Nicky Wieselthaler

Comparison of diagnostic criteria of tuberculous meningitis in human immunodeficiency virus-infected and uninfected children

Introduction: Tuberculous (TB) meningitis is sometimes difficult to diagnose in young children. The decision to start anti-TB treatment of TB meningitis is usually made on clinical grounds and results of special investigations, such as cerebrospinal fluid examination and cranial computerized tomography (CT), because bacteriologic yield is low and the results delayed. Aim: To determine whether the clinical, laboratory, and radiologic criteria used in the diagnosis of TB meningitis in human immunodeficiency virus (HIV)-uninfected children apply to HIV-infected children. Methods: Retrospective, case-control study. Clinical, laboratory, and radiologic features of TB meningitis were compared in 34 HIV-infected and 56 HIV-uninfected patients matched for age and stage of TB meningitis. Results: All clinical differences found between the 2 groups at admission were related to the underlying HIV disease. Neurologic presentation and cerebrospinal fluid findings at admission did not differ significantly between the 2 groups. Significantly more HIV-infected than HIV-uninfected children had evidence of TB on chest radiography. The classic CT signs of TB meningitis (obstructive hydrocephalus and basal enhancement) were significantly less prominent in the HIV-infected group (P < 005). Conclusion: The diagnostic criteria for clinical diagnosis of TB meningitis apply to HIV-infected children. However, cranial CT findings in this group may be misleading and delay the diagnosis of TB meningitis.

Modern imaging of tuberculosis in children: thoracic, central nervous system and abdominal tuberculosis.

Tuberculosis (TB) can affect any organ in the body. Children are a high-risk group for contracting the disease and pose a constant challenge to clinicians with regard to making a definitive diagnosis. Radiologists are playing a more active role in diagnosing TB, and armed with more accurate diagnostic investigations such as CT and MRI, they must face the cost implications as well as technical limitations. This review aims to guide the reader through the modern imaging techniques useful for diagnosing TB of the thorax, central nervous system and abdomen in children. The more specific features of each modality in the particular anatomical regions are highlighted.

Giant congenital melanocytic nevi in a patient with brain structural malformations and multiple lipomatosis.

We present a 9-year-old boy diagnosed from birth with giant congenital melanocytic nevi. He had central structural brain malformations of hemimegalencephaly of the right frontotemporal lobe and left occipitoparietal lobe, choroid plexus hypertrophy, and a Dandy-Walker variant. In addition, he developed multiple lipomatoses. These lesions were cutaneous except for two at the cerebellopontine angles, which were present from birth. This patient represents a rarely documented example of two histopathologies resulting in serious complications. The diagnostic issues and histopathologic process are discussed. (J Child Neurol 2002;17: 289-291).

Cervical spina bifida cystica: MRI differentiation of the subtypes in children

BackgroundCervical spinal dysraphism is a rare condition with only 37 cases reported in the literature, of which only seven patients had undergone preoperative magnetic resonance imaging (MRI).ObjectiveBy using illustrative cases, we demonstrate the value of MRI in distinguishing the two different subtypes of cervical spinal dysraphism, namely, myelocystocele and meningocele.MethodRetrospective review of the MRI scans of six patients with cervical (one high thoracic) posterior cystic swellings, which were diagnosed as cervical dysraphism, was done.ResultsThree patients were diagnosed with myelocystocele and three patients with meningocele. A comparison of MRI features between the two entities, as well as the associated anomalies, is discussed.ConclusionMRI is the imaging modality of choice for suspected cervical dysraphism, prior to surgery. It helps distinguish the subtypes, as well as identify the associated anomalies.

