Applied neurophysiology最新文献

16 subjects with severe spasms secondary to traumatic and nontraumatic myelopathy underwent epidural spinal cord stimulation. 4 patients had a complete motor and sensory spinal cord lesion. 6 of the subjects with an incomplete spinal cord lesion were ambulatory. All patients had previously undergone extensive trials with medications and physical therapy. All 14 subjects in whom a satisfactory placement of the electrode could be obtained had a reduction in the severity of the spasms. In 6 patients, the spasms were almost abolished. Extremity, trunkal and abdominal spasms were affected. Clonus in the upper extremities was consistently reduced. Marked improvement in bladder and bowel function was observed in each of 2 subjects. In over 1-year follow-up, 5 subjects show persistence of the results, with less stimulation required to maintain the therapeutic effects. No neurological deterioration occurred following the procedure or after long-term spinal stimulation. 1 patient showed after several months of continuous stimulation increased voluntary motor control present only when spinal cord stimulation was activated. Complications included 1 system infection, 1 electrode migration, 1 wire breakage and skin breakdown at a connector site, development of high impedance in 1 electrode and 1 skin breakdown over the lead.

We studied 22 patients with amputation due to trauma, gangrene, or cancer. All developed postamputation pain, underwent a dorsal root entry zone (DREZ) procedure, and were followed from 6 months to 4 years after surgery. Overall, only 8 (36%) of these 22 patients had pain relief. However, good results were obtained in 6 (67%) of 9 patients with phantom pain alone, and in 5 (83%) of 6 patients with traumatic amputations associated with root avulsion. Poor results were obtained in patients with both phantom and stump pain, or stump pain alone. The DREZ procedure has a well-defined, but limited role in the treatment of postamputation pain.

A patient developed continuous patterned involuntary movements of abduction-adduction, flexion-extension of his right lower extremity following surgical placement of spinal dorsal root entry zone lesions for the treatment of phantom limb pain. The stereotype movements were monitored by video and electromyographic recording of quadriceps femoris and hamstring muscles. Administration of para-chlorophenylbutyric acid (baclofen) dramatically stopped the involuntary movements and electromyographic silence ensued. Voluntary muscle movements were preserved. The theoretical implications of this unique movement disorder and central patterning of motor activity within the spinal cord are discussed.

The method of radiofrequency heat lesion generation is reviewed with specific reference to the dorsal root entry zone. Experimental data on the impedance of electrolytic media as a function of temperature are reported, and their relation to what should be observed during radiofrequency lesioning in the body is commented upon. The future utility of impedance monitoring is discussed as well as possible implications of bipolar lesion electrode systems.

This paper details the long-term results in patients treated with dorsal root entry zone (DREZ) lesions for the treatment of pain following brachial plexus avulsion, spinal cord injury, and herpes zoster. With our current operative technique, 82% of patients with brachial plexus avulsion injuries were afforded long-term pain relief. Patients with pain confined to dermatomes just below the level of spinal injury also did well with DREZ lesions, although the results were less good in patients with diffuse pain or with sacral pain. The postoperative results in patients with postherpetic pain were disappointing.

The dorsal horn of the spinal cord receives afferent input from innocuous primary afferent neurons via collaterals from the dorsal columns. This input is integrated and relayed primarily by neurons in laminae III-VI. Dorsal horn neurons which encode innocuous inputs project to the medulla and the cervical spinal cord via the dorsal columns and the dorsolateral funiculus. Nociceptive primary afferent neurons enter the spinal dorsal horn via collaterals from Lissauer's tract. Nociceptive input is integrated and relayed by neurons in laminae I, II and V which project to the reticular formation and thalamus via the anterolateral tract.

The dorsal horn region of the spinal cord, particularly the dorsal root entry zone (DREZ), represents the first central integration center for nociceptive afferent impulses. Here, the excitatory neurotransmitters/modulators, products of the primary sensory neurons, are released, the segmental interneuronal influences pertain, and the descending bulbospinal tracts terminate. A vast variety of compounds are thus involved in the processing of nociceptive information in these areas, among which are the 'classical' neurotransmitters and the more recently described neuropeptides. A continued vast interest exists concerning the chemistry of the dorsal horn/DREZ region. The current developments and understanding regarding the pharmacology of this region are presented. Particular emphasis is given to the interactions among the various compounds, the coexistence of some of these within single neuronal populations, the importance of the opiate receptor subtypes, and the actions and localizations of some of the newly discovered neuropeptides.

The brain has long been considered an immunologically privileged site. Tissue transplanted to the central nervous system (CNS) is immunologically better tolerated than grafts to other regions of the body. With improved graft survival, tissue transplantation may provide new treatment options for previously incurable CNS disorders. The normal immune response is reviewed, followed by a discussion of the factors responsible for graft rejection. The modification of these factors to allow successful CNS transplantation is discussed.