurons inhibited from firing
-headache associated with blood flow returning to normal and the pain comes from a large volume of blood being pumped through vasoconstricted veins
what are auras thought to be caused by in migraines?
vasoconstriction of cerebral arteries that results in loss of blood flow to occipital cortex
what is the prevalence of classic migraines?
12% of all migraine sufferers
what differentiates a common migraine from a classic migraine?
no aura
what are cluster headaches?
unilateral headaches that recur for days or weeks before disapperaring
what are treatments for headache?
-pharmaceutical agents
-behaviour or lifestyle changes
what is a possible reason for headache occurences decreasing with age?
learn to cope with stress better
what can headaches be symptoms of?
many diseases of nervous system, such as tumors, head trauma, infection, and hypertension
what are the characteristics and locations of headaches associated with?
causes
what are muscle-contraction headaches results of?
persistent contraction of muscles of scalp and neck due to stress
what are non-migranious vascular hadaches?
just that, vascular headaches associated with dilation of arteries and can be caused by fever, eating disorders, high altitude, food, chemicals, odors
why are nervous system infections so serious?
because the affected neurons/glia usually die, and that is permanent damage
how can infections enter the nervous system
?
-spread from elsewhere in body
-gain access to brain from surgery or other open head injuries
how can infections damage the brain?
-interfering with blood supply –> death of cells and brain tissues
-disrupting metabolism of glucose or oxygen –> no energy for cells
-altering neuronal membranes —> cant keep proteins etc
-forming pus –> can create absesses
-causing swelling
how can one diagnose infections of nervous system?
analyze composition of CSF
What are the types of CNS infections?
viral
bacterial
mycotic
parasitic
how do viral infections work?
virus has and RNA or DNA genome and invades a host cell to replicate
-some viruses attack nervous system preferentially while others attack cells throughout body
name examples of viral infections
Zika
West Nile
how do bacterial infections work?
cell division
what happens in bacterial meningitis?
meninges are infected by bacteria and become inflamed
what are brain abscesses?
pockets of pus produced by bacteria that destroy the cells in the area
what are mycotic infections?
fungal infections of brain by yeasts, mold, and mushroomsx
-rare, brain is usually resistant
when can an individual be at a higher risk for mycotic infection?
following cancer or tuberculosis
how do parasitic infections work?
parasites are living organisms that live inside a host organism usually to their detriment
what is malaria?
a parasite transmitted by mosquitoes, infects brain capillaries and results in local hemorraghes
toxoplasma gondii is an example of what type of infection?
parasitic
how is toxoplasma gondii transmitted?
causes toxoplasmosis and is transmitted from rats to domestic cats who eat them and then to humans who clean litter box
what do most treatments of CNS infections involve?
managing symptoms more than removing infectious agent, especially for viruses
apraxia:
inability, in the absence of paralysis or other motor or sensory impairments, to make or copy voluntary movements, usually follows damage to neocortex
ataxia:
failure of muscular coordination or irregularity of muscular action. follows cerebellar damage
athetosis:
ceaseless slow, sinuous, writing movements especially in the hands, due to abnormal function of extrapyramidal system
catalepsy:
muscular rigidity in which voluntary movements are reduced or absent but posture is maintained. feature of Parkinsons, due to dopamine loss
cataplexy:
complete loss of movement and posture during which muscle tone is absent but consciousness is spared
chorea:
“to dance”, refers to a wide variety of ceaseless jerky movements that appear well coordinated but are performed involuntarily
hemiplegia:
complete or partial paralysis to half of the body. usually follows damage to contralateral motor cortex
palsy
usually refers to persisting movement disorders due to brain damage acquired perinatally
paralysis
complete loss of movement or sensation in a part of the body, permanent after damage to motor neurons, temporary after damage to motor cortex
paraplegia
paralysis or paresis of the lower torso and legs following spinal cord damage
spasticity
increased tone in muscle groups that maintain posture against the force of gravity, if the limb is moved against the rigidity, resistance will initially increase and then tone will suddenly melt (clasp-knife reflex). thought to be produced by damage to the extrapyramidal motor fibers
tardive dyskinesia:
slow, persistent movements, particularly of the mouth and tongue. usually follows long term treatment with anti-psychotic drugs
Myasthenia Gravis
severe muscle weakness characterized by muscle fatigue after little activity or exercise
who is myasthenia gravis most common in?
women, age of onset in the 30s
what are the initial symptoms of myasthenia gravis?
drooping eyelids, difficulty chewing and swallowing
when do myasthenia gravis symptoms usually occur and how can they typically be alleviated?
at the end of the day, relieved by sleep
how does myasthenia gravis happen?
