Obstructive hydrocephalus generally requires surgical treatment, although medical therapy may be used as a temporizing measure until surgery is performed, or it can be used in cases of hydrocephalus that are expected to resolve (as is occasionally seen in meningitis). A medical course of therapy aims to either reduce CSF production or increase CSF absorption. CSF production can be reduced through the use of high-dose acetazolamide (25 mg/kg/d divided into three doses, with a maximum daily dose of 2 g) and furosemide (1 mg/kg/d divided into three doses). Historically, isosorbide has been given for osmotic diuresis, although its effectiveness remains questionable.
Patients with brain metastases who present with acute worsening of mentation should be given corticosteroids to decrease cerebral edema. Dexamethasone is the preferred medication, as it has limited mineralocorticoid action and thereby reduces the potential for fluid retention. Typically, dexamethasone is given as a loading dose of 10 mg, followed by 4 mg every 6 hours. Patients who present with elevated intracranial pressure can also be treated with mannitol to reduce cerebral edema, with a starting dose of 0.5-1.0 g/kg. This can be repeated every 4-6 hours. Patients with rapidly declining mental status can also be intubated and hyperventilated to elicit a transient drop in intracranial pressure. Patients may also present with seizures; in these cases, anticonvulsant medications should be given, although the role of prophylactic anticonvulsants remains controversial.
Surgical treatment is the preferred and definitive mode of treatment. The principle of shunting is used to establish communication between the CSF (ventricular or lumbar) and a drainage cavity (peritoneum, right atrium, pleura). Ventriculoperitoneal shunts that extend from the lateral ventricle to the peritoneum are most commonly used. In those cases in which ventriculoperitoneal shunts are contraindicated, such as peritonitis, morbid obesity, or after exclusive abdominal surgery, ventriculoatrial shunts may be used. Ventriculoatrial shunts, also called vascular shunts, transfer the CSF from the cerebral ventricles to the cardiac atrium by way of the jugular vein and superior vena cava.
A common complication associated with shunt placement is infection of the valve and catheter, which can occasionally cause ventriculitis and bacteremia. Postoperative subdural hygroma or hematoma may occur, as reduced ventricular pressure can cause the bridging veins to stretch and rupture. Ventriculoperitoneal shunts can also result in inguinal hernias, perforation of the abdominal organs, intestinal obstruction, volvulus, and CSF ascites. Other problems encountered include occlusion of the tip of the catheter in the ventricle, orthostatic headaches, and misplacement of a catheter. Another surgical option aims to reduce CSF production by choroid plexectomy or choroid plexus thrombosis. Yet another treatment option is third ventriculostomy, in which a hole is made in the floor of the third ventricle, creating a detour around the blockage that allows the CSF to circulate and be absorbed.
In this case, neurosurgeons were consulted, and the patient received an emergent ventriculostomy. The patient then underwent whole-brain radiation in an attempt to decrease the size of the metastasis. Upon admission, the patient was also found to have a urinary tract infection, which was treated with ciprofloxacin. Following treatment of the urinary tract infection and radiation therapy, she underwent ventriculoperitoneal shunt placement. The patient improved considerably and was successfully discharged from the hospital. Unfortunately, the patient has been lost to follow-up.
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Cite this: Mithula Rao Gopalam, Moiz Kasubhai. Depressed Mentation in a 52-Year-Old Woman - Medscape - Nov 11, 2015.