Symptoms and Treatment Options for Acoustic Neuroma
Acoustic neuromas (vestibular schwannomas) primarily present with unilateral hearing loss, tinnitus, and balance disturbances, with treatment options including observation, stereotactic radiosurgery, and surgical resection based on tumor size, growth rate, and symptom severity. 1, 2
Common Symptoms
Primary Symptoms
- Unilateral sensorineural hearing loss - The most common initial symptom, typically gradual but occasionally sudden or fluctuating 3, 4
- Tinnitus - Often unilateral and persistent 3
- Dizziness/Disequilibrium - Balance disturbances without true vertigo 3
Later or Less Common Symptoms
- Facial numbness or paresthesia - Due to compression of the trigeminal nerve (CN V) 5
- Facial weakness - From compression of the facial nerve (CN VII) 3
- Headaches - More common with larger tumors 3
- Corneal reflex decrease - Found during physical examination 3
- Nystagmus - Observed in advanced cases 3
Atypical Presentations (17.6% of cases)
- Normal hearing with only tinnitus
- Sudden hearing loss with partial recovery
- Fluctuating hearing loss
- Trigeminal symptoms without hearing loss
- Orofacial paresthesia 5, 4
Diagnostic Evaluation
- MRI with gadolinium enhancement - Gold standard for diagnosis 2
- Audiometric evaluation - Shows asymmetric hearing loss with disproportionately poor speech discrimination 3
- Auditory brainstem response (ABR) - Highly sensitive (90.5%) even in patients with normal hearing 6
Treatment Options
1. Observation/Watchful Waiting
- Recommended for: Small tumors (Koos grades I-II), asymptomatic cases, elderly patients, slow growth 2, 7
- Protocol: Annual MRI follow-up for 5 years, with extended intervals if stable 2
- Most common approach: Used in 80.6% of cases in one study 7
2. Stereotactic Radiosurgery (SRS)
- Recommended for: Small to medium tumors when preservation of facial nerve and hearing function is the primary goal 2
- Advantages: Lower risk profile than surgery with good tumor control 2
- Considerations: Appropriate for elderly patients with slow-growing tumors and mild hearing loss 7
3. Surgical Resection
- Recommended for: Large tumors causing brainstem compression, rapid growth, significant hearing deterioration 2, 7
- Surgical approaches:
- Goal: Total or near-total resection when possible 2
4. Combined Approach
- Partial resection followed by SRS - Increasingly popular for large tumors 2
- Advantages: Superior outcomes for facial nerve function and hearing preservation compared to total resection alone 2
Post-Treatment Monitoring
- Annual MRI and audiometry for 5 years
- Extended intervals thereafter if stable
- Additional MRI controls at 2,5, and 10 years post-surgery 2
- Long-term monitoring essential as 7.2% of tumors may exhibit growth after a stable period of 5 years 2
Important Considerations
- Treatment decisions are primarily influenced by tumor size, growth rate, patient age, and hearing status 7
- High-volume centers with experienced surgical teams yield better outcomes 2
- Intraoperative monitoring is essential for preservation of neurological function during surgery 2
- Quality of life impact should be considered, as poor outcomes are more likely in patients with large, symptomatic tumors that were resected 2
Common Pitfalls to Avoid
- Delayed diagnosis - Atypical presentations may lead to larger tumors and more complications 5
- Inadequate follow-up - Even completely resected tumors require long-term monitoring 2
- Treatment at low-volume centers - Associated with poorer outcomes 2
- Overlooking early symptoms - Especially in patients with normal hearing but other symptoms like tinnitus or imbalance 4