Clinical and neuroimaging review of monogenic cerebral small vessel disease from the prenatal to adolescent developmental stage.

Cerebral small vessel disease (cSVD) refers to a group of pathological processes with various etiologies affecting the small vessels of the brain. Most cases are sporadic, with age-related and hypertension-related sSVD and cerebral amyloid angiopathy being the most prevalent forms. Monogenic cSVD accounts for up to 5% of causes of stroke. Several causative genes have been identified. Sporadic cSVD has been widely studied whereas monogenic cSVD is still poorly characterized and understood. The majority of cases of both the sporadic and monogenic types, including cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), typically have their onset in adulthood. Types of cSVD with infantile and childhood onset are rare, and their diagnosis is often challenging. The present review discusses the clinical and neuroimaging findings of monogenic cSVD from the prenatal to adolescent period of development. Early diagnosis is crucial to enabling timely interventions and family counseling.

Utility of MRI in diagnosis and treatment of acute focal bacterial nephritis with abscess formation in a paediatric patient.

Contrast-enhanced CT is the gold standard for the diagnosis of acute focal bacterial nephritis (AFBN). However, owing to radiation exposure and the possibility of contrast agent-induced side effects, contrast-enhanced CT is not always recommended for children. A paediatric patient presenting with a 1-week history of fever was admitted to our hospital. After a urine culture detected Escherichia coli, antimicrobials were administered; however, the fever had not resolved by the third day of hospitalisation. Renal diffusion-weighted MRI was performed and showed multiple wedge-shaped areas of high signal intensity in the right kidney. Additionally, the same site showed an area of low signal intensity in the apparent diffusion coefficient, and a diagnosis of AFBN with abscess was made. A chronic-phase technetium-99m-labelled dimercaptosuccinic acid renal scintigraphy was performed, but there was no renal scarring. MRI may be a more suitable tool for diagnosing AFBN given no radiation exposure.

Fetal MRI of the supratentorial brain abnormalities: what we should know about ventriculomegaly?

Fetal MRI is performed to evaluate the brain in cases where an abnormality is detected by ultrasonography (US). Fetal MRI has higher contrast resolution than US. Because the fetal brain is dynamic structure, it is important to know the normal appearance of the brain at different gestational age to be better able to identify abnormalities using MRI. Fast imaging sequences to minimize artifact from fetal motion are required. The main sequences used are ultrafast T2 weighted imaging. Similar to pediatric neuroimaging, images are acquired in the axial, sagittal, and coronal planes. T1 weighted image and Gradient echo-planar T2 weighted images are performed to detect hemorrhage. Ventriculomegaly is the most common central nervous system abnormality identified on US. The causes of ventriculomegaly are very heterogeneous and include developmental, destructive, and obstructive processes, or a combination thereof. MRI improves diagnostic accuracy and can be used to evaluate the etiology of the ventriculomegaly. Moreover, MRI can play an important role in detecting additional findings, which may help to focus on patient counseling and management. This review summarizes and illustrates common pattern of ventriculomegaly due to mainly supratentorial abnormalities.

Intravenous tocilizumab for Takayasu arteritis with aortic aneurysms, bilateral renal artery stenosis, and atypical aortic coarctation in a 2-year-old girl.

