Brain tumours include all tumours--defined as an abnormal growth of cells--in the cranium or central spinal canal. According to the Brain Science Foundation, even benign tumours such as acoustic neuromas and meningiomas can be life-threatening because of the small space in the skull and central spinal canal.

According to the Acoustic Neuroma Association, or ANA, acoustic neuroma tumours most commonly arise in the temporal bone of the skull, along the eighth cranial nerve at the internal auditory canal near the top of the jaw. The Brain Science Foundation, or BSF, describes meningiomas as tumours that most commonly arise within the skull, developing from the tissue that covers the brain and spinal cord, known as the meninges.

The ANA lists the most common symptoms of acoustic neuroma as hearing loss, ringing in the ears and balance changes. Later symptoms include headaches, walking difficulty, pain, numbness and facial weakness. The BSF lists the most common symptom of meningioma as seizure. Other symptoms vary depending on the tumour's location and include headaches, muscle weakness, confusion, personality changes, visual disorders and hearing loss.

Diagnosing both acoustic neuroma and meningioma presents challenges because of the slow-growing nature of the tumours and subtlety of the symptoms. The Brain Science Foundation and the Acoustic Neuroma Association say diagnosis of both conditions most commonly occurs via magnetic resonance imaging, or MRI.

Treatment options for acoustic neuroma and meningioma depend on the individual patient. The BSF and ANA say doctors may suggest observation for small tumours without debilitating symptoms and elderly patients who won't require treatment during normal life expectancy. Stereotactic radiosurgery--a minimally-invasive technique usually performed as an outpatient procedure--stops or slows tumour growth by precisely delivering a dose or radiation to the abnormal cells. Doctors sometimes use it in conjunction with traditional surgery, which opens the skull under general anaesthesia to remove as much of the tumour as possible to minimise or eliminate debilitating symptoms. Chemotherapy serves as an additional treatment option for meningioma, but surgery and/or stereotactic radiosurgery remain the primary treatments, according to the Brain Science Foundation.

The ANA states that acoustic neuroma occurs in approximately two in 100,000 people, primarily in patients ages 30 to 60 years. The BSF lists the incidence of meningioma as 7.8 out of 100,000 people, primarily in patients ages 40 and 70 years.

All acoustic neuromas and 90 per cent of meningiomas are benign, but dangerous tumours, and treatment successfully eliminates symptoms in most patients.