General Neurology Flashcards
1
Q
What neural tissue is the nervous system derived from?
A
• Nervous system derived from ectoderm
2
Q
Outline the brief derivation of the nervous system.
A
• Ectoderm –> Neural plate –> Neural tube closes –> Neural crest cells give rise to NS cells: Melanocytes, Schwann Cells, Adrenal medullary cells, dorsal root ganglion cells, autonomic ganglion cell
3
Q
List the broad components of the nervous system.
A
- Cells
- Connective Tissue
- Blood vessels
4
Q
List the two cellular categories of the nervous system.
A
- Neurons
* Glial cells
5
Q
Give 3 examples of glial cells and outline their roles.
A
• Oligodendrocytes: myelination formed by these cells which is a spiral multi-layered wrapping of glial membrane increasing AP conduction speed by restriction of ionic current to smaller unmyelinated portions at nodes of Ranvier
- 1 oligodendrocyte to many myelinated CNS axons
• Microglial cells: Immune responses within CNS removing cellular products by phagocytosis assisted by other glia and phagocytes invading CNS from circulation
• Astrocytes: named by morphology with cell body and several branches arising which produces BBB, regulates the CNS microenvironment by buffering EC environment with ions and NTs, local astroglia take up excess K+, post-injury astrocytes ∆ to become reactive astrocytes forming glial scar (segregating damaged tissue) and couples GAP junctions to form sanctum for small molecules and ions to redistribute along concentration gradients or by current glow.
• Ependymal cells: epithelium lining ventricular spaces of the brain which secretes CSF in ventricular system where the substance diffuses readily across ependymal lining between EC space of brain and CSF
• Satellite cells: encapsulate dorsal root and cranial nerve ganglion cells regulating microenvironment like astrocytes
6
Q
What is the role of oligodendocytes?
A
myelination formed by these cells which is a spiral multi-layered wrapping of glial membrane increasing AP conduction speed by restriction of ionic current to smaller unmyelinated portions at nodes of Ranvier
- 1 oligodendrocyte to many myelinated CNS axons
7
Q
What is the role of microglial cells?
A
Immune responses within CNS removing cellular products by phagocytosis assisted by other glia and phagocytes invading CNS from circulation
8
Q
What is the role of astrocytes?
A
named by morphology with cell body and several branches arising which produces BBB, regulates the CNS microenvironment by buffering EC environment with ions and NTs, local astroglia take up excess K+, post-injury astrocytes ∆ to become reactive astrocytes forming glial scar (segregating damaged tissue) and couples GAP junctions to form sanctum for small molecules and ions to redistribute along concentration gradients or by current glow.
9
Q
What is the role of ependymal cells?
A
epithelium lining ventricular spaces of the brain which secretes CSF in ventricular system where the substance diffuses readily across ependymal lining between EC space of brain and CSF
10
Q
What is the role of satellite cells?
A
encapsulate dorsal root and cranial nerve ganglion cells regulating microenvironment like astrocytes
11
Q
List the 3 structural features of a neurone.
A
1) Dendrites: branching extensions of soma which expands SA of neurone
2) Soma (cell body): core of neurone bearing genetic and metabolic centres of neurones
3) Axon: extension of cell body, as proximal dendrite in specialised region called axon hillock, conveying output of cell to other neurones with variable length and diameter ∆s according to neuronal type.
12
Q
Describe what a dendrite is?
A
Dendrites: branching extensions of soma which expands SA of neurone to receive signals from other neurones which can be primary or higher-order. Individual dendrites aggregate into dendritic trees ≈ ∆ between different neurone types, size, number and spatial organisation
13
Q
What is a soma? List 3 cellular organelles it contains.
A
core of neurone bearing genetic and metabolic centres of neurones” nucleus, nucleolus, Nissl bodies (neuronal biosynthetic apparatus ≈ RER + Golgi Body), mitochondria, cytoskeletal elements). Soma receives synaptic input from dendrites
14
Q
What is an axon? List the cellular organelles it may contain.
A
extension of cell body, as proximal dendrite in specialised region called axon hillock, conveying output of cell to other neurones with variable length and diameter ∆s according to neuronal type. Axon is absent of RER, free ribosomes and Golgi apparatus. Axon may terminate in a synapse and may make synapses along its length.
15
Q
Define radial migration.
A
- Cells migrate along radial glia from origin in ventricular and subventricular zones –> formation of cortex and deep nuclear structures
- Radial migration gives rise to projection neurons of the cortex
16
Q
Give an example of the process of nerve cell migration in the brain.
