Headache Flashcards
(123 cards)
1
Q
What causes headache?
A
Thought to do with temporary changes in the chemicals, nerve, and blood vessels in the brain
- Cortical spreading depression propagated thru electrophysiological depolarization from the occipital pole has been correlated with both migraneous symptoms + changes in vascular blood flow
- Ion channel pathology
2
Q
What structures can be involved in a headache?
A
- Trigeminovascular system -> cluster headache
- Meninges -> meningitis
- CSF containing structures -> increased intracranial pressure
- Muscle -> tension headache
- Nerves
3
Q
What processes can lead to a headache?
A
- Neurogenic inflammation -> migraine
- Inflammation -> vascular arteritis
- Infection -> meningitis
- Pressure -> intracranial hypertension/hypotension
- Obstruction -> space occupying lesion
4
Q
What is the difference between primary and secondary headaches? Give examples of each
A
1º headaches: No underlying disease mechanism
- Migraine, cluster headache
2º headaches: Underlying disease mechanism
- SOL, intracranial HTN, vasculitis/arteritis
5
Q
Outline the important components of a headache history
A
PC: SOCRATES for headache pain
- focus on characteristic, onset of pain, and aggregating/relieving factors
PMH: Previous headache, other illnesses which may cause headache
Drug Hx: OCP, Codeine (if taken regularly - drug-induced headache)
Fam Hx: Migraines run in families
Social Hx: Smoking, caffeine, job, impact on daily life
6
Q
What are red flags for headache?
A
- Thunderclap headache = SAH
- Unilateral + eye pain = cluster; acute glaucoma
- Unilateral + ipsilateral symptoms = migraine; tumour; vasculitis
- Cough-initiated headache + worse in morning/bending forward = increased ICP; venous thrombosis
- Persistent + scalp-tenderness + > 50y = giant cell arteritis
- With fever + neck stiffness = meningitis
- Change in pattern of headache
- Decreased level of consciousness
7
Q
What are 2 other important questions to ask someone when taking a headache history?
A
- Recent foreign travel (?malaria)
2. Chance of pregnancy (?pre-eclampsia; especially if hyperproteinuria + hypertension)
8
Q
What are important signs that should not be missed on physical examination of someone complaining of headache?
A
- Papilloedema = Increased intracranial pressure
- Peripheral field loss, enlarged blind spots = increased ICP
- 6th nerve palsy (failure to abduct eye) = increased ICP; giant cell arteritis
- Ataxia + headache = lesion in post. cranial fossa (cerebellum)
- Oral hairy leukoplakia = immunodeficiency (EBV)
- Purpuric rash + sepsis = meningococcal septicemia
- Livedo reticularis with headache = lupus (increased risk of venous clots + vasculitis)
9
Q
Name 3 common investigations performed for those with headache?
A
- CT
- MRI
- CSF monometer (measures P in brain from LP)
10
Q
What would xanthachromic CSF indicate?
A
Indicates presence of bilirubin in the CSF
Diagnosis = subarachnoid hemorrhage
11
Q
If CSF has cells (i.e. neutrophils) in it what does this indicate?
A
Bacterial infection (i.e. meningitis)
12
Q
If on histological examination blood vessels have lots of inflammatory infiltrates + ESR levels are raised what does this suggest?
A
Giant cell arteritis
13
Q
What is the treatment for giant cell arteritis? What can occur without treatment?
A
High dose steroids should be prescribed immediately (prednisolone)
Danger of blindness if not prescribed immediately
14
Q
What is the treatment for hydrocephalus?
A
Placement of a shunt commonly in the R lateral ventricle and draining excess fluid into the abdominal cavity where it is absorbed
15
Q
Name 5 drugs used for migraine prophylaxis
A
- Propranolol (beta blocker) - first line
- Amitriptyline (anti-depressant) - first line
- Topimarate/sodium valproate (anti-seizure medication; teratogenic!) - second line
- Verapamil/Amlodipine (Ca2+ channel blockers) - second line
- Pizotifen (5HT-2a + 2c antagonist, antihistamine, anticholinergic)
16
Q
What are the common symptoms of a migraine?