Takayasu arteritis (TAK) is classified as large vessel vasculitis, and continuous inflammation of the vessel results in aneurysm or stenosis, which leads to various serious complications. Recently, a TAKT [TAK treated with tocilizumab (TCZ)] study showed that subcutaneous TCZ, a humanised anti-interleukin-6 receptor monoclonal antibody, is an effective treatment in patients with TAK above 12 years of age; however, the effectiveness of TCZ for juvenile TAK under 12 years old remains unclear. Here, we described the case of a 2-year-old girl with TAK, which was successfully treated with intravenous TCZ. She was diagnosed with TAK type V (Numano's angiographic classification system) with aortic aneurysms, bilateral renal arteries stenosis, and atypical descending aortic coarctation based on contrast-enhanced computed tomography findings. Treatment was started with 2 mg/kg/day prednisolone (PSL) and methotrexate instead of methylprednisolone pulse due to renovascular hypertension. She was immediately afebrile and her C-reactive protein level decreased, although it was elevated 4 weeks after starting PSL. Intravenous TCZ of 8 mg/kg/2 weeks was added because the progression of aneurysms or stenosis might lead to a poor prognosis. PSL was steadily reduced under intravenous TCZ. Magnetic resonance imaging showed that aortic aneurysms, renal arteries stenosis, and aortic coarctation ameliorated 4 months after starting TCZ, with the amelioration maintained at 1 year after starting TCZ. Aneurysms and stenosis improved; therefore, TCZ may be effective for the treatment of inflammation of vessels, aneurysms, and stenosis. It is desirable to examine the effect of TCZ on TAK patients under 12 years of age.

A Comprehensive Review of Pediatric Acute Encephalopathy.

Acute encephalopathy typically affects previously healthy children and often results in death or severe neurological sequelae. Acute encephalopathy is a group of multiple syndromes characterized by various clinical symptoms, such as loss of consciousness, motor and sensory impairments, and status convulsions. However, there is not only localized encephalopathy but also progression from localized to secondary extensive encephalopathy and to encephalopathy, resulting in a heterogeneous clinical picture. Acute encephalopathy diagnosis has advanced over the years as a result of various causes such as infections, epilepsy, cerebrovascular disorders, electrolyte abnormalities, and medication use, and new types of acute encephalopathies have been identified. In recent years, various tools, including neuroradiological diagnosis, have been developed as methods for analyzing heterogeneous acute encephalopathy. Encephalopathy caused by genetic abnormalities such as CPT2 and SCN1A is also being studied. Researchers were able not only to classify acute encephalopathy from image diagnosis to typology by adjusting the diffusion-weighted imaging/ADC value in magnetic resonance imaging diffusion-weighted images but also fully comprehend the pathogenesis of vascular and cellular edema. Acute encephalopathy is known as a very devastating disease both medically and socially because there are many cases where lifesaving is sometimes difficult. The overall picture of childhood acute encephalopathy is becoming clearer with the emergence of the new acute encephalopathies. Treatment methods such as steroid pulse therapy, immunotherapy, brain hypothermia, and temperature control therapy have also advanced. Acute encephalopathy in children is the result of our predecessor's zealous pursuit of knowledge. It is reasonable to say that it is a field that has advanced dramatically over the years. We would like to provide a comprehensive review of a pediatric acute encephalopathy, highlighting advancements in diagnosis and treatment based on changing disease classification scenarios from the most recent clinical data.

Magnetic resonance imaging of a pediatric case of arthritis associated with acute lymphoblastic leukemia: A case report.

In the present case report, a 3-year-old girl presented with a 1-week history of spontaneously resolving right knee pain. After 1 month, the patient had trouble ambulating due to painful swelling of their ankle. Rheumatic disease, specifically juvenile idiopathic arthritis, was considered. Blood examination could not be conducted because their blood sample was coagulated. T1-weighted magnetic resonance imaging (MRI) revealed abnormally low signals in the femur, tibia, fibula and foot bone marrow. Contrast-enhanced T1-weighted MRI revealed synovial contrast enhancement and synovial fluid retention in the right ankle joint. Blood analysis revealed a white blood cell count of 40,000/µl (blasts, 66%). In addition, a monoclonal increase in the number of lymphoblasts was observed. The patient was subsequently diagnosed with B-cell precursor acute lymphoblastic leukemia. Reports on leukemic arthritis resembling synovitis on MRI remain limited. The findings of this report indicated that pediatricians should consider leukemia in children presenting with joint symptoms.