A
Radial Migration:
• Cells migrate along radial glia from origin in ventricular and subventricular zones –> formation of cortex and deep nuclear structures
• Radial migration gives rise to projection neurons of the cortex
17
Q
List the 4 lobes of the brain and their functions.
A
1) Frontal lobe: Motor functions and Personality and ability to change; ‘frontal lobe personalities’
• Sequencing and fluency
2) Temporal lobes: Memory and speech (L > R)
3) Parietal lobe: Spatial awareness ( R ), Language (L)
4) Occipital lobes: Vision
18
Q
Based on the 4 lobes of the brain and their function, outline a quick functional test for each lobe.
A
1) Frontal lobe: Motor functions and Personality and ability to change; ‘frontal lobe personalities’
• Sequencing and fluency
Test(s):
• Name as many animals in 1 minute or words beginning with FAS
• Luria hand-sequencing task: Repeat back hand sequence
2) Temporal lobes: Memory and speech (L > R)
Test(s):
• Address test: Give a pseudo address and see if they remember it
• Object recall
• Serial 7s
3) Parietal lobe: Spatial awareness ( R ), Language (L)
Tests: • Clock face: Put numbers on and draw ten to two, neglecting one side of space, put all on one side • Naming objects • Drawing cube, interlocking infinity • Agnosia
4) Occipital lobes: Vision
19
Q
Outline the visual field pathway.
A
• Light -> photoreceptors (rods and cones) -> retinal ganglion cells -> leaves orbit via optic canal (passageway between sphenoid bone) -> enters cranial cavity running along surface of middle cranial fossa -> optic nerves from each eye unite ≈ optic chiasm -> fibers from nasal (medial) half of each retina cross over to contralateral optic tract whilst temporal (lateral) halves remain ipsilateral -> Optic tract (L+R) -> synapse in lateral geniculate nucleus (LGN) relay system in thalamus -> axons from LGN carry visual information in optic radiation pathway (upper optic radiation and lower optic radiation) ->
i) Upper optic radiation: Fibres from superior retinal quadrants (correspond to inferior visual field quadrants) travel through parietal lobe to reach visual cortex
ii) Lower optic radiation: Fibres from inferior retinal quadrants (correspond to superior visual field quadrants) travel through temporal lobe via Meyers’ loop pathway to reach visual cortex
20
Q
How much protein is in CSF?
A
• Protein free
21
Q
Where is CSF derived from?
A
• Plasma-derived
22
Q
How much CSF is present in the body?
A
• 120-150ml
23
Q
How much CSF is produced per day and how is this removed?
A
- Constant production: 500ml day
* Reabsorbed in arachnoid granulations in venous sinsuses and nasal
24
Q
Where is CSF reabsorbed?
A
• Reabsorbed in arachnoid granulations in venous sinsuses and nasal lymphatics
25
List the general components of CSF.
* No RBC
* Low WBC <5/ml
* Protein (low) < 0.5mg/ml
* Glucose: 60-70% blood levels ≈ 2.5-5mmol/L)
26
List 5 functions of CSF.
* Buoyancy (weighs less)
* Protection: soft gel in hard box
* Waste clearance
* Homeostasis
* Intracranial pressure regulation
* Immune surveillance
27
Outline the ventricular system of the brain.
set of four interconnected cavities in the brain where CSF is produced (choroid plexus bearing ependymal cells).
1) Lateral ventricle @ cerebral hemisphere
2) Central ventricle @ spinal cord
3) 3rd ventricle @ Diencephalon via aqueduct
4) 4th ventricle @ Brain stem
5) Arachnoid Granulations (in venous sinuses): Reabsorbed
28
Outline the key features of a lumbar puncture.
* Lying left lateral with legs flexed at knee and pulled towards their chest (foetal position)
* Clean with iodine + inject with anesthetic
* Feel for ASIS (L3/L4)
* Lumbar puncture needle, withdraw central core
* Connected to manometer
29
What is a normal reading for a lumbar puncture.
• OP <20cm = normal OP
30
List the 3 reading categories for a lumbar puncture.
* OP <20cm = normal OP
* 21-29 = intermediate
* > 30 cm water = elevated
31
Outline the complications of a lumbar puncture.
* Headache: Low pressure headache, worse standing up, eased lying down, N+V
* Bleeding/bruising
* Nerve damage
* Infection
* Coning/Death
32
What 3 general scenarios are there regarding the blockage and accumulation of CSF.
* Unfused cranial sutures: Expanded cranium
* Fused cranial sutures: Occurs slowly ≈ normal
* Fused cranial sutures: Occurs rapidly
33
List the general pathological causes of elevated CSF.
