BB2 Revision3 Flashcards by patrick ellis

Cerebellar histology

label this A-C

A: purkinje layer
B: molecular layer (outer)
C: granular layer (inner)

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Label A [1]

10 Flocculus of cerebellum

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Label A-C

A: middle cerebellar peduncle

B: cerebellar hemisphere

C: Inferior cerebellar peduncle

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Label A-E

A: Floccus
B: cerebellar tonsil
C: vermis
D: superior cerebellar peduncle
E: 4th ventricle

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Label A

A: middle cerebellar peduncle

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Label A

Superior cerebellar artery

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What are the 3 layers of the cerebellum cells? [3]

The outer, fibre-rich, molecular layer
The intermediate, Purkinje cell layer
The inner granular layer, which is dominated by the granule cell.

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Label A-C

A: molecular layer
B: granular cell layer
C: Purkinje cells

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Inputs and outputs to the cerebellum are via the [], which are either side of the []

Inputs and outputs to the cerebellum are via the cerebellar peduncles, which are either side of the pons

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State if the following contain input or output fibres [3]
State where the fibres go to / come from

Superior cerebellar peduncle
Middle cerebellar peduncle
Inferior cerebellar peduncle

Superior cerebellar peduncle has output fibres only. This is mainly going up to the motor thalamus
Middle cerebellar peduncle (largest of the 3) contains input fibres from the contralateral cerebral cortex and cranial nerves
Inferior cerebellar peduncle has input fibres from the spinal cord

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Describe the course of the spinocerebellar tract (dorsal and ventral spinocerebellar tracts)

first order neuron transmits sensation along the spinal nerve and travels via dorsal root in the spinal cord
Dorsal (posterior) spinocerebellar tract: is wholly ipsilateral. Second order neuron stays on same side and enters cerebellum at inferior cerebellar peduncle on same side
Ventral (anterior) spinocerebellar tract: is contralateral: Second order neuron crosses over, ascends and enters cerebellum where it crosses back over (terminate in the ipsilateral cerebellum.The fibres decussate twice – and so terminate in the ipsilateral cerebellum.

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Name the 4 deep cerebellar nuclei [4]
What is their overall collective function? [1]

“Don’t Eat Greasy Food”

Dentate
Emboliform
Globos
Fastigial

Overall: Relay nuclei which information to the cerebellum passes through

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Which part of the cerebellum is highlighted in green? [1]

Which part of the cerebellum does this structure connect to? [1

How does this part of the cerebellum differ in role to the deep cerebellar nuclei? 1[]

Flocculonodular lobe (anterior view)

Connects to the lateral vestibular nuclei of the pons

same function for the flocculonodular lobe as the deep nuclei do for the other cerebellar zones, but the difference is the deep relay nuclei for this lobe isn’t actually in the cerebellum.

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Cerebellum function

State and describe the location of the three functional zones of the cerebellum

Also state which cerebellar nuclei related to each zone [4]

Vestibulocerebellum comprises the flocculonodular lobe and its connections to the lateral vestibular nucleus of the pons
Spinocerebellum comprises the anterior lobe and vermis, connected to the fastigial, globose and emboliform nuclei
Cerebrocerebellum is comprised of the posterior lobe (cerebellar hemispheres) controlled by the dentate nucleus

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State the function of the spinocerebellum [1]

Via which tract are motor commands from the spinocerebellum sent down? [1]

The spinocerebellum (anterior lobe and vermis) controls locomotion and limb coordination, and balancing your body the ground

It sends motor commands down the reticulospinal tracts to coordinate postural and locomotor movements: i.e. when you run, walk, lean over to grab something, you don’t lose balance and fall over.

(This is a more dynamic balance when compared to the vestibulocerebellum which is more of a static balance)

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State the function of the cerebrocerebellum [1]

From where do the inputs for the cerebrocerebellum come from in the brain [1] & the cerebellum? [1]
From where do the outputs for the cerebrocerebellum go to in the brain [1] & the cerebellum? [1]

Which deep nuclei is involved with the cerebrocerebellum? [1]

Cerebrocerebellum: coordinates movements initiated by the motor cortex. This includes speech, voluntary movements of hands, arms, and hand-eye coordination. It is also involved in speech coordination

Input = from cerebral cortex via middle cerebellar peduncle
Output: To motor thalamus via superior cerebellar peduncle
Deep nuclei involved = dentate

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What is the function of the vestibulocerebellum? [2]

coordinates head and eye movements to ensure the stability of gaze.
It controls balance of the head on the body via the medial vestibulospinal tract and helps balance of the body on the ground via the lateral vestibulospinal tract

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Cerebellar pathologies:

Why do tumours from ependymal cells specifically compress the cerebellum? [1]

What is the name for these types of tumours? [1]

Medulloblastoma:

Tumours which grow from the ependymal cells grows in the 4th ventricle, and it tends to grow in the midline so very specifically compresses the nodulus of the cerebellum.

