Neurology Flashcards
What do the ascending tracts do?
Carry sensory information from the body, up SC to the brain
What are the ascending tracts?
Dorsal column-medial lemniscus and spinothalamic
What does the dorsal column-medial lemniscus tract do?
Carries info about vibration, proprioception, fine touch
What does the spinothalamic tract do?
Carries info about crude touch, pain, temperature and pressure
What do the descending tracts do?
Carry motor info from the brain to the body
What are the descending tracts made up of?
UMNs and LMNs
What are the 2 types of descending tracts?
Pyramidal and extra-pyramidal
What do pyramidal tracts do?
Control fine, voluntary muscle movements
What are the 2 types of pyramidal tracts?
Anterior corticospinal and lateral corticospinal
What do the anterior corticospinal tracts do?
Control muscles of the trunk
What do the lateral corticospinal tracts do?
Control muscles of the extremities
What do the extra-pyramidal tracts do?
Control larger muscles for balance, posture, coordination
Name a condition that shows both UMN and LMN signs.
MND
What do UMNs do?
Transmit info from brain to brainstem/spinal cord
What do LMNs do?
Transmit info from brainstem/spinal cord to skeletal muscles
What are the UMN signs?
Hypertonia - spastic paralysis
Brisk reflexes - hyperreflexia
+ve Babinski’s sign
What causes UMN signs?
Any damage to brain/brainstem/white matter of spinal cord
Give some examples of conditions which present with UMN signs.
Stroke, infection, tumour
What are the LMN signs?
Hypotonia - flaccid paralysis
Reduced/absent tendon reflexes
Muscle wasting
Fasciculations
What causes LMN signs?
Any damage to axons leaving the spinal cord or the anterior horn of the spinal cord
Give some examples of conditions which present with LMN signs.
Peripheral neuropathy, spinal cord injury
What are the 2 types of stroke?
Haemorrhagic and ischaemic
What percentage of strokes are haemorrhagic?
20%
What percentage of strokes are ischaemic?
80%
What conditions are classed as ischaemic events?
TIAs and ischaemic strokes
What conditions are classed as strokes?
Ischaemic stroke, intracerebral haemorrhage and subarachnoid haemorrhage
What conditions are classed as haemorrhagic events?
Intracerebral haemorrhage
Subarachnoid haemorrhage
Subdural haematoma
Extradural haematoma
What are the risk factors for ischaemic stroke?
Alcohol
Obesity
AF
Carotid stenosis
Other CVS disease
CVS risk factors
What CVS risk factors predispose you to ischaemic stroke?
HTN, smoking, diabetes, hypercholesterolaemia
Why is AF a risk factor for ischaemic stroke?
Stasis of blood in poorly contracting atria = thrombus formation
What CVS diseases predispose you to ischaemic stroke?
Valvular disease, angina, previous MI, PVD
What arteries can be affected in an anterior circulation stroke?
Anterior cerebral and middle cerebral arteries
The area of the somatosensory cortex supplied by the ACA is responsible for which parts of the body?
Genitals
Hip
Trunk
Neck
Head
Lower limbs
The area of the somatosensory cortex supplied by the MCA is responsible for which parts of the body?
Entire arms
Eyes
Nose
Face
Mouth
Pharynx
How does an ACA occlusion stroke present?
Contralateral hemiparesis
Sensory loss in lower limbs
Executive dysfunction + emotional disturbance
Akinetic mutism
How does an MCA occlusion present?
Contralateral hemiparesis
Sensory loss of face + upper limb
Legs usually spared
Affects language centres if occlusion is in dominant hemisphere = dysphasia and aphasia
Contralateral homonymous hemianopia
How does executive dysfunction present?
Apathy, reduced concentration, impulsivity
How does akinetic mutism present?
Drowsy and reduced spontaneous speech (lack of movement and speech)
What are the language centres of the brain?
Wernicke’s and Broca’s areas
What is contralateral homonymous hemianopia?
(This would be an occlusion in the right hemisphere)
What is contralateral hemiparesis?
Paralysis on the opposite side of the body to the site of the occlusion
What are fasciculations?
Twitches
What is Babinski’s sign?
What causes dysarthria?
Damage to motor speech pathway
What conditions might cause dysarthria?
Stroke, tumour, MS
What is dysarthria?
Slurred speech/difficulty pronouncing words so patient sounds drunk
What is dysphasia?
Inability to understand or compose language
What area is damaged in expressive dysphasia?
Broca’s area
What lobe is damaged in expressive dysphagia?
Dominant frontal lobe
How does expressive dysphagia present?
Can’t generate language - can understand what is said to them but have difficulty getting words out
What area is damaged in receptive dysphagia?
Wernicke’s area
What lobe is damaged in receptive dysphagia?
Dominant temporal lobe
How does receptive dysphagia present?
Little/no understanding of spoken/written language - can speak fluently but usually makes no sense
Where are the language centres found?
Dominant lobe
How do you know which lobe is dominant?
Right handed = left lobe dominant
What are the 2 types of dysphagia?
Expressive and receptive
What vessels are involved in a posterior circulation stroke?
Basilar and vertebral arteries
What areas do the basilar and vertebral arteries supply?
Occipital lobe, cerebellum, hippocampus, brainstem etc.
What does a PCA stroke affecting the occipital lobe present with?
Contralateral homonymous hemianopia, cortical blindness
What does a PCA stroke affecting the cerebellum present with?