A
- Throbbing pain lasting hours - 3 days
- Can be unilateral or bilateral
- Sensitivity to stimuli (light, sound, smells)
- Nausea
- Aggrevated by physical activity (prefers to lie in dark room)
- Aura if present evolves slowly (in contrast to stroke) and lasts minutes-60min
17
Q
What is the acute treatment for migraines?
A
- Aspirin 900mg
- NSAID taken with metoclopramide/domperidone
- Triptan (i.e. sumatriptan) -> agonists of 5HT-1b + 1d receptors. Should be taken < 10d per month
** Do NOT prescribe opioids for migraine!!
18
Q
What are other potential treatments for migraine (if acute treatments don’t work)?
A
- Botulinum toxin injections (every 12wks around scalp/neck)
- Anti-CGRP monoclonal antibodies (erenumab) -> not licensed in UK yet!
- Acupuncture
19
Q
What are the symptoms of a cluster headache?
A
- More common in men
- Severe pain lasting 30-120min
- Unilateral, side-locked
- Striking circadian rhythm clustering in periods of few weeks
- Autonomic features (associated with trigeminal nerve distribution) = tearing, red conjunctiva, ptosis, mitosis, nasal stuffiness
20
Q
What is the treatment for cluster headaches?
A
- Sumatriptan injection 6mg s.c. (contraindicated for IHD, stroke)
- High-flow O2 thru non-rebreathe mask
- High-dose verapamil (Ca2+ antagonist) - up to 960mg/day
- Prednisolone 60mg for 1wk can abort attacks
- Indomethacin (NSAID) for paroxysmal hemicranias
21
Q
What are the symptoms of a tension-type headache?
A
- Bandlike ache, mostly featureless
- Can have mild photo/phonophobia
- No nausea
22
Q
What is the treatment for tension-type headaches?
A
- Low dose amitryptiline
- Low dose NSAIDs
- Relaxation
23
Q
What are the features of analgesic-overuse headache?
A
- Can be migrainous or tension-type
Triptan intake: >10 days/mo for ≥ 3mo
Simple analgesia intake: > 15 days/mo for ≥ 3mo
24
Q
What is the treatment for analgesic-overuse headaches?
A
Gradually decrease analgesic use (eventually stop)
25
What are the features of raised intracranial pressure?
- Mild headache
- Diurnal variation (worse in morning)
- Mild nausea
- Neurological symptoms (weakness, cerebellar features - ataxia)
- Papilloedema
26
What are 3 causes of raised ICP?
1. Tumours
2. Abscess
3. CSF blockage
27
What are the features of meningitis?
- Fever
- Photophobia
- Neck stiffness
- Altered consciousness
- Purpuric/petechial rash (non-blanching)
28
What is the most common treatment for meningitis?
1. Ceftriaxone/cefotaxime
2. Benzyl penicillin
* Most are viral
29
What are the features of temporal arteritis?
- >50y old
- Features of polymyalgia (tightness in muscles in morning)
- Jaw claudication (b/c arteries are narrowed)
- Tender temporal arteries
- Raised ESR
30
What are the features of cerebral venous thrombosis?
- Often female, on OCP/HRT
- Severe headache
- Often seizures
- May be bilateral
- Raised ICP, bilateral papilloedema
- Diagnose with MRI/magnetic resonance venography
31
What are the features of low ICP?
- Headache on standing, eased with lying down
- Can occur spontaneously
- i.e. after a lumbar puncture -> spontaneous leak of CSF
32
What is the treatment for low ICP due to lumbar puncture?
Blood patch
- Take blood from arm and inject into base of lumbar puncture site to seal hole and prevent pressure from decreasing again
33
What are the risk factors for early morning headaches?
1. Obese
2. History of snoring
3. COPD
4. Headache in morning
Diagnosis = sleep apnea with CO2 retention
34
What 4 conditions has cortical spreading depression been seen in, other than migraine?
