Childhood hypertension, sixth nerve palsy, and renal artery stenosis.

This short report demonstrates an uncommon presentation of intracranial bleeding and sixth nerve palsy in a child with systemic hypertension due to long-standing unilateral renal artery stenosis of unknown etiology that resulted in contracture of the affected kidney and compensatory hypertrophy of the contralateral kidney. Structural renal damage and cardiac ventricular hypertrophy suggested the pathology and ensuing hypertension to be long-standing; however, renal function tests were normal at presentation. The importance of routine outpatient evaluation of systemic blood pressure in children, similar to adults, so as to diagnose and treat secondary hypertension and its causes early, before further systemic and neurological complications set in, is emphasized. The primary neuro-ophthalmological clinical presentation of the child with subsequent confluence of major pediatric domains of medicine, surgery, neurology, cardiology, nephrology, interventional radiology, and ophthalmology toward optimum multidisciplinary etiological and symptomatic management of the condition and its sequelae and subsequent rehabilitation is described. Copyright:

Introduction

Hypertension is uncommon in the pediatric age group.[1] As blood pressure is rarely measured in children as a routine, this can remain undetected for long and may present with systemic and neurological sequelae, which can be life-threatening or may cause significant morbidity.[1] The reported case is unusual because of the unique association of increased intracranial tension (ICT) and sixth nerve palsy with secondary hypertension due to long-standing unilateral renal artery stenosis of unknown etiology. The satisfactory multidisciplinary management of the subject is also described.

Case Report

An 8-year-old female child presented to the ophthalmology outpatient services with sudden-onset diplopia on the right gaze preceded by severe frontal headache, multiple episodes of projectile, nonbilious and nonblood-stained vomiting, one episode of generalized tonic–clonic seizure, and excessive drowsiness. There was no history of trauma.

On general physical examination, she weighed 19.5 kg (normal range for 8 years of age and female gender is about 25–28 kg). The blood pressure was 200 mmHg (systolic) and 120 mmHg (diastolic). The pulse was 96 per minute, regular, symmetrical, and with good volume.

On ophthalmic evaluation, the unaided visual acuity was 6/18 in the right eye and 6/12 in the left eye, with no improvement on pin-hole assessment or significant correctable refractive error in either eye. Pupillary reactions were equal to light and near evaluation in both eyes. There was an obvious esodeviation of the right eye with marked abduction deficit, suggestive of sixth nerve palsy. Diplopia charting confirmed this diagnosis. Visual field evaluation by confrontation as well as haploscopy tests for charting the range of extraocular muscle action was inconclusive at initial evaluation as the child was very drowsy and inconsistent with accurate replies. Fundus evaluation revealed bilateral extensive Grade IV hypertensive retinopathy with papilledema.

Contrast-enhanced computed tomography (CECT) scan of the head revealed intraparenchymal bleed in the right temporo-occipital lobe [Figure 1a]. As the child was drowsy, she was admitted to the pediatric intensive care unit and started on antihypertensive therapy comprising intravenous sodium nitroprusside (0.4 μg/ kg/min), intravenous furosemide (1.5 mg/kg three times daily [TDS]), and oral amlodipine (2.5 mg once a day [OD]) for emergency control of blood pressure, which finally stabilized after 24 h on oral doses of amlodipine (2.5 mg OD), atenolol (25 mg OD), prazosin (2 mg OD), and triamterene (25 mg twice daily [BD]). CT of the abdomen demonstrated a smoothly contracted right kidney with compensatory hypertrophy of the left kidney [Figure 1b, coronal and c, axial]. The right renal artery was markedly constricted on CT angiography [Figure 1d]. Two-dimensional echocardiography showed left ventricular hypertrophy, possibly due to the severe and long-standing secondary systemic hypertension. Renal function tests were normal.

Figure 1

(a) Contrast enhanced axial computed tomography scan of the head demonstrated intraparenchymal bleed in the right parietooccipital lobe (white arrow). (b and c) Coronal and axial computed tomography scan of the abdomen revealed smoothly contracted right kidney (white arrow) and hypertrophied left kidney (black arrow). (d) Right renal artery stenosis was observed on computed tomography angiography (white arrow)

Successful balloon stenting and dilatation (2 cm × 12 mm) of the renal artery were performed. Four weeks later, the decreasing blood pressure stabilized at 130 mmHg (systolic) and 90 mmHg (diastolic) on no antihypertensive therapy. Over the next 3 months, gradual improvement of abduction movements in the right eye was observed till the movements became full [Figure 2a and b]. The patient was patched in the right eye till then to avoid diplopia. The hypertensive retinopathy demonstrated no progression, and the papilledema decreased over the next 6 months [Figure 3a and b]. A repeat CECT of the head after 6 months showed no evidence of the intraparenchymal bleed. The visual acuity improved to unaided 6/6 in both eyes. The patient maintained normal blood pressure on no medications, normal ocular movements, and no other neurological sequelae subsequently, over a follow-up of 2 years.

Figure 2

Pre (a) and post-treatment (b) photographs of the patient in 9 gazes demonstrating normalization of abduction movements in the right eye after antihypertensive therapy and balloon dilatation of the stenosed renal artery

Figure 3

Pre (a, top) and post-treatment (b, bottom) fundus photograph of the right and left eye of the patient demonstrating amelioration of the marked bilateral disc edema (white arrow) after treatment. The bilateral disc edema could have been a direct sequelae of severe systemic hypertension or, alternately, the sequelae of high intracranial tension and papilledema because of the intracranial bleed demonstrated in Figure 1a

Discussion

Renal artery stenosis in children is uncommon and occurs due to congenital constriction of the affected renal artery. It may be the cause of renovascular hypertension.[1] Other reported acquired causes include the mid-aortic syndrome, phacomatosis syndromes such as the Klippel–Trenaunay Weber syndrome, linear sebaceous nevus syndrome (Jadassohn nevus phacomatosis) and neurofibromatosis, inflammatory vasculitis of large- and medium-sized blood vessels as in Takayasu's arteritis, Kawasaki disease, Crohn's disease and disseminated tuberculosis, as well as in collagen vascular diseases affecting large- and medium-sized blood vessels such as Marfan's syndrome and fibromuscular dysplasia.[234] Left untreated, renal artery stenosis in children may cause systemic hypertension associated with neurological sequelae such as stroke and seizures as well as failure to thrive and gradual renal failure, especially if the kidneys are affected bilaterally or if the unilateral stenosis is so severe that the contralateral kidney has to compensate and overwork, gradually taking the body into bilateral chronic renal failure. Fortuitously, for the child, in this report, the acute neuro-ophthalmological presentation of sixth nerve palsy, decrease in vision, bilateral Grade IV hypertensive retinopathy, and signs of increased ICT aided the discovery and management of this long-standing asymptomatic condition before the situation became irreversible in the form of cardiac or renal failure. Appropriate multidisciplinary management of the primary cause was helpful not only in the reversal of most of these systemic sequelae but also in rehabilitating the child toward a more productive and meaningful life. We emphasize that simple measures such as routine office evaluation of blood pressure in children would aid detect systemic hypertension and its causes in this age group before further progression of the condition and its neurological or other systemic sequelae occurs.

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Conflicts of interest

There are no conflicts of interest.