Positive predictive value = TP / (TP + FP) Screening test statistics It would be unusual for a medical exam not to feature a question based around screening test statistics. The available data should be used to construct a contingency …
Facial nerve Supply – ‘face, ear, taste, tear’ face: muscles of facial expression ear: nerve to stapedius taste: supplies anterior two-thirds of tongue tear: parasympathetic fibres to lacrimal glands, also salivary glands Causes of bilateral facial nerve palsy sarcoidosis Guillain-Barre …
Odds and odds ratio Odds are a ratio of the number of people who incur a particular outcome to the number of people who do not incur the outcome. The odds ratio may be defined as the ratio of the …
Study design The following table highlights the main features of the main types of study: Randomized controlled trial Participants randomly allocated to intervention or control group (e.g. standard treatment or placebo) Practical or ethical problems may limit use Cohort study …
HIV: neurocomplications Generalised neurological disease Encephalitis may be due to CMV or HIV itself HSV encephalitis but is relatively rare in the context of HIV CT:oedematous brain Cryptococcus most common fungal infection of CNS headache, fever, malaise, nausea/vomiting, seizures, focal …
The odds of developing hypertension if you work < 40 hours/week is 50 / 1000 = 1 / 20 or 0.05 The odds of developing hypertension if you work > 40 hours/week is 60 / 600 = 1 / 10 …
Down’s syndrome: epidemiology and genetics Risk of Down’s syndrome with increasing maternal age risk at 30 years = 1/1000 35 years = 1/350 40 years = 1/100 45 years = 1/30 One way of remembering this is by starting at …
Antiplatelets TIA: aspirin & dipyridamole ischaemic stroke: clopidogrel Carotid artery endarterectomy is recommend if the patient has suffered a stroke or TIA in the carotid territory and is not severely disabled. It should only be considered if the carotid stenosis …
One of our registered users sent the following mnemonic to us: NF1: chromosome 17 – as neurofibromatosis has 17 characters NF2: chromosome 22 – all the 2’s Neurofibromatosis There are two types of neurofibromatosis, NF1 and NF2. Both are inherited …
This patient has Horner’s syndrome caused by a carotid artery dissection. This may be caused by relatively benign trauma to the neck such as hyperextension whilst doing DIY. Cluster headache would be a differential diagnosis Horner’s syndrome Features miosis (small …