Dr. Jorge Torales
Neurosurgeon · Skull base and spinal endoscopy
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Skull base
Acoustic neuroma (vestibular schwannoma)
Acoustic neuromas are benign tumours of the vestibular nerve. Skull base surgery allows preservation of the facial nerve and, in selected tumours, also hearing.
What is it?
Acoustic neuroma (vestibular schwannoma)
Acoustic neuromas, also known as vestibular schwannomas, are benign tumours that grow in the myelin sheath of the vestibular nerve. They account for 8% of intracranial tumours and 80% of cerebellopontine angle tumours. Initial symptoms are progressive unilateral hearing loss, tinnitus and unsteadiness. Treatment may be observation, radiosurgery or microsurgery depending on size and residual hearing.
8%
of intracranial tumours in adults
>95%
facial nerve preservation in specialist centres
40-70%
useful hearing preservation in tumours <2 cm
Symptoms
When to consult a neurosurgeon?
Symptoms evolve slowly over years:
- Progressive unilateral hearing loss (most frequent symptom, 95% of cases)
- Tinnitus (ringing or buzzing) in the affected ear
- Unsteadiness or a sensation of imbalance
- Vertigo (less frequent, usually mild)
- Facial numbness in large tumours affecting the trigeminal nerve
- Headache and signs of raised intracranial pressure in large tumours (>3 cm)
Urgent attention: Sudden or rapidly progressive hearing loss requires urgent audiometry and MRI.
Treatments
Which techniques do we use?
Retrosigmoid approach
The preferred technique for neurosurgeons. Allows facial nerve preservation and, in tumours of 2 cm or less with useful preoperative hearing, also hearing preservation in 40-70% of cases.
Translabyrinthine approach
Technique of choice in tumours with non-functional hearing. Better facial nerve preservation, at the cost of hearing.
Middle fossa approach
Indicated in small intracanalicular tumours when hearing preservation is the primary goal.
Stereotactic radiosurgery
Gamma Knife or CyberKnife for tumours <3 cm or as treatment for residual tumour. Tumour control of 90-95% at 10 years, but with a relevant side effect: most patients lose hearing within 2 years of follow-up. It is therefore not the first option when hearing preservation is a realistic goal.
Observation (wait-and-scan)
In small tumours (<1.5 cm) that are asymptomatic or cause mild symptoms, especially in patients over 65. Annual MRI.
Facial nerve monitoring
Continuous intraoperative EMG throughout surgery to identify and protect the facial nerve in real time.
Our protocol
How we approach each case
Each case is studied with contrast-enhanced MRI (CISS/FIESTA sequences), pure-tone and speech audiometry, auditory brainstem-evoked potentials (ABR) and facial nerve assessment (House-Brackmann). The therapeutic decision is made on an individual basis considering size, residual hearing, patient age and preferences. When surgery is undertaken, continuous facial nerve monitoring (EMG) is used and, when appropriate, cochlear nerve monitoring as well. Reconstruction of the surgical defect uses autologous abdominal fat and bone cement to prevent CSF fistula.
Presentation with hydrocephalus
It is not uncommon for acoustic neuroma to present with hydrocephalus due to obstruction of normal cerebrospinal fluid flow. In that case, the first step is treating the hydrocephalus: usually with a temporary external ventricular drain and, depending on the clinical course, consideration of a permanent drain (ventriculo-peritoneal shunt). Once hydrocephalus is controlled, neuroma surgery is planned.
Perioperative protocol
How we organise each case
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1 · Preoperative workup
MRI of the internal auditory canal with and without contrast, pure-tone and speech audiometry, auditory evoked potentials (ABR), vestibular assessment. Koos scale and Hannover classification.
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2 · Surgery
Retrosigmoid, translabyrinthine or middle fossa approach depending on size and hearing preservation goal. Continuous facial and cochlear nerve monitoring. Microsurgery with functional preservation as the priority.
