Neurology: stroke Flashcards
What is a neurological disease?
- Disease affecting health, function, structure of nervous system (brain, spinal cord, nerves)
Time scale of neurological events:
- Immediate symptoms: usually A or B in origin
- Rapidly progressive symptoms (over days) may present C or D disease
- Slowly progressive symptoms tend to be caused by diseases
A: vascular (ischaemia/haemorrhage)
B: elecrtical (epilepsy)
C: infective (meningitis)
D: inflammatory
The neuron: A + B terminate in the C
Cell body
Axon
Synapse
Some neurons have an axonal length of more than A and can innervate between several B and C muscle fibres in one leg (= D)
A 1 m
B 100
C 2000
D motor unit
Other neurons have axons <A , terminating on B neuronal cell body(s)
A 100 microm
B one
What symptoms occur when the myelin sheath in destroyed as a function of auto-immune diseases?
(problems movement, coordination, sensation, such as in MS: multiple sclerosis)
What are 7 possible causes for neurological disorders?
- Atherosclerosis -> ischaemia
- Drugs, toxins, and poisons.
- Autoimmune diseases (e.g. MS)
- Injury
- Infection: (e.g. meningitis)
- Inborn errors
What are six common neurological disorders?
- Dementia
- Epilepsy (neurological disorder where the electrical activity of the brain is abnormal,
resulting in recurrent seizures. Common cause = stroke) - Stroke
- Pathogens (encephalitis: inflammation brain, meningitis)
- MS
- Parkinson’s
What are symptoms of a stroke?
- Severe headache
- Weakness
- Numbness
- Vision problems
- Confusion
- Trouble walking/talking
- Dizziness
- Slurred speech
Stroke is the ….. cause of severe disability, ….. people have a stroke each year
Leading
>15 million
What stroke is most common: ischaemic vs haemorrhagic ?
ischaemic
What are causes for ischaemic stroke?
- Blood vessel supplying blood to the brain gets blocked by a blood clot
- Atherosclerosis is responsible for this
- Other causes: atrial fibrillation, heart attack, blood clotting problem
- Damages brain cells
Haemorrhagic strokes account for …% of strokes. The most common cause is… Other causes are….
13%
High blood pressure
- Aneurysms (weakening blood vessel wall that swells)
- AVMs (blood vessel abnormalities)
What are the two types of haemorrhagic strokes + explain
- Subarachnoid haemorrhage: happens between brain and membrane that surrounds it (=subarachnoid space)
- Intracerebral haemorrhage: bleeding inside the brain
Risk factors of stroke?
- Over 60 yo
- Had stroke/TIA before
- Smoke and/or have inactive lifestyle
- High blood pressure, heart disease, high cholesterol, diabetes, obesity
- Family history of strokes
Diagnosis of stroke?
- Check alertness, immobility of one side of the face, trouble with coordination and balance, vision or speech
- Check numbness or weakness in any part of the body
- Physical exam; blood pressure, and listen to the heart
- Blood tests and imaging tests (CT, MRI or ultrasound) to figure out which type of stroke the patient might have had (CT scan to see if there’s bleeding in your brain)
- EKG (checks heart’s electrical activity) and EEG (checks brain’s electrical activity)
What blood tests can be done to check for a stroke?
- Complete blood count
Check level of platelets (cells that help clot blood)
Check electrolyte levels (see how well kidneys work) - Clotting time
PT and PTT check how quickly blood clots. Too long = sign of bleeding problems
Treatment stroke?
After a stroke, brain may need to relearn old skills.
brain’s grey matter has an amazing ability to repair and rewire itself.
Several types of therapy are there to improve physical and mental status
The brain is roughly divided into three regions:
Cerebrum, cerebellum, brain stem
Cerebrum exists of..
2 hemispheres: each has a cortex, each cortex has four lobes:
- frontal
- parietal
- temporal
- occipital
What does the frontal lobe control?
- movement
- executive function
What does the parietal lobe control?
- sensory information (3d)
What does the temporal lobe control?
- hearing
- memory
- smelling
- facial recognition
- language
What does the occipital lobe control?
- vision
What does the cerebellum control?
- muscle coordination
- balance
What does the brain stem control?
- breathing
- heart rate
- blood pressure
- GI function
- conciousness
How does an embolism lead to ischaemic stroke?
- Embolism: blood clot breaks off from one location, gets lodged in another (from atherosclerosis or from the heart: stagnant blood in the heart can clot: route to the brain of lung)
How can shock lead to an ischaemic stroke?
- When the body is in shock, there can be reduction in blood flow throughout the entire body: tissues furthest downstream affected most (e.g. border of two different blood supplies in the brain: watershed infarct)
describe how smoking increases the risk of stroke
- One classic irritant of the endothelium is a toxin found in tobacco
- Damage becomes a site for atherosclerosis
- Plaque forms
explain how braincells can swell (cytotoxic edema) when blood flow is blocked
- No glucose & oxygen: cells run out of energy. High build-up of sodium and calcium levels -> draws water into the cells making them swell.
explain the three typical features of a stroke
- Facial drooping
- Arm weakness
- Speech difficulties
describe how strokes are generally treated and secondary strokes are prevented
- Treatment: Re-establish blood flow as quickly as possible
Thrombolytic enzymes (TPA): to activate the bloods natural clot busting mechanism (time limit)
Aspirin (prevents more clots)
Surgery: physically remove clot - Prevention:
Quit smoking, healthy blood pressure, normal LDL cholesterol, control diabetes - Surgery: help clean arteries, stent