1. Cerebrovascular accident (stroke)
2. Epilepsy
3. Subarachnoid hemorrhage
4. Traumatic brain injury
35
What are some recognised trigger factors for migraine?
1. Cheese
2. Relaxing after stress
3. Jet lag
4. Flickering lights on a tv
5. Menstruation
6. Contraceptive pill
36
Which area in the brain is thought to be involved in the production of the migraine headache?
Trigeminal nucleus caudalis (TNC)
37
What is the mechanism of action of triptans?
Strong agonistic activity at the serotonin receptor. Shown to induce vasoconstriction, mediated by an action on 5-HT 1b receptors in arterial smooth muscle
Vasoconstriction of vasodilated arterioles was thought to be the most likely mechanism of action for triptans in the treatment of acute migraine, in keeping with the theory of vasoconstriction and vasodilatation originally described by Graham & Wolff.
38
Which medical conditions are contraindications to treatment with triptans?
1. Transient ischemic attacks (TIAs)
| 2. Ischemic heart disease
39
What treatment regimen should be followed for migraine if the patient initially doesn't respond to triptan treatment?
Triptan + NSAID (i.e. sumatriptan + naproxen)
OR
Repeat dosage of triptan (2h after initial dose)
40
What are the 4 criteria for consideration of preventative treatment?
1. Quality of life severely affected
2. 2+ attacks/month
3. Migraine attacks don't respond to acute treatment
4. Frequent/long/uncomfortable auras
41
What is the most common bacterial, viral, and fungal cause of sepsis/septic shock?
Bacterial = staphylococci
Viral = Herpes viridae
Fungal = Candida
42
What is the most common bacterial, viral, and fungal cause of meningitis?
Bacterial = streptococcus pneumonia
Viral = Enterovirus
Fungal = Cryptococcus neoformans
43
What is the most common causative agent of neonatal meningitis?
E coli
44
What is the most common bacterial, viral, and parasitic cause of encephalitis?
Bacterial = Listeria monocytogenes
Viral = Herpes simplex, EBV, CMV, Varicella zoster, adenovirus
Parasitic = Neagleria Fowleri
45
What is the most common bacterial and fungal cause of brain abscess?
Bacterial = staph aureus
Fungal = Candida species
46
What is the most common bacterial cause of spondylodiscitis?
Staph aureus
47
What are the differential diagnoses of meningitis?
1. Encephalitis: Most common cause is HSV. Encephalitis is inflammation of the brain and unlike meninigitis it causes confusion or disorientation, drowsiness, seizures and changes in personality and behaviour, such as feeling very agitated.
2. Non-infectious causes (blood, trauma, drugs) of meningeal irritation
3. Subdural empyema: collection of pus in subdural space
48
What are risk factors for meningitis?
1. Extremes of age
2. Living in close proximity (outbreaks can occur in student halls of residence and boarding schools)
3. Vaccination history (absence of)
4. Immune suppression/deficiency
49
What are the signs of encephalitis?
1. Cognitive changes
2. Mood changes
3. Drowsiness
50
What test is used to identify meningeal irritation and how is it performed?
Kernig's Sign
Severe stiffness of the hamstrings causes an inability to straighten the leg when the hip is flexed to 90 degrees.
51
What is included in a full septic screen?
1. Blood test/cultures
2. Chest xray
3. Lumbar puncture
4. Urine test (included for children < 1y)
52
Name 4 contraindications for lumbar puncture
1. Increased ICP (i.e. papilloedema, focal neurological signs)
2. Infection at site of lumbar puncture
3. Coagulation defects (i.e. low platelet counts, anticoagulants)
4. Sepsis
53
What are the 7 structures that the lumbar puncture needle needs to pass through to gain access to CSF?
1. Skin
2. subcutaneous tissue
3. Supraspinous ligament
4. Interspinous ligament
5. Ligamentum flavum
6. Epidural space (containing the internal vertebral venous plexus, dura, arachnoid)
7. Subarachnoid space (which houses the CSF)
54
What are the indications for a lumbar puncture?
