Biomedical subjects
Publications and source records attributed to N K Rollins.
We present a case of extracranial craniopharyngioma simulating a sphenoid sinus mucocele in a 12-year-old female who presented with progressive subacute left-sided visual disturbance. Although infrasellar craniopharyngioma is a rare entity, the presence of foci of calcification within the lesion is a useful finding for diagnosis.
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To assess the risk of deep vein thrombosis in haemophiliacs with long-term central venous catheters, we studied haemophiliacs followed at our centre with implantable venous access devices (ports) in place for > 6 months. Medical records were reviewed for a history of catheter-related complications. Each patient was examined for physical stigmata of thrombosis. Patency of the vessels was evaluated by contrast venography. Of 21 males with ports, 19 had factor VIII deficiency and two factor IX deficiency. Nineteen ports were evaluable (i.e. were in place for > 6 months). Seventeen patients have their original ports in place; two ports were replaced for mechanical dysfunction (1) and recurrent infection (1). Difficulty withdrawing or infusing occurred with three ports, two of which were cleared with urokinase. Physical examination was normal on all 19 patients. Venograms were performed in 13 of 19 patients. Parents of the remaining six patients refused venography because of the need for peripheral venipuncture. One patient had a small nonocclusive thrombus on the same side as his functioning catheter, and another had minimal narrowing of the subclavian vein at the site of a prior catheter. The overall prevalence of clinically relevant upper venous system thrombosis identifiable by contrast venography was zero (95% CI, 0-23%). We conclude that haemophiliacs do not have as high a risk of thrombosis as other populations of patients with central venous catheters. The theoretical risk of thrombosis should not preclude use of central venous catheters in patients with haemophilia.
PURPOSE: We compared visibility of residual juvenile cerebellar pilocytic astrocytomas (JPAs) on early postoperative and follow-up MR studies to determine whether early postoperative MR imaging has a valid role as a baseline study. METHODS: We reviewed the MR images of 21 consecutive children who had undergone resection of cerebellar JPA. The diagnosis of residual tumor was made on the basis of nodular enhancement that corresponded to enhancing tumor on the preoperative MR studies and/or nonenhancing nodular T2 signal that corresponded to nonenhancing tumor. Because no patient received chemotherapy or radiation therapy, abnormal T2 signal or enhancement on the early postoperative study that resolved on the follow-up study was presumed to be due to peritumoral edema and/or surgical manipulation. Nodular T2 signal and/or enhancement in the tumor bed not seen on the initial postoperative MR study but present on the subsequent MR study and unchanged on serial follow-up MR studies was presumed to represent residual tumor rather than tumor that had recurred. RESULTS: Compared with follow-up studies, the initial postoperative MR images were true-positive for residual tumor in six patients, false-positive in five, equivocal for residual tumor in four, true-negative in five, and false-negative in one. Residual tumor did not consistently enhance, and peritumoral edema and changes resulting from surgical manipulation tended to mask or simulate residual tumor. CONCLUSION: Early postoperative MR imaging is not accurate in differentiating residual JPA from postoperative changes, and the role of early postoperative MR imaging as a baseline study for comparison with further studies is questionable.
Seven years after completion of chemotherapy for acute lymphoblastic leukemia, diagnosed at the age of 5 years, a black female presented with signs of increased intracranial pressure. Neuroimaging showed a large enhancing extra-axial occipital tumor mass. The resection specimen showed morphologic, cytogenetic, and immunophenotypic features consistent with relapse of the primary leukemia. Bone marrow examination was negative for malignancy. The long duration of complete remission followed by the formation of a mass in the central nervous system are highly unusual features of recurrent acute lymphoblastic leukemia.
