brainstem by joshua bower peer support 2013/2014 [email protected]
TRANSCRIPT
BRAINSTEM By Joshua BowerPeer Support 2013/[email protected]
Where do the following CNs emerge from?
• CN III+IV• V• VI-VIII• IX+X• XI• XII
MidbrainPonsPontomedullary junctionLateral medullaC1-C5 of SCVentral medulla
What signs might you expect from an infarction in the black area? [2]
• Right ocular palsy• Pupillary changes
CN III and IV affected
A patient suffers from a cortical infarction affecting CN VI-VIII. What signs and symptoms
will you expect to see?
• Limited eye abduction• Diplopia• Bell’s palsy• Loss of balance• Sensorineural hearing loss• Tinnitus
What signs would you expect to see with a UMN lesion of CN VII?
• Contralateral facial paralysis, with forehead sparing
Bulbar palsy(i) Is it UMN or LMN?
(ii) What nerves are affected?(iii) List FOUR symptoms
(iv) List TWO causes
(i) LMN(ii) CN VII-XII(iii) Dysarthria, dysphonia, drooling, poor swallowing, flaccid
paralysis, wasting, fasciculations(i) Due to paralysis of pharynx, soft palate, larynx and tongue
(iv) Polio, radiotherapy, CVE
Which nucleus provides motor supply to the pharynx, palate and larynx?
(a) Nucleus solitarius(b) Nucleus accumbens(c) Nucleus ambiguus(d) Nucleus dorsalis(e) Nucleus pulposus(f) Nucleus vagus
Nucleus ambiguus - gives rise to the branchial efferent motor fibres of CN X
Pseudobulbar palsy(i) Is it UMN or LMN?
(ii) What nerves are affected?(iii) List FOUR symptoms
(iv) List TWO causes
(i) UMN(ii) Bilateral corticobulbar tracts(iii) Similar to bulbar – but can develop spastic paralysis of
pharynx and larynx (airway occlusion emergency)(iv) Head injury, CVE, high brainstem tumour
What system in the brain controls sleep?
(a) Cerebellum(b) Tuberoinfundibular pathway(c) Sensory cortex(d) Posterior parietal lobule(e) Reticular formation(f) Periaqueductal gray
Reticular formation – complex network of fibres with some defined nuclei (raphe nuclei etc) which controls sleep-waking cycle, pain modulation etc
A severely hypertensive patient with poor compliance with treatment suddenly collapsed and was unconscious. He had pin point pupils,
quadriparesis and decerebrate posturing. It was suspected he had suffered pontine haemorrhage.
(i) Explain why a haemorrhage into the pons could cause sudden LOC?
Damaged reticular formation
A severely hypertensive patient with poor compliance with treatment suddenly collapsed and was unconscious. He had pin point pupils,
quadriparesis and decerebrate posturing. It was suspected he had suffered pontine haemorrhage.
(ii) What else must be damaged in the pons to cause quadriparesis?
Descending motor tracts
A severely hypertensive patient with poor compliance with treatment suddenly collapsed and was unconscious. He had pin point pupils,
quadriparesis and decerebrate posturing. It was suspected he had suffered pontine haemorrhage.
(iii) The arterial haemorrgage in the pons would escape into his CSF – what effect(s) would this have on CSF appearance and pressure?
Blood stained CSF, raised pressure
A severely hypertensive patient with poor compliance with treatment suddenly collapsed and was unconscious. He had pin point pupils,
quadriparesis and decerebrate posturing. It was suspected he had suffered pontine haemorrhage.
(iv) Would a lumbar puncture be helpful in this situation? Why/ why not?
No – because of the risk of coning with raised ICP
A neurosurgeon evacuated an extradural haematoma. The patient never regained consciousness, was unable to breathe
spontaneously and had to stay on a ventilator.
Why couldn’t he breathe spontaneously?
Brain stem compression – respiratory centre located here
What are the FOUR functions of CN IX?What nuclei do they project from/to?
Sensation from pharynx, mid ear etc
Taste from tongue (posterior 1/3) and carotid body and sinus input
Motor to stylopharyngeus
Parotid gland secretions
Spinal nucleus of trigeminal n.
Nucleus solitarius
Nucleus ambiguus
Inferior salivatory nucleus
QUESTIONS?By Joshua BowerEaster Revision [email protected]