Christopher M. Loftus

The Timing of Carotid Endarterectomy Post Stroke

The timing of carotid endarterectomy (CEA) post stroke remains a controversial area. Most authorities have advocated waiting at least 2 to 6 weeks after stroke before performing a CEA. More recently, these recommendations have been challenged. This article reviews the background leading to advocacy of delayed CEA after stroke, current literature recommendations regarding CEA after subacute stroke, current literature regarding neuroradiologic imaging findings and their implications in decision making regarding CEA after stroke, and the role of CEA for stroke in evolution.

Small mammal MRI imaging in spinal cord injury: A novel practical technique for using a 1.5 T MRI

The field of spinal cord injury research is an active one. The pathophysiology of SCI is not yet entirely revealed. As such, animal models are required for the exploration of new therapies and treatments. We present a novel technique using available hospital MRI machines to examine SCI in a mouse SCI model. The model is a 60 kdyne direct contusion injury in a mouse thoracic spine. No new electronic equipment is required. A 1.5T MRI machine with a human wrist coil is employed. A standard multisection 2D fast spin-echo (FSE) T2-weighted sequence is used for imaging the mouse. The contrast-to-noise ratio (CNR) between the injured and normal area of the spinal cord showed a three-fold increase in the contrast between these two regions. The MRI findings could be correlated with kinematic outcome scores of ambulation, such as BBB or BMS. The ability to follow a SCI in the same animal over time should improve the quality of data while reducing the quantity of animals required in SCI research. It is the aim of the authors to share this non-invasive technique and to make it available to the scientific research community.

Method to perform IV injections on mice using the facial vein

A novel technique for gaining IV access in a mouse model is presented. Using a cut-down approach, the facial vein is identified through an incision from anterior to the external auditory meatus to posterior to the lateral ispilateral canthus. A small gage needle (30gauge) may be inserted to inject medications. A high success rate (93%) as determined by direct visualization is achieved. The technique would prove especially useful for animals slated for kinematic testing as the incision does not interfere with the animals ventral surface.

CURRENT INDICATIONS FOR CAROTID ENDARTERECTOMY

Four randomized cooperative trials for asymptomatic carotid artery disease and three randomized cooperative trials of symptomatic carotid artery disease have been completed and published. There are now firm and proven indications for carotid artery reconstruction. Asymptomatic carotid artery disease with 60% or greater linear stenosis on angiography has been shown to be better treated with surgery than with medical therapy alone. For symptomatic patients, linear stenoses of 50% of greater have been shown to have a significant benefit with surgical treatment. All surgical recommendations are based on a morbidity/mortality of 3% or less for the individual surgeon.

A murine model of hypertonic saline as a treatment for acute spinal cord injury: effects on autonomic outcome

OBJECT spinal cord injury (SCI) continues to be a problem without a definitive cure. Research based on improved understanding of the immunological aspects of SCI has revealed targets for treating and ameliorating the extent of secondary injury. Hypertonic saline (HTS), a substance both easy to create and to transport, has been investigated as an immunologically active material that can be used in a clinically relevant interval after injury. In this pilot study, HTS was investigated in a murine model for its abilities to ameliorate secondary injury after a severe spinal cord contusion. METHODS female C57Bl/6 mice with severe T8-10 contusion injuries were used as the model subjects. A group of 41 mice were studied in a blinded fashion. Mice received treatments with HTS (HTS, 7.5%) or normal saline solution (NSS, 0.9%) at 2 discreet time points (3 and 24 hours after injury.) A separate group of 9 untreated animals were also used as controls. Animals were assessed for autonomic outcome (bladder function). In a group of 33 mice, histological assessment (cellular infiltration) was also measured. RESULTS bladder function was found to be improved significantly in those treated with HTS compared with those who received NSS and also at later treatment times (24 hours) than at earlier treatment times (3 hours). Decreased cellular infiltration in each group correlated with bladder recovery. CONCLUSIONS the increased effectiveness of later administration time of the more osmotically active and immunomodulatory substance (HTS) suggests that interaction with events occurring around 24 hours after injury is critical. These events may be related to the invasion of leukocytes peaking at 8-24 hours postinjury and/or the peak benefit time of subject rehydration.