Session 9

Question 1

What is the role of the limbic association area?

Answer 1

Attaches emotional connotations to our sensory input and consequent behaviour. Rewards appropriate behaviour with pleasure sensations. Closely related with the ability to learn.

Question 2

What is lateralisation within the brain?

Answer 2

Whereby individuals have a dominant and a non-dominant hemisphere.

Question 3

What is the function of the dominant hemisphere?

Answer 3

Language, maths, logic and motor skills.

Question 4

What is the function of the non-dominant hemisphere?

Answer 4

Emotion, music/art, visuospatial and body awareness.

Question 5

How is language lateralised?

Answer 5

Input into the system is via Wernicke’s area of the temporal lobe. This interprets written and spoken words.
Output is via Broca’s area of the frontal lobe, which formulated the language components.

Question 6

Describe the pathway for speaking a heard word.

Answer 6

Primary auditory area to Wernicke’s area, to Broca’s area, to the motor cortex.

Question 7

Describe the pathway for speaking a written word.

Answer 7

Primary visual area to Wernicke’s area, to Broca’s area, to the motor cortex.

Question 8

What connects Wernicke’s area to Broca’s area?

Answer 8

Arcuate Fasciculus.

Question 9

What is the difference between Wernicke’s aphasia and Broca’s aphasia?

Answer 9

Wernicke’s: Disorder of comprehension, hence fluent but unintelligible speech.

Broca’s: Poorly constructed sentenced and disjointed, yet their comprehension is fine.

Question 10

Name the two types of memory.

Answer 10

Declarative and procedural.

Question 11

What is the difference between the two types of memory?

Answer 11

Declarative: naming of objects/recognition of places/remembering events etc. Rapidly learned but also rapidly forgotten.
Procedural: performance of motor skills that are learnt and perfected with practice, e.g. riding a bike.

Question 12

How do memories form?

Answer 12

Via synaptic links between the cortical and sensory areas, amygdala and hippocampus, and the diencephalon, basal forebrain and the pre-frontal cortex.

Question 13

How can memories be committed from short to long term memory?

Answer 13

Via consolidation. E.g. if there’s emotion involved, rehearsal, repetition, association etc.

Question 14

What is long-term potentiation?

Answer 14

Long-lasting enhancement in signal transmission between two neurones that results from stimulating them synchronously. Makes memories stronger by allowing circuits to adapt.

Question 15

What is the difference between anterograde and retrograde amnesia?

Answer 15

Anterograde: cannot form new memories.
Retrograde: cannot remember previous memories.

Question 16

Give two causes of amnesia.

Answer 16

Vascular interruptions, tumours, trauma, infections or vitamin B deficiency.

Question 17

What is dementia?

Answer 17

Progressive decline of cognitive function, usually affecting the whole cortex.

Question 18

What are the three most common causes of dementia?

Answer 18

Alzheimer’s disease, dementia with Lewy bodies and vascular dementia.

Question 19

Describe Alzheimer’s disease.

Answer 19

Exaggerated ageing process with loss of memory, aphasia, apraxia and behavioural changes. Presents with neurofibrillary tangles and senile plaques. Tau protein become hyperphosphorylated. Reduction in neurotransmitters, loss of connection between cells and death of brain tissue.

Question 20

Describe dementia with Lewy bodies.

Answer 20

Fluctuation in cognition, especially in attention and alertness. Cortical Lewy bodies are seen at autopsy. Very rapid onset of symptoms.

Question 21

Describe vascular dementia.

Answer 21

Caused by multiple infarcts throughout the cortex, causing neuronal death. Memory loss is not so prominent in early stages. Often issues with planning.

Question 22

What investigations are used to diagnose dementia?

Answer 22

Confusion screen, urine dip, mental state examination, refer to local memory clinic. , and an MRI of the head.

Question 23

What treatments are available for Alzheimer’s disease?

Answer 23

• ACh esterase inhbitors, e.g. Donepezil.

- NMDA receptor antagonists, e.g. memantine. Used in severe AD.

Question 24

What do they look at during a confusion screen?

Answer 24

FBC, UandEs, LFT, CRP, glucose, calcium, thyroid function tests, B12 and folate.

Question 25

What symptoms are seen with early stage Alzheimer’s disease?

Answer 25

Mislaying items, forgetting recent events, slow at grasping new ideas, poor judgement.

Question 26

What symptoms are seen with middle stage Alzheimer’s disease?

Answer 26

Not recognising people, confused about where they are, wandering, delusions and hallucinations.

Question 27

What symptoms are seen with late stage Alzheimer’s disease?

Answer 27

Weak and unstable, difficulty eating and swallowing, weight loss, incontinence, gradual loss of speech.

Question 28

What causes epilepsy?

Answer 28

Excessive neuronal activity in the brain.

Question 29

Name three types of generalized epileptic seizures.

Answer 29

Tonic-clonic, atonic, myoclonic and absence seizures.

Question 30

What is given if an epileptic seizure lasts over 5 minutes?

Answer 30

Buccal midazolam or rectal diazepam.

Question 31

Give three routes that microorganisms can enter the CNS.

Answer 31

Direct spread, blood-borne, iatrogenic.

Question 32

What is meningitis?

Answer 32

Inflammation of the leptomeninges (pia mater and arachnoid mater). Presents with headache, neck stiffness and a fever.

Question 33

What are the main causes of meningitis?

Answer 33

Neonates: E.Coli and L.Monocytogenes.
2-5: H.influenza.
5-30: N.meningitides
Over 30: S.pneumoniae.

Question 34

What is chronic meningitis commonly caused by?

Answer 34

Post-primary non-pulmonary mycobacterium tuberculosis.

Question 35

Give two complications of meningitis.

Answer 35

Raised ICP, cerebral infarction, cerebral abscesses, subdural empyema and epilepsy.

Question 36

What is encephalitis?

Answer 36

Infection of the neural parenchyma, resulting in a headache, fever, confusion, drowsiness or fatigue.

Question 37

What are the main causes of encephalitis?

Answer 37

Herpes virus, cytomegalovirus or HIV.

Question 38

What is prion disease?

Answer 38

Result of mutated prion proteins, which are normal constituents at neuronal synapses. These then cause conformational post-translational processes, causing aggregation of the PrPs, which causes neuronal death and holes in the grey mater.

Question 39

How can the brain accommodate for raised ICP?

Answer 39

• Spatial (brain atrophy/shrinkage)
• Reduced blood flow
• Reduced CSF volume

Question 40

Give two causes of RICP

Answer 40

Expanding focal lesions (tumours, haematomas, abscesses), or global increase in brain mass.

Question 41

What will RICP present with?

Answer 41

Headache, vomiting, papilloedema.

Question 42

What are the three main types of brain herniation?

Answer 42

Subfalcine, tentorial and tonsillar.

Question 43

Describe a subfalcine herniation.

Answer 43

Cingulate gyrus pushed under free edge of the falx cerebri. Ischaemia in parts of the parietal and frontal lobes.

Question 44

Describe tentorial herniation.

Answer 44

Uncus herniates through the tentorial notch, resulting in damage to CNIII. Also occlusion of the cerebellar arteries. Commonly fatal due to haemorrhage into the brainstem.

Question 45

Describe tonsillar herniation.

Answer 45

Cerebellar tonsils are pushed into the foramen magnum, with associated compression of the brainstem. Can result in a coma. Compression of the cerebral peduncles can cause hemiparesis.