Delayed and Progressive Hearing Loss after Microvascular Decompression of Cranial Nerves

Abstract

An unusual case of unilateral delayed and progressive hearing loss following a microvascular decompression operation on cranial nerves V, VII, and VIII on the left side is reported. Preoperative and postoperative audiologic evaluation revealed a mild high-frequency hearing loss for both ears, normal thresholds for the acoustic middle ear reflex response, and normal brain stem auditory evoked potentials. Three years after this microvascular decompression procedure, the patient noticed slowly decreasing hearing in her left ear, and subsequent serial audiograms revealed a progressive sensorineural hearing loss and a decrease in her speech discrimination score. Brain stem auditory evoked potentials showed progressive changes. Because of the patient's increasing symptoms of vertigo and tinnitus in the left ear, reexploration of the eighth cranial nerve was performed 5½ years after the initial procedure. This second operation revealed reactive tissue around the eighth cranial nerve that was atrophic and yellow. We interpret the delayed and progressive hearing loss to be a result of reactive scar tissue and progressive atrophy of the auditory nerve.

Keywords

brain stem auditory evoked potentials microvascular decompression progressive hearing loss

Get full access to this article

View all access options for this article.

References

Møller

. The cranial nerve vascular compression syndrome: I. A review of treatment. Acta Neurochir (Wien) 1991; 113: 18–23.

Apfelbaum

. Surgical management of disorders of the lower cranial nerves. In: Schmidek

Sweet

, eds. Operative neurosurgical techniques: Indications, methods and results. Vol 2. Orlando, Fla: Grune and Stratton, 1988: 1097–109.

Jannetta

. Observations on the etiology of trigeminal neuralgia, hemifacial spasm, acoustic nerve dysfunction, and glossopharyngeal neuralgia. Definite microsurgical treatment and results in 117 patients. Neurochirurgia(Stuttg) 1977; 20: 145–54.

Møller

. Disabling positional vertigo. In: Myers

Bluestone

Brackmann

Krause

, eds. Advances in otolaryngology-head and neck surgery. Vol 4. Chicago, Ill: Mosby-Year Book, 1990: 81–106.

Møller

. Cranial nerve dysfunction syndromes: Pathophysiology of microvascular compression. In: Barrow

, ed. Surgery of cranial nerves of the posterior fossa. Park Ridge, Ill: American Association of Neurological Surgeons, 1993: 105–29. (Neurosurgical topics; vol 13.).

Møller

Jannetta

Sekhar

. Diagnosis and surgical treatment of disabling positional vertigo. J Neurosurg 1986; 64: 21–8.

Møller

Jannetta

Jho

Sekhar

. Microvascular decompression of the eighth nerve in patients with disabling positional vertigo: Selection criteria and operative results in 207 patients. Acta Neurochir (Wien) 1993; 125: 75–82.

Møller

. Results of microvascular decompression of the eighth nerve as treatment for disabling positional vertigo. Ann Otol Rhinol Laryngol 1990; 99: 724–9.

Møller

Jannetta

Jho

. Vascular decompression surgery for severe tinnitus: Selection criteria and results. Laryngoscope 1993; 103: 421–7.

10.

Møller

. Audiometric abnormalities in hemifacial spasm. Audiology 1985; 24: 396–405.

11.

Møller

. Does intraoperative monitoring of auditory evoked potentials reduce incidence of hearing loss as a complication of micro vascular decompression of cranial nerves?. Neurosurgery 1989; 24: 257–63.

12.

Fritz

Schafer

Klein

. Hearing loss after microvascular decompression for trigeminal neuralgia. J Neurosurg 1988; 69: 367–70.

13.

Sekiya

Møller

. Cochlear nerve injuries caused by cerebellopontine angle manipulations. An electrophysiological and morphological study in dogs. J Neurosurg 1987; 67: 244–9.

14.

Møller

. Evoked potentials in intraoperative monitoring. Baltimore, Md: Williams and Wilkins, 1988.

15.

McDonnell

Jabban

Spinella

Mueller

Klara

. Delayed hearing loss after neurovascular decompression. Neurosurgery 1990; 27: 997–1003.

16.

Schwartz

Gennarelli

. Delayed sensorineural hearing loss following uncomplicated neurovascular decompression of the trigeminal root entry zone. Am J Otol 1990; 11: 95–8.

17.

Jannetta

. Vascular decompression in trigeminal neuralgia. In: Samii

Jannetta

, eds. The cranial nerves: Anatomy, pathology, pathophysiology, diagnosis, treatment. New York, NY: Springer-Verlag, 1981: 331–40.

18.

Møller

. Loss of auditory function in microvascular decompression for hemifacial spasm: Results in 143 consecutive cases. J Neurosurg 1985; 63: 17–20.