1. Infection (i.e. meningitis, encephalitis)
2. Vascular (i.e. subarachnoid hemorrhage - performed 12h after onset + CT head)
3. Inflammatory (i.e. MS)
4. Oncological
5. Metabolic
55
What are the main complications of a lumbar puncture?
1. Headache (low intracranial pressure)
2. Painful paresthesia
3. Persistent pain/paresthesia
4. Bleeding (brain - subdural; spinal cord)
5. Infection (meningitis)
6. Uncal herniation (part of the temporal lobe herniating into the tentorial notch)
7. Failure of procedure
56
What is the site for lumbar puncture and why?
Between the spinous processes of L3/L4 or between L4/L5
Well below the end of the spinal cord (terminates at L1)
57
What can result in a dry lumbar puncture (no CSF)?
1. Arachnoiditis
2. Meningeal infiltration
3. True low CSF pressure
4. Faulty technique (most common)
58
What is an oligoclonal band screen for?
Presence in the CSF indicates inflammation and if not present in bloods, the patient has multiple sclerosis
59
What is the appearance, WBC count, glucose level, and protein (g/L) for normal CSF?
Clear, colourless
0-5
> 2/3 blood glucose
0.15-0.4
60
What is the appearance, WBC count, glucose level, and protein (g/L) for bacterial CSF?
Turbid
500-10 000 polymorphs
V low
High
61
What is the appearance, WBC count, glucose level, and protein (g/L) for TB CSF?
Turbid, viscous, straw
< 500 lymphocytes/polymorphs
Low
V high
62
What is the appearance, WBC count, glucose level, and protein (g/L) for viral CSF?
Clear
<1000 lymphocytes
Normal
Raised
63
What is the appearance, WBC count, glucose level, and protein (g/L) for fungal CSF?
Viscous, clear
< 500 lymphocytes/polymorphs
Low
Very high
64
What are other important investigations for a patient with suspected meningitis?
1. Blood cultures
2. Serology for viruses causing meningo-encephalitis
3. Throat swab for Neisseria meningitides & Streptococcus pneumonie
4. Urine pneumococcal antigen
65
Name 2 tests for encephalopathy
1. CT or MRI brain (may show oedema of the temporal lobes. It can also be used to rule out other causes of intracranial pathology.)
2. Electroencephalogram EEG (to show characteristic slow waves)
66
What blood tests would you perform on a patient with suspected meningitis or meningococcal sepsis?
1. Blood cultures
2. FBC
3. U+E
4. Creatinine
5. LFTs + clotting screen
6. Procalcitonin (or CRP)
7. Meningicoccal + pneumococcal PCR
8. Serology sample
9. Glucose
67
What is the treatment for suspected bacterial meningitis in hospital? In GP setting?
In hospital:
- 3rd generation IV cephalosporin (i.e. ceftriaxone, cefotaxime) -> 2g 4x/day
AND
- IV Dexamethasone 10mg 4x/day
In GP setting:
IM benzylpenicillin
68
What is the additional antibiotic if Listeria is the suspected cause of meningitis?
Ampicillin
69
What treatment should be added if encephalitis is suspected?
IV antivirals alongside cephalosporins for meningitis
70
If a >60y patient presents with meningitis and has no allergies to pencillins/cephalosporins what is their treatment?
IV cefotaxime/ceftriaxone 2g, 4x/day
IV Dexamethasone 10mg, 4x/day
IV amoxicillin 2g, 4 hourly
71
If penicillin resistance is a possibility what drug would you add for meningitis treatment?
Vancomycin 15-20mg/kg, 2x/day
OR
Rifampicin 600mg, 2x/day
72
If a >60y patient presents with meningitis and has an allergy to pencillins/cephalosporins what is their treatment?
