Pseudohypoxic Brain Swelling after Unilateral Burr Hole Drainage: A Novel Case Report.

An 85-year-old man underwent emergency right trepanation and drainage for a symptomatic chronic subdural hematoma. Pseudohypoxic brain swelling (PHBS) was suspected because magnetic resonance imaging revealed diffuse brain swelling. Although cerebrospinal fluid (CSF) leakage was not obvious during or after surgery, most of the reported PHBS cases have leaked CSF during craniotomy or spine surgery. PHBS has not been previously reported in patients without obvious CSF leakage or after unilateral burr hole drainage. Herein, we report an extremely rare case with a literature review investigating its pathogenesis and clinical features.

Pseudohypoxic brain swelling and secondary hydrocephalus with pseudomeningocele after lumbar surgery: a case report.

BACKGROUND: Postoperative intracranial complications are rare in spine surgery not including cranial procedures. We describe an uncommon case of pseudohypoxic brain swelling (PHBS) and secondary hydrocephalus after transforaminal lumbar interbody fusion (TLIF) presenting as impaired consciousness and repeated seizures. CASE PRESENTATION: A 65-year-old man underwent L4-5 TLIF for lumbar spondylolisthesis and began experiencing generalized seizures immediately postoperatively. Computed tomography (CT) revealed diffuse cerebral edema-like hypoxic ischemic encephalopathy. He was transported to our hospital, at which time epidural drainage was halted and anti-edema therapy was commenced. His impaired consciousness improved. However, he suffered secondary hydrocephalus due to continuous bleeding from a dural defect and spinal epidural fluid collection 3 months later. Following the completion of dural repair and insertion of a ventriculoperitoneal shunt, his neurologic symptoms and neuroimaging findings improved significantly. CONCLUSIONS: PHBS can be considered in patients with unexpected neurological deterioration following lumbar spine surgery even with the absence of documented durotomy. This might be due to postoperative intracranial hypotension-associated venous congestion, and to be distinguished from the more common postoperative cerebral ischemic events-caused by arterial or venous occlusions-or anesthetics complications.

Fatal postoperative intracranial hypotension-associated venous congestion after elective laminectomy.

Postoperative intracranial hypotension-associated venous congestion is a rare complication that features radiologic characteristics suggestive of hypoxic ischaemic encephalopathy without systemic hypoxia or hypotension actually occurring. This makes the condition prone to being misidentified as a complication of anaesthesia. In this case, a patient undergoing emergency haematoma evacuation after a previous lumbar laminectomy lost cerebrospinal fluid rapidly and accidentally via a wound drain. She subsequently developed postoperative seizures and eventually died some days later having never regained consciousness. A magnetic resonance imaging scan acquired after the event showed signs initially thought to be indicative of hypoxic ischaemic encephalopathy but was later identified to be postoperative intracranial hypotension-associated venous congestion due to temporary obstruction of the great cerebral vein, resulting in local rather than systemic hypoxia. Anaesthetists should be aware of this rare condition and be familiar with its pathophysiology and presentation.

Pseudohypoxic Brain Swelling: Report of 2 Cases and Introduction of the Lentiform Rim Sign as Potential MRI Marker.

BACKGROUND: A rare but important complication related to otherwise uneventful brain and spine surgery is becoming more recognized and more frequently reported in the medical literature. This has been variably labeled as pseudohypoxic brain swelling or postoperative hypotension-associated venous congestion. This poorly understood condition occurs in the setting of surgical intervention and is thought to be related to cerebrospinal fluid leak or evacuation, decreased intracranial pressure, and subsequent development of deep venous congestion affecting the basal ganglia, thalami, and cerebellum. Clinically, patients may have global neurologic deficit and outcomes range from full recovery to vegetative state or death. The imaging correlate includes atypical edema, infarction, or hemorrhage and can overlap the appearance of diffuse hypoxic injury, for which this condition can be mistaken both clinically and radiologically. Although this deep brain tissue edema can be associated with other signs of cerebrospinal fluid hypotension such as dural thickening, brain sagging, and cerebellar herniation, it can be isolated, making the diagnosis challenging. CASE DESCRIPTION: We present 2 cases of unexpected clinical deterioration occurring in patients with otherwise uncomplicated neurosurgery, 1 with craniotomy and the other with lumbar spine intervention. Both patients exhibit similar appearing edema in the deep gray structures on postoperative magnetic resonance imaging scans. In addition to reviewing the prior literature and imaging findings, we evaluate the imaging findings to determine if there are unique features or signatures that might allow differentiation of PHBS from hypoxic-ischemic encephalopathy. CONCLUSIONS: The lentiform rim sign can be helpful for differentiation of pseudohypoxic brain swelling versus hypoxic-ischemic encephalopathy.

Pseudohypoxic Brain Swelling After Uncomplicated Lumbar Decompression and Fusion for Spondylolisthesis.

BACKGROUND: Pseudohypoxic brain swelling (PHBS), also known as postoperative intracranial hypotension-associated venous congestion, is a rare complication after neurosurgery characterized by rapid and often severe postoperative deterioration in consciousness and distinct imaging findings on brain magnetic resonance imaging. Imaging findings associated with PHBS include computed tomography and magnetic resonance imaging findings that resemble hypoxic changes and intracranial hypotensive changes in basal ganglia and thalamus, telencephalic, and infratentorial regions without notable changes in intracranial vasculature. CASE DESCRIPTION: This report describes the case of an L4-5 microdiskectomy with posterior decompression and fusion complicated by clinical and radiographic findings resembling PHBS without a known intraoperative durotomy. CONCLUSIONS: Spine surgeons should be alerted to the possibility that PHBS may occur in patients even after an operation without known durotomy or cerebrospinal fluid leakage and with spontaneous clinical resolution unrelated to suction drainage changes or epidural blood patches.

Pseudohypoxic Brain Swelling After Elective Lumbar Spinal Surgery: Case Report.

Pseudohypoxic brain swelling (or the more recent term, postoperative intracranial hypotension-associated venous congestion) is a rare and potentially deadly complication that can occur after routine spine or brain surgery. The mechanism of this injury has been described as a rapid cerebral spinal fluid drainage leading to venous cerebral congestion. The clinical and radiographic findings mimic those found in a patient who has suffered an anoxic brain injury. We present the third reported case of postoperative intracranial hypotension-associated venous congestion following spinal surgery.