Localising the lesion
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Transcript of Localising the lesion
Localising the lesionEd Hutchison and Paul Swift
AimsApproachUMN vs. LMNSpinal tractsCerebellumCerebrumVisual lesionsCases
Approach to localising the lesion
Be systematic!
…A patient presents with arm weakness…
Muscle – e.g. diabetic myopathy
NMJ – e.g. myasthenia gravis
Peripheral nerve – e.g. GBS
Spinal cord – e.g. cord compression
Cerebrum – e.g. Stroke
Timeline
Immediate
Intermediate
Long-term
UMN vs. LMN???
UMN vs. LMNUMN LMNHyperreflexia HyporeflexiaHypertonia HypotoniaClonus Muscle wastingNo muscle wasting/fasciculation
Fasciculation
Plantars upgoing (lower limbs)
Plantars downgoing (lower limbs)
Pyramidal vs. Extrapyramidal
Pyramidal ExtrapyramidalWeakness TremorSpasticity ChoreaPronator drift HemiballismusLoss of skilled movement AthestosisHyperreflexia DystoniaChange in tone/tendon reflexesPlantars upgoingLoss of abdominal/cremasteric reflex
Clonushttp://www.youtube.com/watch?feature=player_detailpage&v=8GC8F2UMYbQ#t=42
Facial nerve palsiesBulbar vs. pseudobulbarPseudobulbar = UMN of CN IX-XII
Spastic tongueSparing of forehead
Bulbar = LMN of CN IX-XIITongue wasting/fasciculationAffects all facial muscles
The tracts
Dorsal column
Corticospinal
Spinothalamic
?
?
?
Lateral Spinothala
micPain and temperatureDecussates at the level of the spinal cord
Anterior Spinothala
micCrude touch and pressureDecussates at the level of the spinal cord
Dorsal columnsDiscrimination, proprioception, vibration.Crosses at the medulla.
Subacute combined degeneration of the cord,Tabes dorsalis,Spinal trauma.
Corticospinal Tracts
Descending motor tracts.Cross at the medulla.
Brown-Sequard
Brainstem
Symptoms/signs:• Dysarthria• Dysphagia/drooling• Tongue weakness• Absent palatial
movement
CN IX-XII
CerebellumCerebellospinal tractsIpsilateral – DO NOT CROSS
Blood Supply
Cerebellar Signs– dysdiadochokinesia – ataxia (truncal and limb)
– nystagmus
– intention tremor
– slurred speech
– hypotonia
DANISH
CausesAlcoholThiamine deficiencyCVAFriedreich’s ataxia
Etc etc…
The Homunculus
Cerebral Artery Territories
Circle of WillisAnterior cerebral artery
Middle cerebral artery
Posterior cerebral artery
Basilar artery
A = ?
B = ?
?Anterior spinal artery
Vertebral artery
Speech Centres
Tono manhttp://www.youtube.com/watch?v=6CJWo5TDHLE
Broca’s dysphasiahttp://www.youtube.com/watch?v=1aplTvEQ6ew
Stroke SyndromesTACS – all 3 PACS – 2 of 3 LACS POCSHemiplegia/hemisensory loss
See left No visual field defect
Bilateral motor or sensory
Visual field disturbance
Pure motor Conjugate eye movement disturbance
Disturbance in higher function – e.g. dyphasia/dysphagia
Pure sensory Cerebellar dysfunction
Sensory-motor
Hemiplegia or cortical blindness
Ataxia
Visual DefectsIpsilateral blindessBilateral hemianopia
Left homonymous hemianopia
Left superior quadrantanopia
Left homonymous hemianopia with macular sparing
Cases
Case 1• 57 year old man complaining of weakness and
altered sensation in upper limbs and lower limbs• Loss of sensation from shoulders and down,
urinary incontinence• On Examination:
• CN intact• Upper limbs weakness, hypotonia, reduced
reflexes• Lower limbs spasticity, hyper-reflexia and
Babinski +ve, reduced sensation from shoulders down
Case 2• 85 year old man with long standing (20yr)
history of balance problems worse in the dark.• Gait is high stepping• On Examination:
• CN intact• Motor intact• Loss of proprioception with +ve Romberg’s
test
Case 323, female presents to her GP with a 2 week history of bilateral leg weakness having started with pins and needles and numbness in her hands and feet. She has had a few days of urinary incontinence which has resolved. 2 years ago she had an episode of blurred vision and pain in the right eye which lasted a month and fully resolved
Case 456 male6 month history of progressive weakness of his right hand. Also had problems with swallowing and has choked whilst eating on several occasionso/e he has wasting of his upper and lower limbs and some fasciculation's were noted his right plantar was up going and his reflexes were generally brisk
Things we’ve not had time to cover
Peripheral neuropathiesMotor neuroneParkinson’sHuntington’sGBSMyasthenia gravis
Peripheral NeuropathiesA – alcoholB – B12 deficiencyC – CKDD – drugs/diabetesE – every vasculitis