Papilledema pathophysiology: Difference between revisions
Jump to navigation
Jump to search
No edit summary |
No edit summary |
||
| Line 8: | Line 8: | ||
==Pathophysiology== | ==Pathophysiology== | ||
* [[Optic nerve]] sheath is continuous with the [[subarachnoid space]] of the [[brain]] and is regarded as an extension of the [[central nervous system]]. | * [[Optic nerve]] sheath is continuous with the [[subarachnoid space]] of the [[brain]] and is regarded as an extension of the [[central nervous system]]. | ||
| Line 25: | Line 23: | ||
* Persistent and extensive [[optic nerve]] head swelling, or [[optic disc]] edema, can lead to loss of these fibers and permanent visual impairment. | * Persistent and extensive [[optic nerve]] head swelling, or [[optic disc]] edema, can lead to loss of these fibers and permanent visual impairment. | ||
* Papilledema may be absent in cases of prior optic atrophy. In these cases, the absence of papilledema is most likely secondary to a decrease in the number of physiologically active nerve fibers. | |||
==References== | ==References== | ||
{{Reflist|2}} | {{Reflist|2}} | ||
Revision as of 00:18, 18 July 2012
|
Papilledema |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Papilledema pathophysiology On the Web |
|
American Roentgen Ray Society Images of Papilledema pathophysiology |
|
Risk calculators and risk factors for Papilledema pathophysiology |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-In-Chief:Kalsang Dolma
Overview
Papilledema results due to transmission of increased intracranial pressure to the anterior end of optic nerve through optic nerve sheath.
Pathophysiology
- Optic nerve sheath is continuous with the subarachnoid space of the brain and is regarded as an extension of the central nervous system.
- The cranium and the vertebral body, along with the relatively inelastic dura, form a rigid container, such that the increase in any of its contents—brain, blood and cerebrospinal fluid can cause increased intracranial pressure.
- The brain itself is relatively spared from pathological consequences of high pressure.
- Increased intracranial pressure is transmitted through to the optic nerve via this optic nerve sheath.
- The anterior end of the optic nerve stops abruptly at the eye. Hence the pressure is asymmetrical and this causes a pinching and protrusion of the optic nerve at its head.
- The fibers of the retinal ganglion cells of the optic disc become engorged and bulge anteriorly.
- Persistent and extensive optic nerve head swelling, or optic disc edema, can lead to loss of these fibers and permanent visual impairment.
- Papilledema may be absent in cases of prior optic atrophy. In these cases, the absence of papilledema is most likely secondary to a decrease in the number of physiologically active nerve fibers.