Week 3 Flashcards
(152 cards)
1
Q
What are the 2 layers of Dura in the brain?
A
Endosteal (Periosteal)
Meningeal
2
Q
At what level does the dura matter end?
A
S2
3
Q
What is the Falx Cerebri and what are its attachments?
A
Sickle-shaped extension of dura matter between cerebral hemispheres (longitudinal fissure)
Attached ant. to Crista Galli
Attached post. to Tentorium Cerebelli
4
Q
The anastomoses of what 2 veins form the straight sinus?
A
Inf. sagittal sinus + great cerebral vein
5
Q
What is the Tentorium Cerebelli?
A
Fold of dura matter that arches like a tent above post. cranial fossa, covering cerebellum.
Lifted up by Falx Cerebri.
Supports occipital lobes of cerebral hemispheres.
Tentorial notch is only connection between supra and infra tentorial compartments
6
Q
What does the post. margin of Tentorium Cerebelli enclose?
A
Transverse Sinuses
7
Q
What does the Tentorium Cerebelli enclose where it attaches to the upper border of the petrous temporal bone?
A
Superior Petrosal sinuses
8
Q
What is an Epidural haemorrhage and what may cause it?
A
Haemorrhage into the epidural space. This will not cross suture lines due to the dura being tightly attached.
Caused by rupture of meningeal a.
Surgical emergency
9
Q
What is an Uncal herniation and what may be a consequence of it?
A
Displacement of uncus of temporal lobe into the tentorial notch.
This will compress ipsilateral crus cerebri (contains corticospinal tract) leading to contralateral motor weakness.
10
Q
What may cause an Uncal herniation?
A
Epidural haemorrhage
11
Q
What is the Diaphragma Sellae?
A
Formed by the tentorium cerebelli on the roof of the sella turcica, covering hypophysis, with a central aperture for hypophyseal stalk
12
Q
Name all structures that pass through the Cavernous sinus
A
CN’s III, IV, Vi, Vii, and VI
Sympathetic fibres
Int. Carotid a.
13
Q
What makes up the walls of cavernous sinus?
A
Lateral Wall:
Continuation of meningeal layer of dura matter from the middle cranial fossa
Roof:
Diaphragma Sellae
14
Q
What sensation can dura matter perceive?
A
Pressure and Stretch
15
Q
What part of the dura is innervated by the Ophthalmic n.?
A
Ant. cranial fossa
Ant. Falx Cerebri
Tentorium Cerebelli
16
Q
What part of the dura is innervated by recurrent meningeal branch of Maxillary n.?
A
Mid. cranial fossa
Mid region of the vault
17
Q
Acute meningitis involving post. cranial fossa is associated with what symptoms?
A
Neck rigidity and often head retraction due to reflex contraction of the post. nuchal muscles, which are supplied by cervical nerves
18
Q
What are Arachnoid granulations?
A
Pierce the dura and enter foveola granulares.
Absorb CSF and return it to venous system via sup. sagittal sinus
19
Q
What structure is present in the Subdural space?
A
Bridging Veins
20
Q
At what vertebral level does the dura and arachnoid matter end?
A
S2
21
Q
What structures are present in the subarachnoid space?
A
Cerebral Arteries
CSF
22
Q
What is a subdural haemorrhage and what is the cause?
A
Haemorrhage in the subdural space (may cross suture lines.
Rupture of bridging veins
23
Q
What is the most common cause of a subarachnoid haemorrhage?
A
Ruptured berry aneurysm (85%) on circle of Willis
24
Q
How will a subarachnoid haemorrhage appear on a CT scan?
A
Blood in basal cisterns, fissures and the depths of cortical sulci
25
What is the name of the ligaments formed by pia matter between roots of spinal nerves?
Denticulate ligaments
26
At what level does pia matter close, and what does it continue as afterwards?
L1/2
Continues as Filum Terminale to S2
27
What are the lateral ventricles located?
Cerebral hemispheres inferior to Corpus Callosum
28
What structure connects the two lateral ventricles and the 3rd ventricle?