OBJECTIVE: To evaluate the safety and efficacy of orally administered perflubron for bowel recognition on MR imaging in a pediatric population. MATERIALS AND METHODS: A multicenter trial evaluated 39 pediatric subjects before and after ingestion of perflubron with T1-, proton-density, and T2-weighted sequences through the abdomen and/or pelvis. Post-contrast images were compared with pre-contrast images. Safety was evaluated through assessment of adverse events, clinical laboratory parameters, and vital signs. RESULTS: With regard to efficacy analysis, improvement in the percent of bowel darkened was observed for 85 % of the subjects on T1-weighted images and for 95 % of the subjects on proton-density and T2-weighted images. For images of the abdominal region, the percent of bowel darkened was improved for 90-92 % of the subjects across pulse sequences. Improvement rates for the images of the pelvic region ranged from 71 % to 100 %. For at least 75 % of the subjects, proton-density and T2-weighted images of the body and tail of the pancreas, left lobe of the liver, mesenteric fat, and pathological tissue were improved relative to predosing images. Twenty-three percent of the subjects experienced some adverse effects, most of which were minor and related to the digestive system. Clinical laboratory and vital sign evaluations revealed no trends associated with the administration of perflubron. CONCLUSION: Perflubron is a relatively safe and effective gastrointestinal MR contrast agent in the pediatric population.
The development of biliary tract calculi after orthotopic liver transplantation presents a unique clinical problem. Previously described techniques for removing biliary stones by shock wave lithotripsy, litholytic therapy with oral bile acids, and endoscopic mechanical extraction may be ineffective or contraindicated in liver transplant patients. For this reason, percutaneous transhepatic electrohydraulic lithotripsy (EHL) was performed using an 11 French flexible ureteroscope in two pediatric patients who developed biliary tract calculi following orthotopic liver transplant. There were no complications and postoperative follow-up over 4 years has been uneventful. To our knowledge, these represent the first reported cases of percutaneous transhepatic endoscopic EHL to fragment biliary tract stones in a transplanted liver, which for us has been a safe and effective therapeutic option.
Despite its usefulness in adults with cerebral gliomas, indications for thallium-201 single-photon emission computed tomography (SPECT) in pediatric brain tumor patients are not well defined. We prospectively compared thallium SPECT with gadolinium-enhanced MR (Gd-MR) to determine if thallium SPECT provides clinically useful information that cannot be derived from Gd-MR. We studied 24 pediatric brain tumor patients, 7 at presentation and 17 during therapy. MR imaging included T2 and pre- and postgadolinium T1 images. Thallium SPECT was done within 48 h of MR imaging; thallium indices were calculated for 12 of 14 lesions which showed thallium uptake. Surgery and/or clinical follow-up are available in all patients. The tumors included pilocytic astrocytoma (7), medulloblastoma (5), brainstem glioma or glioblastoma (4), germinoma (3), optic glioma (2), mixed glioma (1), primitive neuroectodermal tumor (1), and choroid plexus carcinoma (1). Among the primary tumors, compared to MR, thallium SPECT was false-negative for tumor in 1 patient and true-positive in 6 patients. Among the patients studied while on therapy, compared to MR, thallium SPECT was true-negative for tumor in 7, true-positive in 5, false-negative in 3, and false-positive in 2. In both groups of patients, thallium SPECT underestimated tumor burden as nonenhancing regions of the tumors were not thallium-avid. Thallium indices did not correlate with histologic grade, biologic aggressiveness, or tumor type. We were unable to establish indications for the use of thallium SPECT in this setting as there was little clinically useful information derived from thallium SPECT that was not provided by Gd-MR.
Unilateral atrophy of a cerebellar hemisphere occurring as a sequela of ischemic or destructive injury of the contralateral cerebral hemisphere is uncommon in children. We reviewed our experience with this phenomenon and found an unexpected association with extreme prematurity and a complicated perinatal course with a poor subsequent neurologic outcome. We retrospectively identified eight children, aged 8 months to 13 years, in whom cerebellar atrophy associated with cerebral injury was diagnosed on MR or CT, and reviewed their past medical history, neurologic findings, and neuroimaging studies. Seven patients were born extremely premature, EGA 25-28 weeks, and had severe perinatal intracranial hemorrhage. Neurologic problems include severe developmental delay in seven, spastic paresis in six, and seizures in five. Neuroimaging showed severe unilateral holohemispheric atrophy in four, bilateral asymmetric holohemispheric atrophy in two, and left temporoparietal atrophy in one. Cerebellar atrophy was unilateral in five and bilateral but asymmetric in two. Gliosis of the atrophic cerebellum occurred in one patient. Sequential neuroimaging in one patient showed evolution of crossed cerebellar atrophy at 8 months of age. The final patient, a term infant, had an idiopathic perinatal left cerebral infarct. In our experience, crossed cerebellar atrophy was an uncommon manifestation of extreme prematurity complicated by severe intracranial hemorrhage and/or ischemic necrosis of white matter. The cerebellar atrophy is most often a secondary degenerative phenomenon rather than a result of direct cerebellar injury.
