A 34-year-old woman is brought to the emergency department with acute onset of severe headache followed by generalized tonic-clonic seizures. The patient was feeling well until 6 hours ago, when she developed a 10/10 throbbing bilateral headache associated with blurry vision. Her headache is not exacerbated by change in head position, and nothing seems to improve the pain. She denies any nausea, vomiting, photophobia, vertigo, fever, or neck pain. She also denies any recent head or neck trauma. She has had upper respiratory tract symptoms for the last couple of days.
Her other medical problems include chronic migraines and non-essential hypertension related to renal artery stenosis from fibromuscular dysplasia. Her medications include topiramate and multiple anti-hypertensive agents including amlodipine, hydrochlorothiazide, lisinopril, and metoprolol. She also takes birth control pills and vitamins. She has never had a seizure before and has no family history of epilepsy. She works as a secretary and has smoked 2 packs of cigarettes daily for 10 years.
Her temperature is 37 C (98.6 F), blood pressure is 210/140 mm Hg, pulse is 80/min and regular, and respirations are 18/min with normal oxygen saturation. The general physical examination is unremarkable, except for an abdominal bruit. Neurological examination reveals that she is awake and alert, but is only oriented to person and place. Funduscopic examination reveals copper and silver wiring in the retina without papilledema. Pupils are equal, round, and reactive to light. Visual acuity is 20/200 bilaterally with intact visual fields to confrontation. There is no nystagmus and extra-ocular movements are full. The remainder of the neurological examination is unremarkable.
A non-contrast head CT showed hypodense regions with loss of grey-white matter differentiation in the posterior occipital-parietal lobes. An MRI of the brain without gadolinium (shown below) showed a symmetrical, increased T2/FLAIR signal abnormality in the subcortical white matter of the posterior occipital-parietal lobes.

Which of the following is the most likely diagnosis?

Question

A 34-year-old woman is brought to the emergency department with acute onset of severe headache followed by generalized tonic-clonic seizures.  The patient was feeling well until 6 hours ago, when she developed a 10/10 throbbing bilateral headache associated with blurry vision.  Her headache is not exacerbated by change in head position, and nothing seems to improve the pain.  She denies any nausea, vomiting, photophobia, vertigo, fever, or neck pain.  She also denies any recent head or neck trauma.  She has had upper respiratory tract symptoms for the last couple of days.
Her other medical problems include chronic migraines and non-essential hypertension related to renal artery stenosis from fibromuscular dysplasia.  Her medications include topiramate and multiple anti-hypertensive agents including amlodipine, hydrochlorothiazide, lisinopril, and metoprolol.  She also takes birth control pills and vitamins.  She has never had a seizure before and has no family history of epilepsy.  She works as a secretary and has smoked 2 packs of cigarettes daily for 10 years.
Her temperature is 37 C (98.6 F), blood pressure is 210/140 mm Hg, pulse is 80/min and regular, and respirations are 18/min with normal oxygen saturation.  The general physical examination is unremarkable, except for an abdominal bruit.  Neurological examination reveals that she is awake and alert, but is only oriented to person and place.  Funduscopic examination reveals copper and silver wiring in the retina without papilledema.  Pupils are equal, round, and reactive to light.  Visual acuity is 20/200 bilaterally with intact visual fields to confrontation.  There is no nystagmus and extra-ocular movements are full.  The remainder of the neurological examination is unremarkable.
A non-contrast head CT showed hypodense regions with loss of grey-white matter differentiation in the posterior occipital-parietal lobes.  An MRI of the brain without gadolinium (shown below) showed a symmetrical, increased T2/FLAIR signal abnormality in the subcortical white matter of the posterior occipital-parietal lobes.

Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

This patient's presentation is suggestive of posterior reversible encephalopathy syndrome (PRES), which is a clinical radiologic syndrome due to a variety of conditions. It is often seen in the setting of hypertensive crises (hypertensive encephalopathy), chemotherapeutic agents (e.g., cyclosporine), eclampsia/preeclampsia, allogenic bone marrow transplantation, medical renal disease, autoimmune disease, sepsis, and shock. 11ec193a_965b_8362_853d_c73b10c142d5_MD0002_00 PRES is due to brain edema, possibly as a result of diminished sympathetic innervation of the posterior circulation. The posterior regions of the brain are more susceptible to injury from high mean arterial pressures, which lead to increased fluid migration into the brain parenchyma and subsequent vasogenic edema. It may also occur from cerebrovascular endothelial injury (vasculopathy). The parietal and occipital lobes are most commonly affected, followed by the frontal lobes, inferior temporal-occipital junction, and cerebellum. There have been rare case reports of PRES affecting the brainstem and the cervical cord as well. Diffusion weighted MRI studies of the brain are usually normal in the setting of PRES, and therefore confirm that the abnormalities seen in the cortical and subcortical white matter represent reversible vasogenic edema. Treatment includes lowering blood pressure and antiepileptic therapy for seizures, with most patients experiencing reversal of their symptoms within 2 weeks. (Choice A) This patient has fibromuscular dysplasia, which is also associated with cerebral aneurysms. However, subarachnoid hemorrhage usually presents with acute blood products in the cisterns on neuroimaging. subarachnoid hemorrhage (Choice B) Herpes simplex virus encephalitis can present with fever, headache, change in mental status, and seizures. However, imaging usually shows a high signal FLAIR/T2 abnormality with enhancement in the bilateral or unilateral temporal lobes. Herpes simplex virus encephalitis also does not typically present with visual loss. (Choice C) Idiopathic intracranial hypertension usually presents in young obese women with recurrent positional headaches (made worse in supine position) associated with visual obscurations, papilledema, and rarely visual loss. These patients typically do not develop seizures, and their MRI brain is usually unrevealing. (Choice D) Migraines typically present as a unilateral and throbbing headache evolving over hours with photophobia, phonophobia, and nausea/vomiting. Migraine headaches do not usually cause seizures or head MRI/CT imaging abnormalities. Educational objective: Posterior reversible encephalopathy syndrome (PRES) is a condition with broad clinical symptoms. It presents with acute to subacute onset of severe headache (thunderclap), hemiparesis, seizures, altered mentation, and visual impairment. A brain MRI commonly shows evidence of symmetrical hyperintense T2/FLAIR signal abnormalities predominantly in the subcortical white matter of posterior parieto-occipital lobes suggestive of vasogenic edema. Hypertensive crisis is one of the many causes of PRES, which is believed to be the result of impaired cerebral autoregulation. __________ References: Posterior reversible encephalopathy syndrome (http://www.ncbi.nlm.nih.gov/pubmed/18854692) Recurrent posterior reversible encephalopathy syndrome in a hypertensive patient with end-stage renal disease. (http://www.ncbi.nlm.nih.gov/pubmed/19061161)

A 34-Year-Old Woman Is Brought to the Emergency Department with Acute