{"id":828,"date":"2014-10-09T23:40:04","date_gmt":"2014-10-09T23:40:04","guid":{"rendered":"http:\/\/drcrunch.wordpress.com\/?p=828"},"modified":"2014-10-09T23:40:04","modified_gmt":"2014-10-09T23:40:04","slug":"the-four-types-of-dizziness-in-clinical-medicine","status":"publish","type":"post","link":"http:\/\/drcrunch.co.uk\/blog\/2014\/10\/09\/the-four-types-of-dizziness-in-clinical-medicine\/","title":{"rendered":"The four types of dizziness in clinical medicine"},"content":{"rendered":"

\"Dizziness\"<\/a><\/p>\n

A 24 year old woman with a positive pregnancy test is seen in the EPAU with three days of lower abdominal pain. A transvaginal ultrasound shows she is 5 weeks pregnant, but \u2018cannot rule out ectopic pregnancy\u2019.<\/p>\n

The patient is informed of the symptoms of ectopic pregnancy to look out for.<\/p>\n

On mentioning \u2018feeling faint\u2019 as a red flag, she mentions episodes of room spinning for the past three days. She also feels light headed and \u2018about to pass out\u2019.<\/p>\n

These episodes last less than a minute at a time and are provoked by head movements. There is no vomiting. She has no tinnitus or hearing problems. She has no double vision, speech problems, weakness or numbness.<\/p>\n

On examination, her eye movements are conjugate and there is no nystagmus. A Dix-Hallpike manoeuvre is done to confirm the diagnosis.<\/p>\n

This patient was treated as BPPV. However, she had also mentioned feeling light headed and feeling \u2018about to pass out\u2019. How should we sort these symptoms?<\/p>\n

The official NICE CKS<\/a> question for distinguishing vertigo from the other types of dizziness is \u201cWhen you have dizzy spells, do you feel light-headed or do you see the world spin around you as if you had just got off a playground roundabout?\u201d<\/p>\n

For me, dizziness falls into one of four species (vertigo, disequilibrium, presyncope and lightheadedness) in about 80% of cases. Then there\u2019s the 20% who complain of multiple types at once e.g. \u201cIt does feel like the room is spinning and I\u2019m also about to fall over and pass out\u201d. I decided to find out how best to distinguish these types, as well as think about the key questions that lead you to the differential for each of the subtypes.<\/p>\n

True vertigo<\/strong><\/p>\n

\"Vertigo\"<\/p>\n

False sense of movement. Like when you get off a merry go round.<\/p>\n

Top questions: Is it central or peripheral?<\/p>\n

The traditional table as found at Initial Evaluation of Vertigo<\/a>:<\/p>\n\n\n\n\n\n\n\n\n\n
Type<\/td>\nPeripheral<\/b><\/td>\nCentral<\/b><\/td>\n<\/tr>\n
Nystagmus<\/td>\nCombined horizontal and torsional;inhibited by fixation of eyes onto object;fades after a few days; does not change direction with gaze to either side<\/td>\nPurely vertical, horizontal, or torsional;not inhibited by fixation of eyes onto object; may last weeks to months;may change direction with gaze towards fast phase of nystagmus<\/td>\n<\/tr>\n
Imbalance<\/strong><\/td>\nMild to moderate; able to walk<\/td>\nSevere; unable to stand still or walk<\/td>\n<\/tr>\n
Nausea, vomiting<\/strong><\/td>\nMay be severe<\/td>\nVaries<\/td>\n<\/tr>\n
Hearing loss, tinnitus<\/strong><\/td>\nCommon<\/td>\nRare<\/td>\n<\/tr>\n
Nonauditory neurologic symptoms<\/strong><\/td>\nRare<\/td>\nCommon<\/td>\n<\/tr>\n
Latency following provocative diagnostic maneuver<\/strong><\/td>\nLonger (up to 20 seconds)<\/td>\nShorter (up to 5 seconds)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

GP Online<\/a>\u2019s quick answer: Do a head impulse test. If positive, this points to a peripheral cause. If normal, this points to central (or psychogenic) vertigo.<\/p>\n

But how do I do a head impulse test?<\/p>\n