The most common symptoms of an acoustic neuroma are gradual hearing loss and a feeling of fullness in the affected ear, tinnitus (ringing, roaring, hissing, or buzzing in the ear), imbalance or dizziness, and possibly facial numbness or tingling. Hearing loss is the first obvious symptom for the great majority of patients. Early diagnosis of acoustic neuroma is a challenge, however, since symptoms can vary so much and there is no typical symptomatic sequence. There have even been cases of very large tumors that were symptomless until the acute stage. Misdiagnosis is also not unusual. Gradual hearing loss, for example, might be attributed mistakenly to aging or to the buildup of earwax. Or again, a sudden hearing loss, which sometimes occurs, could be misdiagnosed as Meniere’s disease, an abnormality of the middle ear that also has tinnitus as a symptom. Since acoustic neuromas are relatively rare, a family physician may actually never encounter one in his/her practice. Still, a doctor confronted with a case of hearing loss, plus tinnitus, and possibly one of the other brain tumor symptoms mentioned above, would be very likely to suspect an acoustic tumor and recommend an MRI.
Some differences in the pre-diagnosis experience with acoustic neuroma for ANA/NJ members will help to illustrate the great variability there can be in symptoms. As for example:
• A very gradual hearing loss in the right ear was the only problem Jack S experienced in the 10 years before an MRI finally revealed a 2.0 cm acoustic neuroma. There was no tinnitus, no noticeable imbalance. Jack was 55 when diagnosed.
•Three years before diagnosis at age 38, Audrey G began to experience hearing loss, followed after two years by an annoying facial numbness. Imbalance was also a symptom of this 2.4 cm acoustic neuroma, although her doctor had to convince her of this by testing.
• Dave B, who was diagnosed at age 55, understands now that he had acoustic neuroma symptoms for 30 years. The beginning symptoms were hearing loss and tinnitus in one ear. The hearing deteriorated gradually over 25 years, until 5 years before diagnosis it was down 80%. Specialists said the most likely cause was nerve damage due to Dave’s hunting. Also at 5 years before diagnosis, Dave began to experience occasional (2-3 per month) but not severe headaches of 3-4 hours duration. The headaches and hearing loss were the two symptoms present when a new doctor ordered a CT scan followed by an MRI. The diagnosis was a 2.0 x 3.0 cm acoustic neuroma pressing on the brainstem.
• For three years before her diagnosis at age 53, Alice L experienced a wide range of symptoms, as well as some extra problems. Initial symptoms that sent her to two different doctors were a reduction in hearing in the left ear, earache, imbalance and extreme fatigue. Both doctors diagnosed a problem with the eustachian tube. A herniated disc in the neck then complicated matters, but when the doctor who treated this learned of the hearing loss, he immediately sent Alice to an ENT. By this time, additional symptoms were disequilibrium (two bad falls) and facial numbness and pain. The MRI revealed a 2.0+ cm acoustic neuroma pressing on the brain-stem.
• Sharon K (age 23 at diagnosis) has described her unusual experience over an eight-year period. Her symptoms were “typical” for a small acoustic neuroma, i.e., gradual hearing loss and tinnitus in the left ear. The hearing loss started first and ringing in the ear began about two years later. There were no other symptoms before an MRI revealed a 3.0 mm tumor. The surprise in surgery was that what was diagnosed as an acoustic neuroma turned out to be a small hemangioma. This benign blood vessel tumor was of the type that could not safely be removed. The surgeons made room for it to grow and left it to be monitored by MRI.
MRI - The Diagnostic Tool for Acoustic Neuroma Detection
Magnetic Resonance Imaging (MRI), once brain tumor symptoms of AN have been identified, is the most important diagnostic tool for acoustic neuroma. The use of this remarkable technology beginning in 1985 has significantly advanced early detection of even the smallest tumors, and MRI’s ability to produce a clear, three-dimensional image has greatly improved treatment planning as well. The MRI scan is a painless procedure lasting about 40 to 45 minutes. No radiation is involved in the procedure. A contrast agent (gadolinium) is administered intravenously so that the tumor will appear on the scan as a bright white (enhanced) area. For patients who may feel claustrophobic in the tunnel-shaped “closed” MRI machine, a mild sedative can be used. Less constrictive “open” MRI machines have been introduced, but are not recommended for the imaging of acoustic neuroma. Patients are warned that, because strong magnetic fields are generated, an MRI scan is not suitable for everyone, e.g., a patient with a cardiac pacemaker.