Biomedical subjects
J-P Guichard
Publications and source records attributed to J-P Guichard.
Hereditary infantile hemiparesis, retinal arteriolar tortuosity, and leukoencephalopathy.
BACKGROUND: The main hereditary vascular conditions involving both retinal and cerebral vessels include cerebroretinal vasculopathy, HERNS (hereditary endotheliopathy with retinopathy, nephropathy, and stroke), and hereditary vascular retinopathy; all are linked to the same locus on chromosome 3p21. Hereditary retinal arteriolar tortuosity is a distinct, autosomal dominant condition characterized by retinal arteriolar tortuosity and recurrent retinal hemorrhages. This condition is known to affect only retinal vessels. METHODS: Clinical and brain MRI investigations of eight members of a three-generation family and extensive biological and systemic vascular investigations within one affected family member were conducted. RESULTS: Six of eight family members were clinically symptomatic; disorders included infantile hemiparesis (2), migraine with aura (3), and retinal hemorrhage (1). Five individuals had retinal arteriolar tortuosities. A diffuse leukoencephalopathy in association with dilated perivascular spaces was observed in six individuals. Two family members had silent, deep cerebral infarcts as demonstrated on MRI. Genetic linkage analysis strongly suggests that this disorder is not linked to the 3p21 hereditary vascular retinopathy/cerebroretinal vasculopathy/HERNS locus. CONCLUSIONS: The authors describe a novel hereditary autosomal dominant condition affecting both retinal and cerebral vessels and characterized by infantile hemiparesis, migraine with aura, retinal hemorrhage, retinal arterial tortuosity, and leukoencephalopathy with dilatation of perivascular spaces and microbleeds on brain MRI. Investigation of additional families should help to map the gene and to better categorize the spectrum of hereditary cerebroretinal small vessel diseases.
[Scintigraphy by l'Octreoscan in the management of head and neck paragangliomas].
OBJECTIVE: To assess the usefulness of somatostatin receptor scintigraphy [Octreoscan] in a series of 18 patients referred for a suspicion of paraganglioma of the head and neck between July 2001 and February 2002. PATIENTS AND METHODS: Sixteen patients had one or several paragangliomas of the head and neck diagnosed on conclusive conventional imaging including CT and MR scan. In two patients, radiological data were not conclusive. Planar images were obtained 4 and 24 hr after the iv injection of 148-185 MBq [Octreoscan]. RESULTS: Twenty-two hot spot lesions were detected. Twenty of these lesions corresponded to the twenty known paragangliomas. The volume of the smallest tumor was 0.2 cm(3). In one patient, intense thyroid nodule uptake led to the surgical diagnosis of oncocytoma. In two lesions, where conventional imaging was not conclusive, arteriography showed a typical aspect of meningioma; one patient was operated on and histology confirmed this diagnosis. No evidence of abnormal uptake was seen in site previously operated on (3 patients). CONCLUSION: Octreotide scintigraphy is a very sensitive method for detection of paraganglioma of head and neck. It provides information on potential tumor sites in the whole body after one single injection. It could be used as a screening test in patients at risk (familial or known paraganglioma) in order to detect paraganglioma at an early stage and, thus to reduce the surgical morbidity, as well as in the follow-up after surgery to detect recurrences.