Neurology Flashcards
classification of causes of headaches
structures: trigeminovascular system, meninges, CSF containing structures, muscle, nerves
processes: “neurogenic” inflammation, inflammation, infection, pressure, obstruction
papilloedema: def, appearance and cause
swelling of optic disc
appearance: disc pinkness, with blurring and heaping up of disc margins. small haemorrhages surround disc
cause: raised intracranial pressure
prevalence of migraines
1/5 women
1/12 men
what is an aura and symptoms
+diagnostic criteria for it
neurological features preceding headache: visual disturbances (one eye, or one visual file, scintillating scotoma) and sensory symptoms (unilateral parasthesia, ascending numbness of hand, arm, face, lips and tongue)
Symptoms:
- fully reversible
- develop over at least 5 minutes
- lasts for 5-60minutes
what is cortical spreading depression
slow wave of neuronal and glial depolarisation followed by depression of spontaneous neuronal activity spreading from occipital lobe anteriorly across cerebral cortex
look more into this
+ suppression occurs alongside changes in brain blood flow
how does cortical spreading depression cause migraine?
activates trigeminal nerve afferents, causing inflammatory changes in pain-sensitive meninges (causing migraine through peripheral and central reflex mechanism) (can also happen in areas where depolarisation is not consciously perceived)
triggers for migraines
- stress or relaxing after stress
- jet lag/change in sleep/lack of sleep
- tyramine rich foods (i.e. cheese)
- contraceptive pills
- menstruation (fall of oestrogen)
- bright lights, loud sounds, smoky rooms
- eating/Alcohol
- physical exertion
- changes in weather patterns
migraine treatment
-acute: oral triptan + NSAID/paracetamol
-prophylaxis: propranolol or topiramate (consider amitriptyline, acupuncture, sodium valproate if topiramate or propranolol ineffective)
+ oestrogen patches when menstruation precedes it
+ ACEi, ARB, Ca channel blockers may be helpful
can also
-anti-emetics (for nausea and vomiting): domperidone, prochlorperazine and metoclopramide
(-triptans (5-HT receptor agonist): act of pre and post synaptic receptors in midbrain and trigeminal nucleus caudalis + cause vasoconstriction of vasodilated vessels
which medical conditions are contraindicated to treatment with triptans?
(the have peripheral vasoconstrictor action on arterioles)
- ischemic heart disease (including MI)
- transient ischemic attack
- cerebrovascular accident
- mild uncontrolled hypertension
- peripheral vascular disease
- Prinzmetal’s angina
criteria for preventative treatment of migraine
- quality of life/ business duties/ school attendance severely affected
- 2+ attacks/month
- migraine attacks do not respond to acute drug treatment
- frequent, very uncomfortable aura occurs
meningitis symptoms
headache neck stiffness fever photophobia vomiting
bacteria infections leading to meningitis
- neisseria meningitidis
- streptococcus pneumoniae
- haemophilus influenza
- listeria monocytogenes
- staphylococcus aureus
- gram neg bacilli
- mycobacterium tuberculosis
viral infections leading to meningitis
- enterovirus
- herpes simplex
- varicella zoster
- cytomegalovirus
- epstein-barr virus
- adenovirus
fungal infections leading to meningitis
cryptococcus neoformans
differential diagnoses of meningitis
- encephalitis (inflammation of brain)
- non-infective causes of meningeal irritation
- subdural empyema (collection of pockets of pus)
risk factors of meningitis
- extremes of age
- living in close proximity
- absence of vaccination
- immune suppression/deficiency
if meningococcal meningitis what particular sign would there be?
rash or purpura (non blanching)
examination for suspected meningitis
-purpuric rash
-signs of sepsis, shock (+record GCS)
-stiff neck: ask paint to touch chest with neck
-Kernig’s sign
-fundoscopy (for papilloedema)
-full neuro exam
(-cognitive assessment if worried about encephalitis)
investigations for meningitis
- CSF collection (opening pressure, microscopy/culture/sensitivity, protein, glucose, lactate, meningococcal and pneumococcal PCR)
- blood cultures
- urine pneumococcal antigen
- serology for viruses causing meaningo-encephalitis
- throat swab for meningococcus pneumonie and neisseria meningitides
contra-indications of lumbar punctures
- signs of raised intracranial pressure (papillodema or focal neurological signs)
- coagulation defects
- signs of infection at site of needle insertion)
treatment of meningitis
bacterial: empirical therapy with an IV 3rd generation cephalosporin OR IM benzylpenicillin (in GP) + dexamethasone
- if patient over 60: amoxicillin added
- if Listeria suspected: ampicillin added
- if patients travelled to countries with high rate of pneumococcal penicillin resistance, seek advice (vancomycin or rifampicin)
difference between CT and MRI
CT: X ray based
MRI: magnetic waves (better spatial resolution of soft tissue lesions + greater resolution of portico-medullary patterns)
Headache red flag examination
Papilloedema (raised intracranial pressure)
Peripheral visual loss, enlarged ind spots (raised intracranial pressure)
Eye abduction inhibition (raised intracranial pressure or nerve infarction)
Extensor plantar
Pronator drift (pyramidal tract dysfunction due to raised intracranial pressure)
New onset ataxia
Oral hairy leukoplakia (EBV)
Non blanching/purpura rash
Livedo reticularis (risk of venous clots)
emergency/red flag symptoms headaches
Thunderclap onset
New onset neurological deficit/cognitive dysfunction
