Complications Of Brain Metastases

As the most common site of brain metastases is cerebrum, the complications involving the cerebrum will pursue and the functions of cerebrum will be affected.¹ The most common complication of brain metastases is headache with or without nausea and vomiting. These symptoms could be as a result of force from the tumor to the adjoining brain tissue and creation of pressure inside the brain. Headache can also be a result of hydrocephalus, bleeding and swelling inside the brain. Normally, these symptoms worsen in the morning and alleviate as the day passes. The other complications of brain metastases include seizures, problems with speech, cognition, vision, change in taste, abnormal olfaction, confusion, difficulty understanding, focal weakness and numbness, motor incoordination, behavioral and personality changes, forgetfulness, bladder or bowel incontinence. Seizures occur as a result of electrical impulse irregularity due to the pressing tumor that may lead to spasms and other seizure symptoms. The other symptoms are present if the tumor is affecting the specific part of the brain responsible for that function.^{2, 3}

It is a challenge for a doctor to diagnose brain metastases as the signs and symptoms of brain metastases are not exclusive and, on occasions, can be mistaken for other disease complications. The diagnosis always starts with a careful medical history followed by neurological examination and imaging tests. Magnetic Resonance Imaging is the most accurate imaging technique to diagnose a tumor inside the brain, its location and surrounding structures of the brain tissue. It provides a very detailed picture of the brain and detects even small tumors that may be undetectable in a CT scan. Once MRI diagnoses the presence of tumor, a lumbar puncture (spinal tap) or biopsy can be taken to identify the type of tumor/cancer. ⁴

The treatment of brain metastases has advanced in the past few years; therefore, the mortality and morbidity rates have considerably reduced and the survival from brain tumors have improved to some extent. After cancer diagnosis, the treatment plan is carefully developed based on various factors, such as, age, patient condition and health, number of brain metastases, extent and location of lesion, and pursuing complications.

The treatment ranges from surgery to radiation or the combination of the two. Chemotherapy is rarely used for brain metastases as it is not effective due to the presence blood brain barrier, which renders chemotherapeutic agents impenetrable. However, corticosteroids can be given to lessen the swelling and alleviate the pressure secondary to it. Once, the patient survives brain metastases, it is important for them to enroll in rehabilitation center (for physical therapy, occupational therapy or speech and hearing issues) to help them cope up with any limitations caused due to the disease. ⁵

Brain metastases refers to the terminology used in medicine in which the cancer spreads secondarily to the brain whose origin or primary site was some other body part, other than the brain. The cancer that originates in the brain is referred to as primary brain cancer. In general, brain metastases are 10 times more common than primary brain tumor.⁶ The cancers that have higher propensity for brain metastases include lung cancer, breast cancer, colon cancer, kidney cancer and melanoma. 20-40% of all cancer patients develop brain metastases and more than one million people in the US are diagnosed with brain metastases each year. Generally, brain metastases develop in the advanced stages of cancer.

Brain metastases occur due to its direct involvement secondary to systemic cancers. It is more commonly seen in the cerebral cortex of the brain (about 80%), which is associated with sophisticated functions including memory, sensory perceptions, consciousness, language and cognitive functions. About 15% of the brain tumors are found in the cerebellum, which is responsible for voluntary muscle coordination. And only 5% of brain metastases occur in the brain stem responsible for balance control, visual coordination and swallowing.⁷

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