标题: Vertigo 天旋地转 [打印本页] 作者: choi 时间: 3-1-2016 19:43 标题: Vertigo 天旋地转 If you are not a physician (being a biologist is not enough), you probably will not understand. However, the topic and underlying cause are interesting.
Paula Span, A Simple Step to Stop Vertigo's Whirl; A series of head movements can often quickly remedy a frightening loss of bearing. New York Times, Mar 1, 2016 (in her column "The New Old Age," about geriatric issues). http://www.nytimes.com/2016/03/0 ... ix-for-vertigo.html
(the disease: "the most common kind of vertigo[:] * * * enign paroxysmal positional vertigo * * * When the vertigo comes back months or years later, as it tends to do, it can be vanquished again. Often, patients can perform the maneuver at home * * * a non-pharmacological treatment * * * BPPV, as it’s known, occurs when the tiny calcium carbonate crystals of your inner ear loosen and migrate into one of the semicircular canals, where their presence signals the brain that you’re moving when you’re not. The resultant spinning sensation usually lasts only a minute or so, but changes in head position can bring it on multiple times a day")
Excerpt in the window of print: "This is a simple mechanical disorder. You can fix it in minutes." DR CAROL FORSTER[,] UNIVERSITY OF COLORADO HOSPITAL
The English noun vortex 漩涡 also comes from this Latin verb.
(ii) The symptom of vertigo is similar to the concept of vortex. This report describes vertigo correctly: "feeling the room whirling around him."
(i) etiology 病因: "If there are enough otoconia floating around, they can aggregate into a larger clump. Because they are heavy, they migrate into the lowest part of the inner ear, the posterior semicircular canal. Once in the semicircular canal, they may still move when the head changes position, such as looking up or down, over the shoulder, or when rolling over in bed. It is the movement of these stones that causes an unwanted flow of fluid in the semicircular canal even after the head has stopped moving. This leads to a false sense that the head and body are spinning around or that the world around you is spinning around
(ii) diagnosis: "The diagnosis of BPPV is made by the characteristic symptoms and also by observing the nystagmus – the jerking of the eyes that accompanies the severe vertigo patients experience when the position of their head is changed. By tilting a patient’s head way back at the end of an examining table, a doctor will try to provoke the symptoms to see the nystagmus for a thorough diagnosis.
is housed within "bony labyrinth."
(ii) histology 组织学 (under microscope):
(A) otolith https://en.wikipedia.org/wiki/Otolith
("They are sensitive to gravity and linear acceleration. Because of their orientation in the head, the utricle [more or less horizontal, or parallel with the earth surface] is sensitive to a change in horizontal movement, and the saccule [which is more or less perpendicular to the earth surface] gives information about vertical acceleration (such as when in an elevator)" )
(B) This Wiki page is written for most animals that can sense movement and/or gravity. In humans, otoliths are found in both utricle and saccule (not or as stated in the first sentence of this Wiki page).
(C) In humans, the otolith (which is singular) is also known as otoconia (which is the plural form of otoconium). This NYT report identifies it as "canalith," which is almost unheard of.
(D) etymology:
* otolith (Ancient Greek: lithos a stone)
* otoconium (Ancient Greek oûs, ōt-, ot- ear + konía dust) https://en.wiktionary.org/wiki/otoconium
"When the head rotates about any axis, distant visual images are sustained by rotating eyes in the opposite direction on the respective axis.[4] The semicircular canals in the vestibule sense angular acceleration. These send signals to the nuclei for eye movement in the brain. From here, a signal is relayed to the extraocular muscles to allow one’s gaze to fixate on one object as the head moves. Nystagmus occurs when the semicircular canals are being stimulated while the head is not in motion.
"section 1.1 Pathological nystagmus[:] * * * When nystagmus occurs without fulfilling its normal function [see preceding quotation] * * * Variations [of pathological nystagmus]: * * * Positional nystagmus occurs when a person's head is in a specific position. An example of disease state in which this occurs is Benign paroxysmal positional vertigo (BPPV)")
(e) treatment
(i) Epley maneuver ("after the Oregon ear surgeon who devised it in 1980": NYTimes)
Here, the top scheme tells you that a semicircular canal is deemed one-way, partially blocked at one end (called ampulla, because it bulges out) by cupula from floor to ceiling. See the second scheme with purple background (which is microscopic) in semicircular canal. https://en.wikipedia.org/wiki/Semicircular_canal
(ii) "Dr Foster has developed an additional maneuver for home use, called the half-somersault, that is done kneeling on the floor."