Ach receptors at neuromuscular junction are destroyed by immune system
what is multiple sclerosis?
when myelin sheaths are attacked and destroyed in the motor and sensory tracts, means of attack could either be bacteria, virus, or antibodies
where does the loss occur in MS?
in patches throughout the nervous system
what is the symptomatic pattern of MS?
symptoms are off and on
what is the prevalence of MS?
slightly more common in females than males (3:2), more common in northern hemisphere
in paraplegia, where is the damage?
at level of thoracic spine, leading to loss of information for legs
in quadriplegia, where is the damage?
at the level of the cervical spine, loss of information for all 4 limbs
what is Brown-Sequard syndrome?
when just one side of spinal cord is damaged, impacting only some of the ascending and descending pathways
what is hemiplegia?
loss of voluntary movements on one side of body and changes to some reflexes
how does hemiplegia happen?
results from damage to cortex and basal ganglia contralateral to side of motor impairment
in whom are most cases of hemiplegia found and why?
most common in older adults as a result of rupture of blood vessels due to high BP
Babinski sign:
in intact individuals, will flex toes downward after stimulus to bottom of foot
what is the babinski sign in hemiplegic individuals:
extend toes
what are hyper-kinetic distonic syndromes
syndromes that increase motor activity
examples of hyperkinetic-distonic syndromes?
Huntingtons, Tourettes
what are hypokinetic-rigid syndromes?
syndromes that decrease movements
example of a hypokinetic rigid syndrome
Parkinsons
what behaviours are characteristic of Huntington disease?
writhing and twisting movements (choreas)
what does Huntington disease result in?
intellectual deterioration and personality changes
what is the age of onset for Huntington?
30-50 years
what are symptoms of Huntington disease?
impairments of recent memory, slowed information processing, emotional changes such as depression and anxiety
how is Huntington disease cause?
by a mutation of huntington gene (dominant) which results in a defective protein that accumulates in basal ganglia
what does the cortex of Huntington patients show?
thinning and shrinkage
in the basal ganglia, what is the indirect pathway inhibitory for?
voluntary movement
Huntington disease is associated with a ____ in activity in the ______ pathway due to cell loss in the _____ _____and ______, resulting in
decrease
indirect
globus pallidus
putamen
…a decrease in inhibition of movement
what are the 3 stages of progression in Tourettes synrome:
1) tics of face, limb, body
2) tics accompanied with inarticulate cries
3) echolalia and coprolalia added to tics and cries
age of onset of Tourettes
2-15 years
Tourettes patients have a _____ putamen and a ____ thalamus
larger, smaller
Tourettes patients also exhibit __________ difficulties
visuospatial
symptoms of Parkinsons are divided into 2 groups, what are they
positive and negative symptoms
why are positive symptoms of Parkinsons given that title?
describe abnormal behaviours that have been gained
why are negative symptoms of Parkinsons given that title?
describe normal behaviours that have been lost
positive symptoms of Parkinsons:
-tremors
- muscular rigidity due to excitation of both flexor and extensor muscles at same time
-involuntary movements
negative symptoms of Parkinsons:
-postural disorders prevent individual from maintaining the posture of a body part
-righting disorders involve inability of patients to stand up from laying down
-locomotive disorders involve difficulty walking
-speech disturbances include the lack of prosody in the voice
-Akinesia is a poverty or slowness of movement
often, cause of Parkinsonism is
idiopathic
postencephalitic form is
due o damage of cells at substantia nigra following encephalitis
drug- induced Parkinson disease:
can result from drugs used to treat schizophrenia, is reversible
recreational drugs and Parkinsonism:
ie: synthetic form of heroin can cause permanent damage to dopamine cells and cause Parkinsons
parkinson diesase is observed when:
dopamine levels are reduced by more than 90% below normal levels
cure for parkinson disease?
no
some pharmaceutical therapies for Parkinsons:
-L-dopa: cross BBB and be converted to dopamine to convert what has been lost
-monoamine oxidase inhibitory and tricyclic antidepressants enhance dopamine neurotransmission
-anticholinergic drugs are used to block the acetylcholine signaling that increases when dopamine decreases
-DBS
-stem cells to replace lost domapine nneurons
what is a cerebral vascular accident (stroke)
sudden appearance of neurological symptoms as a result of blood supply being interrupted
what is an infarct
region of the brain that is directly impacted by the stroke and is characterized by dead and dying cells
3 types of cerebral vascular disorders:
-cerebral ischemia
-migraine stroke
-cerebral hemorrahage
what is cerebral ischemia
when a blood vessel is blocked, preventing enough blood from reaching the brain
what is thrombosis
a clot in the vessel that has remained where it was formed
what is an embolism
a clot or other plug that formed in a larger vessel and moved until it was stuck in a smaller vessel
what is a migraine stroke
when blood flow is interrupted by a constriction of the blood vessel, cause of vascular spasm not known
what is a cerebral hemmorhage
when a blood vessel fails, resulting in bleeding into the brain. causes can include high BP, trauma, toxic chemicals
what are angiomas
abnormal blood vessels that divert the normal flow of blood. result in abnormalities in the pattern and amount of blood flow
what are aneurysms
when the normal elastic walls of blood vessels is defective, leading to vessel walls ballooning out and weakening structure of the vessel
what is the goal of ideal treatment of cerebral vascular diseases
to restore blood supply, not always possible
what kind of drugs can be effective to block cell death
drugs to block excitation and calcium channels
