Stria vascularis and cochlear hair cell changes in syphilis: A human temporal bone study

Area of Science:

• Otolaryngology
• Pathology
• Infectious Diseases

Background:

• Syphilis is a systemic infection that can affect various organs, including the inner ear.
• Cochlear structures, such as hair cells and the stria vascularis, are crucial for hearing function.
• Damage to these structures can lead to sensorineural hearing loss.

Purpose of the Study:

• To investigate the pathological changes in the stria vascularis and cochlear hair cells in human temporal bone samples from patients with syphilis.
• To compare these changes with those in age-matched controls without syphilis.

Main Methods:

• Human temporal bone samples from 8 patients with syphilis and 9 controls were examined.
• Conventional light microscopy was used to measure the mean area of the stria vascularis.
• Cytocochleograms were used to determine the mean percentage of cochlear hair cell loss.

Main Results:

• Syphilis was associated with endolymphatic hydrops in 61.5% of cases.
• No significant difference in the mean stria vascularis area was observed between syphilis and control groups.
• Significant loss of outer and inner cochlear hair cells was found in patients with syphilis, particularly in the apical and basal/middle turns, respectively.
• Complete or partial loss of the organ of Corti was observed in 7 samples from the syphilis group.

Conclusions:

• Syphilis can cause significant cochlear hair cell loss and damage to the organ of Corti.
• Cochleosaccular hydrops is a common finding in syphilis-affected temporal bones.
• The stria vascularis area does not appear to be altered by syphilis.