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What is the most common type of CNS tumour in children? [1]

Medulloblastoma: tumours arising from cerebellum

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What are the symptoms of flocculonodular syndrome? [3]

little control of axial muscles, wide based ataxic gait with reeling and swaying

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Why do alcoholics often suffer from anterior lobe syndrome? [1]

brain needs B12 for myelin generation and the cerebellum has a higher turnover than most parts of the brain meaning it needs more, so if depleted in alcoholics it causes problems

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What are the characteristics of anterior lobe syndrome? [4]

incoordinaion of the limbs (especially legs)
ataxic gait (walks in a wide platform so they don’t fall over, this overlaps with flocculonodular syndrome).
hypotonia
reflexes appear depressed or pendular (UMN lesion)

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Neocerebellar syndrome occurs due to damage to which functional part of the cerebellum? [1]

What are characterisitic features of neocerebellar syndrome? [5]

Damage to the cerebrocerebellum

Characterisitc features:
* Loss of hand-eye coordination.
* Dysmetria (inaccurate reaching with intention tremor)
* Dysdiadochokinesis (the irregular performance of rapid alternating movements of the hands)
* Intention tremors occur on an attempt to touch an object
* Loss of good speech articulation/slurred speech which is due to a loss of coordination of muscles involved in speech production

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Name 6 characteristics of cerebellar stroke

Dysdiadochokinesia: is the inability to perform rapid alternating muscle movements
Ataxia (gait and posture)
Nystagmus
Intention tremor
Slurred, staccato speech
Hypotonia/heel-shin test

. Headache, vertigo, nausea, vomiting
. Eye changes (nystagmus, ptosis)
. Dysarthria and dysphagia (Dysarthria is a motor disorder of speech weakening the muscles of the mouth, face and respiratory system)
. Ataxia
. Arm weakness and incoordination

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What is the difference in symptoms between a lesion in Broca's area to Cerebrocerebellum? [1]

Broca’s lesions to do with forming words in the **right sequence and getting the right grammar** Cerebrocerebellum can speak fine but they **slur** due to improper movement ( basics of moving the mouth and lips to make the right sounds)

Label A & B

A: inferior cerebellar peduncle B: Vestibular nuclei

interposed nuclei comprise the [] nucleus and the [] nucleus

interposed nuclei comprise the **emboliform** nucleus and the **globose** nucleus

Which functional zone of the cerebellum is the dentate nucleus connected to? [1] Which areas of the brain does this tract connected to the dentate nucleus send to after connecting to the dentate nucleus? [2]

Dentate nucleus: * Connected to **cerebrocerebellum** * Sends information to the contralateral **red nucleus** and the **ventrolateral (VL) thalamic nucleus.**

The vestibulocerebellum: Controls balance of the head on the body via the [] tract Helps balance of the body on the ground via the [] tract

coordinates head and eye movements to ensure the stability of gaze. It controls **balance of the head** on the body via the **medial vestibulospinal tract** Helps **balance of the body** on the ground via the **lateral vestibulospinal tract**

Purkinje cells are GABAergic/Glutaminergic?

Purkinje cells are **GABAergic**

Which spinal tract sends information about nociception? [1] (be specific) Where does the first synapse of this spinal tract occur? [1]

**Lateral spinothalamic tract** First synapse is the **dorsal horn at the spinal level**: target for targets of pain control

Desribe the pathway of the lateral spinothalamic tract [3]

**First-order neurones**" - cell bodies are in the **dorsal root ganglion** whose axons extend from peripheral receptors **Second-order neurones** - cross almost immediately via the anterior spinal commissure and form the **lateral spinothalamic tract** - Then **ascends** in the lateral funiculus. Fibres of this tract are somatotopically organised for their entire course. **Third-order VPL neurons**: - send axons through the posterior limb of the internal capsule to the somatosensory cortex (areas 3, 1, 2).

Why is the dorsal horn horn a useful place to treat pain? [1]

Can target without having to cross the BBB [1]

How are endogneous opioids rapidly inactivated when in circulation? [1]

Peptides are rapidly inactivated by **peptidases** in the circulation

Which familiy is the primary opioid receptor for analgesia? [1] What are potential AEs of using this family? [1]

**Mu family** AEs include **respiratory depression**; **reduced GI motility**; **dependence**

Where are Mu opioid receptors found in the body? [1]

All over of the body: why broad spectrum of AEs occurs Works at **supraspinal and spinal level**

Explain the MoA of morphine [4]

* Mu acts on receptors (e.g. Mu) * Causes **activation of K+ conductance** and **decreased calcium conductance** * This leads to **decreased excitability (K+)** and **decreased release of neurotransmitters (Ca2+)**. * Inhibits **cAMP formation**

Why may you need to give multple doses of naloxone for an opioid overdose? [1]

Opioids often have long half lifes, whilst naloxone has a very short half life

Asides from morphine, name 5 other opioids prescribed

- Herion: **high solubility compared to morphine** - **Dextromoramide**: potent but limited prescription - **Methadone**: large half-life - so used for long dosing. - **Meptazinol**: Mu-1 produces less respiratory depression than morphine

What do you need to consider about tolerance and addiction to opioid prescription [2]

* Tolerance isn't a major problem in the context of **chronic pain or terminal illness** **Tolerance** is a natural process and a **different pathway to the development of addiction** (Generally advised not to under-dose because of fear of tolerance. But be careful) dosing.

