The Posterior Reversible Encephalopathy Syndrome
K. Mandal Sanjay and P. Chakraborty Partha
Department of Medicine, Bankura Sammilani Medical College, Bankura, 1Midnapore Medical College,
The posterior/potentially reversible encephalopathy syndrome is a unique syndrome encountered commonly in hypertensive
encephalopathy. A 13-year-old boy presented with of intermittent high grade fever, throbbing headache and non-projectile
vomiting for 5 days. The patient had a blood pressure of 120/80mmHg but fundoscopy documented grade 3 hypertensive
retinopathy. The patient improved symptomatically following conservative management. However, on the 5th post-admission
day headache reappeared, and blood pressure measured at that time was 240/120 mmHg. Neuroimaging suggested white
matter abnormalities. Search for the etiology of secondary hypertension led to the diagnosis of pheochromocytoma. Repeat
MRI after successful surgical excision of the tumor, patient showed reversal of white matter abnormalities. Reversible
leucoencephalopathy due to pheochromocytoma have not been documented in literature previously. [Indian J Pediatr 2008;
75 (9) : 953-955] Email: docparthapc@ yahoo.co.in
Key words : The Posterior Reversible Encephalopathy Syndrome; Hypertensive encephalopathy; Metachromatic granules;
The Posterior/potentially reversible encephalopathy no signs of meningeal irritation, lymphadenopathy or
syndrome (PRES) is a recently proposed clinico- sternal tenderness. Fundoscopic examination documented
neuroradiological entity. The common causes of PRES are grade 3 hypertensive retinopathy. Neurological
hypertensive encephalopathy, eclampsia, cyclosporin-A evaluation revealed normal tone in the limbs without any
neurotoxicity and uremic encephalopathy. A relatively motor or sensory deficit. The patient had preserved
symmetrical pattern of involvement, typically in the reflexes with down going plantars. Examination of other
subcortical white matter and occasionally in the cortex of systems did not reveal any abnormality. All the peripheral
the posterior circulation area of the cerebrum is evident pulses were equally palpable without any carotid or renal
on magnetic resonance imaging (MRI) studies. Although bruit.
most patients of PRES are markedly hypertensive at
Complete Blood Count showed mild leucocytosis with
presentation, some have only mildly elevated or even
ring forms of Plasmodium falciparum on peripheral smear.
normal blood pressure.
Blood biochemistry (e.g., glucose, urea, creatinine, liver
function test, serum sodium, potassium) and urine
CASE REPORT analysis were within reference range. He was put on oral
quinine sulphate and on the third day of therapy fever
and headache subsided completely.
A 13-year-old boy was referred to us with a 5-day history
of intermittent episodes of high grade fever associated However, on the 5th post-admission day headache
with throbbing headache and two episodes of reappeared, though the patient remained afebrile. Blood
nonprojectile vomiting. There were no histories of cough, pressure measured at that time was 240/120 mm of Hg.
respiratory distress, dysuria, unconsciousness or The patient also developed abnormal posture of his limbs.
convulsion. The patient was restless on presentation with Neurological evaluation revealed increased tone in all
a blood pressure of 120/80mm of Hg. Abdominal limbs with extensor plantars. C.T. scan of brain performed
examination revealed a 2 cm splenomegaly. There were at that time was suggestive of white matter demyelination
(Fig. 1a). MRI of brain done subsequently also
documented periventricular hyperintensities (T2W and
Correspondence and Reprint requests : Dr. Partha Pratim FLAIR) (Fig. 1b). Analysis of cerebrospinal fluid by
Chakraborty, House No. B.E 64; Bidhan Nagar (East); P.O & Dist. guarded lumbar puncture was normal. A thorough
Midnapore, West Bengal-721101, India. Mobile: 91 9830092947 history from patient’s parents revealed that he had been
[Received January 20, 2008; Accepted April 10, 2008] suffering from episodic headache over the last 3 years and
Indian Journal of Pediatrics, Volume 75—September, 2008 953
K.M. Sanjay and P.C. Partha
he was diagnosed and being treated for childhood
migraine by the family physician. Our search for the
etiology of secondary hypertension led to the C.T. scan of
abdomen and it showed a mass (5.3×6.5cm) over left
adrenal gland (Fig.2). Further evaluation revealed
elevated urinary epinephrine [7.78ìgm/day (Normal
<11μgm/day); 12.21μgm/gm creatinine (Normal 1-10μg/
g creatinine)] and nor-epinephrine [2120.22μgm/day
(Normal 12-88 μgm/day);3329.28μgm/gm creatinine
(Normal 15-58 μg/g creatinine)] with normal urinary
dopamine [181.02μgm/day; 284.25μgm/gm creatinine
(Normal <545 μg/g creatinine)]. Urinary metachromatic
granules were absent. A diagnosis of pheochromocytoma
Fig. 3. Normal MRI of brain in Post-operative period.
Our final diagnosis in this patient was PRES secondary to
Fig. 1. CT scan (a) and MRI (T2 flair) (b) of brain documenting DISCUSSION
white matter Abnormality (arrow)
PRES was introduced into clinical practice in 1996 in order
to describe a unique syndrome, expressed mainly during
Hypertensive encephalopathy is characterised
clinically by headache, vomiting, seizures, visual
abnormalities, disturbances in cognition and alteration in
the level of consciousness. Imaging studies often
demonstrate edema of the white matter in the posterior
parietal and occipital areas of the brain. This so-called
PRES, which is the neuro-radiological correlate of
hypertensive encephalopathy, is also associated with a
number of conditions. There are several theories about the
mechanism for PRES, but the most widely accepted
hypotheses are the generation of vasogenic edema caused
by failure of the mechanism that allows self regulation of
the cerebral blood flow, and the production of cytotoxic
edema due to ischemia. 2 MRI with sequences that
evaluate the diffusion of cerebral water is useful in
Fig. 2. CT scan of abdomen showing adrenal mass (arrow) distinguishing between the two mechanisms.
Pheochromocytoma occurs in near about 0.1% of the
was made. MIBG scan excluded other extra-adrenal hypertensive population. It is usually curable if diagnosed
localization of tumor. The blood pressure was controlled and treated in time. In children, one fourth of tumors are
initially with alpha-receptor blocker (labetolol) and bilateral and another fourth are extra adrenal.3 Solitary
calcium channel blocker (Nifedipine) followed by tumor favors the right side. However, in this child, the
nitroprusside infusion per-operatively. After successful tumor was unilateral and was on the left side. No extra
surgical excision of the tumor patient became adrenal tumor was localized by MIBG scan. The initial
normotensive and a repeat MRI of brain after six months diagnosis was cerebral malaria as signs and symptoms at
showed reversal of white matter abnormalities (Fig.3). that time resembled that of cerebral malaria which is very
954 Indian Journal of Pediatrics, Volume 75—September, 2008
The Posterior Reversible Encephalopathy Syndrome
much prevalent in this part of the country. Previously stress upon that repeated blood pressure measurement
episodic headache was treated as migraine. Probably and ophthalmoscopic examination should be done in all
patient’s blood pressure was not measured because of his patients with headache irrespective of age.
younger age or measured during normotensive period.
About 40% patients of pheochromocytoma have blood
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Indian Journal of Pediatrics, Volume 75—September, 2008 955