Endolymphatic hydrops is a disorder of the
inner ear
The inner ear (internal ear, auris interna) is the innermost part of the vertebrate ear. In vertebrates, the inner ear is mainly responsible for sound detection and balance. In mammals, it consists of the bony labyrinth, a hollow cavity in the ...
. It consists of an excessive build-up of the
endolymph
Endolymph is the fluid contained in the membranous labyrinth of the inner ear. The major cation in endolymph is potassium, with the values of sodium and potassium concentration in the endolymph being 0.91 mM and 154 mM, respectively. ...
fluid, which fills the hearing and balance structures of the inner ear. Endolymph fluid, which is partly regulated by the endolymph sac, flows through the inner ear and is critical to the function of all sensory cells in the inner ear. In addition to water, endolymph fluid contains salts such as sodium, potassium, chloride and other electrolytes. If the inner ear is damaged by disease or injury, the volume and composition of the endolymph fluid can change, causing the symptoms of endolymphatic hydrops.
Symptoms
The symptoms of endolymphatic hydrops include the feeling of pressure or fullness in the ears,
hearing loss
Hearing loss is a partial or total inability to hear. Hearing loss may be present at birth or acquired at any time afterwards. Hearing loss may occur in one or both ears. In children, hearing problems can affect the ability to acquire spo ...
,
tinnitus
Tinnitus is a condition when a person hears a ringing sound or a different variety of sound when no corresponding external sound is present and other people cannot hear it. Nearly everyone experiences faint "normal tinnitus" in a completely ...
(ringing in the ears) and
balance problems. Individuals who have
Ménière's disease
Ménière's disease (MD) is a disease of the inner ear that is characterized by potentially severe and incapacitating episodes of vertigo, tinnitus, hearing loss, and a feeling of fullness in the ear. Typically, only one ear is affected in ...
have a degree of endolymphatic hydrops that is strong enough to trigger the symptoms of this disease, but individuals with endolymphatic hydrops do not always progress to Ménière’s disease.
[
]
Causes
Endolymphatic hydrops may occur as a result of trauma such as a blow to the head, infection, degeneration of the inner ear, allergies, dehydration and loss of electrolytes or in extremely rare circumstances a benign tumor
A benign tumor is a mass of Cell (biology), cells (tumor) that does not Cancer invasion, invade neighboring tissue or Metastasis, metastasize (spread throughout the body). Compared to Cancer, malignant (cancerous) tumors, benign tumors generally ...
such as an endolymphatic sac tumor. In many cases, it is not clear what causes the disorder. Ménière’s attacks occur when there is an increase in endolymphatic volume in the inner ear, causing a temporary leak in the membrane separating the perilymph (potassium poor fluid) and the endolymph (potassium rich fluid). The mix of these two fluids surrounding the vestibular sensory cells can lead to a temporary electrical blockade and loss of sensory function. The sudden change in the rate of the vestibular nerve
The vestibular nerve is one of the two branches of the vestibulocochlear nerve (the cochlear nerve being the other). In humans the vestibular nerve transmits sensory information from vestibular hair cells located in the two otolith organs (the u ...
firing results in a disturbance of signal processing in the corresponding brain
The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...
regions, and thus to acute sensations of imbalance, otherwise known as vertigo
Vertigo is a condition in which a person has the sensation that they are moving, or that objects around them are moving, when they are not. Often it feels like a spinning or swaying movement. It may be associated with nausea, vomiting, perspira ...
.
Diagnosis
Posthumous diagnosis can be done using petrous bone autopsy
An autopsy (also referred to as post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of deat ...
, although fixation artifacts during tissue preparation might artificially skew hydrops diagnosis rates. In-vivo
Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and ...
hydrops analysis can be performed using time delayed inner ear MRI
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and rad ...
with contrast agent
A contrast agent (or contrast medium) is a substance used to increase the contrast of structures or fluids within the body in medical imaging. Contrast agents absorb or alter external electromagnetism or ultrasound, which is different from radiop ...
.
Treatment
Low salt, low sugar diet and keeping hydrated.[
Caffeine should be avoided.]
References
{{Reflist
Diseases of inner ear
Neurological disorders
Audiology