August 16, 2019
Ear Canal Infections (Acute Otitis Externa)
A simplistic way of thinking about this condition is to regard it as a “dangerous and abnormal benign positional paroxysmal vertigo (BPPV)” because it can be caused by disease in the brain stem or cerebellum.
These diseases include tumors, sudden bleeds or strokes or conditions such as Multiple Sclerosis (MS) and rarer causes including degenerative conditions of the cerebellum, cancer elsewhere in the body poisoning the brain, generalized brain failure due to many causes including toxins.
These are all very serious conditions, so it is important to be able to identify between the commonplace safe benign positional paroxysmal vertigo (BPPV) and rare dangerous Central Positional Vertigo (CPV).
How does the doctor work out which patient has BPPV or CPV?
This is based on a detailed history of the complaint looking for typical and unusual features then followed by a 2-part examination.
The first is a careful neurological examination focussing on eye movements; the second part is the manipulation of the head into certain classic positions in an attempt to provoke classical eye movements which are associated with the various forms of BPPV.
Both BPPV and CPV present with a complaint of a sensation of spinning when their head is in a certain position.
In classical BPPV the typical experience of “morning vertigo” is a sudden sensation of spinning, either when turning over in bed, bending over or looking up.
It only lasts a few seconds, but it is quite disturbing.
Patients often feel sick and unsteady for many hours after the attack, however, it doesn’t affect hearing or cause any ringing sounds in the ears.
There are no abnormal neurological findings and manipulation of the head generates eye movements which fit with specific types of BPPV.
Central Positional Vertigo (CPV) is different: superficially it is similar to BPPV in that the patient presents with a complaint of a sensation of spinning when their head is in a certain position.
However, the patient may have abnormal findings in neurological examination such as ataxia, saccadic pursuit, gaze evoked nystagmus, down beat nystagmus and impaired fixation suppression of the vestibular ocular reflex; all of which are never found in BPPV.
The first initial manipulation of the head into the classic BPPV head position frequently provokes marked nausea and vomiting – this is unusual with BPPV. The nausea and vomiting is associated with a lack of rapid eye movement (nystagmus).
If the eye movements of BPPV (nystagmus) are present they may not gradually disappear, as they should, but persist and are not associated with the usual feelings of vertigo.
Finally the type of eye movements provoked by the initial manipulation of the head are inconsistent with types of BPPV e.g. rotating eye movement when it should be horizontal ( as seen in horizontal canal BPPV) or up beat nystagmus, rotatory or combined rotatory/horizontal movement ( as in posterior canal BPPV).
Treatment depends on what the cause of the condition is found to be.