Meningiomas are the most common type of primary tumor that develops within the central nervous system, representing approximately one-third of all such diagnoses in adults. These tumors originate from the meninges, the protective membranes surrounding the brain and spinal cord. While many meningiomas remain asymptomatic for long periods, they can cause vertigo, but only when they grow in a specific anatomical location. Vertigo, a feeling of spinning or unsteadiness, indicates that the tumor is interacting with the delicate structures responsible for balance.
Understanding Meningiomas
A meningioma is a growth that develops from the arachnoid cap cells, which are part of the meninges covering the brain and spinal cord. Though often referred to as brain tumors, they do not arise from the actual brain tissue itself. The majority of these tumors are classified by the World Health Organization (WHO) as Grade I, meaning they are typically benign, slow-growing, and non-cancerous.
The incidence of meningiomas is higher in women than in men and they are most commonly diagnosed in individuals between the ages of 40 and 70. Because of their slow growth rate, a person can live with a meningioma for many years without symptoms. Symptoms appear only as the tumor expands and exerts pressure on nearby neurological structures.
Why Location Matters: The Mechanism Behind Vertigo
The mechanism by which a meningioma causes vertigo depends on its precise location within the skull. Vertigo is typically associated with tumors that arise in the posterior fossa, the area at the back and base of the skull. This area houses the brainstem and the cerebellum, which are the primary control centers for posture, coordination, and balance.
Tumors developing in the cerebellopontine angle (CPA), a tight space between the brainstem and the cerebellum, are most likely to produce vertigo. A meningioma here can press directly on the vestibular nerve, which transmits balance information from the inner ear to the brain. This direct pressure disrupts the signals needed for maintaining equilibrium, resulting in rotational vertigo or chronic unsteadiness.
Vertigo caused by a meningioma is a specific neurological symptom. Pressure from the tumor can also disrupt the function of the nearby cerebellum, leading to unsteadiness and poor coordination. Tumors located on the brain’s surface, away from the posterior fossa, can also cause vertigo if they impinge on cortical regions involved in processing vestibular information.
Related Symptoms of Meningioma
Meningiomas can cause a wide range of neurological symptoms depending on the tumor’s site of origin.
Symptoms Based on Location
- Tumors growing near the cerebral cortex may irritate the brain surface, triggering localized seizures.
- A large meningioma can cause persistent headaches, often worse in the morning due to increased pressure inside the skull.
- If the tumor is located near the optic nerve or the sphenoid ridge, it can cause changes in vision, such as blurring, double vision, or gradual loss of sight.
- Meningiomas close to the auditory nerve can manifest as hearing loss or tinnitus (a constant ringing sensation).
- Tumors located in the frontal lobes might cause alterations in personality or difficulty with memory and concentration.
Diagnosis and Management Options
Diagnosis of a suspected meningioma typically involves a neurological and physical examination to assess symptoms. Confirmation requires advanced medical imaging, with Magnetic Resonance Imaging (MRI) being the preferred method. A Computed Tomography (CT) scan is often used in conjunction with the MRI to provide additional information about the tumor’s interaction with the surrounding bone.
Management depends on the tumor’s size, growth rate, location, and the severity of symptoms. For small, asymptomatic tumors, a strategy of watchful waiting is often employed, involving regular follow-up MRI scans. If the tumor is symptomatic, rapidly growing, or threatens neurological function, surgical resection is the primary treatment option.
The goal of surgery is to remove as much of the tumor as safely possible to relieve pressure on the brain and cranial nerves. If the tumor cannot be completely removed, or if it is a higher-grade tumor, radiation therapy may be used. Stereotactic radiosurgery delivers highly focused beams of radiation to stop the growth of small tumors or treat residual tissue left after surgery.