Renovascular hypertension in children with moyamoya disease

Moyamoya Vasculopathy and Moyamoya-Related Systemic Vasculopathy: A Review With Histopathological and Genetic Viewpoints

Systemic vasculopathy has occasionally been reported in cases of moyamoya disease (MMD). Since the pathological relationship between moyamoya vasculopathy (MMV) and moyamoya-related systemic vasculopathy (MMRSV) remains unclear, it was examined herein by a review of histopathologic studies in consideration of clinicopathological and genetic viewpoints. Although luminal stenosis was a common finding in MMV and MMRSV, histopathologic findings of vascular remodeling markedly differed. MMV showed intimal hyperplasia, marked medial atrophy, and redundant tortuosity of the internal elastic lamina, with outer diameter narrowing called negative remodeling. MMRSV showed hyperplasia, mainly in the intima and sometimes in the media, with disrupted stratification of the internal elastic lamina. Systemic vasculopathy has also been observed in patients with non-MMD carrying the RNF213 (ring finger protein 213) mutation, leading to the concept of RNF213 vasculopathy. RNF213 vasculopathy in patients with non-MMD was histopathologically similar to MMRSV. Cases of MMRSV have sometimes been diagnosed with fibromuscular dysplasia. Fibromuscular dysplasia is similar to MMD not only in the histopathologic findings of MMRSV but also from clinicopathological and genetic viewpoints. The significant histopathologic difference between MMV and MMRSV may be attributed to a difference in the original vascular wall structure and its resistance to pathological stress between the intracranial and systemic arteries. To understand the pathogeneses of MMD and MMRSV, a broader perspective that includes RNF213 vasculopathy and fibromuscular dysplasia as well as an examination of the 2- or multiple-hit theory consisting of genetic factors, vascular structural conditions, and vascular environmental factors, such as blood immune cells and hemodynamics, are needed.

Moyamoya disease presenting with tubular dysfunction in a child: pitfalls in diagnosing an atypical hyponatremic-hypertensive syndrome

BACKGROUND

Moyamoya disease, a cause of pediatric stroke, has been shown to affect furthermore extra-cranial districts, mostly the kidney arterial site, resulting in steno-occlusive changes. Unilateral renal artery stenosis accounts for 8%-10% out of cases of renovascular hypertension in childhood, however it rarely underlies a hyponatremic-hypertensive syndrome (HHS).

CASE PRESENTATION

We describe an 18-month-old boy with a recent history of polyuria and polydipsia, who presented an acute febrile gastroenteritis with neurological impairment, severe dehydration, hyponatremia, hypokalemia, kidney tubular dysfunction, and elevated aldosterone and renin even with a normal blood pressure. Fluid and electrolytes correction was performed, with complete recovery. An abdominal ultrasound displayed a smaller right kidney. A brain magnetic resonance and an electroencephalogram did not show any relevant abnormalities. Five months later, the child experienced a left-side hemiparesis after a traumatic concussion, and a severe hypertension. A brain tomography documented a cerebral ischemia. Brain and kidney angiographic studies displayed puff of smoke findings of internal right carotid artery branches and a steno-occlusive pattern of right renal artery, respectively. Hence, moyamoya disease with HHS secondary to unilateral renal artery stenosis was diagnosed. After an unsuccessful antiplatelet and antihypertensive pharmacological treatment, the boy underwent a renal angioplasty and a cerebral STA-MCA bypass (direct superficial temporal artery-to-middle cerebral artery bypass), resulting in a significant improvement of both neurological and kidney disease.

CONCLUSIONS

Although the association between unilateral renal artery stenosis and HHS has been previously shown, this is the first report of atypical HHS, with hypertension preceded by tubular dysfunction, recognized in the framework of moyamoya disease.

Research progress of moyamoya disease combined with renovascular hypertension

Moyamoya disease (MMD) is an idiopathic cerebrovascular disease which was first described by Suzuki and Takaku in 1969. Moyamoya disease is a non-atherosclerotic cerebrovascular structural disorder. MMD has been found all over the world, especially in Japan, Korea, and China. In recent years, many reports pointed out that the changes of vascular stenosis in patients with moyamoya disease occurred not only in intracranial vessels, but also in extracranial vessels, especially the changes of renal artery. Renovascular hypertension (RVH) is considered to be one of the important causes of hypertension in patients with moyamoya disease. The pathogenesis of moyamoya disease combined with renovascular hypertension is still unclear, and the selection of treatment has not yet reached a consensus. This article reviews the latest research progress in epidemiology, RNF213 gene, pathomorphology, clinical characteristics and treatment of moyamoya disease combined with renovascular hypertension, in order to provide reference for clinical workers.

