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Rapid protein test for perilymph fistula
1Ear Research Foundation, Sarasota, FL 34239.
Abstract:
The existence of a perilymph fistula may be difficult to prove preoperatively or at surgery, except in obvious cases in which perilymph can be seen coming out of the inner ear around the stapes footplate or round window niche. Some surgeons doubt the common occurrence of spontaneous perilymph fistula. Most surgeons believe that a perilymph fistula is rare and is produced by some type of trauma and pressure change to the inner ear fluids. Analysis of fluid collected from the oval window area and round window niche may be a great help in confirming or disproving the diagnosis of perilymph fistula. After a myringotomy or tympanotomy, fluid collected in micropipets from the oval window or round window area is analyzed for protein concentration, using rapid protein indicator paper. The original technique was developed in the 1960's to analyze the inner ear fluid as a diagnostic procedure (i.e., diagnostic labyrinthotomy) in acoustic neuroma suspects. Normal perilymph has a protein content of approximately 200 mg %, which turns the indicator paper light green, whereas serum or transudate has a protein content of approximately 7000 mg %, which turns the indicator paper dark green. The protein concentration is determined by comparing the color of the indicator paper with the color developed by known protein standards. A middle ear tap may help avoid negative middle ear exploration for perilymph fistula and helps document the presence or absence of perilymph after the exploration.
Insights
Diagnosing perilymph fistula can be challenging. Analyzing inner ear fluid protein concentration using indicator paper helps confirm or rule out this condition, potentially avoiding unnecessary surgery.
Area of Science:
- Otolaryngology
- Neurosurgery
- Audiology
Background:
- Perilymph fistula diagnosis is often difficult, especially in non-obvious cases.
- Spontaneous perilymph fistulas are considered rare by many surgeons, often linked to trauma or pressure changes.
- Accurate diagnosis is crucial for appropriate patient management.
Purpose of the Study:
- To evaluate the utility of middle ear fluid protein analysis for diagnosing perilymph fistula.
- To establish a reliable method for confirming or excluding perilymph fistula presence.
- To potentially reduce negative middle ear explorations.
Main Methods:
- Fluid samples collected from the oval and round window niches via micropipets after myringotomy or tympanotomy.
- Analysis of protein concentration using rapid protein indicator paper, comparing color changes to known standards.
- Original technique adapted from diagnostic labyrinthotomy procedures used for acoustic neuroma suspects.
Main Results:
- Normal perilymph protein content is approximately 200 mg%, indicated by light green on indicator paper.
- Serum or transudate protein content is around 7000 mg%, indicated by dark green.
- Protein analysis provides objective data to support or refute perilymph fistula diagnosis.
Conclusions:
- Middle ear fluid protein analysis is a valuable tool for diagnosing perilymph fistula.
- This method can help avoid unnecessary surgical interventions for suspected perilymph fistula.
- The technique offers a reliable way to document the presence or absence of perilymph.
