Block 3 reviewKarina and Andrew

What we picked out to cover…

• Stroke • Epilepsy • BG • Depression and pharm mental health • Pain pharm • Anatomy • Some MCQs at the end if we have time

Stroke • Give 4 risk factors for a stroke…

– Hypertension, obesity, AF and hypercholesteraemia• How do you calculate someone's risk of a stroke after a TIA?

– ABCD2– A age >60 years (1 point); B blood pressure >140/90 (1 point); C clinical features: unilateral

weakness (2 points); speech problems (1 point); D duration of symptoms >60 minutes (2 points); 10-1 hour (1 point); D diabetes (1 point)

• What is the scoring system used to predict someones risk of a stroke if they have atrial fibrillation?– CHADSVASC– Congestive heart failure; Hypertension; Age >75years; Diabetes; Stroke; Vascular disease;

Age 65-74years; Sex Category• What are the 4 main types of stroke as outlined by the Oxford Stroke Classification system? • What artery has caused this infarct?

– Left PCA • What are watershed infarcts?

– Infarcts were territories overlap. These areas are very susceptible to ischaemia.• The watershed infarct ACA-MCA causes what symptoms?

– Man in the barrel syndrome: bilateral arm weakness, intact CN & leg function.

Epilepsy

• Sally day dreams a lot in class. The doctor suggests that she has what form of epilepsy? – Absent seizures

• What medication is best given for this type of seizure? – Ethosuximide– Sodium valporate

• Bob is out walking his dog and has a seizure. What are the symptoms of a generalised seizure? – The whole brain is involved.

Symptoms: tonic (whole body stiffness) clonic (muscle jerks) unconsciousness (may stop breathing) slow regain of consciousness no recall of episode.

– Importantly NO aura or hallucinations with this type.

BG and cerebellum• Label these parts of the

BG…• Name a condition which

causes hypokinesia– Parkinsons

• What are the cardinal features of parkinsons– TRAP: tremor, ridgity,

akinesia (bradykinesia) and postural instabilty.

• Which area is affected in parkinsons? – Substantia nigra

• Which area is affecting in someone with hemiballismus? – Subthalamic nuclei

Depression

Rob is a 55 year old accountant suffering with depression. • Give 5 symptoms/signs of depression

– Low mood, anhedonia, fatigue, weight change, sleep change, suicidal thoughts, poor concentration, feelings of worthlessness/ guilt.

• Where is serotonin normally produced? – Raphe nuclei

• Rob wants to swap to MAOIs, what is the MoA? – MAOI stop the action of monoamine oxidase enzyme which means that the monoamines (dopamine, 5HT

and NA) cannot be broken down.• Give an example of an MAOI?

– Phenelzine, isocarboxazide, moclobemide (RIMA – therefore the best)• But Rob loves his cheese why is this a potential problem?

– MAOI must not be taken with yeast, cheese or red wine, This is because they are all tyramines (dietary amines). Because of the affect of MAOI they cannot be broken down and instead act to increase NA (which also cannot be broken down due to the action of MAOI). Therefore, augumenting the adrenergic response - the so called cheese reaction.

– Cheese reaction: hypertension, tachycardia, cardiac arrhythmias, headache, nausea.• Rob decides that giving up cheese just isnt an option and so instead opts for mirtazepine. What is

the MoA of this drug? – Alpha 2 adrenoreceptor antagonist

Head trauma

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• What is the Glasgow Coma Scale?– Tool used to assess level of

consciousness• What are the elements of the

GCS?• Types of brain bleeds• What is a contrecoup injury?– A recoil injury to the opposite side of the brain

after the initial impact• What is a diffuse axonal injury?– When force is applied to the brain with rotation or

deceleration causing a sheering of nerve axons

Pain pharm • What are the steps on the WHO pain ladder?• What are the 2 types of pain?

– Nociceptive and neuropathic• What is nociceptive pain?

– Pain that arises from stimulation of pain receptors and can be somatic or visceral

• Which medication groups are used for nociceptive pain?– NSAIDs and Opioids

• What is neuropathic pain?– Pain that arises from nerve cell injury and can be:

• local e.g. post-herpetic neuralgia or neuroma• radicular e.g. post amputation phantom limb pain, trigeminal neuralgia, post-

stroke pain

• Which medication groups are used for neuropathic pain?– TCAs and AEDs

• A patient ‘accidently’ takes too much of their morphine medication, silly them, what should we give them?– Naloxone

Anatomy 1• Can you name the following?

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What are the two sensory neve fibres that supply the dura? CN5 and cervical spinal nerve

What would happen if the subarachnoid granulations were blocked? What could cause this? Raised ICP. Meningitis

Anatomy 2• Can you name the following?

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Name the hole that these CN come out of: CN4: SOF CN5b: Rotundum CN8: IAM

Anatomy 3• Can you name the following?

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What pattern of tissue injury would follow an infarct? Liquefactive necrosis – the CNS is special in that you see liquefactive and NOT coagulative

Anatomy 4• Can you name the following?

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Brainstem

Stan an 86 year old man has suffered a brain stem stroke. Examination revealed an infarction in the region shown here….• What CN are likely to be affected

– CNVII, VIII and IX• Explain what nuclei are potentially at

risk – Vestibular, cochlea, spinal part of

trigeminal. Superior parts of nucleus ambiguus, solitaris and facial nucleus

• Which artery is most likely blocked to cause the lesion shown in the image? – Anterior inferior cerebellar artery is

the most likely one blocked.

