Abstract and Introduction
Abstract
Introduction: Symptomatic subdural hematoma development is a constant concern for patients who have undergone cerebrospinal fluid shunting procedures to relieve symptoms related to normal-pressure hydrocephalus. Acute subdural hematomas are of particular concern in these patients as even minor head trauma may result in subdural hematoma formation. The presence of a ventricular shunt facilitates further expansion of the subdural hematoma and often necessitates surgical treatment, including subdural hematoma evacuation and shunt ligation.
Case presentation: We present the case of a 63-year-old North American Caucasian man with normal-pressure hydrocephalus with an adjustable valve ventriculoperitoneal shunt who developed an acute subdural hematoma after sustaining head trauma. Conservative treatment was favored over operative evacuation because our patient was neurologically intact, but simple observation was considered to be too high risk in the setting of a low-pressure ventriculoperitoneal shunt. Thus, the valve setting on the ventriculoperitoneal shunt was increased to its maximum pressure setting in order to reduce flow through the shunt and to mildly increase intracranial pressure in an attempt to tamponade any active bleeding and limit hematoma expansion. A repeat computed tomography scan of the head six days after the valve adjustment revealed complete resolution of the acute subdural hematoma. At this time, the valve pressure was reduced to its original setting to treat symptoms of normal-pressure hydrocephalus.
Conclusions: Programmable shunt valves afford the option for non-operative management of acute subdural hematoma in patients with ventricular shunts for normal-pressure hydrocephalus. As illustrated in this case report, increasing the shunt valve pressure may result in rapid resolution of the acute subdural hematoma in some patients.
Introduction
Normal-pressure hydrocephalus (NPH) usually presents in older patients. Patients with NPH frequently present with ventricular dilation, dementia, magnetic gait and urinary incontinence. In 1965, Adams et al. postulated a gradual blockage of cerebrospinal fluid (CSF) drainage as the underlying cause; however, in most patients, NPH is idiopathic and the etiology remains largely unknown. Management of patients with NPH involves placement of a ventriculoperitoneal shunt to aid CSF drainage. The placement of adjustable shunt valves enables easy, non-invasive adjustments in the amount of CSF drainage in order to maximize symptom relief, minimize over-drainage, thus reducing the need for repeated surgical interventions to manage shunt pressure with fixed pressure valves.
A major risk involving both fixed and adjustable ventricular shunts is a predisposition to subdural hematoma (SDH) development. These patients are susceptible to SDH formation due to reduced intracranial pressure (ICP) caused by over-drainage of CSF, acute trauma to the head, or both. Samuelson et al. reported that, following successful ventricular shunt placement and relief of NPH symptoms, five of 24 patients were readmitted for SDH between one and 11 months post-operatively, with one of the five cases reporting a history of trauma. Additionally, patients with NPH were found to be particularly susceptible to SDH formation following ventricular shunt placement, in contrast to a comparatively lower incidence of SDH development after treatment for high-pressure hydrocephalus.
Treatment of acute SDH in patients with NPH is often difficult. Thus, in addition to evacuation of the SDH through burr holes or through a craniotomy, shunt ligature is sometimes needed to prevent reaccumulation or expansion of SDH. We report the case of a patient with NPH who sustained head trauma and developed an acute SDH. Our patient was successfully managed non-operatively to achieve rapid resolution of the acute SDH.