Clinical observation s ACTA PÆDIATR 91 (2002) PCD must be suspected in cases of persistent respiratory distress and/or atelectasis in the newborn, in order to reduce or prevent complications of the disease. References 1. Beardsmore CS, Bar-Yishay E, Maayan C Yahav Y, Katznelson D. Lung function in infants with cystic Ž brosis. Thorax 1988; 43: 545–51 2. Perlman M, Williams J, Hirsch M, Bar-Ziv J. Familial non-cysti c Ž brosis mucus inspissatio n of respirator y tract. Arch Dis Child 1975; 50: 727–30 3. Afzelius BA. A human syndrom e caused by immotile cilia. Science 1976; 193: 317–9 4. Afzelius BA. Situs inversus and ciliary abnormalities . What is the connection ? Int J Dev Biol 1995; 39: 839–44 5. Losa M, GhelŽ D, Hof E, Felix H, Fanconi S. Kartagener syndrome: an uncommon cause of neonatal respiratory distress? Eur J Pediatr 1995; 154: 236–8 6. Pennarun G, Escudier E, Chapelin C, Bridoux AM, Cacheux V, Roger G, et al. Loss-of-functio n mutations in a human gene 1005 related to Chlamydomonas reinhardti i dynein IC78 result in primary ciliary dyskinesia. Am J Hum Genet 1999; 65: 1508–19 7. Olbrich H, Haffner K, Kispert A, Volkel A, Volz A, Sasmaz G, et al. Mutations in DNAH5 cause primary ciliary dyskinesi a and randomizatio n of left–right asymmetry. Nature Genet 2002; 30: 143–4 8. Whitelaw A, Evans A, Corrin B. Immotile cilia syndrome: a new cause of neonatal respirator y distress. Arch Dis Child 1981; 56: 432–5 9. Ramet J, Byloos J, Delree M Sacre L, Clement P. Neonatal diagnosis of the immotile cilia syndrome. Chest 1986; 90: 138– 40 10. Svartengre n K, Philipson K, Svartengren M, Nerbrink O, Camner P. Clearance in smaller airways of inhaled 6-microm particles in subjects with immotile-cilia syndrome. Exp Lung Res 1995; 21: 667–82 11. Cole P. Pathophysiolog y and treatment of airway mucociliary clearance . A moving tale. Minerva Anestesiol. 2001; 67: 206–9 12. Ellerman A, Bisgaard H. Longitudina l study of lung function in a cohort of primary ciliary dyskinesia. Eur Respir J. 1997; 10: 2376–9 Received Oct. 10, 2001; revision received April 29, 2002; accepted May 16, 2002 Reversible brain lesions in childhood hypertension P Singhi, C Subramanian, V Jain, S Singhi and M Ray Division of Pediatric Neurology, Department of Pediatrics, Advanced Pediatric Centre, Postgraduat e Institute of Medical Education and Research, Chandigarh , India Singhi P, Subramanian C, Jain V, Singhi S, Ray M. Reversible brain lesions in childhood hypertension. Acta Pædiatr 2002; 91: 1005–1007. Stockholm, ISSN 0803-5253 Posterior leukoencephalopathy syndrome is characterized by an acute, usually reversible, encephalopathy with transient occipital lobe abnormalities detected on MRI that occur mostly in association with acute hypertension. The clinical presentation includes seizures, headache, altered mental status and blindness. Disturbed autoregulation of cerebral blood  ow and endothelial injury are central to the pathogenesis of this disorder. Prompt control of hypertension results in rapid and complete neurological recovery. In this report we discuss the cases of two children with acute onset hypertension of different aetiologies that presented with the characteristic features of posterior leukoencephalopathy syndrome. Conclusion: Early recognition of this readily treatable condition may obviate the need for extensive and invasive investigations. Despite the alarming lesions on the MRI, prompt control of hypertension carries a uniformly favourable prognosis. Key words: Acute hypertension, autoregulation , cerebral blood  ow, posterior leukoencephalopathy syndrome Pratibha Singhi, Division of Pediatric Neurology, Department of Pediatrics, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India (Tel. ‡91 1727 47585, ext. 486, fax. ‡91 172 744 401/745 038, e-mail. drsinghi@glide.net.in) Posterior leukoencephalopathy syndrome (PLES) is a recently recognized neurological syndrome presenting with altered mental status, visual loss, stupor, seizures and unique radiological manifestations. Common triggers include severe hypertension, immunosuppressive drugs (cyclosporine, tacrolimus),  uid retention and renal decompensation (1, 2). Here we describe the clinical and neuroimaging features of PLES in two children with hypertension of different aetiologies who recovered after control of hypertension. 