Congenital
```
Acquired
• Infections
• Inflammation
• Tumours: Malignant meningitis
• Vascular
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34
Outline an intervention to manage a raise in ICP due to accumulation of CSF.
• Ventriculoperitoneal shunt (VPS)
35
Which two groups of people are more likely to suffer from Idiopathic Intracranial Hypertension? (IHH)
* Female > Male
| * Usually Overweight
36
List 3 signs (general or specific) of raised intracranial pressure.
* Symptoms of raised ICP
* Visual disturbances
* Diplopia
• Papilloedema
37
List the main concern regarding complication of IIH.
• Blindness (check visual acuity and fields)
38
Give two investigations you would order in a patient with IHH.
* MRV
| * Lumbar puncture: Raised pressure in 30cm/40cm
39
Outline the management for IHH.
* Supportive: Weight loss and analgesics
* Acetazolamide: reduce production of fluid in the eye (CA inhibitor)
* Repeated LP: Remove some of the CSF
* Shunt: Ventriculoperitoneal shunt
40
Outline key points about low pressure headaches.
```
Low Pressure Headaches
• Eased on lying down
• Worse on standing up
• Occur spontaneously (v. rare)
• Usually post-LP
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41
Outline the disease of syringomyelia. Signs and symptoms; Investigations and Management.
= fluid-filled cavity or cyst (syrinx) forms within spinal cord. Expanding syrinx compresses and destroys surrounding nervous tissue.
```
Signs and Sx:
• Neck and shoulder pain
• Muscle weakness
• Pain
• Stiffness in legs
• Numbness
• Decreased sensation
• Scoliosis
• Ataxia
```
Investigations:
• MRI: Chiari malformation
Management:
• Supportive
42
What occurs if a syrinx is in the medial tract?
Syrinx is in medial tract ≈ affecting spinothalamic tracts where nerve fibres cross with LMN problems in hand (distance to synapse) and UMN problems in legs (distance to synapse)
43
Outline important areas to cover in a meningitis history.
* Exposure
* Petechial rash
* Recent infection
* Recent travel – endemic regions?
* History of IVDU
* History of recent or remote head trauma
* Otorrhea or rhinorrhea
* HIV infection or risk factors
* Immunocompromising conditions
44
Outline key features in the presentation of meningitis.
* Stiff neck**
* Altered mental state (confusion, delirium, drowsiness, impaired consciousness)
* Non-blanching rash
* Bulging fontanelle (infants)
* Photophobia (Meningiococcal disease)
* Kernig’s Sign
* Brudzinski’s Sign
* Coma
* Paresis
* Focal neurological deficit
* Seizures
```
Constitutional:
• Fever
• Nausea
• Vomiting
• Lethargy
• Irritable
• Anorexia
• Headache
• Muscle ache
• Joint pain
• Cough
```
45
What is a key differentiating symptom for the diagnosis of meningitis.
• Stiff neck**
46
Give considerations for a patient presenting with potential bacterial meningitis.
* Age of patient
* Vaccination status
* Immune status – primary or acquired immunodeficiency
47
What is the importance of the Blood-brain barrier?
BBB prevents fluctuations in nutrients, metabolites or blood-borne substances ≈ regulated environment + homeostasis ≈ protection of brain from systemic events regulated by tight junctions + astrocyte processes contact vessel from neuropil side ≈ separates blood compartment from neuropil compartment. Transport across BBB limited to small lipophilic molecules, water and gases with other substances requiring active transport.
48
What is the main method of neuronal communication and where does this occur?
Neurones communicate via synapses which occurs between axons and dendrites either by direct electrical communication or neurotransmitter diffusion to propagate the electrical charge (action potential)
49
What is a ganglion? What is a nucleus? How do ganglions and nucleus differ?
Ganglion: Collection of nerve cell bodies outside the CNS
Nucleus: Collection of nerve cell bodies inside the CNS
50
What are the two gross appearances of the nervous system? What are the differences between these?
1) Grey Matter: Cell bodies of neurones + neuroglia + unmyelinated neurones
• Nucleus (CNS)
• Ganglion (PNS)
• Surface of cerebral and cerebella hemispheres
Locations:
• Brain: Grey matter outside
• Spinal cord: Grey matter in centre
2) White Matter: Axons of myelinated neurones.
Locations:
• Brain: White matter is central
• Spinal cord: White matter is peripheral
51
What are the regions of the central nervous system?