The clinical courses of 8 term infants with focal cerebral infarction or neonatal stroke were studied to determine whether such infants can be identified by current markers of perinatal distress, and whether changes in cerebral blood flow velocity (CBFV) occur during the acute phase of the disease. CBFV was measured from the middle cerebral artery (MCA) and anterior cerebral artery (ACA) utilizing duplex Doppler. Seven of the 8 patients required no resuscitation in the delivery room; 1 infant required brief bag and mask ventilation. No infant had evidence of severe fetal acidemia (i.e., cord pH < 7). All 8 infants were initially admitted to the newborn nursery. Infants were identified on the basis of abnormal clinical findings observed during the first 48 hours: seizures (n = 6) and hypotonia and apnea (n = 2). Serum electrolytes, calcium, magnesium, and glucose levels were normal, and the sepsis evaluation including a spinal tap was sterile in all patients. Neuroimaging revealed nonhemorrhagic left focal MCA infarction (n = 6) and right focal MCA infarction (n = 2). Duplex Doppler demonstrated transient ipsilateral decreases in CBFV as compared to the contralateral unaffected side at clinical presentation in 4 infants. In 2 of these infants the decrease in CBFV involved both the MCA and ACA, and in 2 infants, only the MCA vessels. These side-to-side differences were not present at subsequent CBFV measurements. The data indicate that infants who develop neonatal stroke cannot be distinguished from infants who do not develop the lesion by current markers of perinatal distress.(ABSTRACT TRUNCATED AT 250 WORDS)
PURPOSE: To define the role of MR in evaluating term neonates with seizures the most common clinical manifestation of cerebral injury in neonates. METHODS: Fifteen term infants with seizures underwent MR imaging. The presence and pattern of MR findings were compared with clinical markers of perinatal distress, cause of cerebral injury, and short-term neurologic outcome. RESULTS: Seizures were caused by hypoxic-ischemic encephalopathy in three patients, bacterial meningitis in three, and prenatal cocaine exposure in one. Nine patients had no identifiable risk factors. By MR, five patients had focal ischemic injury of the cerebral hemispheres and/or basal ganglia and brain stem. Six patients had diffuse cerebral edema: of these, five had basal ganglia edema; one had brain stem edema. One patient had superior sagittal sinus thrombosis with venous infarcts. Three patients had normal MR studies. There was no correlation between markers of perinatal distress, risk factors for seizures, and presence or pattern of MR findings. There was some correlation between MR findings of diffuse cerebral injury and neurologic outcome, and between MR findings of basal ganglia and brain stem abnormalities and neurologic outcome; these findings correlated with spasticity and hemiplegia at 6 to 24 months follow-up. CONCLUSION: The presence or pattern of MR findings does not appear to correlate with with clinical signs of perinatal distress or presumed causes of perinatal cerebral injury. Further investigation is needed to identify prospectively neonates with seizures who are at risk for significant neurologic morbidity.
Two cases of smooth muscle tumor developing in immunocompromised children are described. Both children presented after transplant surgery, one with a hepatic leiomyoma and the other with a hepatic leiomyosarcoma.
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PURPOSE: To determine the prevalence and clinical significance of dilated Virchow-Robin spaces in pediatric patients. MATERIALS AND METHODS: Cranial magnetic resonance (MR) studies of 1,250 children who underwent imaging during 12 consecutive months were prospectively evaluated. RESULTS: Thirty-seven patients had prominent Virchow-Robin spaces. The most common indications for imaging in these patients were headache (n = 10), developmental delay (n = 8), and psychiatric problems (n = 7). Medical records revealed that 12 of the 37 patients had severe headaches, 17 had moderate or severe delay in development, and 18 had serious behavioral or psychiatric problems. An association was found between presence or absence of dilated Virchow-Robin spaces and presence or absence of developmental delay (odds ratio = 4.9; 95% confidence interval [CI] = 2.1, 11.1; P < .001), psychiatric problems (odds ratio = 12.6; 95% CI = 5.0, 31.8; P < .001), and headaches (odds ratio = 37; 95% CI = 14.7, 93.2; P < .001). CONCLUSION: There appears to be a correlation between functional neuropsychiatric disorders in children and the presence of Virchow-Robin spaces in the cerebral hemispheres at MR imaging.
