What are the causes of Meniere's disease?

Causes of Meniere's Disease

The exact cause of Meniere's disease remains unknown (idiopathic), but the disorder is believed to result from excessive fluid accumulation (endolymphatic hydrops) within the inner ear, with multiple contributing factors including genetic predisposition, autoimmune processes, infection, trauma, and vascular insufficiency. 1, 2

Primary Pathophysiologic Mechanism

Endolymphatic hydrops (EH) is the key histopathological hallmark of Meniere's disease, characterized by excessive buildup of endolymph fluid in the membranous labyrinth of the inner ear. 1, 2, 3 However, it is critical to understand that:

• Hydrops is not always present in patients with Meniere's symptoms, and hydrops alone does not always cause Meniere's disease 4
• The relationship between endolymphatic hydrops and clinical symptoms requires further clarification, as some patients develop symptoms early in EH development while others only after considerable accumulation 3
• Hydrops should not be considered the ultimate cause but rather a common pathologic endpoint of various underlying processes 4

Multifactorial Etiologic Contributors

The etiology of Meniere's disease involves several biological and bioenvironmental factors that may trigger or contribute to endolymphatic hydrops: 2, 3

Genetic Factors

• Genetic predisposition plays a role, with racial and familial clustering observed in some populations 5
• Genetic changes associated with hydropic changes in the inner ear have been documented 6

Autoimmune Mechanisms

• Autoimmune injury to the inner ear structures may contribute to disease development 2, 4
• Inflammatory changes targeting the endolymphatic system are implicated 6

Infectious Causes

• Prior viral or bacterial infections affecting the inner ear may trigger the disease process 2

Vascular/Ischemic Injury

• Ischemic injury to inner ear structures represents a potential causative mechanism 4
• Vascular insufficiency may compromise endolymph absorption 5

Anatomic/Mechanical Factors

• Emerging theories suggest saccular otoconia may block the endolymphatic duct and sac 2
• Deficiency in endolymph absorption at the endolymphatic sac level 5

Environmental Triggers

• Trauma to the inner ear 2
• Allergic factors 2

Important Clinical Distinctions

When evaluating causes, distinguish between: 5

• Meniere's disease: Idiopathic presentation with no identifiable underlying cause
• Meniere's syndrome: Secondary presentation with a known and well-established cause (such as post-traumatic, post-infectious, or autoimmune-related)

Common Pitfalls in Understanding Causation

• Do not assume hydrops equals Meniere's disease: Endolymphatic hydrops can exist without symptoms and symptoms can exist without demonstrable hydrops 4
• Avoid single-cause thinking: Meniere's disease likely represents a common endpoint of multiple anatomic or physiologic variables rather than a single disease entity 4
• Recognize the diagnostic challenge: The diagnosis remains one of exclusion, as no single causative factor can be identified in most cases 5