Posterior Reversible Leukoencephalopathy Syndrome Presenting with Global Cerebral Edema and Herniation
- First Online:
- Cite this article as:
- Lee, V.H., Temes, R.E., John, S. et al. Neurocrit Care (2013) 18: 81. doi:10.1007/s12028-012-9798-6
- 456 Views
We report a case of global cerebral edema and herniation due to Posterior Reversible Leukoencephalopathy Syndrome (PRES).
A 37-year-old healthy female developed persistent severe occipital headache, and after 1 month of persistent headache, developed an episode of loss of consciousness. CT brain showed diffuse cerebral edema and effacement of the sulci and basal cisterns. Her initial neurological examination was nonfocal but with severe headache. Overnight, she acutely became unresponsive with fixed dilated pupils, tachycardia, and hypertension. She was intubated and treated with hypertonic saline and mannitol with improvement in her clinical status. Intracranial Pressure (ICP) monitor showed elevated ICPs to 37 mmHg which responded to mannitol. MRI brain showed diffuse vasogenic edema predominantly in the white matter without enhancement. Cerebral angiogram was unremarkable. Cerebrospinal fluid including infectious work-up was negative. With supportive care, her mental status improved. On her 3 month follow-up visit, she was asymptomatic and had returned to work. Repeat MRI brain at 3 months showed persistent white matter changes that subsequently resolved at 9 months.
Although PRES is typically considered to have a benign clinical course, clinician should be aware that severe cases can present with global cerebral edema and associated complications including intracranial hypertension and herniation.
KeywordsPosterior Reversible Leukoencephalopathy SyndromeGlobal cerebral edemaHerniation
Report of a Case
At her 1 month follow-up visit, she had persistent daily headache, but was otherwise nonfocal. On her 3 month follow-up visit, her headaches had resolved and she was asymptomatic. Repeat MRI brain at 3 months showed that the white matter changes were persistent, although slightly improved (Fig. 2). Formal neuro-ophtholmologic exam at 4 months showed bilateral disk edema consistent with papilledema and mild visual field loss (right greater than left) without enlargement of the blind spot. Follow-up eye exam at 6 months showed that the previously seen disk edema and mild visual field loss had resolved. Repeat MRI brain at 9 months showed complete resolution of the white matter changes (Fig. 2).
Posterior Reversible Encephalopathy Syndrome (PRES) is characterized by headaches, encephalopathy, cortical blindness, and seizures in association with characteristic neuroimaging findings of reversible vasogenic edema which typically reverse within days to weeks [1, 2]. PRES tends to preferentially affect the posterior head regions, but anterior involvement is commonly seen typically in a patchy distribution . Although PRES is typically considered to have a benign clinical outcome, the acute presentation PRES can be associated with life-threatening complications such as hemorrhage or status epilepticus [3–5]. Severe brainstem edema from PRES has also rarely been reported to cause acute obstructive hydrocephalus due to compression of the fourth ventricle necessitating placement of an external ventricular drain .
Our patient was unusual because she presented with diffuse white matter changes and global cerebral edema that was severe enough to cause clinical herniation without obstructive hydrocephalus or hemorrhage. The widespread confluent vasogenic edema was severe enough to elevate intracranial pressure. This is supported by the neuro-ophtholmologic findings on follow-up of papilledema. Although the precipitating trigger was never identified for our patient, the fact that the clinical symptoms and radiographic findings of leukencephalopathy resolved spontaneously excludes other ominous causes. Despite the severity of the patient’s initial presentation, her subsequent clinical outcome was good with complete resolution of vasogenic edema on follow-up MRI, as is expected with PRES. Of note, the patient’s 3 month MRI brain still showed persistent leukoencephalopathy, which later resolved on the 9 month MRI. This prolonged delay in radiographic resolution is atypical for PRES (which typically resolves radiographically within weeks)  and was likely an indicator that this represented a particularly malignant case of the PRES.
Our case likely represents a severe case of PRES given the prolonged prodrome (over 1 month of headaches), severity of initial CT findings of global cerebral edema, and prolonged delay to resolution on MRI (seen at 9 months). Clinicians should be aware that malignant presentations of PRES can be associated with global cerebral edema, intracranial hypertension, and herniation, and that aggressive treatment of these potentially fatal complications can result in a good long-term clinical outcome.