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3 · Immediate postoperative period
ICU for 24h. Postoperative MRI within 72h. Facial assessment with House-Brackmann scale. Follow-up audiometry.
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4 · Discharge and follow-up
Discharge after 4-6 days. Vestibular rehabilitation and, if facial weakness is present, specific physiotherapy. Annual MRI follow-up for at least 5 years.
Team
Neurosurgeons who treat this condition
Dr. Abel Ferrés Pijoan
Neurosurgeon · Spine, neuro-oncology and skull base
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Outcomes
Prognosis and recovery
Facial nerve preservation in specialist centres exceeds 95% in tumours <2 cm and 85% in large tumours. Even when postoperative facial palsy occurs, in most cases it is temporary and recovers progressively over the following months, including in large tumours. Surgical mortality is below 1%. Typical hospital stay is 5-7 days and return to work occurs between 6 and 8 weeks. Balance adapts progressively over 4-8 weeks (vestibular compensation).
On hearing: no technique can restore hearing that was already lost before surgery. The realistic goal is preserving existing hearing, not restoring it. In tumours <2 cm with useful preoperative hearing, approaches that spare the cochlear nerve achieve hearing preservation in 40-70% of cases.
Frequently asked questions
Answers to your questions
What is an acoustic neuroma?
It is a benign tumour that grows in the myelin sheath of the vestibular nerve (balance), inside the internal auditory canal or at the cerebellopontine angle. It is also called vestibular schwannoma. It accounts for 8% of intracranial tumours in adults.
Can hearing be preserved with surgery?
In tumours smaller than 2 cm with useful preoperative hearing, the retrosigmoid or middle fossa approach allows hearing preservation in 40-70% of cases. In large tumours with already compromised hearing, the main goal is facial nerve preservation.
What are the alternatives to surgery?
In small tumours (<2-3 cm), observation with annual MRI or stereotactic radiosurgery (Gamma Knife) may be indicated. The decision depends on size, age, residual hearing and patient preferences.
What are the risks of surgery?
The main risks are facial palsy (transient in 20-30%, permanent in 3-10% with appropriate technique), ipsilateral hearing loss, cerebrospinal fluid fistula (3-5%) and chronic postoperative headache.
How long does recovery take?
Typical hospital stay of 5-7 days. Balance adapts progressively over 4-8 weeks (vestibular compensation). Facial function may take 6-12 months to recover if postoperative paresis occurred.
References
What the clinical guidelines say
"Treatment of vestibular schwannoma requires a multidisciplinary team comprising neurosurgery, otology and intraoperative neurophysiology. Functional outcomes are directly proportional to the volume and specialisation of the centre."
"Observation is a reasonable strategy in small tumours that are asymptomatic or cause only mild symptoms."
Bibliography
Scientific references consulted
Studies and clinical guidelines on which we base our approach to this condition.
- Goldbrunner R. et al. EANO guideline on the diagnosis and treatment of vestibular schwannoma. Neuro-Oncology. 2020. View publication
- Carlson ML, Link MJ. Vestibular Schwannomas. N Engl J Med. 2021. View publication
- Koos WT. et al. Neurotopographic considerations in the microsurgical treatment of small acoustic neurinomas. J Neurosurg. 1998. View publication
- Pollock BE. et al. Patient outcomes after vestibular schwannoma management. Neurosurgery. 2006. View publication
- House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg. 1985. View publication
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What our patients say
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"I arrived with a glioma I had been told was inoperable. Here they reviewed it at the tumour board and offered me a plan. The surgery was a success. Four years on, I am well."
Cervical disc herniation
"For years I had a cervical disc herniation, operated on by another team with no improvement. Minimally invasive surgery gave me back my mobility and took the pain away."
International patient
"I travelled from outside Spain. The team reviewed my case before I came and gave me a clear plan. Caring people and impeccable technique."
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Acoustic neuroma assessment
Send us your MRI and audiometry. We review your case in our skull base board and advise on the optimal strategy: observation, radiosurgery or surgery.