1. Spinal cord
2. Brainstem (nuclei of all CN bar CN I + CN II)
a) Medulla
b) Pons
c) Midbrain
3. Cerebellum
4. Cerebrum
a) Telencephalon (cerebral hemispheres)
b) Diencephalon (thalamus + hypothalamus)
52
What are the functional units of the nervous system?
Neurones, excitable nerve cells which transmit information as electric signals (action potentials).
53
What is the structure of a neurone?
1. Soma
2. Axon = single extension of soma which can be covered in myelin and transmitting electrical charge (AP) along the length which terminates at the distal synaptic boutons which transmit the AP to the next neurone via NT or AP across synaptic cleft
3. Dendrites = multiple, thin extensions of the soma receiving AP from other neurones
54
What are the types of neurones?
1. Multipolar neurone: Most abundant in CNS where dendrites branch directly of soma and single axon arises from axon hillock
2. Pseudounipolar neurone: Spinal ganglion with dendritic axon receiving sensory information from periphery sending to spinal cord via an axon bypassing cell body along the way ≈ relay sensory information from peripheral receptor to CNS w/o modifying signal
3. Bipolar neurone: retina and olfactory epithelium with main dendrite receiving synaptic input conveyed to cell body and from there through axon to next layer of cells. Bipolar neurones integrates multiple inputs and then bypasses modified information to next neurone in the chain. Difference between pseudounipolar and bipolar neurone ≈ amount of processing occurring in neurone
55
Where are you most likely to find a pseudounipolar neurone in the CNS?
Spinal ganglion: Dendritic axon receives sensory information bypassing cell body along the way to relay information from peripheral receptor to CNS
56
Where are you most likely to find a bipolar neurone?
Retina/Olfactory epithelium: Main dendrite receives synaptic input conveyed to cell body through axon to next layer of cells. Bipolar neurone integrates multiple inputs and bypasses information to next neurone in chain
57
List the three types of synapse.
1. Axodendritic synapse
2. Axosomatic synapse
3. Axoaxonal synapse
58
What are the two anatomical divisions of the nervous system?
1) CNS = Encephalon + Spinal cord
- Lined by membranes (≈ meninges)
- Suspended in cerebrospinal fluid (CSF)
2) PNS = Cranial + Spinal nerves + ganglia
59
What are the two functional divisions of the nervous system?
1) Sensory (afferent): Sensory (afferent) neurones converging information from receptors in peripheral tissues + organs to CNS
• Somatic: skeletal muscle innervation
• Visceral: innervation of internal organs
2) Motor (efferent): Motor (efferent) neurones transmitting signals from the CNS to effector cells (skeletal and smooth muscles, organs, glands)
• Somatic: skeletal muscle innervation
• Visceral: innervation of internal organs
i) Parasympathetic
ii) Sympathetic
iii) Enteric
60
Outline the two main divisions of the Autonomic Nervous System: Outflow regions; Pre-ganglionic neurone and post-ganglionic neurone NTs; Effects.
1) Sympathetic
• Thoracolumbar
• Pre-ganglionic sympathetic neurons: T1-L2 spinal cord (thoracolumbar)
• Ganglia in sympathetic chain
• Pre-ganglionic NT: ACh @ Nicotinic (NB: Sweat gland is ACh and Adrenal Medulla)
• Post-ganglionic NT: NE @ Adrenergic
• Effects: Mydriasis, tachycardia, vasoconstriction, tachypnea, bronchodilation, glycogenic, diaphoresis
2) Parasympathetic
• Craniosacral
• Pre-ganglionic parasympathetic neurons: brainstem + S2-S4
• Pre-ganglionic NT: ACh @ Nicotinic
• Post-ganglionic NT: ACh @ Muscarinic (PAM)
• Effects: Meiosis, GI motility (peristalsis), glandular secretion, excretion (defaecation) and micturition
61
What is the levels of spinal cord which sympathetic outflow occurs?
* Thoracolumbar
| * Pre-ganglionic sympathetic neurons: T1-L2 spinal cord (thoracolumbar)
62
What is the main pre-ganglionic NT in the sympathetic nervous system? What receptor does this NT bind to?
• Pre-ganglionic NT: ACh @ Nicotinic
63
List the general effects of the sympathetic nervous system.
• Effects: Mydriasis, tachycardia, vasoconstriction, tachypnea, bronchodilation, glycogenic, diaphoresis
64
What is the main post-ganglionic NT of the sympathetic nervous system? Give two other examples, and the NT, where this may not be the case.