Intraventricular foramen
29
Where is the 3rd ventricle located?
In the diencephalon between left and right Thalamus
30
What structure connects the 3rd and 4th ventricle?
Cerebral Aqueduct
31
Where is the 4th Ventricle located?
Between pons, medulla and cerebellum
32
CSF leaving the ventricles travel through what structure to reach the subarachnoid space?
Lateral apertures or the median aperture (both stem from 4th ventricle and exit at the cisterna magna)
33
CSF is produced in what structure?
Choroid Plexus
pia matter + ependymal cells + choroidal vessels
34
What is Communication hydrocephalus?
Flow of CSF blocked after exiting ventricles
OR
Reduced absorption of CSF
35
What is Non-communicating hydrocephalus?
Flow of CSF is blocked
36
What is a suboccipital puncture and where would it enter?
Needle inserted in to the Cisterna magna to obtain CSF or to administer drug/vaccine
37
What makes the BBB?
Astrocyte foot processes
Endothelial tight junctions
Basement membrane
38
In what structures are there no BBB?
Area Postrema
Neurohypophysis
Pineal Gland
39
What can pass the blood brain barrier?
Lipophilic, non-polar molecules
Gases, water, glucose and aa's
40
For how long is the BBB defective for after injury?
2 to 3 Weeks
(can be taken advantage of with contrast agents for MRI scans)
41
Name structures
^^^
42
What structures make up the Pharyngeal Apparatus?
Pharyngeal arches
Pharyngeal clefts
Pharyngeal pouches
43
What is an old term that may be used interchangeably with the word "Pharyngeal"?
Branchial
44
What Pharyngeal arch is missing in humans?
5th (only in fish)
45
What are Epipharyngeal Placodes?
Ectodermal thickenings, contribute to cranial nerve ganglia
46
What hard tissues of the cranium does the Neural crest give rise to?
Viscerocranium, Frontal, Squamous Temporal
47
What hard tissues of the cranium does the Paraxial mesoderm give rise to?
Parietal, Petrous Temporal, Occipital
48
What hard tissues of the cranium does the Lateral plate mesoderm give rise to?
Laryngeal cartilages
49
What CN is associated with the 1st pharyngeal arch?
Viii (Mandibular division of Trigeminal n.)
50
What CN is associated with the 2nd pharyngeal arch?
VII (Facial)
51
What CN is associated with the 3rd pharyngeal arch?
IX (Glossopharyngeal)
52
What CN is associated with the 4th pharyngeal arch?
X (Superior laryngeal)
53
What CN is associated with the 6th pharyngeal arch?
X (Recurrent laryngeal)
54
What pharyngeal arches does the hyoid bone originate from?
2nd (lesser horn & sup. body)
&
3rd (greater horn & lower body)
55
What arteries stem from the 1st Pharyngeal arch?
Maxillary & external carotid arteries
56
What arteries stem from the 2nd Pharyngeal arch?
Hyoid & stapedial arteries
57
What arteries stem from the 3rd Pharyngeal arch?
Common carotid & first part of the int. carotid arteries
58
What arteries stem from the left side of the 4th Pharyngeal arch?
Arch of aorta from the left common carotid to the left subclavian arteries
59
What arteries stem from the right side of the 4th Pharyngeal arch?
Right subclavian artery (proximal portion)
60
What arteries stem from the left side of the 6th Pharyngeal arch?
Left Pulmonary artery & ductus arteriosus
61
What arteries stem from the right side of the 6th Pharyngeal arch?
Right pulmonary artery
62
What is the name of the 1st pharyngeal Pouch?
Tubotympanic recess
63
What is formed from the Tubotympanic recess?
Eustachian tube
Tubal tonsil
Middle ear cavity
Tympanic membrane
64
What is formed by the 2nd pharyngeal pouch?
Palatine tonsil
Tonsillar fossa
65
What is formed by the 3rd pharyngeal pouch?
Inf. parathyroid gland
Thymus (migrates inferiorly)
66
What is formed by the 4th pharyngeal pouch?
