– an abnormal inner ear fluid balance caused by a malabsorption in the endolyphatic sac or blockage in the endolyphatic duct.
– chronic disease caused by an increase in endolymphatic pressure High in males (40-60 years old)
* fluctuating, progressive sensorineural hearing loss
* tinnitus or a roaring sound
* feeling of pressure or fullness in the ear
* episodic, incapaciating vertigo (severe dizziness)
* nausea and vomiting
The endolymph and perilymph (ie, fluids that fill the chambers of the inner ear) are separated by thin membranes that house the neural apparatus of hearing and balance. Fluctuations in pressure stress these nerve-rich membranes, causing hearing disturbance, tinnitus, vertigo, imbalance, and a pressure sensation in the ear. Attacks of hydrops probably are caused by an increase in endolymphatic pressure, which, in turn, causes a break in the membrane that separates the perilymph (potassium-poor extracellular fluid) from the endolymph (potassium-rich intracellular fluid).
The resultant chemical mixture bathes the vestibular nerve receptors, leading to a depolarization blockade and transient loss of function. The sudden change in the rate of vestibular nerve firing creates an acute vestibular imbalance (ie, vertigo). The physical distention caused by increased endolymphatic pressure also leads to a mechanical disturbance of the auditory and otolithic organs.
Because the utricle and saccule are responsible for linear and translational motion detection (as opposed to angular and rotational acceleration), irritation of these organs may produce nonrotational vestibular symptoms. This physical distention causes mechanical disturbance of the organ of Corti as well. Distortion of the basilar membrane and the inner and outer hair cells may cause hearing loss and/or tinnitus.
Since the apex of the cochlea is wound much tighter than the base, the apex is more sensitive to pressure changes than the base. This explains why hydrops preferentially affects low frequencies (at the apex) as opposed to high frequencies (at the relatively wider base). Symptoms improve after the membrane is repaired as sodium and potassium concentrations revert to normal. Various extrinsic mechanisms are thought to contribute to the development of endolymphatic hydrops, including infection, trauma, and allergens.
Diet: Low salt or Sodium
* Meclizine (Antivert)-suppresses the vestibular system
* Diazepam (Valium)-may be used in acute instances to help control vertigo. Antiemetics
* Promethazine (Phenergan)-suppositories help control the nausea and vomiting and the vertigo because of their antihistamine effect. Diuretic therapy
* (hydrochlorothiazine (diazide), triamterene (dyrenium)) -may relieve symptoms by lowering the pressure in the endolymphatic system.
Endolymphatic sac decompression or shunting
-theoretically equalizes the pressure in the endolymphatic space.
-a shunt or drain is inserted in the endolymphatic sac through a postauricular incision. Vestibular Nerve Sectioning
-cutting the nerve and prevents the brain from receiving input from the semicircular canal Labyrinthectomy
– surgical removal of the membranous labyrinth through the oval window or through the mastoid bone
Baldonado, Nicasio Jr. J.