neurologic disorders
Overview of Intracranial Tumors
Symptoms and Signs of Intracranial Tumors
Symptoms caused by primary tumors and metastatic tumors are the same. Many symptoms result from increased intracranial pressure: Headache Deterioration in mental status Focal brain dysfunction Headacheis the most common symptom. Headache may be most intense when patients awake from deep nonrapid eye movement (non-REM) sleep (usually several hours after falling asleep) because hypoventilation, which increases cerebral blood flow and thus intracranial pressure, is usually maximal during non-REM sleep. Headache is also progressive and may be worsened by recumbency or the Valsalva maneuver. When intracranial pressure is very high, the headache may be accompanied by vomiting, sometimes with little nausea preceding it. Papilledema develops in about 25% of patients with a brain tumor but may be absent even when intracranial pressure is increased. In infants and very young children, increased intracranial pressure may enlarge the head. If intracranial pressure increases sufficiently, Brain Herniation occurs. Deterioration in mental statusis the 2nd most common symptom. Manifestations include drowsiness, lethargy, personality changes, disordered conduct, and impaired cognition, particularly with malignant brain tumors. Airway reflexes may be impaired. Focal brain dysfunctioncauses some symptoms. Focal neurologic deficits, endocrine dysfunction, or focal seizures (sometimes with secondary generalization) may develop depending on the tumor’s location (see table). Focal deficits often suggest the tumor’s location. However, sometimes focal deficits do not correspond to the tumor’s location. Such deficits, called false localizing signs, include the following: Unilateral or bilateral lateral rectus palsy (with paresis of eye abduction) due to increased intracranial pressure compressing the 6th cranial nerve Ipsilateral hemiplegia due to compression of the contralateral cerebral peduncle against the tentorium (Kernohan notch) Ipsilateral visual field defect due to ischemia in the contralateral occipital lobe Seizure Disorders may occur, more often with primary than metastatic brain tumors. Some tumors cause meningeal inflammation, resulting in Subacute and Chronic Meningitis . 