Ataxia, nystagmus, N+V, dysarthria
What does a PCA stroke affecting the brainstem present as?
CN palsies causing diplopia, facial sensory loss/weakness, dysphagia etc.
What are lacunar strokes?
Small strokes due to blockages in small arteries supplying deep brain structures
What structures might be affected by lacunar strokes?
Thalamus, pons etc.
How do lacunar strokes present?
Cortical function is preserved
Could be purely motor, purely sensory or sensorimotor symptoms
What are the purely motor symptoms of a lacunar stroke?
Weakness in contralateral arm, leg, face
What are the purely sensory symptoms in a lacunar stroke?
Sudden paraesthesia in contralateral arm, leg, face
What are the sensorimotor symptoms of a lacunar stroke?
Ataxia, dysarthria, clumsy hands
What is the first line investigation for a suspected stroke? Why?
Immediate non-contrast CT head to rule out haemorrhage
Why does a haemorrhage need to be ruled out for a suspected stroke?
Thrombolysis dissolves the clot so can cause bleeding, which is very dangerous to give to a patient with a haemorrhage
What does an infarct look like on CT?
Hypodense (dark) area
What are the 2nd line investigations for a suspected stroke?
Bloods - look for underlying cause/RFs
ECG - look for AF
Carotid doppler - look for carotid stenosis
CT angiography - find cause
MRI later if CT didn’t show infarct and still suspected
What is the 1st line immediate management for an ischaemic stroke?
Thrombolysis with alteplase
When must alteplase be given for a stroke?
Within 4.5 hours of onset of symptoms and after a haemorrhage is excluded
What are the contraindications to thrombolysis?
Haemorrhage
On anticoagulants
>4.5 hours after onset of symptoms (or unknown onset time)
Recent surgery or GI bleed
Active cancer
HTN cut off = 185/110
What 1st line treatment is given for ischaemic stroke if thrombolysis is contraindicated?
Thrombectomy
What is the second line treatment for ischaemic stroke?
300mg aspirin for 2 weeks/until discharge
What is the long-term management of an ischaemic stroke?
Clopidogrel 75mg daily (antiplatelet) after 2 weeks of aspirin
Treat modifiable risk factors
If patient has carotid artery disease, consider for carotid endarterectomy within 2 weeks
Give some examples of modifiable risk factors can be treated after a stroke.
Manage BP and diabetes
Monitor cholesterol levels - start statins
Smoking cessation, diet, exercise, weight loss
Investigate for AF - consider need for anticoagulants e.g. warfarin
What supportive management is provided after a stroke?
Admit patient and must be seen by specialist within 24 hrs
BP control - keep high
O2 and glucose levels
Swallow assessment - NBM/NG tube and nutrition
Mobilise ASAP - physio and OT input
No driving for 1 month after stroke/longer if symptoms ongoing
Why must BP be kept high immediatley after a stroke?
A small fall can massively reduce cerebral perfusion
What 2 scores would we consider before starting anticoagulants in a patient with AF?
CHADSVASc – risk of stroke in a patient with AF
HASBLED – risk of bleeding in a patient with AF
What is a transient ischaemic attack (TIA)?
Transient neurological dysfunction
What causes a TIA?
Ischaemia without infarction
How does a TIA present?
Presents similarly to an ischaemic stroke
Sudden loss of function for a few mins to 24 hours with complete recovery
What is the immediate management of a TIA?
None
What is the long-term management of a TIA?
Long-term same as stroke
300mg aspirin
Secondary prevention for CVD
Long-term clopidogrel and physio
What is amaurosis fugax?
Sudden transient loss of vision in one eye like ‘a curtain coming down’
What causes amaurosis fugax?
Occlusion of retinal artery
What risk score predicts the risk of a stroke after a TIA?
ABCD2 score - determines management/time to see a specialist
What is the ABCD2 score?
Age > 60 = 1
Blood pressure > 140/90mmHg = 1
Clinical features:
Unilateral weakness = 2
Speech disturbance without weakness = 1
Duration of symptoms:
Symptoms lasting more than 1 hour = 2
Symptoms lasting 10-59 mins = 1
Diabetes = 1
What is a subarachnoid haemorrhage?
Bleeding into the subarachnoid space between arachnoid and pia mater
What are the risk factors for SAH?
HTN
Smoking
XS alcohol
Cocaine
FHx
What diseases is SAH associated with?
Autosomal dominant PKD
Sickle cell anaemia
Connective tissue disorders
What causes a SAH?
Rupture of berry aneurysm (most common)
Arteriovenous malformation
How does an SAH present?
Sudden onset ‘worst ever’ thunderclap occipital headache
Neck stiffness
Photophobia
N+V
May have signs of raised ICP - reduced consciousness
What investigations are done for an SAH?
Immediate CT head
LP 12 hours after onset of symptoms if CT doesn’t confirm SAH
CT angiography once confirmed to show source of bleeding
What would an LP show 12 hours after the onset of symptoms of an SAH?
Xanthochromia - yellow CSF due to presence of bilirubin (breakdown of haem)
What does an SAH look like on CT?
Blood is white (hyperdense) on CT - blood in subarachnoid space, sometimes looks like a star as it fills all the sulci
How is SAH managed?
ABCDE management + rapid BP lowering
Monitor GCS
Surgical = coiling or clipping
Treat complications e.g. nimodipine (CCB for vasospasm)
What are the complications of SAH?
High mortality
Rebleeding
Vasospasm which can lead to ischaemia
Seizures
Hydrocephalus
