A labyrinthine fistula is an abnormal opening in the inner ear. This can result in leakage of the perilymph into the middle ear. This includes specifically a perilymph fistula (PLF), an abnormal connection between the fluid of the inner ear and the air-filled middle ear. This is caused by a rupture of the round window or oval window ligaments separating the inner and middle ear.Another type of labyrinthine fistula is the superior semicircular canal dehiscence, which allows the inner ear to be influenced by the intracranial pressure directly. Signs and symptoms
PLF usually induces one or all the following pathological states: aural fullness, fluctuating or non-fluctuating hearing loss, tinnitus and dizziness, which may sometimes include vertigo and balance disorders. Cause
Labyrinthine fistula can be both congenital or develop over time with the thinning of the otic capsule by the persistent pulsations of the intracranial pressures against the bones of the skull. Finally, disease conditions—for example cholesteatoma—can result in a labyrinthine fistula. Traumatic events, with excessive pressure changes to the inner ear such as in scuba diving, head trauma, or an extremely loud noise can lead to rupture and leakage. The most common causes of PLF are: head or ear traumas, rapid increases of intracranial pressure, congenital abnormalities (in children), complication of stapedectomy, barotraumas (e.g. slap/suction, scuba diving, skydiving, strong and repetitive nose-blowing or sneezing, heavy lifting). Diagnosis
When diagnosing, PLF should be differentiated from Ménières disease. Tympanostomy has been reported to be a way to diagnose and cure PLF.
Atrophic gastritis is often a precursor to gastric cancer.Although the exact role of Helicobacter pylori infection in PA remains controversial, evidence indicates H. pylori is involved in the pathogenesis of the disease. A long-standing H. pylori infection may cause gastric autoimmunity by a mechanism known as molecular mimicry. Antibodies produced by the immune system can be cross-reactive and may bind to both H. pylori antigens and those found in the gastric mucosa. The antibodies are produced by activated B cells that recognise both pathogen and self-derived peptides. The autoantigens believed to cause the autoreactivity are the alpha and beta subunits of the sodium-potassium pump. In a study, B12 deficiency caused by Helicobacter pylori was positively correlated with CagA positivity and gastric inflammatory activity, rather than gastric atrophy. Less commonly, H. pylori and Zollinger-Ellison syndrome may cause a form of nonautoimmune gastritis that can lead to pernicious anemia.Impaired B12 absorption can also occur following gastric removal (gastrectomy) or gastric bypass surgery. In these surgeries, either the parts of the stomach that produce gastric secretions are removed or they are bypassed. This means intrinsic factor, as well as other factors required for B12 absorption, are not available. However, B12 deficiency after gastric surgery does not usually become a clinical issue. This is probably because the body stores many years worth of B12 in the liver and gastric surgery patients are adequately supplemented with the vitamin.Although no specific PA susceptibility genes have been identified, a genetic factor likely is involved in the disease.