Labyrinthitis

SEMINAR

1. Labyrinthitis R.Anusha Pharm D V l Year Roll no : 170514882007

2. Introduction Labyrinthitis- This is the inflammation of inner ear (Cochlea) and / or balance organ (Utricle, Saccule and Semicircular Canals) which are intimately connected to each other inside the skull adjacent to outer ear. It is the often a complication of infection of the middle year(otitis media).

3. Function of labyrinth The semi-circular canals sense movement of the head and help to control balance and posture. The cochlea is concerned with hearing. Head movements are sensed because when we move our head, the fluid in the labyrinth within the semi-circular canals moves too. The movement of the fluid moves tiny hairs on the inside lining of the labyrinth. When the hairs move, this triggers nerve messages to be sent to the brain via vestibular nerve.

4. Types of labyrinthitis There are three types of labyrinthitis: Circumscribed Thinning or erosion of bony capsule of labyrinth—usually horizontal semicircular canal. Diffuse serous Diffuse intra labyrinthine inflammation without pus formation.Reversible if treated early. Diffuse suppurative Diffuse pyogenic infection of the labyrinth Permanent loss of vestibular and cochlear functions.

5. Etiology Viral or bacterial infections Cholesteatoma Drug toxicity(Aminoglycosides) Head injury Tumour Vasculitis

6. Clinical manifestations Vestibular manifestations (vertigo) Cochlear manifestations (hearing loss) Nausea and vomiting

7. Pathology Infection usually occurs by one of three routes: – From the meninges(Internal auditory canal, Cochlear aqueduct or both) – From the middle ear space – Hematogenous spread

8. Investigation Based on symptoms, medical history and physical examination. Vestibular Testing Audiography CT(to rule out meningitis) and MRI ( to rule out acoustic neuroma, stroke, brain abscess, or epidural hematoma)

9. Treatment Conservative treatment: Antibiotics that cross the BBB to guard against meningitis. Labyrinthitis sedatives : Anti histamines: Meclizine, Dimenhydrate 25 mg TID, Cinnarizine: 25 mg TID, Phenothiazine derivatives: Prochlorperazine 5 mg TID, Promethazine: 25 mg TID. Benzodiazepines: Diazepam Antiemetics: Ondansetron

10. Anti histamines: These have antiemetic, anticholinergic and antihistaminic properties. It reduces the sensitivity of labyrinthine apparatus. Meclizine: Vertigo: 25 – 100 mg daily in divided doses used as needed for 2-3 days. Dimenhydrate : Vertigo: 25-50 mg PO Q8H

11. Phenothiazine derivatives: Antidopaminergic drugs that can depress reticular activating system(this effect may be responsible for relief of nausea and vomiting) Promethazine: Nausea and vomiting: 25 mg TID Prochlorperazine: Nausea and vomiting: 5 mg TID

12. Viral labyrinthitis: A short course of oral corticosteroids may be helpful in reducing labyrinthine inflammation and prevent the sequelae of labyrinthitis due to infectious or inflammatory causes. Currently, the role of antiviral therapy is not established. Bacterial labyrinthitis: Antibiotic treatment is based on culture and sensitivity. Antibiotic treatment should consist of broad spectrum antibiotic or combination therapy with CNS penetration until culture results are available.

13. Surgical treatment: Mastoid exploration is often required in chronic otitis media and cholesteatoma. Cortical mastoidectomy for control of suppurative otitis media or Radical mastoidectomy and labyrinthitis with dead labyrinth to prevent intracranial extension of infection. Surgical excision of cholesteatoma Incision and drainage Labyrinthectomy

14. References https://studylib.net Ear infections Diseases of Ear, Nose and Throat and head and neck surgery, PL Dhingra, S Dhingra. 6th edition Medscape