Ring Finger Protein 213 in Moyamoya Disease With Pulmonary Arterial Hypertension: A Mini-Review

Moyamoya disease (MMD), most often diagnosed in children and adolescents, is a chronic cerebrovascular disease characterized by progressive stenosis at the terminal portion of the internal carotid artery and an abnormal vascular network at the base of the brain. Recently, many investigators show a great interest in MMD with pulmonary arterial hypertension (PAH). Ring finger protein 213 (RNF213) is a major susceptibility gene for MMD and also has strong correlations with PAH. Therefore, this review encapsulates current cases of MMD with PAH and discusses MMD with PAH in the aspects of epidemiology, pathology, possible pathogenesis, clinical manifestations, diagnosis, and treatment.

Moyamoya disease associated with pediatric pulmonary hypertension-a case report

Moyamoya disease (MD) is a rare vaso-occlusive disorder that primarily affects intracranial cerebral arteries. The involvement of extracranial vessels is unusual. However, there are previous reports suggesting MD to be a systemic disorder, causing disease manifestations in vessels of other parts of the body. We report the case of a female patient with MD and multiple episodes of ischemic strokes followed by bypass surgery of cerebral arteries during infancy. Due to corresponding ischemic lesions the girl showed global retardation of psychomotor development and central right sided movement disorder. At the age of 10 years the girl was admitted to our hospital with recurrent syncope. While cranial MRI excluded any newly added ischemic lesions, electrocardiography revealed evidence of right ventricular hypertrophy, and subsequent echocardiography then indicated pulmonary hypertension, which was confirmed by cardiac catheterization. Despite an upfront combination pulmonary vasodilating therapy, the pulmonary vascular disease appeared to be progressive. Genetic analysis showed heterozygous c.12341C>T mutation in the RNF213 gene. This case presentation demonstrates that pulmonary arterial hypertension is a rare comorbidity in patients with MD, especially in patients with genetic predictors such as the RNF213 mutation. Thus, regular echocardiographic screening for early signs of pulmonary arterial hypertension in patients with MD should be part of regular clinical work-up. Early detection and treatment of pulmonary arterial hypertension in MD might help to improve the long-term outcome in the individual patient.

Hypertension and childhood stroke

Cerebrovascular disease (stroke) is one of the ten leading causes of death in children and adolescents. Multiple etiologies, from arteriopathies to prothrombic states, can cause stroke in youth. In adult stroke, hypertension has been shown to be the single most important modifiable risk factor. Although hypertension has not been strongly identified as a risk factor in childhood stroke to date, there is preliminary evidence that suggests that hypertension may also be associated with stroke in children. In this review, we summarize the literature that may link hypertension to stroke in the young. We have identified a series of barriers and limitations in the fields of pediatric hypertension and pediatric neurology that might explain why hypertension has been overlooked in childhood stroke. We suggest that hypertension may be a relevant risk factor that, alone or in combination with other multiple factors, contributes to the development of stroke in children. Currently, there are no consensus guidelines for the management of post-stroke hypertension in children. Thus, we recommend that blood pressure be assessed carefully in every child presenting with acute stroke in order to better understand the effects of hypertension in the development and the outcome of childhood stroke. We suggest a treatment algorithm to help practitioners manage hypertension after a stroke.

De Novo Renal Artery Stenosis Developed in Initially Normal Renal Arteries during the Long-Term Follow-Up of Patients with Moyamoya Disease

BACKGROUND

The de novo occurrence of renal artery stenosis in renal arteries that were angiographically confirmed to be normal in the past has never been reported before in patients with moyamoya disease.