• Post-ganglionic NT: NE @ Adrenergic (NB: Sweat gland is ACh and Adrenal Medulla)
65
What is the levels of spinal cord which parasympathetic outflow occurs?
* Craniosacral
| * Pre-ganglionic parasympathetic neurons: brainstem + S2-S4
66
What is the main pre-ganglionic NT in the parasympathetic nervous system? What receptor does this NT bind to?
• Pre-ganglionic NT: ACh @ Nicotinic
67
What is the main post-ganglionic NT of the parasympathetic nervous system?
• Post-ganglionic NT: ACh @ Muscarinic (PAM)
68
List the general effects of the sympathetic nervous system.
• Effects: Meiosis, GI motility (peristalsis), glandular secretion, excretion (defaecation) and micturition
69
What are the meninges?
Membranes which protect the encephalon and spinal cord in addition to bones and vertebra and cerebrospinal fluid
70
What are the three meningeal layers?
1) Dura mater: superficial and toughest meninges layer which has two layers: outer periosteal layer and inner meningeal layer. Apart from the dural sinuses, these two layers are in apposition.
• Inward septa of dura (Dural partitions) where inner layer delves between cerebral hemispheres ≈ secure brain to skull, reduce movement and divide cranial cavity
• Identifiable regions of Dural septa (partitions): tentorium cerebelli + tentorial notch + falx cerebelli
2) Arachnoid mater: Middle layer, adhered closely to the dura with a web-like appearance
3) Pia mater: Deepest layer which is in direct contact with CNS tissue (encephalon + spinal cord) which is highly vascular and enters every sulci
71
List the three dural septa (partitions).
Tentorium cerebelli
Tentorium notch
Falx cerebelli
72
List the 3 main meningeal spaces. Which are potential spaces?
1) Epidural space: Potential space of Dura mater to Bone
2) Subdural space: Potential space of Dura to Arachnoid
3) Subarachnoid space: Real space containing CSF + Cerebral arteries between Arachnoid and Pia mater
73
Which of the meningeal layers is a main space, not potential? List two things it contains.
Subarachnoid space: Real space containing CSF + Cerebral arteries between Arachnoid and Pia mater
74
List the two types of invaginations/ evaginations of the cerebrum.
1) Gyri (gyrus): In-folding
| 2) Sulci (sulcus): Rises
75
Give the term for the sulcus separating the two cerebral hemispheres
Median longitudinal fissure
76
Outline the lobes of the cerebrum and their functions. Give a test for each.
1) Frontal lobe: Motor functions and Personality and ability to change; ‘frontal lobe personalities’
• Sequencing and fluency
Test(s):
• Name as many animals in 1 minute or words beginning with FAS
• Luria hand-sequencing task: Repeat back hand sequence
2) Temporal lobes: Memory and speech (L > R)
Test(s):
• Address test: Give a pseudo address and see if they remember it
• Object recall
• Serial 7s
3) Parietal lobe: Spatial awareness ( R ), Language (L)
```
Tests:
• Clock face: Put numbers on and draw ten to two, neglecting one side of space, put all on one side
• Naming objects
• Drawing cube, interlocking infinity
• Agnosia
```
• ACEmobile.org
4) Occipital lobes: Vision
77
What are the lateralisation of cortical function?
Hemispheres show lateralisation of cortical function with left hemisphere (dominant) ≈ language + maths cf right hemisphere ≈ visual-spatial skills and creativity
78
What are the regions of the diencephalon and its functions?
1) Thalamus ≈ relay station for:
- Sensory impulses ascending to sensory cortex
- Inputs from subcortical motor nuclei + cerebellum travelling to cerebral motor cortex
- Encloses 3rd ventricle
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2) Hypothalamus
- Autonomic control
- Endocrine control (HPA)
- Regulation of thirst (fluid-electrolyte balance)
- Eating (energy balance)
- Sexual behaviour reproduction
- Body temperature
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79
What is the midbrain functions?
1. Visual + Auditory reflex centres ≈ superior + inferior colliculi
2. Subcortical motor centre ≈ red nucleus
3. Reward-seeking, motor learning + others ≈ substantia nigra
80
What is pyramidal ducssation?
crossing of corticospinal axons thus lesions above decussation ≈ symptoms on contralateral side cf lesions below decussation ≈ ipsilateral side
81
crossing of corticospinal axons thus lesions above decussation ≈ symptoms on contralateral side cf lesions below decussation ≈ ipsilateral side
Cerebellum found in cerebellar fossa with two hemispheres. Convoluted with internal gray matter nuclei, surrounded by white matter and outside cortex of gray matter. The cerebellum is connected to brain stem by cerebellar peduncles (superior, middle and inferior).
