Migraines And Emesis Flashcards
What is a headache often associated with
Aura- migrating visual or other sensory disturbance lasting up to an hour
What is a migraine often preceded by
Prodromal signs- hyperactivity yawning food craving neck stiffness
What does the pain in an migraine come from
Neurovascular?
Activation of Trigeminal nerve terminals on blood vessels (=nausea) pain transmitted from Trigeminal to Cortex
Brain arteriolar dilation and of temporal artery
What do sensory nerves release in a migraine
CGRP and NO
What are migraine diagnostic characteristics
2 or more : unilateral, pulsating, painful, aggravated my normal physical activity
Usually associated with : aura nausea photophobia and photophobia
What are the main diagnostic subdivisions of a migraine
Without aura
Aura
Retinal
What increased the risk of migraine
FDR
Morning
Explain spreading depression
Sustained depolarisation associated with waves of metabolic over-stimulation followed by inhibition
Waves spread across surface of cortex disrupting local function - visual cortex =zigzags
What is the therapy for migraines
acute - NSAIDS/analgesics ibruprofen paracetamol and diclofenac
TRIPTANS- 5HT1b and 5HT1d receptor agonists-construction of brain blood vessels and therefore inhibition of neuropeptide release
What prophylaxis exists for migraines
Avoid known triggers B-blockers Calcium channel blockers Anticonvulsants Pre-menstrual oestrogen
For treatment resistant patients what is recommended
Acupuncture is gabapentin
What Things accompany nausea
Cold sweat Pallor Salivation Self absorption Loss of gastric tons Duodenal contractions Reflux of intestinal context into stomach
What is the sequence that leads to vomiting
Woeful sustained contraction of abdominal chest wall and diaphragm muscles, increase intra-gastric pressure, opening of cardioesophageal sphincter glottis and jaws
Name seven causes of nausea and vomiting
Iatrogenic (chemo radio, opiates, antibiotics) Motion sickness Pregnancy Poisoning Gastroenteritis Meningitis and intracranial haemorrhage Bulimia nervosa
What is the main vomiting centre input
Chemoreceptor trigger zone at the base of the forth ventricle has D2 5HT opioid and Ach NK1 receptors
What alternative inputs are there to the vomiting centre
Area postrema Vagal gag reflex (5HT and NK1) Vestibular system ( m Ach and H1 Rs) Gut 5HT3 Sight of smell of vomit
When would you induce vomiting
Poison in stomach
Swallow an emetic- ipecacuanha
Or induce gag reflex
What drugs are used to control emesis most effectively
NK1 reception antagonism (aprepitant) because substance p is major output transmitter from vomiting centre
What is used for motion sickness
H1 and 2 antagonists
How is chemo therapy induced emesis controlled
Corticosteroids NK1 antagonist and 5HT3 antagonist
How is nausea controlled
Mild sedation ( benzodiazepines) and anti-emetics
Define a migraine
Painful pulsing headache typically lasting 4hrs-3days often unilateral with photophobia