Diagnosis and Treatment for Acute Focal Bacterial Nephritis With Renal Abscess Based on Magnetic Resonance Imaging Evaluation.

A 5-year-old boy was diagnosed with left acute focal bacterial nephritis (AFBN) complicated with renal abscess (RA) on magnetic resonance imaging (MRI). MRI is useful for diagnosing AFBN and RA complications. He was administered antibiotics for 3 weeks on evaluation of MRI findings. Evaluation of apparent diffusion coefficient values over time may be useful as an index of treatment of RA.

Central hypothyroidism in a pediatric case of primary acute monoblastic leukemia with central nervous system infiltration: A case report.

RATIONALE: Central nervous system (CNS) leukemia is a frequent diagnosis in pediatric acute myeloblastic leukemia (AML) and includes neural symptoms. However, CNS leukemia is rarely associated with central hypsothyroidism. PATIENT CONCERNS AND DIAGNOSES: A 2-year-old female with AML with MLL rearrangement presented with CNS infiltration. Laboratory tests suggested the presence of central hypothyroidism (thyroid-stimulating hormone [TSH]: 0.48 mIU/ml, normal range 0.7-6.4 mIU/ml; serum free thyroxine [FT4]: 0.62 ng/dl, normal range 0.8-2.2 ng/dl; free triiodothyronine: 1.57 pg/ml, normal range 2.7-5.6 pg/ml). Magnetic resonance imaging detected no lesions in the hypothalamus, pituitary, or thyroid. INTERVENTIONS AND OUTCOMES: Levothyroxine (2.5 mg/kg/day) was administered together with chemotherapy and intrathecal injection of methotrexate, cytarabine, and hydrocortisone into the cerebrospinal fluid. The FT4 concentration increased after levothyroxine treatment, but later decreased after relapse of CNS leukemia. The TSH concentrations remained low. After remission of CNS leukemia, the TSH and FT4 concentrations quickly recovered to their normal ranges. LESSONS: We believe that the CNS leukemia directly affected TSH and thyroid hormone secretion in our patient.

Usefulness of 18F-Fluorodeoxyglucose Positron Emission Tomography for Follow-Up of 13-cis-Retinoic Acid Treatment for Residual Neuroblastoma After Myeloablative Chemotherapy.

13-cis-retinoic acid (13-cis-RA) treatment is used as a second-line treatment for residual or recurrent neuroblastoma. However, determining the duration of 13-cis-RA treatment for residual and recurrent neuroblastoma can be a problem because it is difficult to evaluate the effectiveness of the treatment.We performed 13-cis-RA treatment to remove residual active neuroblastoma cells in an 8-year-old boy with stage 4 neuroblastoma that developed from a left sympathetic ganglion and had been treated with chemotherapy, surgery, autologous peripheral blood stem-cell transplantation, and radiotherapy. F-fluorodeoxyglucose positron emission tomography (F-FDG-PET) and iodine-123 metaiodobenzylguanidine (I-MIBG) scintigraphy obtained immediately before 13-cis-RA treatment both showed positive findings in the area of the primary lesion. At 18 months after 13-cis-RA treatment, there was accumulation on I-MIBG scintigraphy but no uptake on F-FDG-PET, and 13-cis-RA treatment was suspended. The patient has been in complete remission for 3 years. In comparing the effectiveness of the 2 imaging modalities for monitoring the response to 13-cis-RA treatment, we considered that F-FDG-PET was superior to I-MIBG scintigraphy because F-FDG-PET images were not affected by the cell differentiation induced by 13-cis-RA treatment in our case. Thus, F-FDG-PET was useful for determining the treatment response and outcomes.We have reported a case of residual neuroblastoma treated with differentiation-inducing 13-cis-RA therapy. Different results were produced with F-FDG-PET and I-MIBG scintigraphy. The cessation of 13-cis-RA treatment was based on F-FDG-PET findings and there has been no relapse for 3 years.