Sup. parathyroid gland
Ultimopharyngeal body (C cells of thyroid)
67
The remnants of clefts 2, 3 and 4 become what structure, and what does this structure do?
Become the Cervical sinus, which usually obliterates
68
What happens if the Cervical sinus doesn't obliterate?
You get a Branchial (Lateral cervical) cyst and fistula
Cyst = no connection to int. or ext. surface
Fistula = connects either ext. or int.
Located ant. to SCM
69
What is the path of neural crest cells?
Originate from Hind brain region divisions called rhombomeres before migrating to the pharyngeal arches
70
What is the pattern of neural crest cells migrating to the pharyngeal arches?
R1/2 to arch 1
R4 to arch 2
R6/7 to arches 3,4,6
71
What are the odds of having a Craniofacial defect at birth?
1/500
72
Describe Treacher Collins syndrome
Autosomal Dom.
1st / 2nd arch syndrome
Defective protein called Treacle
Failure of formation of neural crest cells and migration into 1st and 2nd pharyngeal arches
73
List symptoms of Treacher Collins syndrome
Abnormal eye shape
Microganthia (underdeveloped jaw)
Conductive hearing loss
Underdeveloped zygoma
Malformed ears
74
Describe Di George syndrome
22q11 deletion
3rd & 4th pouches fail to develop = thalamus and parathyroids defective
75
List Symptoms of Di George syndrome
Cardiac abnormality (especially tetralogy of fallot)
Abnormal facies
Thymic aplasia - infection prone
Cleft palate
Hypocalcaemia
76
What is Craniosynostosis?
Range of syndromes where cranial sutures close prematurely
FGF receptor mutations cause imbalance in mesenchymal proliferation at sutures = premature closure
77
What do you get with inadequate and excessive SHH function?
Cyclopia and Diprosopus
78
What is the most common cause of Traumatic Brain Injury (TBI)?
Falls - 47%
79
What is the ratio of men/women for TBI's?
M 1.5/1.0 F
80
What is the treatment for TBI?
No real treatment (only for secondary stuff)
81
When assessed pre admission, 50% of TBI cases will have what?
SpO2 < 90%
82
What are the GCS score catagories?
Mild 13-15
Moderate 9-12
Severe < 8
83
What 3 things are assessed in a GCS?
Eye opening
Verbal response
Motor response
84
How do you assess eye opening in a GCS?
1-4
4. Open spontaneously
3. Open to speech
2. Open in response to pressure
1. Do not open
NT. can't assess
85
How do you assess verbal response in GCS?
1-5
5. Orientated
4. Confused
3. Inappropriate words
2. Incomprehensible sounds
1. No response to verbal and physical stimuli
NT. can't be assess
86
How do you assess motor response in a GCS?
1-6
6. Obeys response
5. Localises to central pain
4. Normal flexion toward source of pain
3. Abnormal flexion
2. Extension to pain
1. No response to painful stimuli
87
What symptoms of TBI warrant going to hospital?
Under 5 / Over 65
Amnesia
Loss of consciousness
High energy injury
Vomiting
Seizure
Bleeding / Clotting disorders
88
What are examples of Secondary brain injuries in TBI?
Neurotransmitter release (glutamate)
Free radical generation
Calcium mediated damage
Inflammatory response
Mitochondrial dysfunction
Early gene activation
89
Define Secondary Brain Injuries in the context of TBI
Secondary processes which occur at the cell & molecular level to exacerbate neurological damage
90
How do you minimise secondary brain injury in TBI?
Optimise Oxygenation
Optimise Cerebral Perfusion
Blood glucose
Hypocapnia / Hypercapnia
Body temp
91
How do you calculate Cerebral Perfusion pressure?
Mean art. pressure - Intracranial pressure
92
What features suggest an individual is at risk of intracranial mass?
High impact injury
Significant retrograde amnesia
History of coagulopathy
Post traumatic seizure
GCS of 12/15 or less
Clinical signs of skull fracture
93
What is a sign of ant. cranial fossa fracture?