CASE DESCRIPTION

During the long-term follow-up of pediatric patients with moyamoya disease, we observed 3 patients who developed de novo renal artery stenosis in arteries that had been angiographically confirmed to be normal 1 year after the surgery (7 years on average, ranging from 4 to 11 years). All of these patients were neurologically stable after successful indirect bypass surgery during childhood. However, more than 10 years after the surgery (15 years on average, ranging from 14 to 23 years), they developed hypertension and were found to have de novo renal artery stenosis, which was ameliorated by endovascular angioplasty. During the follow-up after angioplasty, 1 patient experienced a recurrence of hypertension and required a second and third angioplasty for restenosis. Another patient died of intracranial hemorrhage 2 years after angioplasty. In the 2 surviving patients, gene analysis of the ring finger protein 213 (RNF213; p.R4810K) point mutation, the susceptibility gene for moyamoya disease in the Asian population, was positive for the heterozygous variant.

CONCLUSIONS

De novo renal artery stenosis might develop in initially normal arteries during long-term follow-up, particularly among pediatric patients with moyamoya disease. Considering the extracranial manifestations of moyamoya disease, clinicians should keep in mind that de novo renal artery stenosis could emerge later in their life. Thus, it is crucial to continue to follow these patients for decades, even if the patients are neurologically stable after bypass surgery. Monitoring for blood pressure and the de novo occurrence of renal artery stenosis is important to prevent hypertension-related morbidity and mortality, such as intracranial hemorrhage, in this disease population.

Moyamoya disease associated with fibromuscular dysplasia of intrapulmonary bronchial arteries-a case report

A case is reported of a 40-year-old woman clinically diagnosed as moyamoya disease with associated fibromuscular dysplasia of intrapulmonary bronchial arteries incidentally revealed during autoptic examination. Moyamoya disease represents an idiopathic noninflammatory and nonatherosclerotic arterio-occlusive process of intracranial arteries. Prolonged brain ischemia leads to formation of tiny and fragile collaterals. Clinically, patients with moyamoya angiopathy commonly present with severe neurological symptoms caused by brain infarction or hemorrhage. Histologically, the steno-occlusive process is based on fibrocellular thickening of intima and intimal smooth muscle cell proliferation. In the literature, extracranial arterial involvement, i.e. fibromuscular dysplasia of renal or pulmonary arteries, has been described in several cases of moyamoya disease. Our aim is to show a unique case of moyamoya disease associated with fibromuscular dysplasia affecting an uncommon site.

High prevalence of systemic hypertension in pediatric patients with moyamoya disease years after surgical treatment

OBJECTIVE

Although an association between moyamoya disease (MMD) and renovascular hypertension has been acknowledged, the literature on systemic hypertension without renal artery stenosis among patients with MMD is scarce. The authors aimed to evaluate the prevalence and risk factors of hypertension using data from MMD patients who visited an outpatient clinic of a pediatric neurosurgical department in 2016.

METHODS

The authors evaluated the blood pressure (BP) of pediatric MMD patients at their postsurgical appointment following the American Academy of Pediatrics clinical practice guideline on high BP, in which hypertension was defined as BP measurements higher than the value of age-, sex-, and height-specific 95th percentile of the general population from at least 3 separate visits. Growth of patients was determined using 2017 Korean National Growth Charts for children and adolescents. The cutoff value of the 95th percentile of BP was determined by referring to normative BP tables of Korean children and adolescents. A logistic regression model was used to assess the associations between patients' clinical characteristics and prevalent hypertension.

RESULTS

In total, 131 surgically treated pediatric MMD patients were included, of whom 38.9% were male and the median age at diagnosis was 8.0 years (range 1.2-15.0 years). The definition of hypertension was met in 38 patients, with a prevalence of 29.0% (95% CI 21.2%-36.8%). A tendency was observed for a higher prevalence of hypertension in male patients (31.4%), in patients with posterior cerebral artery (PCA) involvement (47.8%), and in cases in which infarction was shown on initial MRI (37.3%). Age at diagnosis (adjusted OR [aOR] 0.82, 95% CI 0.70-0.97), PCA involvement (aOR 3.81, 95% CI 1.29-11.23), body mass index (aOR 1.30, 95% CI 1.13-1.51), and years of follow-up since surgery (aOR 0.80, 95% CI 0.68-0.94) were related to systemic hypertension.

CONCLUSIONS

A high prevalence of hypertension was demonstrated in pediatric MMD patients. Therefore, adequate attention should be paid to reduce BP and prevent subsequent events.

