Biomedical subjects

Derek Armstrong

Publications and source records attributed to Derek Armstrong.

22 records · Page 2Linked to original sources

PubMed2003

Intra-arterial tissue plasminogen activator for thrombosis complicating cerebral angiography in a 17-year-old girl.

Few reports describe the use of intraarterial recombinant tissue plasminogen activator to treat intracranial thrombosis in children. A 17-year-old girl with a history of prior venous thrombosis developed a left middle cerebral artery thrombus during diagnostic cerebral angiogram. Therapy with intra-arterial tissue plasminogen activator was initiated. An immediate follow-up angiogram demonstrated recanalization, and diffusion-weighted magnetic resonance imaging 9 hours later showed no evidence of infarction. Following the angiogram, femoral artery thrombosis developed. Treatment with supratherapeutic levels of heparin, localized delivery of intra-arterial tissue plasminogen activator, embolectomy, danaparoid, and dipyridamole failed to re-establish perfusion to the lower leg, and below the knee amputation was required. Neurologic examination remained normal 1 year later. Cerebral damage was avoided with the use of emergency intra-arterial tissue plasminogen activator for cerebral artery thrombosis in this child.

Adolescent↗

PubMed2003

Basilar artery duplication associated with pituitary duplication: a new finding.

Pituitary duplication is a rare malformation, reported previously in approximately 18 patients. It is usually unsuspected before imaging, although it occurs most commonly in association with complicated midline and skull base anomalies. It is easily shown by MR imaging. Five new cases of pituitary duplication were diagnosed by using MR imaging studies reviewed at the Hospital for Sick Children. Among the many associated midline abnormalities, partial basilar artery duplication is a previously undescribed finding that we observed in all our cases. Cases of basilar artery duplication or fenestration are associated with altered flow dynamics, leading to a higher incidence of aneurysms. Periodic surveillance for this potential complication may be warranted.

Basilar Artery↗

PubMed2002

Venous vascular malformations in pediatric patients: comparison of results of alcohol sclerotherapy with proposed MR imaging classification.

PURPOSE: To compare the clinical results of percutaneous sclerotherapy of venous vascular malformations (VVMs) with the authors' proposed magnetic resonance (MR) imaging classification. MATERIALS AND METHODS: MR findings and clinical results of percutaneous alcohol sclerotherapy in 59 pediatric patients with VVMs were retrospectively reviewed. Before treatment, lesions were graded with MR imaging on the basis of margins and size, respectively: grade 1, well defined, less than or equal to 5 cm; grade 2A, well defined, greater than 5 cm; grade 2B, ill defined, less than or equal to 5 cm; and grade 3, ill defined, greater than 5 cm. Regression models were used to test trends in therapy across the MR classification grades, including the repeat sclerotherapies, volumes of ethanol and metrizamide administered for each lesion, and number of access sites. Clinical response to sclerotherapy, which was evaluated with consensus by a multidisciplinary team, was graded as poor, good, or excellent. Association between MR imaging grade and clinical assessment was tested with the Fisher exact test. RESULTS: There were 14 grade 1 lesions, nine grade 2A, 15 grade 2B, and 21 grade 3. Twenty-four patients had a poor response to sclerotherapy; 19, good; and 16, excellent. Ten of 14 (71%) grade 1 lesions had an excellent response; none, a poor response. Twelve of 21 (57%) grade 3 lesions had a poor response; none, an excellent result. Grade 2 lesions were relatively equally distributed among the three categories, with the exception of nine of 15 (60%) grade 2B lesions that had a poor response (P <.001). There was a trend with increasing lesion grade for increasing numbers of sclerotherapy sessions, volumes of ethanol and metrizamide for each lesion, and numbers of access sites. CONCLUSION: There is a strong association between this proposed MR imaging classification and the results of percutaneous sclerotherapy.

Adolescent↗

PubMedDate not supplied

Orbital involvement by nasopharyngeal angiofibroma.

This article describes a rare cause of orbital apex syndrome in a child--juvenile nasopharyngeal angiofibroma. A high level of suspicion while treating an adolescent male with chronic nasal obstruction, epistaxis, and a nasal mass will promote early diagnosis. Multidisciplinary care is advisable, especially for advanced disease.

Angiofibroma↗