Stereotactic and functional neurosurgery
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We have reviewed our experience with spinal cord stimulation (SCS) in patients with low back and leg pain. 33 patients complaining of leg and low back pain underwent percutaneous tests of SCS. 28 patients had failed back surgery syndromes, 1 patient had pain related to an L1 vertebral body fracture, another from Tarlow cysts and the remaining 3 patients had lumbosacral spondyloarthrosis and osteoporosis without radiological signs of root compression. 28 patients showed mono- or pluriradicular deficits. At the end of the test period (5-65 days), 21 patients (63.6%) reported more than 50% of pain relief (mean analgesia 75%) and were submitted to chronic stimulation. The mean follow-up was 45.5 months. At maximum available follow-up, 40% of the patients (13 out of the 33 initial patients) were successfully using the stimulator (mean analgesia 66.6%).
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Stereotact Funct Neurosurg · Jan 1994
Comparative StudyAnalgesic action of acute and chronic intraspinally administered opiate and alpha 2-adrenergic agonists in chronic neuropathic pain.
Intrathecal (IT) administration of opiate analgesics has become a popular method of pain control in patients with pain of both malignant and nonmalignant origin. Therapeutic efficacy for nonmalignant pain states might be improved by having a broader range of available pharmacologic agents for intrathecal administration. Toward this aim, we have applied a new model of neuropathic pain in the rat to evaluate the relative analgesic efficacy and potential cross tolerance of both acutely and chronically administered IT morphine (MS) and tizanidine (TZ), an alpha 2-adrenergic agonist. ⋯ The animals rapidly became tolerant to these agents so that by day 4, neither drug had an analgesic effect. No significant cross tolerance between MS and TZ was observed. Thus, both IT MS and TZ are analgesic in experimental chronic neuropathic pain.(ABSTRACT TRUNCATED AT 400 WORDS)
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Stereotact Funct Neurosurg · Jan 1994
An experimental animal model of spinal cord stimulation for pain.
In spite of the routine usage of spinal cord stimulation (SCS) as treatment of chronic pain, there is an insufficient understanding of the mechanisms underlying its effect. The method was originally developed as a spin-off from experiments demonstrating the inhibitory control of nociceptive signals by the activation of large afferent fibers, and on the basis of these findings the gate-control theory was advanced. Later experiments showed that stimulation of the dorsal columns can inhibit the relay of nociceptive impulses to second-order neurons in the dorsal horn. ⋯ SCS was applied at the approximate level of Th-XII during 10-20 min and produced a marked augmentation of the stimulus threshold. This abnormally high threshold was not normalized until 30-60 min after the end of SCS. In awake animals SCS was applied via an implanted spinal electrode and the effect on behavior changes associated with mononeuropathy was studied.(ABSTRACT TRUNCATED AT 250 WORDS)
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Stereotact Funct Neurosurg · Jan 1994
Case Reports Comparative StudyIncrease of cerebral blood flow and improvement of brain motor control following spinal cord stimulation in ischemic spastic hemiparesis.
A 64-year-old man had an ischemic stroke in the left parietotemporal cortical-subcortical areas. He developed a severe right spastic hemiparesis and dysphasia. An angiographic study showed left internal carotid artery occlusion and right internal carotid artery stenosis. ⋯ Such a TCD pattern, suggesting an increase of cerebral blood flow (CBF) during SCS, was reproducible. This case confirms efficacy of SCS in the treatment of ischemic hemiparesis and the increase of CBF following cervical SCS in man. The marked increase of CBF, particularly evident on the ischemic side, may play a role in mediating the improvement of motor control in our patient together with a possible arousal of the so-called 'sleeping neurons' of the penumbra zone.
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Stereotact Funct Neurosurg · Jan 1994
Case ReportsUse of a frameless isocentric stereotactic system (NEURO-SAT) combined with the intraoperative microrecording.
Combining the frameless isocentric stereotactic system (NEURO-SAT) and intraoperative microrecording, we performed stereotactic biopsies of deep-seated brain tumors in two cases. Case 1 was a 58-year-old male suffering from a right thalamus to basal ganglia tumor and case 2 was a 29-year-old male suffering from brain stem tumor. ⋯ NEURO-SAT provides three-dimensional real-time surgical navigation by displaying the positional information on the MRI images, and intraoperative microrecording shows a clear delineation between the tumor and the normal tissue in both cases. Therefore, since this combined method provides real-time surgical navigation and clear delineation of the tumor and normal tissue, it is a promising method of accurate and reliable image-directed stereotactic biopsy of deep-seated brain tumor.