Symptoms of brain and other CNS metastases

An Interview with Andrew Seidman, MD, Memorial Sloan-Kettering Cancer Center

Part 2:  Symptoms 

Musa Mayer: Could you take us through the process of diagnosis of a patient’s brain metastases—what you commonly do when a patient reports a symptom, and then what tests you will send her for, what other specialists you would suggest that she see?   

Andrew Seidman:  I think it’s important in answering these questions to be clear about what we’re saying when we refer to “neurological symptoms.”  During the day, I think we all have neurological symptoms—you and I, and patients with breast cancer, and without breast cancer. We commonly experience headaches, and maybe even sometimes visual changes which aren’t necessarily related to any central nervous system process, but possibly an ophthalmologic problem.  In deciding what level of attention is necessary for a specific symptom, sometimes it’s not appropriate at the first sign of a headache to jump to order an MRI scan.  I might do so if a patient, however, reports a headache that is, “the worst headache of my life.” Often headaches associated with brain metastases, but not always, tend to occur earlier in the morning rather than later in the day.  They can sometimes be associated with light, where bright lights can bother patients. They can sometimes be associated with nausea and vomiting.  So certainly that constellation of complaints: a headache that’s unlike any other, that tends to occur in the morning, that may be associated with nausea or vomiting, or just feel different than other headaches—these are situations where I’d have a very low threshold for referring a patient for an MRI scan. 

 MM: What about dizziness and unsteadiness?   

AS:  That’s a very good point…there’s a large differential diagnosis for dizziness and unsteadiness in people without cancer.  One of the more common reasons for dizziness is imbalances in the fluid in the middle ear that can lead to a condition called vestibulitis or vertigo, a sensation that the room is spinning around.  Patients may have a prior history of this and recognize the symptoms when they recur.  Often a simple trial of drugs such as meclizine, or Antivert, can make those symptoms abate.  But if those symptoms are persistant, or particularly disabling, this also can be a sign of brain metastasis.  The cerebellum, which is the part of the brain that’s located posteriorly, controls the balance, and cerebellar metastases, as well as in other locations, can cause dizziness. Cancer metastasizing to the cerebellum can cause imbalance.  Patients may notice that their gait lists off to one side when they walk, or that it’s hard to walk with the feet close together.  They may need to walk with a more broad-based gait to maintain balance.  That can also be a possible sign of brain metastasis.

 MM:  Would it be correct to say that the symptoms are distributed between those from “mass effect,” or swelling, and symptoms that are specific to the part of the brain in which the lesion is?   

AS:  When there’s mass effect and swelling, we refer to this as edema, or swelling of the tissues that can occur with brain metastases.  That implies that there are more nerve connections that are affected.  If I had a patient who was in an isolated area who wasn’t able to get to a CT scanner or MRI scanner, maybe someone who lives in rural Nebraska is in a snowstorm, and it would be a day or two before she would get there.  If I spoke to her on the phone, and she had symptoms, and I was very concerned about the possibility that she had brain metastasis, one thing that’s not unreasonable to do is to give such a patient a trial of a steroid, such a dexamethasone, or Decadron.  Often within hours of a single dose of dexamethasone, if a patient has brain metastases with swelling or edema, the symptoms will subside significantly.  That doesn’t make the diagnosis, but it makes it very likely that there’s a process going on in the brain that’s associated with swelling and inflammation.  In a patient with known metastatic breast cancer, the most likely cause would indeed be brain metastases. So the empiric use of steroids for worrisome neurologic symptoms and the response to those steroids can be a clue to the presence of brain metastases that have edema.

  Interview continues in Part 3...