IV Chloramphenicol 25mg/kg 4x/day
IV Dexamethasone 10mg, 4x/day
Co-trimoxazole 10-20mg/kg, in 4 divided doses
73
Name 2 organisms that cause meningitis and where there is a risk of transmission to others.
Name the antimicrobial prescribed as prophylaxis to others in this case.
Haemophilus influenzae, Neisseria meningitis
Offer rifampicin
74
What are 6 important questions to ask someone with a headache?
1. Can you remember how the headache started?
2. Do the headaches vary depending on time of day?
3. Do you have any other symptoms with the headache, such as a change in vision or problems in your arms or legs?
4. Are you usually prone to headaches?
5. How are you feeling in general?
6. How have you been using medication for your headache?
75
What is the relevance of pronator drift?
Subtle pyramidal tract dysfunction (UMN lesion). With a history of raised ICP this could indicate a SOL. CT head scan should be performed
76
What is not an indication for neuroimaging in a patient with headache?
Visual aura associated with episodic throbbing headaches (migraine)
77
What are 4 indications for neuroimaging in a patient with headache?
1. Worsening headaches which are waking the patient at night
2. Focal neurological findings on examination
3. A change in pattern and severity of longstanding headaches
4. New onset headache in a 55y patient
78
A 23-year-old married woman presents with a 2 year history of episodic, unilateral throbbing headaches. Sometimes before the headache she gets ‘zig-zag’ visual spectra in her left visual field. The headaches are occurring 3 times per month and last for 2 days at a time.
What is the most appropriate pharmacological management for this patient?
Propranolol modified release 80mg OD
This patient has classical migraine with visual aura. The frequency is more than 2 headaches per month, so most people would elect to treat her with some form of migraine prophylaxis. Beta blockers or tricyclics are generally used first. Topiramate and valproate are both good migraine drugs, but are usually used second line. Ibuprofen and other NSAIDs can relieve migrainous headaches but regular use, as with paracetamol and codeine, can actually worsen migraine headaches and lead to ‘transformation’ into chronic migraine.
79
Name 4 signs associated with raised intracranial pressure
1. Papilloedema
2. 6th nerve palsy
3. Enlarged blind spots
4. Vomiting
80
Name 4 pathophysiological processes that have been associated with migraine
1. Cortical spreading depression
2. Vasoconstriction + vasodilation
3. Neurogenic inflammation
4. Patent foramen ovale
81
A 60-year-old woman complains of 2 months of predominantly left sided headaches. She also says that last week she lost vision in her left eye for about 2 hours – this was not associated with any pain. On examination she has normal cranial nerves, upper limbs and lower limbs. Her scalp is tender on the left side.
What is the most appropriate first line investigation?
ESR and CRP
This patient has temporal arteritis (TA)and biospy of her temporal artery would show giant cell arteritis (localised vasculitis with skip lesions and giant cells). This overlaps with polymyalgia rheumatica (PMR), where constitutional symtoms predominated with limb girdle pain and stiffness particularly on a morning. Once TA is diagnosed, then this is a medical emergency with checking of her ESR and CRP and starting on high dose steroids. Failure to act would be negligent as she is at high risk of sudden blindness. A temporal artery biopsy could then be organized to confirm the diagnosis. However, this is not usually necessary as there should be a dramatic improvement on steroids (within 48hours usually) and this is considered diagnositic.
82
A 24 year old man presents to A+E with severe right sided headaches at night. The brief headaches wake him from sleep several times per night and have been going on for the last 2 weeks. During the headache his eye waters and his nose feels blocked. He describes the headaches as the most severe he’s ever had. Neurological examination is normal. He is otherwise fit and well. He smokes 20 cigarettes per day and does not drink alcohol. He works shifts as a safety operative in a nuclear power plant.
What is the likely cause of his headaches?
Cluster headache
83
What is the most appropriate first line test for suspected subarachnoid haemorrhage?