How can patients modify their own dose of analgesia? [1]

Use **Patient controlled analgesia**: The pump is set to deliver a small, constant flow of pain medication. Additional doses of medication can be self-administered as needed by having the patient press a button

Regarding the Mu receptor, why is there such a vast patient variability with pain? [1]

Patient variability: more than **100 genetic polymorphisms** have been identified in the mu opioid receptor gene

Explain MoA of paracetamol [1]

reduces the active oxidized form of COX-2 / **selective COX-2 inhibitor**

Explain mechanism of aspirin [1]

**Aspirin**: COX-1 and COX-2 inhibitor

Which of the following has a significnt risk or cardiovascular events Ibuprofen Diclofenec Ketoprufen Pregabalin Celecoxib

Which of the following has a significnt risk or cardiovascular events Ibuprofen Diclofenec Ketoprufen Pregabalin **Celecoxib**

tricylic anti-depressants work by inhbiting the reuptake of which of the following Ca2+ AMPA glutamate receptor Amines GABA NMDA Glutamate receptor

tricylic anti-depressants work by inhbiting the reuptake of which of the following **Amines**: **serotonin and norepinephrine in presynaptic terminals,**

Ketamine works as an antagonist to which of the following? Ca2+ AMPA glutamate receptor Amines GABA NMDA Glutamate receptor

Ketamine works as an antagonist to which of the following? **NMDA Glutamate receptor**

Baclofen is an agonist to which of the following Ca2+ AMPA glutamate receptor Amines GABA NMDA Glutamate receptor

Baclofen is an agonist to which of the following Ca2+ AMPA glutamate receptor Amines **GABA** NMDA Glutamate receptor

Describe mechanism of Ibuprofen, diclofenac, ketoprofen [1]

COX-1 and COX-2 inhibition plus additional mechanisms

Celecoxib is a selective COX-2 inhibitor, but has a significant risk of what? [1]

significant risk of cardiovascular events

Carbamazepine, sodium valproate, pregabalin treat what type of pain? [2]

Neuropathic pain; Trigeminal neuralgia

Name a tricyclic antidepressant that is used to treaet neuropathic and cancer pain [1]

**Amitriptyline**

Explain the mechanism of action of tricylic anti-depressants [2]

Tricylic antidepressants **inhibit** the **reuptake of amines** (dopamine, norepinephrine, adrenaline, noradrenaline histamine, and serotonin) and also **block sodium and calcium channels**

Name a drug used to treat migraines [1] Describe its MoA [1]

**Sumatriptan**: vasoconstriction of cerebral arteries reducing inflammatory response and trigeminal activation

# Pain management for complex pain types Describe MoA of ketamine [1]

NMDA glutamate receptor antagonist

# Pain management for complex pain types Name two calcium channel ligands [2]

**gabapentin, pregabalin** [2] Binds α2δ 1 and 2 in voltage gated calcium channels to reduce calcium currents

# Pain management for complex pain types What is the MoA of baclofen? [1] What type of pathologies is it used to treat? [2]

**GABA receptor agonists** It's used to relieve muscle spasms, cramping or tightness caused by conditions such as MS, cerebral palsy

# Pain management for complex pain types Describe the MoA of tramadol & tapentadol [2]

Opioid receptor agonist AND amine reuptake inhibition

What are the first three firstline drug classes recommended for neuropathic pain? [3]

* **SNRIs** (duloxetine) * **tricyclic antidepressants** (amitrypyline) * **calcium channel blockers** (gabapentin, pregabalin)

# Local anaesthetics Name 3 examples [3] MoA? [1]

**lignocaine, bupivacaine, prilocaine** (all end in -caine) **Block Na channels**

# General anaesthetics Mode of administration? [2] Mechanism of action? [2]

Mode of administration: **inhalational or intravenous** Mechanism of action: **activation of inhibitory receptors or inhibition of excitatory receptors**

Which drug acts as a general anaesthetic AND acts as an analgesic? [1]

**ketamine**

Name some inhaled anaesthetics [2] and IV anaesthetics [2]

**Inhaled:** [end with -ane] Halothane Enflurane Isoflurane Nitrous oxide **Intravenous anaesthetics**: Propofol Thiopental Etomidate Ketamine Midazolam

Define trigeminal neuralgia [1]

is sudden, severe facial pain. It's often described as a sharp shooting pain or like having an electric shock in the jaw, teeth or gums

What is trigeminal neuralgia caused by? [1]

Compression, distortion or stretching of the nerve V root fibres by a branch of the anterior or posterior inferior cerebellar artery

Treatment for trigeminal neuralgia? [5]

**carbamazepine** (sodium channel blocker): 1st line **baclofen** (GABAB agonist): 1st line if unresponsive **phenytoin** (sodium channel blocker) **valproate** (sodium channel blocker and other targets) **clonazepam** (benzodiazepine)

BB2 Revision3 Flashcards

(66 cards)