1006 Clinical observation s Case 1 A 4-y-old boy presented with a 2-d history of headache and vomiting, and generalized tonic clonic seizures followed by unconsciousness for 6 h. After recovery of sensorium, the boy complained of loss of vision, for which he was referred to our hospital. At admission his blood pressure was 220/180 mmHg; he was drowsy, had normal-sized reacting pupils, exaggerated deep tendon re exes and bilateral upgoing plantars with no focal neurological deŽ cits. The fundus showed bilateral papilloedema and hard exudates. The patient’s blood counts, serum electrolytes and renal function were normal. Antinuclear antibody and antineutrophil antibody titres were negative. Urine 24-h vanillyl-mandelic acid (VMA) and metanephrines were within normal limits. Magnetic resonance imaging (MRI) of the brain at admission showed hypo-intense signals over the occipital lobes on the T1-weighted image. On the T2weighted image (Fig. 1) there were hyper-intense signals in the occipital lobes, basal ganglia and caudate nucleus that intensiŽ ed on the  uid attenuated inversion recovery (FLAIR) sequence. The patient’s hypertension was initially controlled with sodium nitroprusside infusion, later with oral antihypertensives. The child’s sensorium and abnormal neurological Ž ndings normalized and his vision improved over the next 48 h. MRI repeated after one week of admission was normal (Fig. 2). Magnetic resonance angiography of the abdominal aorta ruled out middle aortic syndrome but revealed narrowing of one of the segmental branches of the left renal artery. Percutaneous transluminal renal angio- Fig. 1. Axial T2 -weighted image shows hyperintens e signals in the occipital lobes, basal ganglia and caudate nucleus. ACTA PÆDIATR 91 (2002) plasty could not be undertaken. The child is now being treated with tapering doses of oral antihypertensives and is doing well. Case 2 A 9-y-old male presented with a 2-d history of abdominal pain, recurrent vomiting and fever followed by two episodes of generalized tonic clonic seizures. He was treated in a hospital with intravenous dextrose, phenytoin and antibiotics and given a presumptive diagnosis of meningoencephalitis. As his condition continued to deteriorate, he was referred to our hospital. At admission, the patient was comatose, had hypertension (180/120 mmHg), tachycardia (130/min) and fever, and had decreased muscle tone, diminished re exes and upgoing plantars. His pupils were of equal size reacting to light. The fundii were normal. MRI revealed involvement of occipital lobes with hypointense signals on T1-weighted images and hyperintense signals on T2weighted images. A nerve conduction study showed evidence of axonal motor neuropathy. The possibility of acute intermittent porphyria (AIP) was considered. Biochemical assessments of serum and cerebrospinal  uid were normal. Though plasma lead level was normal (0.055 mmol/L; normal <1 mmol/L), urinary excretions of ¯-amino levulinic acid (600 mmol/d; normal <60 mmol/d) and porphobilinoge n (480 mmol/d; normal <10 mmol/d) were elevated. The patient was managed with intravenous glucose (300 g/d), haematin was not available, and his blood pressure was stabilized Fig. 2. Magnetic resonanc e image (MRI) of case 1 after 1 wk of the acute phase: The T2 -weighted image at the same level does not show any signal abnormalit y Clinical observation s ACTA PÆDIATR 91 (2002) on intravenous nitroprusside drip followed by oral propranolol. Seizures were controlled with clonazepam. The patient’s sensorium improved over the next 3 d, but he complained of blindness. Over the next 2 wk his vision and neurological status normalized. Follow-up MRI showed resolution of the lesions. Discussion The PLES is associated predominantly with white matter oedema in the posterior parts of the brain. It is usually attributed to severe elevations in blood pressure but may also occur in normotensive patients (1, 2). Although initially termed “reversible posterior leukoencephalopathy syndrome”, PLES may not always be reversible (3). Differentiating this syndrome from stroke, cerebral venous sinus thrombosis, acute disseminated encephalomyelitis or encephalitis is of paramount importance, as prompt initiation of antihypertensive therapy can lead to complete clinical and radiological recovery. Reversible cerebral lesions with cortical blindness have been documented in adult patients with acute intermittent porphyria, but this has not been reported in children (4–6). The exact pathophysiolog y is unknown but a probable mechanism involved is a capillary leak due to hypertension,  uid retention and in cases of immunosuppressive agents possibly the cytotoxic effect on the vascular endothelium (2). During elevations of blood pressure