1. Processes + interprets impulses from motor cortex + sensory pathways
2. Motor activity coordination ≈ smooth, well-times movements
3. Balance
82
What are the main regions in a cross-section/transverse section of the spinal cord?
1. Gray matter: H-shaped, containing neuronal cell bodies within ‘horns’
i. Dorsal/posterior horns ≈ interneurones
ii. Lateral horns ≈ visceral (autonomic) + motor neurones
iii. Ventral/anterior horns ≈ somatic motor neurones
2. Central canal
3. White matter: columns containing a number of ascending and descending tracts. All tracts are paired and most decussate:
i. Ventral (anterior columns)
ii. Lateral columns
iii. Dorsal (posterior) columns
83
What are the spinal cord segments?
- Cervical (8)
- Thoracic (12)
- Lumbar (5)
- Sacral (5)
- Coccygeal (1)
84
What is a spinal nerve?
mixed nerve carrying motor, sensory and autonomic signals between the spinal cord and the body. Sympathetic root derived from lateral horn of ventral region and synapses at combines with sensory root from dorsal root to form a spinal nerve which then leaves the intervertebral foramen ≈ dorsal-ramus (motor + sensory) and anterior ramus (motor + sensory)
85
What is a dermatome?
single area of skin supplied by one spinal nerve which can be used to detect area of sensory loss ≈ detect a localised region of spinal tension
86
List the Cranial Nerves in order.
```
CN I - Olfactory
CN II - Optic
CN III - Oculomotor
CN IV - Trochlea
CN V - Trigeminal
CN VI - Abducens
CN VII - Facial
CN VIII - Vestibulocochlear
CN IX - Glossopharyngeal
CN X - Vagus
CN XI - Accessory
CN XII - Hypoglossal
```
87
What is the major muscle supplied by the axillary nerve? What actions does this muscle carry out.
Deltoid
Anterior fibres: Flexion and internal rotation
Middle fibres: Abduction beyond 15º
Posterior fibres: Extension and lateral rotation
88
What is the root value for the axillary nerve?
C5, C6
89
State the root value for the ulnar nerve.
(C7), C8, T1
90
List the radial nerve innervations.
Triceps brachii, posterior forearm
Brachioradialis
Extensor Carpi Radialis Brevis and Longus
Anconeus
Extensor Digiti Minimi
Extensor Digitorum
Extensor Carpi Ulnaris
91
State the root value of the radial nerve.
C5-T1
92
State the root value of the median nerve.
C5-T1
93
State the root value of the musculocutaneous nerve
C5, C6
94
Outline the pathophysiology of Saturday Night Palsy.
Alcoholic/Binge Drinking --> Fall asleep with outstretched arm and pressure on posterior forearm --> Compression of radial nerve ≈ wrist drop
95
Which nerves contribute to flexion of the hip? Give the muscle responsible for this.
L1-L3
Iliopsoas.
96
Which nerves contribute to extension of the hip? Give the muscle responsible for this.
Gluteus
L5-S1
97
State the muscles responsible for extension of the leg at the knee. Give the nerve roots and the main nerve innervating these muscles.
Quadriceps (v. medialis, v. lateralis, v. intermedius, rectus femoris)
Femoral Nerve (L2-L4)
98
State the muscles responsible for dorsiflexion of the foot. Give the nerve roots and the main nerve innervating these muscles.
Extensor digitorum, tibialis anterior, extensor hallucis longus
Deep fibular nerve (L4, L5)
99
State the muscles responsible for plantarflexion of the foot. Give the nerve roots and the main nerve innervating these muscles.
Gastrocnemius, Soleus
Tibial nerve (L4-S3) - mainly S1
100
What nerve root is most commonly affected in Sciatica and how do you most commonly test this - which muscles are implicated? No reflex test for L5.
Sciatica results in Sciatic nerve (L4-S3) impingement which can be tested by asking patients to flex their big toe, via flexor hallucis longus - innervated by tibial nerve (L4-S3) - L5*
101
What is the main nerve root supplying triceps?
Radial nerve is C5-T1 with C7 being main root supplying triceps
102
What nerve roots does the Knee-Jerk reflex test?
L3, L4
Femoral nerve (L2-L4) innervating Extensor compartment of thigh
103
A patient gets a tight cast fitted on their leg, what may this result in and why?
Superficial fibular nerve compression which innervates the anterior compartment of the leg - tibialis anterior, extensor digitorum and extensor hallucis longus thus causing foot drop
104
Where do ascending pathways enter the spinal cord via? How does this differ from the descending pathways exiting the spinal cord?
