Approach to patients with CNS disorders Flashcards
Frontal lobe is involved in =
Intellectual function Praxis Motor function Inhibition Bladder continence Saccadic eye movements Broca's area - expression of language
Praxis =
Conception and planning of a new action, the performance of an action
Difficulty in activites requiring coordination and movement =
Dyspraxia
Internal capsule separates =
Thalamus, caudate nucleus and globus pallidus/putamen
In the motor homonculus, what is most lateral?
Face - arm
In the motor homonculus what is msot medial?
Lower limb
Pre-central gyrus =
Primary motor cortex
Post-central gyrus =
Primary sensory cortex
Problem with Broca’s area =
Expressive dysphasia
Where does the majority of the corticospinal tract decussate?
Medullary pyramids
What does the corticospinal tract split into?
Lateral, anterior
Lateral corticospinal tract =
Distal, fine movements (voluntary)
Anterior corticospinal tract =
Proximal muscles
lesion in the right motor cortex/right internal capsule will lead to what?
left sided upper motor neurone weakness
Lesion to right cranial nerve nuclei in brainstem causes:
Right sided lower motor neurone weakness
Temporal lobe is involved in:
Memory Smell Auditory cortex Vestibular Emotion Wernickes
Occipital lobe is involved in:
Vision
Lesion in the occipital lobe causes what?
Contralateral homonymous hemianopia
Parietal lobe is involved in:
Sensory integration
Wernickes area problem =
Expressive dysphasia
Dysphasia vs dysarthria =
Dysphasia = langusage Dysarthria = words
Lesion in dominant parietal lobe:
Dyslexia
Acalculia
Poor left-right discrimination
Agnosia
Spinothalamic tract carries what modalities:
Pain, temperature, crude touch
Spinothalamic tract splits into
Anterior (crude touch)
Lateral (pain, temp)
Where does the spinothalamic tract decussate?
About 2 spinal levels above entry - early!
DCML carries what modalities
Fine touch, pressure, vibration
Fasiculus cuneatus =
info from upper body
Fasiculus gracillis
info from lower body
Where does DCML decussate?
Medulla
Spinocerebellar tract remains
Ipsilateral
What does the spinocerebellar tract carry
Conscious proprioception
Why do lesions in the spinocerebellar tract often not show?
Damaged with other tracts - weakness usually disguises any loss of coordination
Brown-sequard syndrome:
Damage to 1 side of spinal cord: ipsilateral posterior column loss
contralateral spinothalamic loss
Lesion in cortex, internal capsule or thalamus does what to tracts?
full contralateral sensory deficit
Weber syndrome is also known as
Midbrain syndrome
Weber syndrome effects which CN
CN III
Wallenburg syndrome also known as
Lateral medullary syndrome
3 zones of cerebellum and functions:
cerebrocerebellum = planning movements and motor learning, fine motor spinocerebllum = postural tone, correcting movements vestibulocerebellum = balance
Acronym to remember features of cerebellar dysfunction:
VANISH’D
VANISH’D =
Vertigo Ataxia Nystagmus Intention tremor Slurred speech Hypotonia Dysmetria (past-posting), dysdiadochokinesis
Most malignant primary brain tumour =
Glioblastoma multiforme
Features of a complete CN III plasy =
Eyes down and out
Mydriasis
Partial ptosis
Why is the ptosis in CNIII plasey only partial?
Lost levator palpebrase superioris but not Muller’s muscle (which has sympathetic innervation)
Horner’s syndrome is due to problems with which nerve supply?
Sympathetic
Symptoms of horner’s syndrome:
Miosis
Ptosis
Anhydrosis
Enopthalmos
Causes of horner’s
Idiopathic
C8/T1 pathology
Carotid dissection Pancoast tumor
Features of a CN IV plasy =
eyes cannot look down
Features of an CN VI palsy:
Eye in, diplopia
Diplopia =
Double vision
CN VI plasy can be indicitive of:
Pons lesion, infarction
Facial UMN vs LMN lesion:
UMN: only bottom half effected, upper face has a dual nerve supply
LMN: both halves effected
Bells palsy is a what lesion of what nerve
LMN lesion of CN VII
Bells palsy effects what parts of face?
Both halves on ipsilateral side
Plasy of facial nerve features:
Ipsilateral wekaness of muscles on top and bottom of face Incomplete eye closure Abnormal taste sensation on ant 2/3rds Hyperacussis Decreased lacrimation and saliva
Why might CN VII plasy cause hyperacussis?
Supplies the stapedius nerve (one of the ossicles)
Features of CN XI plasy:
difficulty shrugging, paralysis of sternocleidomastoid
Features of CN XII plasy:
Wasting of tongue Fasiculations Weakness of tongue Tongue deviates to side of lesion Dysarthria
Tongue in LMN lesion points
towards side of lesion
Tongue in UMN lesion points
away from side of lesion
Ex of tone pathologies:
Cog-wheel
Clasp-knife
Lead pipe
2 types of rigiditiy associated with Parkinson’s
Cog-wheel
Leadpipe
What is used to grade power?
MRC scale
MRC scale goes from:
0-5
MRC scale =
0- no movement 1- flicker of movement 2- movement with gravity eliminated 3- movement against gravity 4- movement against resistance 5- normal power
Examples of LMN lesion areas:
anterior horn nerve root brachial, lumbar plexus named nerve NMJ muscle
Romberg’s test assesses
Vestibular function. patient stands with feet together and closes eyes. patient will wobble and lose balance with vestibular dysfunction
