Facial Paralysis After Meningioma Resection: Risk and Recovery

Although meningioma is a tumor originating from the meninges and is usually benign, surgical intervention is performed in a sensitive anatomical area, especially when located near the skull base and brain stem. The close proximity of the facial nerve, which is responsible for facial expressions, to the surgical site in this region may raise the risk of facial paralysis after surgery. If you would like more detailed information on this topic, please take a look at our content.

What Is Meningioma?

A meningioma is a tumor that originates from the membrane layers (meninges) surrounding the brain and spinal cord and is usually benign. This tumor develops from arachnoid cells and usually grows slowly; therefore, it may not cause symptoms for a long time. However, as it grows, it can press on the surrounding brain tissue, nerves, or blood vessels, causing complaints such as headache, seizures, visual impairment, loss of balance, or neurological weakness. In this context, small and asymptomatic lesions can be monitored regularly; however, surgical resection is preferred for tumors that cause symptoms or show a tendency to grow, and in some cases, advanced treatment options such as radiosurgery may be considered.

What Are the Symptoms of Meningiomas?

Meningioma has specific symptoms. These symptoms vary depending on the size of the tumor, its location, and the pressure it exerts on surrounding tissues. However, the general symptoms of the disease are as follows:

• Headache (especially one that gradually worsens and becomes chronic)

• Epileptic seizures

• Vision problems (blurred vision, double vision, loss of visual field)
• Hearing loss or ringing in the ears (especially in skull base locations)

• Loss of balance and dizziness

• Weakness in the arms or legs

• Numbness in the face or facial weakness

• Memory problems and difficulty concentrating

• Personality changes or behavioral differences

• Nausea and vomiting (due to increased intracranial pressure)

In Which Areas Does Meningioma Occur?

Meningiomas can occur in different areas throughout the central nervous system because they originate from the meninges tissue surrounding the brain and spinal cord. In this context, the areas where meningiomas occur are as follows:

• Convexity (brain surface): Located on the outer surface of the cerebral hemispheres. This is the most common location.
• Parasagittal region: Develops along the midline separating the two cerebral hemispheres, adjacent to the superior sagittal sinus.
• Falx cerebri: May be located along the membrane separating the cerebral hemispheres.
• Sphenoid wing (base of the skull): May be close to the optic nerve and orbital structures; may cause vision problems.
• Cerebellopontine angle: Located between the brain stem and cerebellum; may cause hearing and balance problems.
• Olfactory groove (olfactory sulcus): Located in the anterior skull base; loss of smell and personality changes may occur.
• Tuberculum sellae: Located near the pituitary gland and optic nerve.
• Tentorium cerebelli: May develop in the membrane structure between the cerebellum and the brain.
• Spinal (around the spinal cord): Originating from the spinal cord membranes, it may cause back pain and neurological deficits.

How Is Meningioma Diagnosed?

The diagnosis of meningioma begins with the evaluation of the patient's clinical complaints and neurological examination findings and is confirmed with advanced imaging techniques. At this point, the most fundamental diagnostic tool is magnetic resonance imaging (MRI). Contrast-enhanced brain MRI examination shows the location, size, relationship with surrounding tissues, and possible brain edema of the tumor in detail. In some cases, computed tomography (CT) provides additional information to assess bone involvement or the presence of calcification. Furthermore, MR angiography or digital angiography may be planned to understand the tumor's relationship with vascular structures. The definitive histopathological diagnosis is usually made by pathological examination of the tissue removed after surgical resection; this examination determines the tumor's grade (WHO classification) and aggressiveness potential.

What Causes Facial Paralysis Following Meningioma Resection?

The primary cause of facial paralysis following meningioma resection is the close anatomical relationship between the facial nerve (7th cranial nerve), which is responsible for facial movements, and the surgical field. Particularly in meningiomas located at the skull base and cerebellopontine angle, the tumor may be adjacent to the facial nerve; it may have displaced, thinned, or adhered to the nerve.

During surgery, tension, pressure, thermal damage, or microscopic trauma may occur to the nerve when separating it from the tumor. In addition, postoperative edema, inflammation, or involvement of the small vessels supplying blood to the nerve may also lead to temporary loss of neurological function. In rarer cases, partial or complete structural damage to the nerve may result in permanent facial paralysis. Therefore, the risk varies depending on factors such as the size of the tumor, its location, the degree of adhesion to the nerve, and the surgical technique used.

Treatment Methods for Facial Paralysis Caused by Meningioma Resection

The treatment approach for facial paralysis developing after meningioma surgery is planned according to the degree of damage, the integrity of the nerve, and the duration of the paralysis. In this context, the main treatment methods are as follows:

• Selective Myectomies (Selective Myectomy)

Following meningioma surgery, if the facial nerve has partially recovered but irregular nerve connections have formed, certain muscle groups may overwork, leading to facial pulling or a stiff expression. Selective myectomy surgery involves the controlled weakening or removal of overactive muscle fibers. This method does not restore new movement; rather, it aims to correct facial symmetry and reduce involuntary contractions. It is generally performed in the chronic phase, particularly in patients who have developed synkinesis.