Ascending Pathway: Sensory neurones enter via dorsal root to synapse in dorsal horn (substantia gelatinosa)
Descending Pathway: Motor neurones exit via ventral root
105
Which ascending pathway is tested via joint position sense?
Dorsal column-medial lemniscus pathway
106
Which ascending pathway is tested via pain and temperature?
Lateral spinothalamic tracts
107
What is vibration sense a good test for?
Good screening for several pathologies via 125kHz screening fork
108
62 year old patient wakes with severe chest pain, radiating to back, doesn't go to doctor. Next day difficulty with micturition, pain below umbilicus, unable to feel hot water in legs. Spinothalamic sensory level at T10, normal tone and power.
Where is the lesion and explain your answer. Give a differential.
Spinothalamic tract as pain (+ temperature) runs in lateral spinothalamic tract which decussates early on (1-2 vertebral levels above).
Location: T9 (artery of Adamkiewicz --> anterior spinal artery))
Spares dorsal columns if anterior spinal cord affected (e.g. from aortic dissection).
Anterior spinal cord syndrome bilaterally
109
62 year old patient wakes with severe chest pain, radiating to back, doesn't go to doctor. Next day difficulty with micturition, pain below umbilicus, unable to feel hot water in legs. Spinothalamic sensory level at T10, normal tone and power.
Where is the lesion and explain your answer. Give a differential.
Spinothalamic tract as pain (+ temperature) runs in lateral spinothalamic tract which decussates early on (1-2 vertebral levels above).
Location: T9 (artery of Adamkiewicz --> anterior spinal artery))
Spares dorsal columns if anterior spinal cord affected (e.g. from aortic dissection).
Anterior spinal cord syndrome bilaterally
110
54 year old nurse, pain down whole of right arm and neck. O/E no atrophy, normal power, absent biceps and supinator reflexes but brisk triceps.
Where is the lesion and explain your answer. Give a differential.
Corticospinal tract as somatic motor (body cf head and neck) thus not corticobulbar.
Location: C5, C6 (absent biceps and supinator reflexes) partial C7 ? (brisk triceps - hyperreflexia)
Lower Motor Neurone Lesion of Biceps (absent biceps) cf Upper motor neurone lesion (triceps hyper-reflexia)
Disc spondylolisthesis at C5, C6 hitting nerve roots and pressing on spinal cord causing lower motor neurone lesion at the level or above and upper motor neurone lesion below the level of injury - brisk, exaggerated C7 (reduced inhibition of triceps)
111
48 year old, obese, developed patch of numbness over left thigh, increased in size over a week, some pain around groin. O/E oval patch of sensory loss 20cm x 10cm
Where is the lesion and explain your answer. Give a differential.
Dorsal column medial lemniscus pathway at level (sensory loss)
Spinothalamic tract (pain around groin)
L2/L3 region affected (lateral cutaneous nerve of the thigh) however spinothalamic tract crosses early on (lesion is contralateral if on left)
Meralgia paresthetica
N.B. may need edit
112
Which brainstem nuclei does not strictly obey the rule of 4 in each region?
Trigeminal nerve nuclei does not, present all throughout
113
45 year old male presents with sudden onset of dysarthria. O/E left hemiplegia, deviation of tongue to right and loss of JPS to upper and lower left limbs.
Where is the lesion and explain your answer. Give a differential.
Lesion is medial: 1) right corticospinal tract (motor) so UMN signs in left upper and lower limbs
2) Right medial lemniscus so loss of JPS, fin touch and vibration sense from left side of body (decussates in medulla)
Lesion is in the medulla: Right hypoglossal nucleus thus right side tongue weakness (dysarthria). May observe atrophy and fasciculation as LMN signs)
Sudden onset: Anterior spinal artery stroke likely. Medial medullary syndrome
Medial medullary syndrome - right side of medulla affected.
114
40 year old woman undergoing physical exam at her GP. O/E impaired adduction in left eye when asked to look to the right. Apparent nystagmus in right abducting eye. Found to have impaired adduction of right eye when asked to look left. There is also an apparent nystagmus in the left abducting eye. On further questioning, she tells her GP she had an episode of pain behind her right eye with partial loss of colour vision which lasted 1 month in her 30s.