CT features of tuberculous intracranial abscesses in children

BackgroundIntracranial tuberculous (TB) abscesses still cause a diagnostic dilemma on both CT and MRI as they may mimic neoplasms. Recognition of TB abscesses may prompt further imaging and appropriate trial of therapy, and may reduce the need for biopsy.ObjectiveTo report the CT features of eight intracranial TB lesions in children initially diagnosed as neoplasms and eventually treated as TB abscesses.Materials and methodsWe undertook a 3-year retrospective review of children with an initial CT diagnosis of intracranial neoplasm who were subsequently diagnosed as having TB abscesses.ResultsEight patients out of 60 with an initial diagnosis of a neoplasm on CT were misdiagnosed and were ultimately determined to have TB abscesses after biopsy or a trial of anti-TB therapy. The most consistent constellation of findings for the lesions were low density (n = 5), ring enhancement (n = 8), cerebral hemisphere location (n = 7), mass effect (n = 6), surrounding oedema (n = 5) and absence of a soft-tissue-density mass (n = 8).ConclusionIn endemic regions, intracranial lesions with these appearances on CT should undergo further imaging and possibly a trial of anti-TB therapy before considering biopsy.

Imaging the Rex vein preoperatively using wedged hepatic venous portography

BackgroundMesentericoportal bypass, the Rex shunt, restores the physiological hepatic portal flow and reduces the clinical sequelae of portal hypertension in children with extrahepatic portal vein obstruction (EHPVO). The preoperative evaluation includes an accurate assessment of the portal venous inflow and outflow. The former is readily assessed by ultrasound and MRI, while the outflow intrahepatic portal vein is harder to assess.PurposeTo assess the efficacy of wedged hepatic venous portography (WHVP) at detecting a patent Rex vein preoperatively in children with EHPVO who were considered for mesenterico-portal bypass.Materials and methodsA single-institution retrospective chart review was undertaken for children with EHPVO who had been considered for a mesoportal bypass between January 2001 and January 2010.ResultsSixteen children were considered for mesoportal bypass, including four post reduced-size liver transplant patients. Ten children (63%) underwent WHVP. The Rex vein was clearly identified in 8/10 (80%). One Rex vein was seen at surgery but not demonstrated at WHVP. Six mesoportal bypasses were performed without WHVP, of which three (50%) were successful.ConclusionWHVP had a sensitivity of more than 80% and specificity of 100% in the preoperative patency assessment of the Rex vein.

Imaging Features of the Brain, Cerebral Vessels and Spine in Pediatric Tuberculous Meningitis With Associated Hydrocephalus.

Background: Pediatric tuberculous meningitis (TBM) leads to high rates of mortality and morbidity. Prompt diagnosis and initiation of treatment are challenging; imaging findings play a key role in establishing the presumptive diagnosis. General brain imaging findings are well reported; however, specific data on cerebral vascular and spinal involvement in children are sparse. Methods: This prospective cohort study examined admission and followed up computed tomography brain scans and magnetic resonance imaging scans of the brain, cerebral vessels (magnetic resonance angiogram) and spine at 3 weeks in children treated for TBM with hydrocephalus (HCP; inclusion criteria). Exclusion criteria were no HCP on admission, treatment of HCP or commencement of antituberculosis treatment before study enrollment. Imaging findings were examined in association with outcome at 6 months. Results: Forty-four patients (median age 3.3 [0.3–13.1] years) with definite (54%) or probable TBM were enrolled. Good clinical outcome was reported in 72%; the mortality rate was 16%. Infarcts were reported in 66% of patients and were predictive of poor outcome. Magnetic resonance angiogram abnormalities were reported in 55% of patients. Delayed tuberculomas developed in 11% of patients (after starting treatment). Spinal pathology was more common than expected, occurring in 76% of patients. Exudate in the spinal canal increased the difficulty of lumbar puncture and correlated with high cerebrospinal fluid protein content. Conclusion: TBM involves extensive pathology in the central nervous system. Severe infarction was predictive of poor outcome although this was not the case for angiographic abnormalities. Spinal disease occurs commonly and has important implications for diagnosis and treatment. Comprehensive imaging of the brain, spine and cerebral vessels adds insight into disease pathophysiology.