CT scan
84
The following CSF results are obtained in a patient presenting with acute headache, fever and neck stiffness:
Opening Pressure: 28cm (nr <20cm)
CSF white cell count – 566 (90% neutrophils) (nr <4WBC)
CSF protein – 1.1g/L (nr <0.4g/L) CSF glucose – 2.8mmol/L (nr >50% plasma gluc)
Plasma glucose 6.1mmol/L
What is the diagnosis?
Bacterial meningitis
85
Which combination of features in the history of someone with episodic headaches most supports a diagnosis of migraine?
Photophobia, phonophobia, mechanophobia
86
An elderly man with worsening headache has a left inferior homonymous hemianopia on examination. Where is the likely site of the lesion?
R parietal lobe
87
What is the main side effect of sumatriptan?
Drowsiness
88
Practice prescribing a once only dose of treatment for a patient with an acute migraine, selected from the list below. The time is now 10am. The patient has no known drug allergies.
10am, Sumatriptan 50mg, Oral
89
Name the most common kind of benign and malignant primary brain tumours
Benign (42%) -> Meningioma (20%)
Malignant (58%) -> Glioblastoma multiforme - grade 4 (25%)
90
What are the 6 most common cancers that metastasize to the brain?
1. Bronchus
2. Breast
3. Stomach
4. Prostate
5. Thyroid
6. Kidney
91
What are the 4 broad possible causes of SOL?
1. Tumours
2. Infection (brain abscess, subdural empyema, granuloma (TB), parasitic)
3. Vascular (EDH, SDH, SAH, parenchymal hemorrhage, cavernoma/vascular malformations, infarct in brain)
4. Hydrocephalus
92
What are the 3 different causes of hydrocephalus?
1. Non-communicating (obstruction in flow of CSF) -> tumours, cysts, intraventricular hemorrhage
2. Communicating (absorption problem) -> meningitis, SAH
3. Overproduction of CSF (rare) -> choroid plexus papilloma
93
What are 5 possible symptom presentations of a brain tumour?
1. Increased intracranial pressure
2. Neurological deficits due to compression/damage of adjacent structures
3. Cortical/meninggeal irritation
4. Hormonal effects
5. Systemic effects/generally unwell
94
What are the signs and symptoms of raised ICP?
Symptoms:
1. Headache
2. Nausea/vomiting
3. Blurring of vision
4. Decreased conscious level (respiratory depression)
Signs (late onset):
1. Bradycardia
2. Papilloedema
3. Hypertension
95
What are the local effects of a SOL in the frontal lobe?
1. Weakness
2. Dysphasia
3. Personality changes
4. Dementia
96
What are the local effects of a SOL in the parietal lobe?
1. Sensory symptoms
2. Dressing apraxia
3. Visual field defects
97
What are the local effects of a SOL in the temporal lobe?
1. Dysphasia
| 2. Visual field defects
98
What are the local effects of a SOL in the occipital lobe?
1. Visual fields
99
What are the local effects of a SOL in the posterior fossa/cerebellum?
1. Dysmetria
2. In-coordination
3. Gait ataxia
4. CN palsies
5. Tremors
6. Nystagmus
100
Name at least 2 types of familial brain tumours
1. Neurofibromatosis 1
2. Neurofibromatosis 2
3. Von Hippel Lindau Syndrome
4. Tuberous Sclerosis
5. Li-fraumeni Syndrome
101
What features on a CT indicate a secondary tumour?
1. Highly uniformly enhancing
2. Multiple structures
3. Increased inflammation!
102
What are the management options for tumours?
1. Surgery (limited value - reduce bulk of tumour)
2. Steroids (symptom control)
3. Radiotherapy
4. Chemotherapy
103
Explain a meningioma
- Arises from arachnoid cap cells
- Generally benign
- Trauma, radiation, oncogenic virus, hormones = implicated in their causation
- Surgical excision if possible
104
Explain vestibular schwannoma
- Benign + slow growing
- From nerve sheath of vestibular nerves often at cerebellopontine angle (i.e. acoustic neuroma due to NF1)
- Present with ipsilateral hearing problems + tinnitus (CN5, 7, or lower nerves can be effected)
- Surgical treatment required
105
What is the normal ICP of an adult? High ICP?