Lesion is medial: 1) Eyeball movements affected by Median Longitudinal Fasciculus causing poor eye movement to the right when asked. Left eye impaired thus medial rectus (lesion affecting Abducens nucleus or Oculomotor nucleus)
Lesion is in the midbrain/medulla
Inter-nuclear ophthalmoplegia (demyelination conditions e.g. Multiple Sclerosis)
115
A 60 year old male presents with sudden onset dysphagia and difficulty walking. He noticed his right eyelid had suddenly dropped. When he entered the room his gait seemed ataxic. On examination he has partial ptosis and meiosis of right eye, with loss of pain and temperature sensation on the same side of the face. In his left lower limbs he has lost sense of pain and temperature, however joint position sense remains intact. His palate has deviated to the left.
Lesion is lateral:
1) Spinothalamic Tract: Loss of pain and temperature, crude touch from left upper and lower limbs and face
2) Spinocerebellar Tract: Limb ataxia on right side
3) Sympathetic pathway: Right Horner's Syndrome
4) Trigeminal nucleus: Loss of pain and temperature from right side of face
Lesion likely to be at level of medulla:
- Nucleus ambiguus: Dysphagia, ipsilateral loss of gag reflex and palate will pull up to left side
- Ipsilateral SCM ± trapezius weakness
Lateral medullary syndrome (Sx onset PICA or vertebral artery stroke)
116
A 35 year old female presents with tinnitus and gradual loss of hearing in the right ear. The patient mentions she has also been having symptoms of vertigo over the past few weeks with occasional vomiting, in addition to slight weakness on the right side of her face. On examination she is found to have mild nystagmus, a right-sided facial paraesthesia and loss of corneal reflex.
Lesion is lateral and at level of the pons:
Tinnitus and sensorineural hearing loss in the right ear and vertigo so right vestibulocochlear nerve/nucleus
Right facial weakness and paraesthesia so facial nerve/nuclei and trigeminal nerve/nuclei on the right. Loss of corneal reflex is an early sign along with weakness of muscles of mastications.
Right cerebellum maybe involved so nystagmus (ataxia, intention tremor (arm) are also possible.
Acoustic neuroma/vestibular schwannoma (benign tumour) growing gradually in the cerebellar-pontine angle cistern
117
What anti-emetic would you prescribe for someone with labyrinthitis?
Prochlorperazine
118
Give two drugs you would prescribe for a patient with labyrinthitis.
Prochlorperazine - blocks D2 dopamine receptors, anti-dopaminergic
Betahistine - blood flow to ear, reduce fluid (endolymph)
119
A patient presents with diploma on looking to the RHS, inadequate abduction of the right eye and lower motor neurone facial nerve weakness on the RHS.
What diagnosis would you give at the time.
Bell's Palsy
Brainstem lesion
Stroke
Benign Positional Vertigo
Labyrinthitis
Brainstem lesion
Facial nerve loops around abducens nerve nucleus in brainstem thus single site may be in the Pons
120
You suspect rapidly progressing multiple sclerosis in a patient with hyperintense lesions shown in the brain parenchyma.
Give the precise Rx details.
Methylprednisolone
PO 1g/day for 3 days
121
Inflammation of the optic nerve is termed..
Optic neuritis
122
How do most episodes of multiple sclerosis present? What type would this be....
Relapses (= episodic periods of inflammation)
Relapsing-Remitting Multiple Sclerosis
123
What part of the face/head is usually sparred in upper motor neurone lesions?
Forehead is spared in UMN cf LMN it is present.
Muscles above level of eye in cortex are bilaterally represented thus muscles raising eyebrows and raising forehead are bilaterally represented in the cerebral cortex
124
List 5 factors which may suggest a worse prognosis in a patient with MS.
- Male
- Low vitamin D
- Family History of MS
- Multiple relapses
- Motor problems on presentation
- High level of inflammation on MRI
125
Can Vitamin D treat MS?
No, but evidence for low vitamin D associated with higher relapse rate in MS.
Association with higher levels of vitamin D (above 50nmol/L) less likely to have relapses or new MRI lesions after 5 years
126
What are the associated risks of taking too much vitamin D?
Hypercalcemia, Hypercalciuria, Kidney stones (urolithiasis), Bile stones (choledolithiasis), bone pain, nausea, vomiting, psychological effects, abnormal heart rhythms
127
Give 3 management options for a patient with multiple sclerosis.
1) Supportive and observe for a month
2) Dimethyl fumarate: Mild drug
3) Natalizumab/Alemtuzumab: Powerful drug
128
A patient presents with progressive distal wasting and weakness. You notice an apparent inverted champagne bottle legs.
A sural nerve biopsy shows loss of sensation with demyelination and plaques.
What is your differential?
Charcot-Marie-Tooth Disease