Peri-orbital bruising
94
What is a sign of Petrous temporal bone fracture?
Battle's sign
95
When should you immediately request a CT scan in TBI?
GCS<13 on initial assessment
GCS<15 two hours after injury
Open or suspected depressed skull
Any sign of Basal skull injury
Post traumatic seizure
Vomiting
Amnesia for events over 30mins before event
96
What are common traits of an Extradural Haematoma?
Associated w/ skull fracture
Middle meningeal a. damage
1/3 due to venous bleeding
Biconvex on scan
97
What are common traits of a Subdural Haemorrhage?
20-30% of brain injuries
Rupture of bridging veins
Crescentic appearance on scan
98
What are common traits of a Subarachnoid Haemorrhage?
Assoc. w/ ruptured aneurysm of circle of willis
More commonly caused by head injury
99
What are common traits of an Intracerebral Haemorrhage?
Stretching & shearing injury
Impact on inside of skull
Often contrecoup injury
100
What are the clinical signs of herniation (in brain)?
Dilated or unreactive pupils
Extensor posturing
Decrease in GCS of 2 or more points
101
What are the most common headaches?
Migraine
Muscular tension
Analgesia overuse
Systemic illness
Cervicogenic
102
What are some of the most serious causes of headaches?
Subarachnoid haemorrhage
Raised intercranial pressure
Low intercranial pressure
Infection - Meningitis
Temporal Arteritis
Cerebral venous sinus thrombosis
103
What are some treatments for Tension headaches?
-Reassure the severity (or lack there of) to the patient
-Reduce analgesia (paracetamol / ibuprofen)
-Low dose amitriptyline (10-20mg)
104
What kind of headache is most associated with nausea?
Migraine
105
What other symptoms come along with Migraines?
Photophobia, phonophobia and gut symptoms
+/- Aura (visual issues around periphery ie. scotoma)
106
What are the two types of Scotoma, and what are they associated with?
Black and white - Migraine
Coloured - Epilepsy
107
What are thought to be causes of Migraines?
Vascular and neural theories (mechanisms unclear)
108
Treatments for Acute Migraine?
---Triptans---
(agonists at 5HT-1b and 5HT-1d receptors)
Aspirin, paracetamol, anti-nausea (metoclopramide)
109
Prophylaxis for Migraines
Beta blockers, low does amitriptyline, Pizotifen
ect.
110
What is an example of Migraine treatment that doesn't use medication?
Botox injection (back of neck/head)
Acupuncture
111
What is contraindicated in women with migraines and aura, and why?
Oral contraceptive pill due to risk of stroke
112
A cluster headache is a common type of what?
Trigeminal Autonomic Cephalagia (TAC)
113
Symptoms of Cluster headache
Unilateral often around the eye
Striking circadian rhythm, same time of day
More common in males
114
Symptoms of Paroxysmal hemicrania (type of TAC)
More common in women
Shorter more frequent attacks
responds to indomethacin
115
Treatments of TACs
Triptans
Oxygen - high dose
High dose verapamil (up to 960mg/day)
116
What may cause a medication overuse headache?
Using too much simple analgesia >15 days/month
or
>10 days for other acute eg. triptans
117
What is a thunderclap headache?
Instant or rapid onset (<60 sec) very severe pain
Possible sub-arachnoid haemorrhage
CT head for blood immediately
Can be exertional (often during sex) due to migraine from vasospasm, quickly reversible
118
Give examples of early morning headaches
Cervicogenic + Sleep apnoea w/ CO2 retention
119
Causes of Cervicogenic headache
Poor posture when sleeping
Over exertion
Spinal degeneration
Usually muscular
120
Causes of Sleep apnoea w/ C02 retention
Obesity
History snoring - common w/ alcohol
Treated w/ +ve pressure Oxygen (mask)
121
What is the presentation of raised intracranial pressure and what may be a potential cause?
Headache (mild)
Diurnal variation
Often mild nausea
Abscess or CSF blockage
122
Presentation of meningitis?
