Biomedical subjects

Augustin Ozanne

Publications and source records attributed to Augustin Ozanne.

4 recordsLinked to original sources

PubMed2006

A report of two cases with dolichosegmental intracranial arteries as a new feature of PHACES syndrome.

BACKGROUND: We describe two previously unreported cases with complete or incomplete expression of PHACES syndrome, a rare congenital syndromal pediatric disorder, which is characterized by posterior cranial fossa malformations, large facial hemangiomas, arterial anomalies, coarctation of the aorta and cardiac defects, abnormalities of the eye, sternal and supraabdominal raphe defects. CASE REPORTS: These two children exhibited a feature not reviewed extensively in the literature, namely, segmental elongation and dilatation of intracranial arteries associated with intracranial occlusive arterial disease, predominantly on the anterior division of the internal carotid artery (ICA) and on the P2 segment of the posterior cerebral artery. This dolichoectasia was found at the distal cervical internal carotid artery, the intradural segment of the ICA before the division, the trigeminal artery, and the posterior division of the ICA. We presume that the different forms of arterial involvement in PHACES syndrome (arterial stenoses, segmental agenesis of vessels, and the dolichoectasia described in this study) constitute a spectrum of angiogenetic dysfunctions related to an embryonic event involving several cephalic neural crest segments of the dorsal aorta.

Brain↗

PubMed2005

The bihemispheric posterior inferior cerebellar artery.

Rarely, a solitary posterior inferior cerebellar artery (PICA) will supply both cerebellar hemispheres. We report four cases of this variant. We present a retrospective review of clinical information and imaging of patients undergoing angiography at our institution to identify patients with a bihemispheric PICA. There were four patients: three males and one female. One patient presented with a ruptured arteriovenous malformation, and one with a ruptured aneurysm. Two patients had normal angiograms. The bihemispheric PICA was an incidental finding in all cases. The bihemispheric vessel arose from the dominant left vertebral artery, and the contralateral posterior inferior cerebellar artery was absent or hypoplastic. In all cases, contralateral cerebellar supply arose from a continuation of the ipsilateral PICA distal to the choroidal point and which crossed the midline dorsal to the vermis. We conclude that the PICA may supply both cerebellar hemispheres. This rare anatomic variant should be considered when evaluating patients with posterior fossa neurovascular disease.

Adolescent↗

PubMed2005

Intracranial aneurysms in children aged under 15 years: review of 59 consecutive children with 75 aneurysms.

OBJECTIVE: The objective was to review the clinical aspects and therapeutic strategies in a series of aneurysmal vasculopathies seen in children 15 years or under. METHODS: From our dedicated neurovascular databank of patients, we reviewed 59 consecutive children who had 75 separate lesions. RESULTS: The children were divided into four age groups: below 2 years (22%), 2-5 years (24%), 6-10 years (24%) and 11-15 years (30%). Thirty-three children had dissecting aneurysms, 2 had chronic post-traumatic aneurysms, 8 had infectious aneurysms and 16 had saccular lesions. Twenty-seven percent of the lesions were in the posterior circulation, and 21% developed on the middle cerebral artery. Most dissecting lesions were encountered in the vertebrobasilar system, while saccular lesions were present mostly in the anterior circulation. Half of all cases presented with haemorrhage. Haemorrhage in patients below 2 years of age was due to dissecting aneurysms, while saccular aneurysms were responsible for haemorrhage in patients above 5 years of age. Five children had familial disease and 9 presented with multiple aneurysms. Forty-eight children were referred to us for treatment. Thirty-two underwent surgical (21.9%), endovascular (62.8%) or combined (9.3%) treatment. Eleven patients were treated conservatively and in 5 patients the aneurysms had spontaneously thrombosed at admission. Overall, complete or partial spontaneous thrombosis was seen in 10 patients (16.9%). Dissecting aneurysms were frequent in children of all ages with either associated thrombosis or arterial tear with repeated acute haemorrhage and poor outcome. Two types of dissection seem identifiable despite the small number of cases collected: acute segmental arterial tear without thrombosis, acute subarachnoid haemorrhage (SAH) and recurrence before 5 years; and subacute focal dissection with partial thrombosis (or mural haematoma), rare SAH and no early recurrence. The former would require aggressive management whereas the latter often do not require interventional approaches. The mortality in our series of aneurysms is low in the treated group (10.42%). The overall tolerance to haemorrhage seems better than in adults, as already stressed in the literature. CONCLUSION: The multiple etiologies encountered confirm the heterogenous nature of "aneurysms". The variety of treatments used suggests the need to categorise aneurysms into subgroups in sufficient numbers to fully appreciate the behavior of the lesions and make the appropriate therapeutic decisions.

Adolescent↗

PubMedDate not supplied

MR diffusion tensor imaging and fiber tracking in spinal cord compression.

BACKGROUND AND PURPOSE: Spinal cord damage can result in major functional disability. Alteration of the spinal cord structural integrity can be assessed by using diffusion tensor imaging methods. Our objective is to evaluate the diagnostic accuracy of apparent diffusion coefficient (ADC), fractional anisotropy (FA), and fiber tracking in both acute and slowly progressive spinal cord compressions. METHODS: Fifteen patients with clinical symptoms of acute (n = 2) or slowly progressive (n = 13) spinal cord compression and 11 healthy volunteers were prospectively selected. We performed T2-weighted fast spin echo (FSE) and diffusion tensor imaging by using a 1.5-T MR scanner. ADC and FA maps were computed. Regions of interest were placed at the cervical, upper and lower thoracic cord levels for the healthy subjects and on the area with abnormal T2-weighted signal intensity in the patients with cord compression. In three patients, we used fiber tracking to locate the areas of cord compression precisely. Data were analyzed by using a mixed model. The sensitivity (SE) and specificity (sp) of imaging (T2, ADC, and FA maps) in the detection of spinal cord abnormality were statistically evaluated. RESULTS: For the healthy subjects, averaged ADC values ranged from 0.96 10(-3) mm(2)/s to 1.05 10(-3) mm(2)/s and averaged FA values ranged from 0.745 to 0.751. Ten patients had decreased FA (0.67 +/- 0.087), and one had increased FA values (0.831); only two patients had increased ADC values (1.03 +/- 0.177). There was a statistically significant difference in the FA values between volunteers and patients (P = .012). FA had a much higher sensitivity (SE = 73.3%) and specificity (sp = 100%) in spinal cord abnormalities detection compared with T2-weighted FSE imaging (se = 46.7%, sp = 100%) and ADC (SE = 13.4%, sp = 80%). CONCLUSIONS: FA has the highest sensitivity and specificity in the detection of acute spinal cord abnormalities. Spinal cord fiber tracking is a useful tool to focus measurements on the compressed spinal cord.

Acute Disease↗