Normal: < 15mmHg
High: > 20mmHg
106
What is the Monro-Kellie Doctrine?
Describes auto-regulation of the brain + compliance
An increase in 1 component (brain swelling) or addition of new component (hematoma) displaces another
107
What is the intracranial volume and its breakdown as components in %?
Intracranial volume= 1400-1700mL
80% brain parenchyma
10% CSF
10% blood
108
What are the 3 main causes of increased ICP?
1. Increased brain volume
- Cerebral oedema, SOL
2. Increased CSF volume
- Obstruction, decrease in CSF absorption, increase in CSF production
3. Increased blood volume
- Raised pCO2, venous obstruction, increased temperature
109
What is the equation for cerebral perfusion pressure?
CPP = ABP - ICP
110
What is the gold standard in measuring ICP?
External ventricular drain (catheter in ventricle of brain)
111
What is the treatment for acute increased ICP?
1. Head up tilt (30-45º) = decreased venous pressure
2. Keep neck straight = decreases obstruction of venous outflow
3. Avoid hypotension = use vasopressors as required to maintain cerebral blood flow
4. Maintain adequate sedation = decrease metabolic demands
5. Maintain euvolemia + normo-hyper osmolar state = decreases cerebral oedema
6. Maintain normal pCO2 = increased pCO2 -> cerebral vasodilation -> increased cerebral blood V -> increased ICP (only use in acute setting for short period of time!)
112
What is the treatment for sustained increased ICP?
1. Sedation
2. CSF drainage
3. Mannitol (osmotic therapy)
4. Hpyerventilation
5. Barbiturate therapy
6. Decompressive craniectomy
113
What is the mechanism of action of mannitol?
Decreases blood volume by drawing free H2O out of tissue into circulation (dehydrates brain parenchyma)
Bolus dose 100mL, effect within minutes
May cause rebound increase in ICP
114
What is the benefit of hyperventilation in decreasing ICP?
Rapid reductio din ICP (effect is short lived)
Decrease in blood flow = decrease in cerebral perfusion = worsening of brain injury
115
What is the mechanism of action of barbiturates? Name 2 examples
Phenobarbitone, thiopentone
Decreases brain metabolism + cerebral blood flow = reduced ICP
Need EEG monitoring b/c side effects are common (i.e. hypotension)
116
What is the gold standard for brain imaging?
MRI
117
Describe an extra-dural hematoma
Biconvex shape seen on CT
- Relatively uncommon
- Associated with skull fracture
- Middle meningeal artery bleed
- 1/3 due to venous bleeding
- Classic lucid interval (temporary improvement)
- Generally good outcome if treated quickly
118
Describe a subdural hematoma
Crescentric shape seen on CT
Significant mass effect (pressure effect) + midline shift
- Common
- Complicates 20-30% of head injuries
- Rupture of the veins travelling from surface to sagittal sinus
- Prognosis worse as hematoma develops very slowly b/c of venous oozing
- Headache, drowsiness, confusion
- Fluctuating levels of consciousness b/c hematoma contract + expands with osmotic effects
119
Describe a subarachnoid hemorrhage
- Associated with ruptured aneurysm (i.e. Berry aneurysm) -> white areas within brain = blood
- More commonly caused by head injury
120
Describe an intracerebral hemorrhage
- Stretching + shearing injury
- Impact on inside of skull
- Often termed "contre-coup" injury
121
What are the clinical signs of herniation?
1. Dilated/unreactive pupils
2. GCS decreased by 2+ points
3. Extensor posturing
122
When prescribing use generic drug names except for which 3 drugs would you use the brand names?
1. Lithium
2. Theophylline
3. Phenytoin
123
What can trigger a migraine?
CHOCOLATE
```
Ch - chocolate
O - oral contraceptive pill
C - Caffeine (or withdrawal)
Ol - Alcohol
T - travel
E - exercise
```