Brainstem Rule of 4• What type of signs and

symptoms are you likely to experience with the different types of brainstem infarcts?! THIS IS HARD

• The 4 rules of 41. There are 4 cranial nerves above

the pons (CN III and IV and 2 in the midbrain – CN I and CN II), 4 in the pons (CN V, VI, VII, VIII) and 4 in the medulla (CN IX, X, XI, XII)

Brainstem Rule of 4• The 4 rules of 4

2. The 4 motor nuclei that are in the midline are those that divide equally into 12 except for 1 and 2, that is 3, 4, 6 and 12(5, 7, 9 and 11 are in the lateral brainstem)

Brainstem Rule of 4• The 4 rules of 4

3. There are 4 structures in the ‘midline‘ (medial) beginning with M

• Motor pathway (or corticospinal tract):contralateral weakness of the arm and leg

• Medial Lemniscus:contralateral loss of vibration and proprioception in the arm and leg

• Medial longitudinal fasciculus:ipsilateral inter-nuclear ophthalmoplegia(failure of adduction of the ipsilateral eye towards the nose and nystagmus in the opposite eye as it looks laterally)

• Motor nucleus and nerve:ipsilateral loss of the cranial nerve that is affected (3, 4, 6 or 12)

4. There are 4 structures to the ‘side‘ (lateral) beginning with S

• Spinocerebellar pathway:ipsilateral ataxia of the arm and leg

• Spinothalamic pathway:contralateral alteration of pain and temperature affecting the arm, leg and rarely the trunk

• Sensory nucleus of the 5th cranial nerve:ipsilateral alteration of pain and temperature on the face in the distributionof the 5th cranial nerve(this nucleus is a long vertical structure that extends in the lateral aspect of the pons down into the medulla)

• Sympathetic pathway:ipsilateral Horner’s syndrome, that is partial ptosis and a small pupil (miosis)

Brainstem Rule of 4

• So don’t panic!! Think…which cranial nerves are affected? Then what else is affected – is it a midline or ‘side’ (lateral) effect?– A ‘medial brainstem syndrome (infarct)’ will damage the 4 M’s and

the 4 motor nuclei of CN III, IV, VI and XII– A ‘lateral brainstem syndrome (infarct)’ will damage the 4 S’s and

depending on if in pons (CN V-VIII) and medulla (CN IX – XII)

Also arterial supply helps: The Medial (‘midline’) aspect of the brainstem is supplied by the penetrating ‘paramedian branches’ of the basilar and vertebral arteries.The lateral aspect of the brainstem is supplied by the long outside arteries SCA, AICA and PICA.So if the question is ‘a man has PICA syndrome, what are his signs and symptoms’ you can work it out!

MCQ A 73 year old male is reviewed following recovery from a recent stroke. He states that he has not noticed any major problems in his activities of daily living. You notice, however, that he seems oblivious to the fact that his left arm is moving erratically. You ask him to raise both arms and he raises only the right arm and as you move around him to stand on his left side he seems unaware of your presence there. Which lobe is most likely to have been affected by the stroke in this patient?A. Frontal B. Limbic C. Parietal D. Temporal E. Occipital

MCQ

A 34 year old man is brought into the Emergency Department after being found unconscious in his flat following an overdose of diamorphine. On making your initial examination you notice his pupils are fixed and pinpoint. To manage the coma you administer a combination of thiamine, dextrose, naloxone, flumazenil and oxygen. Which component of this combination will reverse the miosis?A. Dextrose B. Flumazenil C. Naloxone D. OxygenE. Thiamine

MCQ

A 14 year old girl is brought into the Emergency Department with photophobia, neck stiffness and a non-blanching rash. Which cell type would be predominant in a cerebrospinal fluid sample taken from the girl?A. BasophilsB. Eosinophils C. Lymphocytes D. Macrophages E. Neutrophils

MCQ

A 64 year old man suffered an infarction of his cerebral cortex in the region marked X in the diagram that resulted in a specific functional deficit.A. Expressive dysphasia B. Receptive dysphaia C. Right apraxia D. Right facial anaesthesia E. Right facial palsy with forehead sparing

What is this area called?

Spinal Tracts

Spinothalamic – decussates a few levels above spinal cord level

Dorsal Spinocerebellar (lower limb) – does not decussate

Dorsal Spinocerebellar (upper limb) – does not decussate

Ventral Spinocerebellar (lower limb) - decussates at level and again in pons

Ventral Spinocerebellar (upper limb) does not decussate

Fasciculus Gracilis – decussates in medulla

Fasciculus Cuneatus – decussates in medulla

Corticospinal – lateral in medulla; ventral at spinal cord level

Tectospinal – decussates in midbrain

Rubrospinal – decussate in midbrain

Reticulospinal – does not decussate but 2 strands join in Renshaw cells

Vestibulospinal – does not decussate

First 7 – Ascending Second 5 – Descending

Spinal Tracts Dorsal Spinocerebellar (lower limb) – does not decussate

Spinothalamic – decussates a few levels above spinal cord level

Dorsal Spinocerebellar (upper limb) – does not decussate

Ventral Spinocerebellar (upper limb) does not decussate

Ventral Spinocerebellar (lower limb) - decussates at level and again in pons

Fasciculus Gracilis – decussates in medulla

Corticospinal – lateral in medulla; ventral at spinal cord level

Fasciculus Cuneatus – decussates in medulla

Tectospinal – decussates in midbrain

Reticulospinal – does not decussate but 2 strands join in Renshaw cells

Rubrospinal – decussate in midbrain

Vestibulospinal – does not decussate

First 7 – Ascending Second 5 – Descending