Vestibular schwannoma: 825 cases from a 25-year experience

Abstract

Summary Introduction: Acoustic nerve tumors have been recognized as a clinico-pathologic entity for at least 200 years, and they represent 90% of cerebellopontine angle diseases. Histologically, the tumors are derived from Schwann cells of the myelin sheath, with smaller tumors consisting of elongated palisade cells, while in large tumors, cystic degeneration can be found in the central areas, possibly due to deficient vascularization. We retrospectively reviewed 825 cases of vestibular schwannomas, reported between January 1984 and August 2006, in which the patients underwent surgery to remove the tumor. Objective: To evaluate signs, symptoms, aspects of clinical diagnosis, including the results of audiological and imaging studies, and surgical techniques and complications. Methods: A retrospective chart review. The medical records of all patients undergoing surgical treatment for schwannoma during the period indicated were reviewed. Results and Conclusion: Hearing loss was the first symptom reported in almost all cases, and tumor size was not proportional to the impairment of the auditory threshold. The surgical techniques allowed safe preservation of facial function. In particular, the retrolabyrinthine route proved useful in small tumors, with 50% preservation of hearing.

Facial nerve function and hearing after microsurgical removal of sporadic vestibular schwannomas in a population-based cohort

“…Hearing impairment is the most common initial symptom of VS and the natural course has been shown to lead to nonseviceable hearing in 50% of patients over a 5-year period in patients with good initial hearing [39,42,53]. Accordingly, hearing is impaired in most patients already before surgery.…”

Vestibular Schwannoma Presenting as Oral Dysgeusia: An Easily Missed Diagnosis

“…Vestibular schwannomas, also termed acoustic neuromas, are benign tumours of the vestibulocochlear nerve [ 7 – 14 ]. They arise from the Schwann cells which comprise the myelin sheath surrounding the vestibular branch of the eighth cranial nerve [ 14 ] and account for 80–90% of cerebellopontine angle tumours [ 7 , 8 , 11 , 12 ]. The aetiology of vestibular schwannoma is unknown.…”

“…Compression of the trigeminal nerve can lead to facial hypoesthesia, which is found in 7–26% of patients with vestibular schwannoma [ 9 , 15 ], and usually begins in the region of the anterior mandible [ 9 ]. In 2.2–17% of patients the facial nerve is affected, due to the close anatomical relationship of the facial nerve to the vestibulocochlear nerve in the region of the cerebellopontine angle [ 9 , 11 , 15 ]. Pressure on the motor fibres can lead to facial weakness; and involvement of the sensory branch, the nervus intermedius which receives special sensory taste information from the anterior two-thirds of the tongue, via the chorda tympani, can have an impact on taste [ 15 , 16 ].…”

Diagnosis of retrocochlear lesions with emphasis on expansion of the cerebellopontine angle

“…The third most common initial symptom is subclinical tinnitus without any detectable hearing impairment, which occurs in about 6-8% of the cases of CPA tumours (overall, tinnitus occurs in about 70% of all patients with CPA tumours) (ref. 3 ). Only 2-4% of the patients with CPA tumours have a different presenting symptom, usually because that symptom is due to a pre-existing disorder that can cause hearing loss and that happens to co-exist with the problem resulting from compression of the nerve and its vascular supply due to a CPA tumour, e.g.…”