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)