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The Posterior Reversible Encephalopathy Syndrome

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					Clinical Brief



The Posterior Reversible Encephalopathy Syndrome
K. Mandal Sanjay and P. Chakraborty Partha

Department of Medicine, Bankura Sammilani Medical College, Bankura, 1Midnapore Medical College,
Midnapore, India



                                                          ABSTRACT
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;
            Pheochromocytoma


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
                                                                  pheochromocytoma.


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.1
                                                                     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
pressure elevations only during an attack and the                                   REFERENCES
diagnosis can be missed if blood pressure is not measured
at the time of crisis. Initial headache and fever were due
                                                               1. Petrovic B, Kostic V, Sternic N, Kolar J, Tasic N. Posterior
to cerebral malaria as blood pressure at that time was
                                                                  reversible encephalopathy syndrome. Srp Arh Celok Lek 2003;
normal. However, the fundoscopic examination gave us              131 : 461-466.
the clue. Later on the headache was due to hypertensive        2. Alurralde AM, di Egidio M, Saizar R, Consalvo D,Villa AM.
crisis.                                                           Reversible posterior leucoencephalopathy syndrome a case
                                                                  report and review of its physiopathology based on
   Cases of reversible leucoencephalopathy due to                 neuroradiological findings. Rev Neurol 2004; 38 : 541-544.
various causes were reported previously. The commonly          3. Landsberg L, Young JB. Pheochromocytoma. In : Kasper DL,
encountered etiologies are hypertension2 due to different         Braunwald E, Fauci AS, Hauser SL,Longo DL, Jameson JL.
                                                                  Eds. Harrison’s Principles of Internal Medicine, 16th ed. New
causes, post bone marrow tranaplantation 4 ,
                                                                  York; McGraw Hill, 2005: 2148–2152.
hypercalcemia,5 and connective tissue diseases like SLE        4. Teive HA, Brandi IV, Camargo CH,Bittencourt MA, Bonfim
with vasculitis, 6 undifferentiated connective tissue             CM et al. Reversible posterior leucoencephalopathy syndrome
disease,7 scleroderma8 and nonsteroidal antiinflammatory          associated with bone marrow transplantation. Arq
drug.9                                                            Neropsiquiatr 2001; 59 : 784-789.
                                                               5. Klomp CM, van den Broek MW, Buijs J, Beekman R.
   Leucoencephalopathy due to systemic arterial                   Reversible posterior leucoencephalopathy due to
hypertension associated with pheochromocytoma is                  hypercalcaemia. Ned Tijdschr Geneeskd 2006; 150 : 505-508.
extremely rare. There is very little documentation of such     6. Primavera A, Audenino D, Mavilio N, Cocito L. Reversible
                                                                  posterior leucoencephalopathy syndrome in systemic lupus
association and only one such case with almost similar            and vasculitis. Ann Rheum Dis 2001; 60 : 534-537.
presentation had been reported earlier in literature.          7. Singh S, Balakrishnan C, Mangat G, Maheshwari S. Reversible
Interestingly enough, that patient was also being treated         posterior leucoencephalopathy syndrome in a patient with
for migraine before the definitive diagnosis.10 Particular        undifferentiated connective tissue disease. Scand J Rheumatol
attention needs to be given to PRES because initiation of         2006; 35 : 248-249.
                                                               8. Poon WL, Mok CC. Reversible posterior leucoencephalopathy
appropriate intervention can reverse the encephalopathic
                                                                  in scleroderma. Ann Rheum Dis 2005; 64: 1803-1804.
condition and imaging abnormalities in most cases.             9. Yokobori S, Yokota H, Yamamoto Y. Pediatric posterior
Although this condition is usually transient and                  reversible     leukoencephalopathy         syndrome       and
completely reversible if treatment is instituted, delayed         NSAIDinduced acute tubular interstitial nephritis. Pediatr
diagnosis and therapy can result in ischemic injury and           Neurol 2006; 34 : 245-247.
                                                              10. Moorthy S, Subramaniam TS, Prabhu NK, Sree KK, Nair RG.
irreversible damage with chronic neurological sequelae
                                                                  Posterior reversible encephalopathy syndrome in a child with
and even death. Last, but not least we would also like to         pheochromocytoma. Indian J Radiol Imaging 2002; 12 : 321-324.




Indian Journal of Pediatrics, Volume 75—September, 2008                                                                    955

				
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