• Selective Neurolysis (Selektif Nörolizis)

During nerve healing, faulty reconnection may occur, and the patient may involuntarily contract other muscles while performing a specific movement. Selective neurolysis is a procedure that aims to eliminate these contractions. The goal is to correct faulty nerve transmission and provide more natural, controlled facial movement. This method is particularly preferred in patients who have shown partial recovery but still experience functional irregularities.

• Gracilis Muscle Transplant

In cases of long-term facial paralysis (usually exceeding 12–18 months), the facial muscles may have lost their function and become atrophied. In such cases, the gracilis muscle taken from the inner thigh is transferred to the face using microsurgical techniques. This allows the blood vessels and nerve connections of the new muscle to be reestablished, enabling active contraction. Furthermore, the gracilis muscle transfer method is a dynamic (movement-restoring) reconstruction and is an effective option, particularly in cases of permanent complete paralysis.

• Gracilis Muscle Transplant (Masseter Nerve)

In this technique, the gracilis muscle is activated via the masseter nerve, which stimulates the chewing muscle. Thus, the gracilis muscle transfer method provides faster and stronger contraction. It is particularly preferred in unilateral facial paralysis and offers the advantage of early functional recovery. Over time, the patient can make this movement more natural.

• Cross Facial Nerve Graft (CFNG)

If the facial nerve on the unaffected side is completely intact, a nerve graft taken from the unaffected side is extended to the paralyzed side. This transmits the natural facial expression signals from the unaffected side to the paralyzed side. The aforementioned cross facial nerve graft procedure results in a more natural and synchronized smile. It is also planned as a two-stage surgery, and movement recovery occurs over a longer period. It is particularly preferred in young and suitable patients.

• Free Functional Muscle Flap

This method is the general name for free muscle transfer, and the gracilis muscle is most commonly used. In this context, the free functional muscle flap procedure is performed in cases of long-term and complete facial paralysis where recovery of facial muscles is not possible. Additionally, muscle tissue is transferred to the face using microsurgery, and vascular and nerve connections are established. The goal is to achieve active, strong, and permanent facial movement.

• Temporalis Muscle Flap

The temporalis muscle (chewing muscle) is directed and attached to the corner of the mouth, causing a smile to form when the patient clenches their teeth. This is advantageous for some patients because it does not require microsurgery, has a shorter surgery time, and has a faster recovery process. In addition, the temporalis muscle flap may be preferred in older patients or patients who are not suitable for long surgery.

• Static Support Surgery

Static support surgeries involve facial suspension procedures. These methods do not restore movement; however, they correct drooping of the corners of the mouth and improve symmetry at rest. They are particularly used in cases where movement restoration is not possible or when the patient only desires aesthetic improvement. As a result, it is a lower-risk and supportive approach.

Recovery Process After Facial Paralysis Surgery Caused by Meningioma Resection

The recovery process following reconstructive procedures such as nerve repair, nerve transfer, or muscle grafting used to treat facial paralysis that develops after meningioma resection progresses gradually depending on the surgical technique used and the condition of the nerve tissue. Therefore, immediately after surgery, edema and temporary swelling, bruising, and noticeable weakness in facial movements due to surgical trauma may be observed; this period generally covers the first few weeks. If nerve repair or nerve transfer has been performed, functional improvement usually begins within 3–6 months and can continue for up to 12 months, as nerve regeneration progresses at a rate of approximately 1 mm per day per millimeter.

In dynamic reconstructions such as free muscle transfer, it takes several months for the new muscle to integrate with the nerve and develop active contraction; regular physical therapy is critical during this process. Consequently, evaluation of the final functional and aesthetic results may take 9–12 months in most patients; therefore, a patient and disciplined rehabilitation process is crucial for long-term success.

Postoperative Care for Facial Paralysis Caused by Meningioma Resection

Postoperative care for facial paralysis developing after meningioma surgery is planned to support nerve healing, prevent complications, and minimize loss of function. Therefore, the main points to consider when providing care are as follows:

• Artificial Tears and Ointments: Use artificial tear drops frequently throughout the day as recommended by your doctor. Apply thicker ointments at night to keep your eyes moist while you sleep.
• Eye Covering (Eye Patch): A sterile eye patch or protective transparent covers (moisture chamber) should be used during sleep to prevent the eye from drying out or rubbing against the pillow.
• Sunglasses: Sunglasses must be worn when going outside to protect against wind, dust, and sunlight.
• Facial Exercises: Mimic exercises such as raising the eyebrows, closing the eyes, smiling, and whistling, as recommended by the doctor, should be performed regularly in front of a mirror.
• Neuromuscular Reeducation: To prevent muscles from moving incorrectly (synkinesis) while the nerve is healing, you should work with a specialist physical therapist.
• Heat Application and Massage: Light circular massages on the paralyzed side of the face increase blood circulation and soften stiffened tissues.
• Recovery Monitoring: Nerve recovery is gradual and slow (it can take months). Therefore, the nerve's recovery rate should be periodically monitored using tests such as EMG.