OBJECTIVE: Patency of the hepatic artery in patients with liver transplants is evaluated with duplex Doppler sonography. In many centers, loss of an arterial waveform in the liver hilum is an indication for immediate arteriography to confirm the presence of hepatic artery thrombosis. We describe the findings in four children with liver transplants in whom occlusion of the graft artery was erroneously suggested by findings on duplex Doppler sonography and angiography. MATERIALS AND METHODS: We describe four patients 14-26 months old who had undergone liver transplant 9 days to 9 weeks earlier. The patients were critically ill with sepsis and hypotension. Duplex Doppler sonography was performed by interrogation of the hepatic artery in the liver hilum and parenchyma. When loss of an arterial waveform in the hilum was identified, angiography was performed immediately. Angiography consisted of aortography in all patients and selective celiac or superior mesenteric angiography in three patients. Autopsy was performed in all patients. RESULTS: Duplex Doppler sonography showed loss of arterial waveforms in the liver hilum in all patients; intrahepatic arterial waveforms were absent in three. The hepatic artery was not opacified at arteriography, but all patients had a patent hepatic artery at autopsy. Postmortem hepatic histology showed massive hepatic necrosis in three patients--necrosis without rejection in two and necrotizing vasculitis associated with severe rejection in one. The fourth patient had minor hepatic parenchymal injury. CONCLUSION: We conclude that failure to show flow in the hepatic artery with duplex Doppler sonography and arteriography is not necessarily indicative of arterial thrombosis. A low-flow nonocclusive phenomenon caused by massive hepatic necrosis or systemic hypotension may not be distinguishable from arterial occlusion.
Portal vein stenosis complicating orthotopic liver transplantation in children is uncommon. The authors report their early experience with transhepatic portal vein angioplasty in the treatment of portal vein stenosis in this setting. The technique was used in two children (aged 2 and 6 years) who had undergone liver transplantation for biliary atresia 15 and 42 months earlier, respectively. Both patients presented with chronic anemia and intermittent gastrointestinal bleeding. The diagnosis of portal vein stenosis was confirmed at fine-needle splenoportography. Access to the portal venous system was gained by means of a transhepatic approach. Low-profile angioplasty balloon catheters were used to dilate anastomotic strictures of the portal vein in both children. At the end of the procedure, the tract within the liver was occluded with gelatin sponge pledgets. Both procedures were technically successful and caused no complications, and in both patients gastrointestinal bleeding ceased.
Noninvasive imaging of portomesenteric venous anatomy in prospective pediatric liver transplant recipients may be limited by the small size of the vessels. A simple technique of percutaneous transhepatic portal venography was developed that involves the use of a 22-gauge needle and hand injection of contrast material. The technique was used in six infants (aged 4-15 months) with portal hypertension and end-stage liver disease due to biliary atresia. The portal vein was diagnostically opacified in four of the six patients. There were no complications related to the procedure.
We conducted a third placebo-controlled, double-blind study of dexamethasone as adjunctive therapy for bacterial meningitis. Thirty-one patients received cefuroxime sodium (300 mg/kg per day in 3 doses) and dexamethasone phosphate (0.6 mg/kg per day in 4 doses for 4 days), and 29 received cefuroxime and placebo. The groups were comparable at the beginning of therapy. Magnetic resonance imaging performed between days 2 and 5 of therapy was used to assess brain water content indirectly. There were no differences between the 2 treatment groups with respect to the T1- or T2-weighted images. Fifty-two patients (88%) had normal magnetic resonance images; 5 patients had parietal or bifrontal extra-axial fluid collections, and 2 children had areas of abnormal signal intensity in the brain on T2-weighted images. Abnormal findings on magnetic resonance imaging did not alter clinical management, and there was no correlation between the results of magnetic resonance imaging and the outcome of meningitis. The number of patients in this study was too small to determine any statistically significant differences in rates of hearing impairment; however, the cerebrospinal fluid findings and clinical outcome in dexamethasone-treated patients further support the previously reported beneficial effect of corticosteroid treatment in patients with bacterial meningitis.