Acquired Demyelinating Disorders of Childhood in the Western Cape, South Africa

In a retrospective review of patients with acquired demyelinating disorders of the central nervous system, 19 children (0.6%) were identified from the Paediatric Neurology database of 3159 patients; 7 had acute disseminated encephalomyelitis, 1 had Schilder’s disease, 5 had multiple sclerosis, and 6 had acute transverse myelitis. The median age of presentation was 83 months, with increased incidence during the summer and winter months. The commonest presentation was hemiparesis. The commonest regions of magnetic resonance imaging (MRI) abnormalities were the deep white matter (68%) and cerebellum (48%).The patients with multiple sclerosis had more monosymptomatic presentations (P < .02), raised cerebrospinal fluid protein (P = .022), and contrast enhancement of lesions (P = .05) compared with the acute disseminated encephalomyelitis group. Neuroepidemiological published surveillances of African children provide no data about these disorders. The prevalence of acquired demyelinating disorders in resource-poor settings is under-estimated because of the large burden of infections and limited access to neuroimaging.

Melanotic neuroectodermal tumour of infancy, a rare cause for a bump on the head

Melanotic neuroectodermal tumour of infancy (MNTI) is a rare neoplasm occurring in children during the first year of life. It was originally described by Krompecher in 1918 as a congenital melanocarcinoma [14]. Numerous descriptive terms have been used since, including melanotic progonoma, congenital melanosarcoma, retinal anlage tumour, atypical melanoblastoma, melanotic adamantinoma or ameloblastoma, pigmented epulis, retinoblastic teratoma and melanotic epithelial odontoma. Conflicting opinions prevailed regarding its histogenesis, and only in 1966 did Borello and Gorlin describe an association with high urinary vanillylmandelic acid (VMA) levels, suggesting a neural crest origin. These two authors named the condition melanotic neuroectodermal tumour of infancy [3]. Based on modern ultrastructural, immunocytochemical and electron microscopic studies, it is currently widely accepted to be of neural crest origin [4, 6, 23]. Approximately 360 cases of MNTI have been reported in the literature [15]. Patients generally present with a progressively enlarging craniofacial mass without associated neurological symptoms [1]. The majority of cases (91.1 %) present before the age of 1 year, with the mean age at time of diagnosis being 4.3 months [1, 15]. The male-to-female ratio is almost equal [1, 4]. The most common anatomical location is the maxilla (61.4 %). Other described sites include the skull, mandible, brain, epididymis and rarely the mediastinum, long bones, soft tissues and uterus [1, 4, 15]. MNTI has to be considered in the differential diagnosis of benign or malignant lesions of the calvarium as it is characterised by an alarming local growth rate and propensity for recurrence that make it a serious and difficult lesion to manage. We present two cases of MNTI arising in the skull and describe the imaging features on plain radiographs, computed tomography and magnetic resonance imaging together with histopathological confirmation. Both cases are unusual as only 10.8 % of MNTI involves the skull, but are typical in terms of patient’s age, histological features and clinical course.

Cerebrovascular disease in children with HIV-1 infection

An estimated 3.2 million children worldwide have human immunodeficiency virus (HIV) infection. Antiretroviral therapy (ART) has resulted in prolonged survival, leading to an increase in complications previously recognized in adults. Children with HIV infection have increased risk of cerebrovascular disease from multiple aetiologies including HIV‐associated vasculopathy, opportunistic vasculitis, cardioembolism or coagulopathy, all of which may be secondary to the infection. Prevalence of cerebrovascular disease in HIV‐infected children is underestimated because of limited neuroimaging in low and middle income countries, silent events without overt motor manifestations, and mislabeling as HIV encephalopathy for non‐motor manifestations such as behavioural and cognitive difficulties. No management guidelines for cerebrovascular disease in HIV‐infected children exist but common practices target risk factors for stroke in low and middle income countries. Where capacity permits, screening for opportunistic infections, vasculitis, coagulopathy and cardioembolism is important. Optimising virological suppression, correction of anaemia, control of seizures and aspirin prophylaxis are management priorities. Neurosurgical interventions may have a role.