BRAINSTEM By Joshua Bower Peer Support 2013/2014

Where do the following CNs emerge from? CN III+IV V VI-VIII IX+X XI XII  Midbrain  Pons  Pontomedullary junction  Lateral medulla  C1-C5 of SC  Ventral 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 Bower Easter Revision 2014