Meningioma in Cats​

Meningiomas are one of the most common types of brain tumors in cats. These tumors arise from the meninges, the protective membranes that cover the brain and spinal cord. While meningiomas are typically benign (non-cancerous), their location and size can lead to significant neurological symptoms, making early detection and treatment critical for your cat's well-being. This article will explore what meningiomas are, their symptoms, the prognosis for cats diagnosed with meningiomas, and the available treatment options.

What is a Meningioma in Cats?

A meningioma is a type of tumor that originates from the meninges, which are the three protective layers surrounding the brain and spinal cord. The meninges are composed of the dura mater, arachnoid, and pia mater, and their primary function is to protect and cushion the brain. Meningiomas in cats typically develop within the dura mater, the outermost and most fibrous layer of the meninges, although they can sometimes originate from other parts of the meninges as well.

Meningiomas are generally benign tumors, meaning they are not cancerous and do not spread to other parts of the body. However, they can cause significant problems due to their location. Because the brain is confined within the skull, even a benign tumor can cause pressure on the brain, leading to neurological dysfunction. In some cases, these tumors may become malignant (cancerous) or undergo transformation over time, though this is less common.

In cats, meningiomas are more frequently seen in older cats (usually over 9 years of age), with the majority occurring in the brain rather than the spinal cord. While not as common as other types of tumors, meningiomas are still a significant cause of neurological symptoms in cats and can lead to serious complications if left untreated.

Symptoms of Meningiomas in Cats

Meningiomas can cause a variety of symptoms, depending on the tumor’s size, location, and rate of growth. The most common symptoms of meningiomas in cats are neurological and often progressive. Common symptoms include:

1. Changes in Behavior

Cats with meningiomas may exhibit behavioral changes, including increased aggression, irritability, confusion, or altered responsiveness to their surroundings. They may appear disoriented, have difficulty recognizing familiar people or animals, or show signs of anxiety and stress.

2. Seizures

Seizures are one of the most common signs of a meningioma, especially if the tumor is located near the cerebral cortex or other areas of the brain involved in motor function. Seizures in cats can range from mild to severe, and they may appear as sudden, involuntary movements, twitching, or even loss of consciousness.

3. Circling or Abnormal Gait

Cats with meningiomas often display signs of neurological deficits, such as circling, stumbling, or an unsteady gait. They may walk in circles, lean to one side, or show signs of weakness on one side of the body (hemiparesis).

4. Vision Problems

If the tumor affects the areas of the brain responsible for vision, the cat may experience vision problems, which can manifest as blindness or partial loss of vision. This may result in the cat becoming disoriented, having difficulty navigating familiar spaces, or being hesitant to move around.

5. Head Tilt

A common sign of a brain issue, including a meningioma, is a head tilt. This may be caused by pressure on the brainstem or vestibular system, leading to a loss of balance. The cat may tilt its head to one side and appear uncoordinated.

6. Vomiting and Nausea

Due to the increased pressure on the brain, cats with meningiomas may suffer from nausea and vomiting. This is often a secondary symptom caused by the tumor’s effect on the areas of the brain that control appetite and digestion.

7. Incontinence

In some cases, especially with larger tumors or those affecting specific brain regions, cats with meningiomas may have difficulty controlling their bladder or bowels, leading to urinary or fecal incontinence.

8. Loss of Appetite and Weight Loss

Cats with meningiomas often lose their appetite, which can result in weight loss. This may be due to the tumor’s effect on the hypothalamus, which plays a role in regulating hunger and satiety, or it may be a result of the overall weakness and malaise associated with the disease.

9. Changes in Reflexes

Meningiomas may affect a cat’s reflexes, causing them to become hyperactive (exaggerated responses) or diminished (weak responses) to stimuli.

Diagnosing Meningioma in Cats

When a cat shows signs of neurological dysfunction, it’s important to seek veterinary attention immediately. The veterinarian will perform a thorough neurological exam and may use a combination of diagnostic tests to confirm the presence of a meningioma and rule out other potential causes of the symptoms.