Pediatric renovascular hypertension: Treatment outcome according to underlying disease

BACKGROUND

Renovascular hypertension (RVH) accounts for 5-10% of pediatric hypertension, and can be associated with underlying disease involving other organs. The purpose of this study was to evaluate the clinical characteristics and assess the treatment outcomes of Korean pediatric patients with RVH.

METHODS

The medical records of 25 Korean pediatric patients with RVH were retrospectively reviewed.

RESULTS

Twenty-four patients had underlying disease, and the most common cause was moyamoya disease (MMD; n = 10; 40%). Of 10 patients with MMD, seven had RVH prior to MMD. All patients required antihypertensive medication as the initial treatment and 22 patients subsequently underwent percutaneous transluminal angioplasty (PTA). The majority of patients with MMD had ostial lesions on angiography. Eight patients had favorable outcomes after the first PTA. One patient received nephrectomy, and two patients received bypass surgery because of restenosis after PTA and technical failure of PTA, respectively. During follow up, blood pressure was well-controlled in nine patients, but only four patients were able to discontinue medication. Eight patients had target-organ damage of the brain, heart, and retina at the time of initial diagnosis, and five patients developed chronic kidney disease during follow up.

CONCLUSION

The most common cause of RVH in Korean children is MMD, and RVH caused by MMD with an ostial lesion is associated with poor PTA outcomes. Angioplasty alone does not appear to control blood pressure effectively in MMD patients, and combined treatment is necessary to prevent target organ damage.

Long-Term Outcomes of Pediatric Renovascular Hypertension

BACKGROUND/AIMS

Renovascular hypertension (RVHT) is an important cause of childhood hypertension. This study evaluated the clinical characteristics and outcomes of Korean children with RVHT.

METHODS

Children treated for RVHT between 2000 and 2015 at our center were retrospectively reviewed.

RESULTS

Forty-six children were followed for a median of 6.5 (0.66-27.23) years. Forty-five percutaneous transluminal angioplasties (PTAs) were performed in 32 children. At the last visit, clinical benefit was observed in 53.3% of children. Patients with comorbid cerebrovascular disease (CVD) showed less favorable long-term outcomes after PTA (clinical benefit in 41.7% vs. 61.1% in others) and higher restenosis rates (50% vs. 31.6% in others). Surgical procedures (bypass or nephrectomy) were performed in 8 patients. After surgery, blood pressure was normalized in 2 patients, improved in 3 patients, and unchanged in the remaining patients. Between PTA group (n=21) and medication group (n=14), percentage of atrophic kidneys became higher after follow-up period in medication group than in PTA group (60.0% vs. 26.1%, P=0.037).

CONCLUSION

Aggressive treatment of pediatric RVHT yielded fair outcomes in our cohort. CVD comorbidity was associated with relatively poor PTA outcomes. To confirm our findings, larger cohort studies with a longer follow-up period are warranted.

Associated extrarenal vascular diseases may complicate the treatment and outcome of renovascular hypertension

AIM

This studied reviewed renovascular hypertension (RVH) due to renal artery stenosis (RAS) in two Serbian paediatric centres from 2001 to 2013.

METHODS

The patients' demographic data, underlying syndromes, blood pressure (BP), antihypertensive treatments and outcomes were reviewed.

RESULTS

The incidence of RVH was 1.9 per million children per year during the study period, and there were 25 patients with RAS, aged 10.4 ± 5.2 years. At presentation, their mean blood pressure (BP) standard deviation scores were 6.9 ± 3.4 systolic and 5.2 ± 2.6 diastolic. BP loads on 24-hour ambulatory BP were 88 ± 14% systolic and 80 ± 29% diastolic. We found that 72% had fibromuscular dysplasia and 28% had underlying syndromes. RAS was unilateral in 64% and bilateral in 28%, and 8% had RAS of a single kidney. Antihypertensive treatment included antihypertensive drugs (100%), percutaneous transluminal angioplasty (92%), renal auto-transplantation (16%), surgical revascularisation (12%) and nephrectomy (12%). After 4.4 ± 3.6 years of follow-up, high BP was cured in 40% of the patients and 39.4% of the kidneys and improved in 48% (75.7%), with BP decreases of 20.3 ± 3.7% systolic and 16.3 ± 6.2% diastolic.

CONCLUSION

Fibromuscular dysplasia was the most common cause of RVH in this study, and hypertension was cured or improved in 88% of the patients.

