Neurosurgery
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Methods were invented that made it possible to image peripheral nerves in the body and to image neural tracts in the brain. The history, physical basis, and dyadic tensor concept underlying the methods are reviewed. Over a 15-year period, these techniques-magnetic resonance neurography (MRN) and diffusion tensor imaging-were deployed in the clinical and research community in more than 2500 published research reports and applied to approximately 50,000 patients. Within this group, approximately 5000 patients having MRN were carefully tracked on a prospective basis. ⋯ MRN and diffusion tensor imaging neural tract imaging have been validated as indispensable clinical diagnostic methods that provide reliable anatomic pathological information. There is no alternative diagnostic method in many situations. With the elapsing of 15 years, tens of thousands of imaging studies, and thousands of publications, these methods should no longer be considered experimental.
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Traumatic brain injury (TBI) causes an increase in matrix metalloproteinases (MMPs), which are associated with neuroinflammation, blood-brain barrier disruption, hemorrhage, and cell death. We hypothesized that patients with TBI have an increase in MMPs in ventricular cerebrospinal fluid (CSF) and plasma. ⋯ We show that MMPs are increased in the CSF of TBI patients. Although the number of patients was small, the results were robust and clearly demonstrated increases in MMP-3 and MMP-9 in ventricular CSF in TBI patients compared with controls. Although these preliminary results will need to be replicated, we propose that MMPs may be important in blood-brain barrier opening and hemorrhage secondary to brain injury in patients.
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Surgical planning for deep brain stimulation implantation procedures requires T1-weighted imaging (T1WI) for stereotactic navigation. Because the subthalamic nucleus, the main target for deep brain stimulation, and other midbrain nuclei cannot be visualized on the stereotactic guidance T1WI, additional T2-weighted imaging (T2WI) is generally obtained and registered to the T1WI for surgical targeting. ⋯ The scan parameters of 3-dimensional spoiled gradient recalled acquisition in steady state are chosen in a way that T1WI can be obtained from conventional magnitude reconstruction and images with improved contrast between midbrain nuclei and surrounding tissues can be produced from the same data by performing susceptibility-weighted imaging reconstruction on a chosen region of interest. In addition, our preliminary experience suggests that the resulting contrast between the midbrain nuclei is superior to the current state-of-the-art fast spin echo T2WI in depicting the subthalamic nucleus as distinct from the substantia nigra pars reticulata and clear depiction of the nucleus ventrointermedius externus of thalamus.
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Intraventricular hemorrhage (IVH) is a serious complication of intracerebral hemorrhage (ICH). We hypothesized that antiplatelet medication use and platelet activity would be associated with more IVH. ⋯ Reduced platelet activity was related to more IVH as a complication of ICH. The relationship of platelet activity to IVH deserves further study.
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Hemangiomas of the brachial plexus are very rare, and there has not been a collection of multiple cases published in the literature to date. Extraneural brachial plexus hemangiomas typically present with similar signs and symptoms as nerve sheath tumors, including pain, paresthesia, and occasionally weakness, in addition to nonspecific imaging findings, making their diagnosis difficult. Exploratory surgery can lead to significant bleeding and nerve injury when a hemangioma or an associated aneurysm is encountered intraoperatively. We present 5 cases of extraneural hemangiomas causing brachial plexopathy, including pre-, intra-, and postoperative decision making, with an emphasis on diagnostic and management issues as well as outcomes. ⋯ Extraneural hemangiomas of the brachial plexus are very rare, but a high index of suspicion and appropriate preoperative evaluation, including angiography with the option for embolization, can result in decreased intraoperative hemorrhage and better patient outcomes.