Localising the lesion
Ed Hutchison and Paul Swift
Aims
Approach
UMN vs. LMN
Spinal tracts
Cerebellum
Cerebrum
Visual lesions
Cases
Approach to localising the
lesion
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. LMN
UMN
LMN
Hyperreflexia
Hyporeflexia
Hypertonia
Hypotonia
Clonus
Muscle wasting
No muscle wasting/fasciculation
Fasciculation
Plantars upgoing (lower limbs)
Plantars downgoing (lower limbs)
Pyramidal vs. Extrapyramidal
Pyramidal
Extrapyramidal
Weakness
Tremor
Spasticity
Chorea
Pronator drift
Hemiballismus
Loss of skilled movement
Athestosis
Hyperreflexia
Dystonia
Change in tone/tendon reflexes
Plantars upgoing
Loss of abdominal/cremasteric reflex
Clonus
http://www.youtube.com/watch?feature=player_detailp
age&v=8GC8F2UMYbQ#t=42
Facial nerve palsies
Bulbar vs. pseudobulbar
Pseudobulbar = UMN of CN IX-XII
Spastic tongue
Sparing of forehead
Bulbar = LMN of CN IX-XII
Tongue wasting/fasciculation
Affects all facial muscles
The tracts
Dorsal column
?
?
Spinothalamic
?
Corticospinal
Lateral
Spinothalamic
Pain and temperature
Decussates at the level of the
spinal cord
Anterior
Spinothalamic
Crude touch and pressure
Decussates at the level of the
spinal cord
Dorsal
columns
Discrimination,
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
CN IX-XII
Symptoms/signs:
• Dysarthria
• Dysphagia/drooling
• Tongue weakness
• Absent palatial
movement
Cerebellum
Cerebellospinal tracts
Ipsilateral – DO NOT
CROSS
Blood Supply
Cerebellar Signs
D – dysdiadochokinesia
A – ataxia (truncal and limb)
N – nystagmus
I – intention tremor
S – slurred speech
–
hypotonia
H
Causes
Alcohol
Thiamine deficiency
CVA
Friedreich’s ataxia
Etc etc…
The Homunculus
Cerebral Artery Territories
Circle of Willis
Anterior cerebral artery
Middle cerebral artery
Posterior cerebral artery
?
Basilar artery
A=?
Vertebral
artery
Anterior spinal
B = ? artery
Speech Centres
Tono man
http://www.youtube.com/watch?v=6CJWo5TDHLE
Broca’s dysphasia
http://www.youtube.com/watch?v=1aplTvEQ6ew
Stroke Syndromes
TACS – all 3
PACS – 2 of 3
LACS
POCS
Hemiplegia/hemi See left
sensory loss
No visual field
defect
Bilateral motor or
sensory
Visual field
disturbance
Pure motor
Conjugate eye
movement
disturbance
Disturbance in
higher function –
e.g.
dyphasia/dysphag
ia
Pure sensory
Cerebellar
dysfunction
Sensory-motor
Hemiplegia or
cortical blindness
Ataxia
Visual Defects
Ipsilateral blindess
Bilateral 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 3
23, 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 4
56 male
6 month history of progressive weakness of his right
hand. Also had problems with swallowing and has
choked whilst eating on several occasions
o/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 neuropathies
Motor neurone
Parkinson’s
Huntington’s
GBS
Myasthenia gravis
Peripheral Neuropathies
A – alcohol
B – B12 deficiency
C – CKD
D – drugs/diabetes
E – every vasculitis