Neuro Flashcards
Causes of TIA
Cardioembolism from valve disease, prosthetic valve, post-MI, AF etc
Hyperviscosity e.g. polycythaemia, sickle cell anaemia, VERY HIGH WBC, myeloma
Artherothromboembolism
ALSO, hypoperfusion (important to think abt in young people)
e.g. cardiac dysrhythmia, postural hypotension
Define a TIA
Acute loss of cerebral/ocular function lasting < 24 hours
Complete clinical recovery
RF TIA
Same as IHD
M > F
Black ethnicity have ↑ risk (bc ↑ risk of HTN, atherosclerosis etc)
Age
HTN, Smoking, Heart disease
Peripheral arterial disease
ALSO, combined oral contraceptive pill (bc ↑ risk of clots)
Key presentation of TIA
Sudden loss of function with complete recovery
FAST
What part of the circulation is more commonly affected?
Anterior circulation (90%) - carotid artery
Describe some signs/symptoms if the anterior circulation (carotid artery) is occluded in TIA
Weak, numb contralateral leg and/or similar but milder arm symptoms
Hemiparesis
Hemi-sensory disturbance
Amaurosis Fugax
Dysphasia
Describe some signs/symptoms if the posterior circulation (vertebrobasilar artery) is occluded in TIA
Diplopia, vertigo
Vomiting
Choking and dysarthria
Ataxia
Hemi-sensory loss
Tetraparesis
WHat do oligodendrocytes do?
Myelinate axons in brain (CNS)
What do Schwann cells do?
Myelinate axons in the rest of the body (PNS)
What does white matter contain?
Myelinated axons
What does grey matter contain?
Cell bodies, no myelin sheaths
What are afferents?
Axons which take info towards CNS
What are efferents?
Axons which take info from CNS to rest of body
Function of frontal lobe
Voluntary movement on opposite side of body
Frontal lobe of dom hemisphere controls speech (Broca’s!) and writing
Also, intellectual function, thinking, reasoning and memory
Function of parietal lobe
Receives/interprets sensations
e.g. pain, touch, pressure, body-part awareness (proprioception)
Temporal lobe function
Understanding the spoken word (Wernicke’s), and sounds, memory and emotions
Occipital lobe function
Understanding visual images and meaning of written words
What is CSF produced by?
Mostly by ependymal cells in the choroid plexuses of lateral ventricles
DDx
Hypoglycaemia!!
Intracranial lesion
Migrainous aura
1st line Ix TIA
ROSIER scale - in emergency department
Describe the ROSIER scale
ABCD2 score - risk score of strokes (max = 7)]
A - Age ≥ 60 (1)
B - Blood pressure (at presentation), 140/90 or more (1)
C - Clinical features
Unilateral weakness (2)
Speech disturbance without weakness (1)
D - Duration, 60 mins or longer (2), 10 - 59 mins (1) D - Presence of diabetes (1)
—-
High risk :
- ABCD2 score of 4 or more
- AF
- More than TIA in one week
- TIA whilst on anti-coagulation
Low risk :
- None of the above
- Present more than a week after their last symptoms have resolved
Describe the signs/symptoms if the Anterior cerebral artery (ACA) is occluded in stroke
DCLIT
Drowsiness
Contralateral leg weakness and sensory loss (more leg than arm bc ACA)
Logical thinking and personality affected
Incontinence
Truncal/gait ataxia
Describe the signs/symptoms if the middle cerebral artery (MCA) is occluded in stroke
Contralateral motor weakness/sensory loss (BOTH arms and legs)
Hemiplegia
Aphasia - Wernicke’s and Broca’s
Facial droop
Describe the signs/symptoms if the posterior cerebral artery (PCA) is occluded in stroke
Contralateral homonymous hemianopia
Disorders of perception