Prevalence and clinical implications of renal artery stenosis in pediatric moyamoya disease

PURPOSE

Until recently, extracranial involvement of moyamoya disease (MMD) had not been fully elucidated. The purpose of this study was to determine the prevalence and clinical implications of renal artery stenosis in pediatric MMD patients.

MATERIALS & METHODS

This retrospective study included 101 pediatric (<18 years old) MMD patients who visited our hospital from July 2008 to May 2013. All patients had legible abdominal or renal angiography. Baseline characteristics, including hypertension (HT) and angiographic findings, were retrospectively evaluated.

RESULT

The median age was 8 (range 2-16) years. Six patients (5.9%) had HT. Renal artery stenosis was identified in 8 patients (7.9%). Five of 8 renal artery stenosis patients had HT. Statistical analysis showed that advanced stages of MMD and HT were associated with renal artery stenosis (p < 0.05).

CONCLUSION

Renal artery stenosis was not uncommon in pediatric MMD. Renal artery evaluation could help determine the cause of HT in advanced pediatric MMD cases. Further prospective and large-scale studies may be helpful in elucidating the extracranial manifestation of MMD.

An analysis of long-term occurrence of renal complications following pediatric pyeloplasty

OBJECTIVE

Few reports discuss post-pubertal renal complications after pyeloplasty. We analyzed long-term complications, such as decreased renal function (RF) measured by serum creatinine (SCr), hypertension (HTN), or proteinuria (protU) following pediatric pyeloplasty.

SUBJECTS AND METHODS

We retrospectively investigated 257 patients who underwent dismembered pyeloplasty due to ureteropelvic junction obstruction from January 1986 to December 2001. Medical history, preoperative and postoperative blood pressure, urinalysis, and SCr results were reviewed.

RESULTS

Fifty-five patients (47 male, 8 female) who were followed up for at least 10 years with post-pubertal follow-up data available were analyzed. Seven (12.7%) patients were diagnosed with HTN, and 10 (18.2%) with protU. The grade of hydronephrosis decreased, and the differential RF measured by MAG-3 renal scan significantly increased at final analysis (p<0.001). Presence of preoperative symptoms (p=0.034), and SCr elevation (p=0.018) showed correlation with HTN. HTN took 15.7 (±5.8) (7-25) years, and protU detection took 16.2 (±5.9) (6-23) years, with the highest incidence of both HTN and protU between 15 and 20 years postoperatively.

CONCLUSION

According to our investigation, a prudent evaluation of signs of RF decrease at 10 years after surgery, and then every 5 years, until 20 years should be recommended, although further studies are necessary.

Pediatric renovascular hypertension in Thailand: CT angiographic findings

BACKGROUND

Renovascular disease is an uncommon but important cause of hypertension in children. When unrecognized and untreated, renovascular hypertension in children can have serious complications.

OBJECTIVE

To review the causes of renovascular hypertension and computed tomography angiographic (CTA) findings in children and adolescents.

MATERIALS AND METHODS

Twenty-eight CTAs from January 2004 to March 2008 of 23 children and adolescents with hypertension were reviewed for the causes and CTA findings.

RESULTS

Nine of the 23 children (39%) had abnormal renal arteries with or without abnormal abdominal aortas. Four of these children had Takayasu arteritis, one had moyamoya disease, and one had median arcuate ligament syndrome. One with chronic pyelonephritis had severe stenosis of the proximal right renal artery. The other two children had renal artery stenosis with a nonspecific cause. One child with a normal abdominal aorta and renal arteries had a right suprarenal mass. On pathological examination a ganglioneuroma was found.

CONCLUSION

CTA can help in diagnosis of renovascular hypertension in children and adolescents. Although CTA is not a screening modality, it is appropriate in some situations.

Siblings with infantile cerebral stroke and delayed multivessel involvement--a new hereditary vasculopathy?

