Pearls & Oy-sters: Spontaneous intracranial hypotension and posterior reversible encephalopathy syndrome

Abstract

Pearls & Oy-sters: Spontaneous intracranial hypotension and posterior reversible encephalopathy syndrome PEARLS• Although rare, cases of posterior reversible encephalopathy syndrome (PRES) secondary to CSF leak and intracranial hypotension have been documented in the literature.• The pathogenesis of PRES in these settings has been associated with both arterial and venous cerebrovascular dysfunction. OY-STERS• PRES should be suspected in patients with CSF leak who continue to experience headache, visual changes, and altered mentation despite conservative management.• The mainstay of treatment involves resolution of the CSF leak, typically with an autologous epidural blood patch.CASE REPORT A 65-year-old woman with no significant medical history was brought to the emergency room after experiencing 2 weeks of band-like occipital headaches and 2 days of progressive mental status changes. Her neurologic examination was significant for decreased alertness, disorientation to time, confabulation, loss of recent and remote memory, diffuse hyperreflexia, and a left Hoffmann sign. MRI of the brain with contrast showed bilateral subdural hygromas, diffuse enhancement of the dura mater, with mild sagging of the brainstem suggestive of intracranial hypotension (figure 1, A and B). MRI of the spine showed a large collection of CSF in the lumbar epidural space ( figure 2A); however, the tear site was not identified. EEG also revealed generalized slowing with no evidence of seizure activity. Her mental status continued to deteriorate despite conservative measures such as aggressive hydration, caffeine intake, and bedrest in the Trendelenburg position. A head CT was ordered for worsening mental status and revealed symmetric hypoattenuation of the bilateral parasagittal occipital cortices consistent with PRES ( figure 2B), a finding that was not present on the initial MRI. She then received an emergent lumbar epidural blood patch, resulting in dramatic improvement in mental status several hours later. She was discharged without any focal neurologic deficits. An MRI performed 10 days later revealed no evidence of PRES in the occipital region. An MRI of the lumbar spine performed 5 weeks later showed resolution of the fluid collection (figure 3).DISCUSSION Spontaneous intracranial hypotension (SIH) is a known neurologic condition characterized by occipital headaches, neck stiffness, and altered mentation that results from leakage of CSF through a structural break in the meninges. Distinct abnormalities on MRI support the diagnosis, including diffuse meningeal enhancement, subdural fluid collections, engorgement of the dural sinuses, and downward displacement of the brain that can result in compression of vital structures (figure 1, A and B). Stupor and coma, for example, have been linked to compression of the diencephalon. 1 While our patient's altered mental status was initially attributed to brain sagging, her clinical deterioration was complicated by a transient occipital hypodensity concerning for PRES (figure 2B). Although rare...

Posterior reversible encephalopathy syndrome with lumbar drainage and surgery: coincidence or correlation? A case report

“…Recently, intracranial hypotension has also been associated with PRES [17]. Demonstrating the occurrence of intracranial hypotension is challenging given the absence of ICP measurement in our patient.…”

“…This phenomenon may lead to increased perfusion pressure and passive edema [18]. Increased perfusion pressure could potentially lead to over-distension of cerebral veins and arterioles causing hydrostatic extravasation of fluid [17]. Reduced CSF volume leading to increased perfusion has been reported following repeated lumbar punctures or lumbar drainage thereby leading to the development of PRES [9, 10].…”

Posterior Reversible Encephalopathy Syndrome Secondary to Intracranial Hypotension

“…2 In addition, PRES due to intracranial hypotension is attributed to abnormal flow of the venous system. 4,5 According to the Monro-Kellie doctrine, the intracranial volume consists of three components: brain, blood, and CSF. The brain parenchyma is less flexible, so changes in blood volume are inevitable in alteration of the CSF volume to maintain the normal intracranial pressure.…”

Posterior Reversible Encephalopathy Syndrome Developing after Aggressive Posterior Fossa Tumor Surgery

“… 1 PRES is associated with many different conditions like malignant hypertension, immunosuppressive therapy, eclampsia, electrolyte imbalances, and autoimmune diseases. 2 3 A history of chemotherapy, 4 steroid use, 5 intracranial hypotension, 6 shunt revision, 7 peri- and postoperative hypertension, 8 and hypertension due to manipulation of the brain stem (especially at the ventrolateral medulla) 9 10 11 might contribute to PRES development.…”