Related Experiment Video
Updated: Jun 24, 2026
06:59
Intrathecal Application of a Fluorescent Dye for the Identification of Cerebrospinal Fluid Leaks in Cochlear Malformation
Published on: February 29, 2020
8.6K
Otopathologic Analysis of Patterns of Postmeningitis Labyrinthitis Ossificans
Danielle R Trakimas1, Renata M Knoll2, Melissa Castillo-Bustamante2
1Department of Otolaryngology, Johns Hopkins Medical School, Baltimore, Maryland, USA.
Summary
Labyrinthitis ossificans (LO) after meningitis causes bone growth in the cochlea, complicating cochlear implantation. Early fibrosis appears within weeks, while ossification takes years, often starting at the round window membrane.
Area of Science:
- Otopathology
- Cochlear Anatomy
- Histopathology
Background:
- Labyrinthitis ossificans (LO) is a potential complication following meningitis.
- LO can impede electrode insertion during cochlear implantation.
- Histopathology offers higher sensitivity than imaging for LO detection.
Purpose of the Study:
- To investigate the timing and location of intracochlear tissue formation after meningitic labyrinthitis (ML).
- To characterize the progression of ossification in human temporal bone specimens.
Main Methods:
- Retrospective review of 51 temporal bone specimens with a history of bacterial ML.
- Histological evaluation of intracochlear tissue formation in the scala tympani (ST) and scala vestibuli (SV).
- Quantification of spiral ganglion neuron counts.
Main Results:
- Fibrosis was observed as early as 1.5 weeks post-ML; ossification occurred years later.
- All LO cases exhibited ossification of the ST at the round window membrane (RWM), extending into the basal turn.
- Spiral ganglion neuron counts were reduced compared to age-matched controls.
Conclusions:
- Post-meningitic LO involves RWM ossification with extension into the ST and variable SV involvement.
- Identifying a patent basal turn beyond RWM ossification in the ST is crucial for successful cochlear implant electrode insertion.
Related Concept Videos
01:18Viral Meningitis
Viral meningitis is the most common form of meningitis and is often referred to as aseptic meningitis to indicate the absence of bacterial involvement. It is generally milder than bacterial meningitis, with symptoms including fever, headache, stiff neck, drowsiness, nausea, photophobia, and vomiting. Rarely, more severe manifestations or death may occur. Common causative agents include enteroviruses, particularly coxsackie A and B viruses and echoviruses, all members of the Enterovirus genus...
01:22Bacterial Meningitis I: Introduction
Bacterial meningitis is a severe, life-threatening inflammation of the meninges, particularly the pia mater and arachnoid mater, affecting the subarachnoid space, ventricles, and cerebrospinal fluid (CSF). If untreated, it can lead to significant neurological complications or death.Causative AgentsCommon pathogens vary with age and immune status. In adults, major organisms include Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Streptococcus agalactiae (group B...
01:26Bacterial Meningitis II: Pathophysiology
Bacterial meningitis typically begins when pathogens such as Neisseria meningitidis and Streptococcus pneumoniae colonize the nasopharynx and invade the bloodstream. This process is facilitated by bacterial virulence factors, such as polysaccharide capsules, which resist phagocytosis and complement-mediated killing. Less commonly, bacteria reach the central nervous system via contiguous spread from infections like otitis media or sinusitis, through congenital or acquired dural defects, or...
01:26Encephalitis ll: Pathophysiology
Encephalitis is inflammation of the brain parenchyma caused by direct viral invasion or immune-mediated mechanisms triggered by infections or tumors. Both processes lead to neuronal injury, disrupted neurotransmission, and diverse neurological symptoms, often with overlapping clinical and pathological features.Autoimmune EncephalitisIn autoimmune encephalitis, antibodies target neuronal antigens on cell surfaces, synapses, or within neurons. A key example is anti-NMDAR encephalitis, which can...
01:26Brain Abscess l: Introduction
A brain abscess is a focal, intracerebral infection characterized by a localized collection of pus within the brain parenchyma, resulting from microbial invasion and the body’s inflammatory response. It progresses through stages: early and late cerebritis, followed by early and late capsule formation, reflecting tissue destruction, immune response, and eventual encapsulation.Etiology and PathogenesisCausative organisms vary with source and host factors, often involving polymicrobial infections,...