The seizures were successfully treated with 2×5 mg rectal diazepam. Because of suspected shock with tachycardia, unmeasurable blood pressure and reduced capillary refill, volume expansion (20 ml/kg NaCl 0.9%) was given three times. Furthermore, the girl was treated with intravenous broad spectrum antibiotics and antiviral medication (acyclovir).
During admission she developed fever (39.6C). After a few hours she had a second convulsion with loss of consciousness and repetitive movements of the right hand, which could not be controlled with intravenous midazolam. At that moment an unexpectedly high blood pressure of 156/119 mm Hg (95th Percentile 110/72 mm Hg) was measured, which made it critical to transfer the patient to the intensive care unit of our tertiary hospital for treatment of malignant hypertension.
On admission, we saw a somnolent girl with cyanotic episodes, temperature 38.3C, blood pressure 140/118 mm Hg and normal capillary refill. Laboratory investigation revealed CRP 37 mg/l, leucocytes 13.4×109/l, urea 5.7 mmol/l, creatinine 34 µmol/l, low potassium (2.2 mmol/l) and metabolic alkalosis (pH 7.49, pCO2 5.3 kPa, bicarbonate 30 mmol/l); analysis of the cerebrospinal fluid was normal. An electro encephalogram (EEG) showed signs of continuous seizure activity. MRI of the brain demonstrated bilateral increased intensity in the area of the cerebral medial and posterior arteries and diffuse abnormalities in the brain stem and basal nuclei (). This led to the working diagnosis of PRES (see Discussion).
MRI of the brain showing area's with increased intensity in the occipital region, suggestive of posterior reversible encephalopathy syndrome.
Treatment with valproic acid followed by fenytoin terminated seizure activity. In addition, for treatment of hypertension intravenous labetalol was started. Suppletion of potassium was initiated.
After 24 h intravenous labetalol could be substituted by oral labetalol in combination with amlodipine.
Antibiotics and antiviral medication could be discontinued after 3 days because of sterile cultures and negative PCR of blood and cerebrospinal fluid.
The girl had never complained of headache, vision problems or nose bleedings. She did not eat licorice and never had urinary tract infections or periods of unexplained fever. Echocardiography showed a structurally normal heart with slightly elevated left ventricle wall mass (LVED 36 mm = 95th percentile), indicative of pre-existent hypertension. Funduscopy demonstrated small retinal haemorrhages consistent with malignant hypertension but no signs of chronic hypertensive retinopathy. Renal function and urinary microscopy were normal, but there was significant albuminuria (234 mg/mmol creatinine, normal <20 mg/mmol), indicative of some renal impairment. Furthermore, plasma renin activity (PRA) was extremely high (68 µg/l/h, normal range 0–2.5 μg/l/h).
The combination of elevated PRA with hypokalemia and metabolic alkalosis raised the suspicion of a renal artery stenosis, parenchymal scars after pyelonephritis or a renin-producing tumour, which is extremely rare in children.
Ultrasound of the urinary tract showed a small right kidney (5 cm, - 2SD) and a normal left kidney (7,3 cm, +1 SD). Dimercaptosuccinic acid scintigraphy demonstrated partial loss of function of the right kidney (right-left kidney function 18–82%) without renal scarring. A right renal artery stenosis was suspected but could not be confirmed by angiography. In contrast, angiography demonstrated areas with diffuse hypoplasia of peripheral arteries of both kidneys, which were most pronounced in the upper pole of the right kidney. These findings are very specific for renal segmental hypoplasia, also called Ask-Upmark kidney ( and ).
Angiography of arterial vascularisation of the right kidney showing diffuse narrowing of the small arteries and loss of cortical visualization mainly in the upper pole, consistent with renal segmental hypoplasia (Ask-Upmark kidney).
Figure 3 Angiography of arterial vascularisation of the left kidney showing a non-significant origostenosis of the left renal artery and diffuse narrowing of the small arteries and loss of cortical visualization in both upper and lower pole, consistent with renal (more ...)