Fever
Rash that doesn't leave when pressed by glass
Photophobia
123
Treatment for Meningitis
Benzyl penicillin
124
Presentation of Temporal arteritis
Never below 50 y/o
Jaw claudication (jaw pain on chewing)
125
How to test for Temporal arteritis?
Palpate temporal arteries for tenderness (if not tender, probably not temp arteritis)
126
Treatment for Temporal arteritis
Use high dose steroids early (note it is hard to get them off as they enjoy them)
127
Presentation of Cerebral venous sinus thrombosis
Often F on oral contraceptive pill
Headache
Raised intercranial pressure
MRI of head shows haem bilaterally and empty delta sign
128
Cause of low intercranial pressure
Following lumbar puncture (not immediate)
due to CSF leakage through hole left in dura
129
Presentation of low intercranial pressure
Headache on standing, eased w/ lying
Can develop into fits as the brain is supported less
If left can cause death
130
Treatment of low intercranial pressure
Blood patch for post-LP headache - stops leaking
131
Name all strucures
^^^
132
What are the functions of the basal ganglia?
-Smooth movement
-Switching behaviour
-Reward system
-Linked to thalamus, cortex, limbic system
133
What is the neostriatum?
Caudate nuc. + Putamen
(dorsal striatum)
134
What are the 2 pathways of the Motor loop?
Direct & Indirect pathways
135
Stimulation of the direct pathway causes what?
Movement
136
Stimulation of the Indirect pathway causes what?
Inhibits Movement
137
What receptors are present in the striatal neurons on the Direct & Indirect pathway?
D1 - Direct
D2 - Indirect
(dopamine)
138
What specifically happens in the direct pathway of the basal ganglia?
Cortical excitation of neostriatum leads to disinhibition of thalamic nuc.
Movement follow activation of putamen by cortical areas
139
What specifically happens in the indirect pathway of the basal ganglia?
Cortical excitation of neostriatum leads to inhibition of inhibitory input to subthalamus.
Activation of indirect pathway leads to inhibition of cortical areas
140
Give examples of clinical problems with the Basal Ganglia
Parkinson's disease (substantia pars compacta)
Huntington's disease - chorea (caudate)
Hemiballism (subthalamic)
Wilson's disease (lenticular)
141
What are some clinical features of Parkinson's disease?
TRAP
Tremor at rest
cogwheel Rigidity
Akinesia
Postural instability
142
Describe the pathophysiology of Parkinson's
Degeneration of dopaminergic neurons of substantia pars compacta means lack of inhibition of indirect pathway, and a lack of excitation of direct pathway.
143
What causes Huntington's disease?
Autosomal dom
CAG triple repeat (>40 repeats)
144
What structural changes are associated with Huntington's disease?
Caudate nuc. wasting leading to increase volume of lateral ventricles
145
What pathway is affected in Huntington's disease and what are the symptoms caused by such?
Indirect is affected
Hyperkinesia, dyskinesia
Inappropriate or repetitive movement
146
What is used to treat Huntington's disease?
Dopamine antagonist effective in reducing involuntary movement (Chlorpromazine)
147
What is Wilson's disease?
Autosomal recessive
Abnormal copper accumulation (rings in eyes)
148
What is an example of first line treatment for Parkinson's?
Levodopa
combined with a dopa decarboxylase inhibitor (lowers dose needed and peripheral system side effects such a HT and nausea)
149
What are some long term side effects of Levodopa?
Involuntary writhing (dyskinesia) may appear within 2 years on face and limbs
Rapid fluctuations in clinical state (doing well one day, then bad the next)
150
Give examples of Dopamine agonists used in Parkinson's treatment
Ropinirole
Rotigotine (transdermal patch)
Apomorphine (injection)
151
What is the function of MAOI in Parkinson's disease?
Inhibition of MAO-B protects dopamine from extra neuronal degradation therefore increasing conc of Dopamine
152
What antiviral may be used for Parkinson's?
Amantadine
