It most often starts in people 40 to 60 years old. Females are more commonly affected than males. After 5 to 15 years of symptoms, the episodes of the world spinning sometimes stop and the person is left with loss of balance, poor hearing in the affected ear, and ringing or other sounds in the affected ear or ears. Signs and symptoms
Ménières is characterized by recurrent episodes of vertigo, fluctuating hearing loss, and tinnitus; episodes may be preceded by a headache and a feeling of fullness in the ears. People may also experience additional symptoms related to irregular reactions of the autonomic nervous system. These symptoms are not symptoms of Menieres disease per se, but rather are side effects resulting from failure of the organ of hearing and balance, and include nausea, vomiting, and sweating, which are typically symptoms of vertigo, and not of Ménières. This includes a sensation of being pushed sharply to the floor from behind. Sudden falls without loss of consciousness (drop attacks) may be experienced by some people. Causes
The cause of Ménières disease is unclear, but likely involves both genetic and environmental factors. A number of theories exist including constrictions in blood vessels, viral infections, and autoimmune reactions. Mechanism
The initial triggers of Ménières disease are not fully understood, with a variety of potential inflammatory causes that lead to endolymphatic hydrops (EH), a distension of the endolymphatic spaces in the inner ear.
The deep tendon reflex is also lost in patients with DSMA1.Uterine growth retardation and poor foetal movement have been observed in severe DSMA1 cases. Causes
DSMA1 is caused by a genetic mutation in the IGHMBP2 gene (located on chromosome 11, locus 11q13.3), which codes the immunoglobulin helicase μ-binding protein 2. The role of the IGHMBP2 protein is not fully understood, but it is known to affect mRNA processing. The cellular mechanisms of the mutation, as well as the protein mechanisms disrupted by the mutation, are unknown. IGHMBP2 mutations are usually random mutations which are normally not passed down through generations. Pathophysiology
The pathology underlying the observable characteristics of DSMA1 is cell body degeneration of motor nerves. Specifically, the anterior horn α-motorneurons degenerate within the first six months of life leading to a variety of symptoms. Muscle deterioration increases at around 1–2 years of age, resulting in reduced motor function. The most severely affected muscles include facial muscles and the tongue (which may develop a twitch due to hypoglossal nerve paralysis). Reduced pain sensation and excessive sweating are sometimes observed. Non-ambulant patients may develop pressure ulcers, severe constipation, urinary incontinence, and (rarely) reflux nephropathy in the advanced stages of the disease. Diagnosis
The diagnosis for DMSA1 is usually masked by a diagnosis for a respiratory disorder. In infants, DMSAI is usually the cause of acute respiratory insufficiency in the first 6 months of life. The respiratory distress should be confirmed as diaphragmatic palsy by fluoroscopy or by electromyography.