Bell's palsy pathophysiology: Difference between revisions
Jump to navigation
Jump to search
No edit summary |
No edit summary |
||
| Line 8: | Line 8: | ||
==Pathophysiology== | ==Pathophysiology== | ||
===Possible mechanisms=== | |||
:*The majority of patients with blepharospasm have a high incidence of local ocular symptoms prior to or at the onset of blepharospasm, such as blepharitis, conjunctivitis, dry eyes or photophobia. | |||
:*Chronically disturbed sensory inputs to the central nervous system due to lagophthalmos and corneal irritation may contribute to the generation of blepharospasm. | |||
:*In patients with Bell’s palsy, there is an enhanced blink reflex secondary to inputs from the paralyzed side compared which those of the non-paralyzed side. | |||
:*Abnormal afferent input from the paralyzed side contributes to the abnormal sensitization of the blink reflex, thus facilitating the induction of abnormal facial motor outputs such as blepharospasm. | |||
:*It is unclear why Bell’s palsy-induced blepharospasm is extremely rare. | |||
=== Microscopic Pathology === | === Microscopic Pathology === | ||
Revision as of 13:44, 22 August 2012
|
Bell's palsy Microchapters |
|
Diagnosis |
|---|
|
Treatment |
|
Case Studies |
|
Bell's palsy pathophysiology On the Web |
|
American Roentgen Ray Society Images of Bell's palsy pathophysiology |
|
Risk calculators and risk factors for Bell's palsy pathophysiology |
Please help WikiDoc by adding more content here. It's easy! Click here to learn about editing.
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Pathophysiology
Possible mechanisms
- The majority of patients with blepharospasm have a high incidence of local ocular symptoms prior to or at the onset of blepharospasm, such as blepharitis, conjunctivitis, dry eyes or photophobia.
- Chronically disturbed sensory inputs to the central nervous system due to lagophthalmos and corneal irritation may contribute to the generation of blepharospasm.
- In patients with Bell’s palsy, there is an enhanced blink reflex secondary to inputs from the paralyzed side compared which those of the non-paralyzed side.
- Abnormal afferent input from the paralyzed side contributes to the abnormal sensitization of the blink reflex, thus facilitating the induction of abnormal facial motor outputs such as blepharospasm.
- It is unclear why Bell’s palsy-induced blepharospasm is extremely rare.
Microscopic Pathology
- The facial nerve has an edematous, thickened perineurium with infiltrates of inflammatory cells between nerve bundles and around blood vessels.
- It appears that the histology of the facial nerve in Bell's palsy is similar to Herpes Zoster infection, suggestive of an infectious cause.