Neurological research
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Neurological research · Jun 2004
Comparative StudyMuscle-nerve-muscle neurotization for the reinnervation of denervated somatic muscle.
Muscle-Nerve-Muscle (MNM) is the reinnervation of a denervated (recipient) muscle via a nerve graft inserted into the belly of an innervated (donor) muscle. MNM is studied for the reinnervation of intrinsic denervated somatic skeletal muscle by evaluating both restored muscle contractile ability and innervation state. In a rat model, muscle function is tested following MNM neurotization from an innervated (donor), extensor digitorum longus muscle to a denervated (recipient), peroneus digit quinti (PDQ) muscle. ⋯ MNM neurotization reinnervates 62% of the previously denervated muscle fibers in the PDQ muscle. No decrement in force capacity is observed in the donor EDL muscle. Nerve grafting for MNM neurotization may restore modest contractile function to denervated muscle and reinnervate relatively more denervated muscle fibers than the Denervated-control.
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Neurological research · Jun 2004
Comparative StudyThe role of a barrier between two nerve fascicles in adjacency after transection and repair of a peripheral nerve trunk.
Aberrant reinnervation of target organs caused by misdirected axonal growth at the repair site is a major reason for the poor functional outcome usually seen after peripheral nerve transection and repair. The following two studies investigate whether criss-crossing of regenerating rat sciatic nerve axons between tibial and peroneal nerve fascicles can be reduced by using a barrier at the coaption site. The left sciatic nerve was transected and repaired at mid-thigh as follows: epineural sutures (group A, A-II), fascicular repair of tibial and peroneal nerve fascicles (group B, B-II), fascicular repair of tibial and peroneal nerve fascicles separating the two fascicles with a pedicled fat flap (group C), Integra (group D) or non-vascularized autologous fascia (group C-II). ⋯ The histological picture indicated that this inferior result in group C-II was due to nerve compression caused by fibrotic scar tissue at the site of the fascia graft. Results of this study show that a pedicle fat flap and Integra used as barrier significantly prevent aberrant reinnervation between two sutured nerve fascicles in adjacency resulting in improved motor recovery in rats. Non-vascularized autologous fascia however, reduces also criss-crossing of regenerating axons between the fascicles, but causes significant nerve compression.
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Neurological research · Apr 2004
Case ReportsBasilar artery to bilateral posterior cerebral artery 'Y stenting' for endovascular reconstruction of wide-necked basilar apex aneurysms: report of three cases.
Endovascular reconstruction of basilar artery (BA) apex aneurysms has been augmented by adjunctive techniques such as balloon and stent assistance. We present three cases of a wide-necked BA apex aneurysm involving the bilateral P1 segments of both posterior cerebral arteries (PCAs) treated by placement of BA to PCA stents bilaterally in a 'Y' configuration to reconstruct the BA apex for effective coil embolization. Three patients (aged 70, 65 and 37 years) with wide-necked basilar artery aneurysms presented for endovascular treatment. ⋯ The third patient suffered an upper GI bleed and was treated an additional 3 days in hospital. Oral clopidogrel (75 mg by mouth) and aspirin (325 mg by mouth) were continued daily for 4 weeks. The 'Y' stent configuration for reconstruction of the BA apex is a safe effective technique in patients with wide-necked BA aneurysms.
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Neurological research · Jan 2004
Post-operative hematoma after surgery for intracranial meningiomas: causes, avoidable risk factors and clinical outcome.
Intracranial meningiomas are mainly benign lesions amenable for surgical resection. However, removal of an intracranial meningioma carries a higher risk of post-operative hemorrhage compared to surgery for other intracranial neoplasms. Because avoidance of post-operative hematoma is of vital interest for neurosurgical patients, the aim of this retrospective study was to analyze risk factors of post-operative hematoma associated with meningioma surgery. ⋯ Meningioma surgery carries a higher risk for post-operative hematoma in the elderly. Thrombocytopenia and other hemostatic disorders were frequently associated with post-operative hemorrhage after meningioma surgery, while no surgical factors could be defined. Extending coagulation tests and specific replacement therapy may prevent hematoma formation and improve the patients outcome.
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Neurological research · Jun 2003
Online assessment of brain tissue oxygen autoregulation in traumatic brain injury and subarachnoid hemorrhage.
Monitoring of brain tissue oxygenation (ptiO2) enables early diagnosis of secondary cerebral ischemia and may guide a cerebral perfusion pressure (CPP) orientated therapy. The purpose of our study was to explain the concept of ptiO2-autoregulation, defined as the ability of the brain to maintain ptiO2 despite changes in CPP, and to show the different states of ptiO2-autoregulation we found. Microcatheters to assess ptiO2 and intracranial pressure were implanted into cerebral 'tissue at risk' of patients suffering from traumatic brain injury or subarachnoid hemorrhage. ⋯ When ptiO2-autoregulation is present, an elevation in CPP is ineffective to raise ptiO2. In contrast, an increase in CPP elevates ptiO2 more pronounced in impaired than in moderate ptiO2- autoregulation, but decreases ptiO2 in inverse ptiO2-autoregulation. We conclude that online assessment of ptiO2-autoregulation gives valuable information on which patient will benefit from an increase in CPP and which CPP should be achieved to do so.