Stroke Alfred Sat Flashcards
What fibers cross over at lower medulla?
Motor fibres
Posterior fibres (vibration, proproception, light touch)
What fibers do the external capsule carry?
Cholinergic fibers from basal forebrain to the cerebral cortex
What fibers are carried in the internal capsule:
- Anterior limb
- Genu
- Posterior limb
- Anterior limb
- Thoracocortical to frontal lobe
- Frontopontine (SHAM functions - emotional smile, horizontal gaze, accomodation, micturition)
- Genu
- Corticobulbar
- Posterior limb
- Thoracocortical fibers to the parietal lobe (general sensation)
- Corticospinal fibers + corticorubral fibers
What is the definition of lower motor neuron?
Anterior horn cell + after
Where are the 5th and 7th CN located in the pons?
5th nerve exits from the middle of the pons
7th nerve exits from the lower pons
So a lesion in the higher pons causes a contralateral facial (CN VII) UMN paralysis and a lower pontine lesion causes an ipsilateral LMN 7th
What are the clinical manifestations of a medial pontine lesion?
Motor dysfunction and INO and gaze palsy
What are the clinical manifestations of a lateral pontine lesion
- Pain and temperature (below high pons pain and temp are lost ipsilaterally in the face and contralaterally in the limbs)
- Vertica nystagmus
- 8th nerve dysfunction
- Ipsilateral ataxia
- Ipsilateral horner’s in high pontine lesion
What are the manifestations of lateral medullary syndrome
Ipsilateral:
- facial numbness
- limb ataxia
- Horner’s syndrome
Contralateral:
- loss of pinprick and temperature in arm and leg
What causes:
1) lower quadrant hemianopia
2) upper quadrant hemianopia
1) Parietal
2) Temporal
What other fibers do the optic nerve carry? (aside from vision)
Afferent fibers for light reflex
What are the findings in a cranial nerve IV palsy?
Superior oblique affected - weakness of downward eye movement with vertical diplopia that is worse when the eye is adducted and improved on contralateral gaze
Weakness of intorsion, in particular with the eye abducted
What are the 2 gaze centers and 2 connections involved in an INO?
Gaze centres:
- Frontal gaze centre and contralateral pontine gaze centre
Tracts:
- Medial longitudinal fasicle connects 3rd CN nuceus to pontine gaze centre
- Paramedian pontine reticular formation connects 6th nerve nucleus to pontine gaze centre
What is the clinical manifestation of damage to the frontal gaze centre?
Cannot look towards paralysed size (deviates away from hemiparetic limb)
What are the 3 causes of complex opthalmoplegia?
Myasthenia
Graves eye disease
Mitochondrial myopathies
What nerves comprise the gag reflex?
Sensory - CN IX (glossopharyngeal)
Motor - CN X (vagus)
What is the CN that is most likely to be affected in the cerebellopontine angle?
CN 8 but also 5-7
What nerves are involved in cavernous sinus lesions?
CN 3-6
What speech patterns are present in pseudobular palsy vs bulbar palsy?
Pseudobulbar palsy is nasal
Bulbar is spastic
Where do pain and temperature fibers cross over?
At the level of entry
Where do proprioception and vibration cross over ?
At the lower level of the medulla
Where do light touch fibers cross over?
Both at the level of entr into the spinal cord and in the lower medulla
How are the fibers of the corticospinal tract laid out in the spinal cord (e.g. is arm medial or latera)
Medial - > Lateral
Arm -> trunk -> leg
Loss of motor functions, pain/temperature with sparing of proprioception and vibratory sense with initial tone flaccid and loss and deep tendon reflexes
Anterior spinal artery syndrome
LMN weakness with no sensory finding
Diagnosis?
Anterior horn cells affected - likely polio
Loss of proprioception and UMN weakness - diagnosis?
Subacute combined degeneration
What area is purely supplied by the radial nerve without any overlap?
Anatomical snuffbox
Where is the damage to the radial nerve is there is no sensory deficits and only partial wrist drop, finer drop and weakness in extension of the hand and fingers?
Radial head/entrapment in the arcade of frohse (posterior interosseous)
Which finger flexion points does the median nerve supply?
All PIP joint
Index and middle finger flexion at DIP
Lumbricals to digits 2 and 3 (flexion at MCP)
Thumb movements
What is pyramidal weakness?
UMN weakness pattern - antigravity muscles are weaker than pro gravity