We describe an unusual vasculopathy in two sisters of non-consanguineous parents. The first child developed an acute hemiparesis and focal seizures at the age of 6 months during a febrile illness. Magnetic resonance imaging (MRI) of the brain showed bilateral cortical-subcortical infarction not confined to a vascular territory. Subsequently, the child had a persistent stable neurological deficit. Her younger sister had a similar encephalitis-like episode at the age of 4 months, with left-sided cortical-subcortical ischaemic lesions. Two months later she had left-sided focal seizures. MRI showed a right-sided cortical enhancement, magnetic resonance angiography (MRA) was normal. The neurological deficit was stable and she was seizure free. These episodes were initially interpreted as metabolic strokes, but work-up was normal and mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) was excluded. In their teens both sisters were diagnosed with pulmonary and systemic hypertension and, due to the arterial hypertension, myocardial hypertrophy. Renal artery stenosis, pathological pulmonary arteries, and stenosis and rarefication of coronary arteries were found; the aorta and retinal vessels were normal. Repeat cranial MRI and MRA showed multiple collaterals, while the carotid and basilar arteries were extremely narrowed (moyamoya appearance). We suggest the diagnosis is a hereditary systemic vasculopathy of unknown origin.

Fibromuscular dysplasia as the substrate for systemic and pulmonary hypertension in the setting of Moya-Moya disease

We report the first case, to the best of our knowledge, of a child with the unusual association of Moya-Moya disease and both systemic and pulmonary hypertension. Histological examination revealed fibromuscular dysplasia as the common denominator for a diffuse arteriopathy.

Treatment of severe renal artery stenosis by percutaneous transluminal renal angioplasty and stent implantation: review of the pediatric experience: apropos of two cases

The clinical course of two children with mid-aortic syndrome and renal artery stenosis (RAS) who suffered from severe arterial hypertension is described. Hypertension was uncontrollable by antihypertensive medication and was managed by percutaneous transluminal renal angioplasty (PTRA) with stent implantation. The pediatric experience with PTRA is limited, and there are only few cases reported with additional stent implantation. Complications of these procedures are well known from experience with adult patients. However, since surgical revascularization may be technically difficult especially in small children, PTRA with or without stenting should be considered as a valuable treatment option in pediatric RAS.

Prevalence of stenoocclusive lesions in the renal and abdominal arteries in moyamoya disease

OBJECTIVE

The extracranial involvement of moyamoya disease has been reported in several studies. The main purpose of this study was to determine the prevalence of stenoocclusive lesions in the renal and major abdominal arteries in moyamoya disease.

MATERIALS AND METHODS

Abdominal angiography was performed in 73 patients with idiopathic moyamoya disease. The findings of abdominal angiography were retrospectively reviewed for the presence and appearance of stenosis in the renal and other major abdominal arteries.

RESULTS

Four (5%) of 73 patients presented with unilateral renal artery stenosis. Three patients had moderate stenosis, and one patient had mild stenosis. In the three patients with moderate stenosis, the renal artery stenosis was located in the proximal region of the main branch. Two patients (3%) with moderate stenosis of the unilateral renal artery had renovascular hypertension. No statistically significant differences were observed in age, sex, and the cerebral angiographic stage between patients with and without renal artery stenosis. No stenosis was found in the abdominal aorta or celiac, superior mesenteric, common hepatic, splenic, and proximal common iliac arteries. No occlusions were found in any abdominal arteries.

CONCLUSION

The prevalence of renal artery stenosis in patients with moyamoya disease was 5% (4/73). Involvement of the proximal region of the renal artery was dominant. No stenosis was found in other abdominal arteries.

Intravascular ultrasound detects coarctation of the renal artery in a patient with Moyamoya disease

A 19-year-old man with moyamoya disease was diagnosed as having renovascular hypertension, based on stenosis of the proximal portion of the right renal artery with elevated plasma renin activity. Intravascular ultrasound (IVUS) imaging at the renal artery lesion revealed focal narrowing of the renal artery without vascular wall thickening (i.e., coarctation). The coarctation of the renal artery was adequately dilated by stent implantation after suboptimal balloon angioplasty. After the procedure, the patient's hypertension improved. The findings of the present case suggest that IVUS-guided renal angioplasty is an effective therapeutic procedure for correcting coarctation of the renal artery in patients with moyamoya disease.

Moyamoya disease complicated with renal artery stenosis and nephrotic syndrome: reversal of nephrotic syndrome after nephrectomy

A 7-year-old boy with moyamoya disease developed sustained hypertension, nephrotic syndrome, hyperreninemia, and occlusion of the right renal artery. After right nephrectomy, hyperreninemia and hypertension improved. Proteinuria was resolved after nephrectomy, in parallel with the decrease in plasma renin activity. Moyamoya disease can cause nephrotic-range proteinuria, which is caused hemodynamically by hyperreninemia.