within the cerebral auto regulative range (60– 150 mmHg mean arterial pressure), the large- and medium-sized intracranial vessels constrict under the in uence of the sympathetic nervous system and reduce the cerebral blood  ow. This contributes to maintaining the cerebral perfusion pressure within the physiologic range (7–9). However, with severe hypertension, the auto-regulatory mechanism is lost and there is forcible dilatation of small resistance vessels, with leakage of plasma into the extra-vascular space, producing vasogenic cerebral oedema (7, 9). These changes are more pronounced in the occipital lobes possibly because of the less dense sympathetic nervous system innervation of the posterior cerebral circulation (10). Vasospasm caused by transient deŽ ciency of nitric oxide and acute elevations in blood pressure have been implicated as the underlying mechanism for PLES in patients with AIP (4, 5). Sodium nitroprusside, is known to cause dilatation of cerebral vessels; however, it was safely used in our patient, as human studies have shown that autoregulation of cerebral blood  ow is well preserved with moderate (0.5–3 mg kg¡1 min¡1) doses of sodium nitroprusside (11). In PLES, white matter oedema involves the posterior portion of the cerebral hemispheres: calcarine Ž ssure is usually spared, which distinguishes it from bilateral infarction of the posterior cerebral artery territory. On 1007 MRI, T1-weighted images during the acute phase may be normal or show few, usually asymmetrical, hypointense signals selectively in the posterior cerebral hemispheres, cerebellum, basal ganglia and thalami. FLAIR sequences and T2-weighted images reveal hyperintense signals in the corresponding regions, representing extra cellular oedema (2, 12). Recently, other MRI techniques such as echo planar diffusionweighted imaging (DWI) and apparent diffusion coefŽ cient (ADC) maps have been found to be more accurate in differentiating PLES from other conditions causing cerebral ischaemia (13). In Case 1, the MR Ž ndings were typical of vasogenic brain oedema, and reversed within 48 h of control of blood pressure. In conclusion, PLES is an acute neurological syndrome that occurs in speciŽ c clinical settings and is associated with distinct neuroimaging Ž ndings. Reversibility of this syndrome on prompt control of hypertension or removal of other triggering factors emphasizes the need for its immediate recognition. References 1. Garg RK. Posterior leukoencephalopath y syndrome. Postgrad Med J 2001; 77: 24–8 2. Hinchey J, Chaves C, Appignani B, et al. A reversibl e posterior leukoencephalopath y syndrome. N Engl J Med 1996; 334: 494– 500 3. Antunes NL, Small TN, George D, Bouldad F, Lis E. Posterior leukoencephalopath y syndrom e may not be reversible . Pediatr Neurol 1999; 20: 241–3 4. Garg MK, Mohapatro AK, Dugal JS, Singh AP. Cortical blindness in acute intermitten t porphyria. JAPI 1999; 47: 727–9 5. Kupferschmid t H, Bont A, Schnorf H, et al. Transient cortical blindness and bioccipita l brain lesions in two patients with acute intermitten t porphyria. Ann Intern Med 1995; 123: 598–600 6. King PH, Bragdon CA. MRI reveals multiple reversibl e cerebral lesions in an acute attack of acute intermitten t porphyria . Neurology 1991; 41: 1300–2 7. Johanssao n B. The blood brain barrier and cerebral blood  ow in acute hypertension . Acta Med Scand 1983; Suppl 678: 107–12 8. Paulson OB, Strandgaar d S, Edvinsson L. Cerebral autoregula tion. Cerebrovas c Brain Metab Rev 1990; 2: 161–92 9. Miller JD. Basic intracrania l dynamics. In: Minns RA, editor. Problems of intracrania l pressure in childhood . London: MacKeith Press; 1991, p. 1–12 10. Sundt T Jr. The cerebral autonomic nervous system: a proposed physiologi c function and pathophysiologi c response in subarachnoid hemorrhag e and in focal cerebral ischemia. Mayo Clin Proc 1973; 48: 127–37 11. Henriksen L, Paulson OB. The effects of sodium nitroprussid e on cerebral blood  ow and cerebral venous blood gases in man. Acta Med Scand 1983; Suppl 678: 91–6 12. Bakshi R, Bates V, Mechtler L, Kinkel P, Kinkel W. Occipital lobe seizures as the major clinical manifestation of reversibl e posterior leukoencephalopath y syndrome: magnetic resonance imaging Ž ndings. Epilepsia 1998; 39: 295–9 13. Ay H, Buonanno FS, Schaefer PW, et al. Posterior leukoencephalopath y syndrome without severe hypertension : utility of diffusion-weighte d MRI. Neurology 1998; 51: 1369–76 Received June 26, 2001; revisions received Dec. 4, 2001 and March 11, 2002; accepted March 27, 2002