1. Imaging Tests

• MRI (Magnetic Resonance Imaging):
  MRI is the gold standard for diagnosing brain tumors in cats, including meningiomas. This imaging technique provides detailed pictures of the brain and allows the veterinarian to locate the tumor, assess its size, and determine its impact on surrounding brain tissue.
• CT Scan (Computed Tomography):
  In some cases, a CT scan may be used as an alternative to MRI, though it’s less detailed for soft tissue structures. It can still provide useful information about the location and size of the tumor.

2. Cerebrospinal Fluid Analysis

A sample of the cat’s cerebrospinal fluid (CSF) may be collected and analyzed to look for signs of inflammation, infection, or cancer cells. While CSF analysis is not definitive for diagnosing a meningioma, it can help rule out other conditions, such as infections or inflammation.

3. Biopsy

In some cases, a biopsy may be necessary to definitively confirm that the tumor is a meningioma. However, obtaining a tissue sample directly from the brain is often not feasible without surgery, so biopsy is generally reserved for cases where other diagnostic tests are inconclusive.

Treatment for Meningioma in Cats

Treatment options for meningiomas in cats depend on the size, location, and operability of the tumor, as well as the cat’s overall health. There are three main treatment options for cats with meningiomas:

1. Surgical Removal

Surgical resection is often the preferred treatment for accessible meningiomas. If the tumor is confined to one area of the brain and can be safely removed without causing significant neurological damage, surgery may offer the best chance for recovery. However, surgery carries risks, including infection, bleeding, and further neurological damage, and not all meningiomas are surgically accessible.

2. Radiation Therapy

Radiation therapy is commonly used for meningiomas that cannot be surgically removed or if surgery carries too high a risk. Radiation can shrink the tumor or prevent it from growing further. This treatment is often recommended for tumors that are difficult to reach or are located in areas of the brain that are too delicate for surgery.

3. Palliative Care

In cases where the tumor is inoperable, or if the cat’s prognosis is poor, palliative care may be the best option. This may involve medications to manage symptoms such as seizures, nausea, and pain, as well as making the cat as comfortable as possible. While palliative care does not treat the tumor itself, it can help improve the quality of life for cats with advanced disease.

Prognosis for Meningiomas in Cats

The prognosis for cats diagnosed with meningiomas depends on several factors, including the size and location of the tumor, the age and health of the cat, and how early treatment is initiated. 

Benign Meningiomas:
If the meningioma is benign and surgically removed, the prognosis is generally good. Cats can live for several years without recurrence, and many experience a significant improvement in quality of life after treatment. However, the location of the tumor can affect the success of the surgery, and some cats may experience complications or neurological deficits even after successful tumor removal.

Malignant Meningiomas:
If the meningioma is malignant, meaning it has spread or is highly aggressive, the prognosis is much more guarded. Malignant tumors are more difficult to treat and may recur after surgery or radiation therapy. The prognosis in such cases is typically poorer, and survival times are often shorter.

Surgical Success:
The success of surgery is highly dependent on the tumor’s location and size. Tumors located near vital brain structures may be more difficult to remove without causing significant damage. If the tumor cannot be completely removed, additional treatments such as radiation therapy may be required to prevent regrowth.

Quality of Life:
Many cats with meningiomas, even those diagnosed at an advanced stage, can live for several months to years with appropriate treatment. Managing symptoms and providing supportive care can significantly enhance their quality of life.

Conclusion

Meningiomas in cats are serious but treatable conditions. While benign meningiomas have a relatively good prognosis when treated appropriately, the location, size, and type of the tumor can greatly impact treatment outcomes. Early detection, through vigilant observation of symptoms and prompt veterinary care, is crucial for managing meningiomas and giving your cat the best chance for a positive outcome. If your cat is diagnosed with a meningioma, working closely with your veterinarian and a veterinary neurologist will help ensure the most appropriate treatment plan and provide your cat with the best possible care.