Moyamoya syndrome after radiation therapy for optic pathway glioma: case report

We present a 4-year-old girl with neurofibromatosis-1 who developed moyamoya syndrome characterized by bilateral stenosis or occlusion of the distal internal carotid arteries and their branches, leading to the development of an abnormal vascular network. In light of a literature review, the postradiation vasculopathy of the moyamoya type and its relationship with neurofibromatosis-1 are discussed.

Multivisceral fibromuscular dysplasia in childhood: case report and review of the literature

We report here a 9-year-old girl with fibromuscular dysplasia of many muscular arteries including both renal and internal carotid arteries, the celiac artery, superior mesenteric artery, and one external carotid artery. She suffered from severe renovascular hypertension with beginning secondary cardiac decompensation, typical angina abdominalis, and neurological signs, including severe headaches and hemianopsia. Surgery was performed for all major vessels and the outcome is good 2.5 years after the operation. The clinical presentation, differential diagnosis, and treatment options of fibromuscular dysplasia in childhood are discussed and the literature is reviewed.

Cerebral blood flow velocities in an infant with moyamoya disease

Moyamoya disease is a progressive cerebrovascular disorder with bilateral occlusion of the basal circulation and development of collateral blood supply. In a 6-month-old female with multifocal ischemic infarctions, transcranial pulsed Doppler sonography revealed extremely high and low cerebral blood flow velocities, dampened waveforms, reversed flow, and musical murmurs. Magnetic resonance angiography revealed different degrees of vascular stenosis and an abnormal collateral network. Moyamoya disease was confirmed by conventional angiography at the age of 10.5 months. Pulsed-wave transcranial Doppler sonography is a noninvasive screening method in infants at risk of moyamoya disease.

Hypothalamic-pituitary dysfunction associated with Moyamoya disease in children

Moyamoya disease is a rare cerebral vascular disease that results in narrowing of the vessels of the circle of Willis and the formation of a network of collateral vessels at the base of the brain for compensatory perfusion. Moyamoya disease has the highest incidence during the first decade of life, and children present most frequently with transient ischemic attacks. We present two cases of Moyamoya disease in children with associated hypothalamic-pituitary dysfunction. Both children presented to the endocrinologist for decreased growth velocity. One child had hypothyroidism and both had growth hormone deficiency. A review of the literature reveals a few isolated case reports of hypothalamic-pituitary dysfunction occurring with Moyamoya disease and with other states of cerebral vascular insufficiency. We suggest that children with compromise of cerebral vascular perfusion be monitored closely for clinical signs and symptoms of hypothalamic-pituitary dysfunction.

Central deafness in a young child with Moyamoya disease: paternal linkage in a Caucasian family: two case reports and a review of the literature

A case of 'central deafness' is presented in a 3-year-old male Caucasian child with Moyamoya disease (MMD); a rare, progressive and occlusive cerebrovascular disorder predominantly affecting the carotid artery system. Documentation of normal peripheral auditory function and brainstem pathway integrity is provided by acoustic admittance, otoacoustic emission and brainstem auditory evoked potential measurements. The lack of behavioral response to sound, and absent middle and long latency auditory evoked potentials suggest thalamo-cortical dysfunction. Magnetic resonance imaging showed diffuse ischemic damage in subcortical white matter including areas of the temporal lobes. In addition, there were multiple and focal cortical infarctions in both cerebral hemispheres, focused primarily in the frontal, parietal and temporal areas. Taken together, these structural and functional abnormalities in addition to severely delayed speech and language development are consistent with the diagnosis of central deafness and suggest a disconnection between higher brainstem and cortical auditory areas. The child's father also has MMD, but was diagnosed only recently. The presence of paternal linkage is informative since it rules out x-linked recessive and maternal inheritance. To our knowledge, this represents the first documented case of paternal linkage in MMD with central deafness in a Caucasian child with no apparent Japanese ancestry. Herein, we focus on central auditory dysfunction and consider how lesion-induced changes have contributed to a deficit in basic auditory responsiveness, including a severe disturbance in receptive and expressive auditory-based speech and language skills.