Hearing loss usually fluctuates in the beginning stages and becomes more permanent in later stages. MD has a course of 5–15 years, and people generally end up with mild disequilibrium, tinnitus, and moderate hearing loss in one ear. Epidemiology
From 3 to 11% of diagnosed dizziness in neuro-otological clinics are due to MD. The annual incidence rate is estimated to be about 15 cases per 100,000 people and the prevalence rate is about 218 per 100,000, and around 15% of people with Menieres disease are older than 65. In around 9% of cases, a relative also had MD, indicating a genetic predisposition in some cases.The odds of MD are greater for people of white ethnicity, with severe obesity, and women. Several conditions are often comorbid with MD, including arthritis, psoriasis, gastroesophageal reflux disease, irritable bowel syndrome, and migraine. History
The condition is named after the French physician Prosper Menière, who in an 1861 article described the main symptoms and was the first to suggest a single disorder for all of the symptoms, in the combined organ of balance and hearing in the inner ear.The American Academy of Otolaryngology–Head and Neck Surgery Committee on Hearing and Equilibrium set criteria for diagnosing MD, as well as defining two subcategories – cochlear (without vertigo) and vestibular (without deafness).In 1972, the academy defined criteria for diagnosing MD as:
Fluctuating, progressive, sensorineural deafness
Episodic, characteristic definitive spells of vertigo lasting 20 minutes to 24 hours with no unconsciousness, vestibular nystagmus always present.
Syndactyly is a condition wherein two or more digits are fused together. It occurs normally in some mammals, such as the siamang and diprotodontia, but is an unusual condition in humans. The term is from Greek σύν, syn together and δάκτυλος, daktulos finger. Classification
Syndactyly can be simple or complex. In simple syndactyly, adjacent fingers or toes are joined by soft tissue. In complex syndactyly, the bones of adjacent digits are fused. The kangaroo exhibits complex syndactyly.Syndactyly can be complete or incomplete. In complete syndactyly, the skin is joined all the way to the tip of the involved digits. In incomplete syndactyly, the skin is only joined part of the distance to the tip of the involved digits.Complex syndactyly occurs as part of a syndrome (such as Apert syndrome) and typically involves more digits than simple syndactyly. Fenestrated syndactyly, also known as acrosyndactyly or terminal syndactyly, means the skin is joined for most of the digit but in a proximal area there are gaps in the syndactyly with normal skin. This type of syndactyly is found in amniotic band syndrome. Simple syndactyly can be full or partial, and is present at birth (congenital). In early human fetal development, webbing (syndactyly) of the toes and fingers is normal. At about 6 weeks of gestation, apoptosis takes place due to a protein named sonic hedgehog, also known as SHH, which dissolves the tissue between the fingers and toes, and the webbing disappears.