Elaborate 3D Analysis Reveals Insights into Ménière’s Disease

New Study Provides Understanding of Disease Process

Elaborate 3D analysis of the inner ear now, for the first time, provide insights into volume changes of special structures in sufferers of the so-called Ménière’s disease. The cause of this rare disease remains unclear to this day, although it leads to severe balance disorders, among other things. A successful collaboration between the Karl Landsteiner University of Health Sciences (Krems, Austria) and Harvard Medical School and Johns Hopkins University (both USA) has now provided new insights into the disease process. Using 3D-reconstructions of inner ears (based on anatomical slices) the international team was able to measure for the first time altered volumes of structures known as endolymphatic compartments in patients with the disease. A connection with the thickness of special membranes in the inner ear was also identified. In addition, further evidence was found concerning the functioning of a poorly understood structure in the inner ear (Bast’s valve).

Ménière’s Disease: A Challenging Condition

Nausea, spinning dizziness, tinnitus, and hearing loss – the so-called Ménière’s disease can really throw you off track. As rare as the disease is, so difficult is its treatment. In extreme cases, the vestibular nerve must be severed, or the vestibular organ surgically removed. For milder cases, antibiotic treatment has proven effective. This was confirmed by the team of the Karl Landsteiner University of Health Sciences (KL Krems) five years ago, despite an unexplained mechanism of action. The site of origin of the disease is the organ of equilibrium in the inner ear where, according to the latest findings of KL Krems, a pressure increase occurs in the case of disease. The effect on specific regions (endolymphatic compartments) of the inner ear has now been looked at in detail by the KL Krems team together with internationally renowned partners – and surprising things have been found.

3D Inner Ear Analysis

In addition to the cochlear duct, important parts of the inner ear are the cavernous extensions at the outer end of the cochlear duct known as sacculus and utriculus. In their study, now published in Otology & Neurotology, the team led by Dr. Béla Büki, Krems University Hospital (education and research site of KL Krems), compared inner ears of nine Ménière’s patients with those of ten healthy individuals. For this, digital 3D models were created on the basis of numerous anatomical slices. These were then used to determine the volumes of the above-mentioned compartments as well as the thickness of special membranes (Reissner’s membrane) and also the condition of the so-called Bast’s valve.

Key Findings

• The volume of the external cochlear duct and the sacculus was enlarged in affected patients.
• The volume of the utriculus had also increased in numerous, but less affected individuals.
• The thickness of Reissner’s membrane in the utriculus was thicker compared to the cochlear canal and sacculus in healthy subjects.
• The utriculus was less frequently dilated due to the thicker membrane, preventing volume expansion when endolymph pressure is increased.
• In cases where the utriculus was swollen, the Bast’s valve was open or the surrounding membrane was ruptured, suggesting a pressure-regulating function of the valve.

Conclusion

This successful collaboration of KL Krems with Harvard Medical School and Johns Hopkins University makes an important contribution to a better understanding of Ménière’s disease. The findings shed light on the volume changes and membrane thickness in the inner ear, as well as the potential role of the Bast’s valve. Further research in this area may lead to improved treatment options for patients with this debilitating condition.