Chapter 75: Tumors of the Nervous System
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Approach to the patient: Tumors of the Nervous System
Brain tumors can present with general and/or focal symptoms and signs. Nonspecific symptoms include headache with or without nausea and vomiting, cognitive difficulties, personality change, and gait disorder. The classic brain tumor headache predominates in the morning and improves during the day, but this pattern is seen only in a minority of pts. Papilledema may suggest elevated intracranial pressure. Focal symptoms and signs include hemiparesis, aphasia, or visual field deficit; these are typically subacute and progressive. Seizures are common, occurring in ∼25% of pts with brain metastases or malignant glioma, and are the presenting symptom in up to 90% of pts with low-grade glioma.
Primary brain tumors, unlike metastases, have no serologic features of malignancy such as an elevated ESR or tumor-specific antigens. Cranial MRI with contrast is the preferred diagnostic test for any pt suspected of having a brain tumor; CT should be reserved for pts unable to undergo MRI. Malignant brain tumors typically enhance with contrast and may have central areas of necrosis; they are characteristically surrounded by edema of the neighboring white matter. Low-grade gliomas typically do not enhance. Meningiomas have a typical appearance on MRI because they are dural-based enhancing tumors with a dural tail that compress but do not invade the brain. Additional testing such as cerebral angiogram, EEG, or lumbar puncture is rarely indicated or helpful.