head trauma (w/in last 3 months)
photophobia + nuchal rigidity + fever +/- rash
reduced consciousness
acute red eye/acute angle closure glaucoma
new onset in third trimester pregnancy/early postpartum
change in personality
headache triggered couch, sneeze or valsa
Headache triggered by exercise
Symptoms suggestive giant cell arthritis
Substantial change in character of headache
When do you refer and/or further investigations with headache
Emergency/red flag symptoms
OR if present with new onset headache:
- immunocompromised (drugs/HIV)
- <20 yo and history of malignancy
- history of malignancy that metastasise to brain
- vomiting without other obvious cause
What should be recorded in headache diary
Frequency, duration and severity of headache Associated symptoms Medications taken to relieve headache Possible précipitants Relationship headaches and menstruation
Migraine symptoms
Unilateral or bilateral
Pulsing (throbbing/banging)
Moderate or severe intensity of pain
Unusual sensitivity to light and/or sound or nausea/vomiting
Aura (symptoms are reversible, develop over 5 minutes and lasts 5-60 minutes)
quick onset symptoms points towards what type of meningitis
bacterial
CSF interpretation: clear, colourless WCC count: 0.5 Glucose > 2/3 blood glucose Protein (g/L): 0.15-0.4
normal
CSF interpretation: turbid appearance WCC count: 500-10000 polymorphs Glucose: v low Protein (g/L): high
bacterial meningitis
CSF interpretation
- appearance: turbid, viscous, straw
- WCC count: <500 lymphocytes/polymorphs
- glucose: low
- protein: v high
tuberculosis meningitis:
CSF interpretation:
- appearance: viscous, clear
- WCC count <500 lymphocytes/polymorphs
- glucose: low
- protein: v high
fungal meningitis
when do you offer antimicrobial (rifampicin) to household who has come into contact with meningitis
haemophilus influenzae (esp non vaccine types) Neisseria meningitis
CSF interpretation:
- appearance: clear
- WCC count <1000 lymphocytes
- glucose: normal
- protein: raised
viral meningitis
types of intracranial space occupying lesions
- tumours (primary/secondary)
- infections (brain abscess, subdural empyema, granuloma, parasitic)
- vascular (haemorrhages, vascular malformations, infarction)
- hydrocephalus (obstructive, communicating, overproduction)
signs/symptoms of raised intracranial pressure
symptoms: headache, vomiting, blurred vision, decrease in consciousness level
signs: late in the process: bradycardia, hypertension, papilloedema, respiratory depression
space occupying lesions effect by location
- frontal lobe: weakness, dysphagia, personality changes, dementia
- parietal lobe: sensory symptoms, Dressing apraxia, visual field defects
- temporal lobe: dysphagia, visual field defects
- posterior fossa: dysmetria, in-coordination gait ataxia, CN palsy, tremors, nystagmus etc
- brain irritation: seizures
sites of origin of secondary metastases of brain
bronchus, breast, stomach, prostate, thyroid, kidney
primary malignant brain tumours
- astrocytes: glioblastoma multiforme, anaplasie astrocytoma
- oligodendrocytes: oligodendroglioma
- mixed malignant glioma (can arise from glial and oligodendrocytes)
- ependydmal cells: ependymoma
- cerebellum: medulloblastoma
benign brain tumours
- meninges: meningioma
- myelin: nerve sheath tumour
- pituitary gland: pituitary tumour, craniopharyngioma
- astrocytes: astroctyoma
diagnosis of brain tumours
neuro exam
scans
(CSF studies
bloods)
WHO grading of glioma
grade 1: pilocytic astrocytoma
grade 2: low grade astrocytoma
grade 3: anaplastic astrocytoma
grade 4: glioblastoma multiforme
(high grades can arise de novo or from malignant changes of low grade)
normal intracranial pressure value
<15 mmHg in adults
lower in children and negative in newborns
pathological ICP
persistent pressure >20 mmHg
Monro-Kellie doctrine
changes in one of the intracranial components (blood, CSF or brain parenchyma) causes displacement or replacement of another (usually CSF)
= compliance
causes of raised ICP
- increase in brain/tissue/mass volume (cerebral oedema, SOL)
- increase in CSF volume (obstruction of CSF circulate, reduced CSF absorption, increased CSF production)
- increase in blood volume (raised arterial PCO2, venous obstruction, raised T°)
cerebral perfusion pressure formula
arterial BP - ICP
why is it important to know ICP in head injury
auto regulation of cerebral perfusion pressure in impaired:
if you know ICP, you can adapt ABP
how do you measure ICP
- EVD with strain-gauge pressure transducer (GOLD standard)
- fibre optic intra-parenchymal transducer
- air-pouch balloon
- combined with temperature and micro dialysis
management of ICP
- promote venous outflow: 30-45° head tilt up, neck straight, no tight ETT tapes
- maintain cerebral blood flow: avoid hypotension, maintain normal PCO2
- reduce cerebral oedema: maintain euvolaemia and norm-hyper osmolar state
- reduce metabolic demands: maintain adequate sedation
If this isn’t enough:
- CSF drainage
- mannitol (osmotic therapy)
- hyperventilation
- barbituates
- decompressive craniectomy
- removal of space occupying lesion
symptoms of giant cell arthritis?
- head pain and tenderness (usually affecting both temples)
- scalp tenderness
- jaw pain when you chew or open mouth
- fever
- fatigue
- unintended weight loss
- vision loss or double vision
- sudden permanent loss of vision in one eye
diagnosis of giant cell arthritis
- bloods: CRP, erythrocyte sedimentation rate (f RBC drop quickly, can indicate inflame)
- biopsy of temporal artery
