Stereotactic and functional neurosurgery
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Stereotact Funct Neurosurg · Jan 1997
Positron emission tomography during motor cortex stimulation for pain control.
We studied regional changes in cerebral flood flow (rCBF) in 9 patients undergoing motor cortex stimulation (MCS) for pain control. Significant increase in rCBF was observed in the lateral thalamus ipsilateral to MCS probably reflecting corticothalamic connections from motor/premotor areas. Subsignificant increases were observed in the anterior cingulate, left insula and upper brainstem. ⋯ Our results support a model of MCS action whereby activation of thalamic nuclei directly connected with motor and premotor cortices would entail a cascade of synaptic events in other pain-related structures, including the anterior cingulate and the periaqueductal gray. MCS could influence the affective-emotional component of chronic pain by way of cingulate activation, and lead to descending inhibition of pain impulses by activation of the brainstem. Such effects may be obtained only if thalamic activation reaches a 'threshold' level, below which the analgesic cascade would not be successfully triggered.
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Stereotact Funct Neurosurg · Jan 1997
Can neuronavigation contribute to standardization of selective amygdalohippocampectomy?
Tailored selective amygdalohippocampal resections seem to be an interesting application for neuronavigation. The accuracy of freehand frameless neuronavigation was assessed in 28 patients for its ability to determine the hippocampal resection length, as compared to postoperative MRI. ⋯ The discrepancy is explained by an anterior-posterior component of brain collapse in a tilted head. Horizontal positioning of the head or navigational marking prior to the occurrence of brain collapse may overcome the problem.
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Stereotact Funct Neurosurg · Jan 1997
Microvascular decompression and percutaneous rhizotomy in trigeminal neuralgia.
We analyzed 417 patients with trigeminal neuralgia who underwent microvascular decompression (MVD; n = 146) or percutaneous procedures, i.e. radiofrequency rhizotomy (RFR; n = 235) and glycerol rhizotomy (GR; n = 36) between March 1973 and December 1996. MVD and RFR showed the highest rates of initial pain relief (MVD 96.5%; RFR 92.3%; GR 82.8%). ⋯ We concluded that MVD is the treatment of choice for tolerant younger patients and should be recommended for patients who desire no sensory deficit. We also determined that radiofrequency rhizotomy is the procedure of choice for patients in whom MVD failed.
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Stereotact Funct Neurosurg · Jan 1997
Modulation of spinal pain mechanisms by spinal cord stimulation and the potential role of adjuvant pharmacotherapy.
Experimental studies indicate that the effects of spinal cord stimulation (SCS) on 'hypersymptoms' in neuropathic pain conditions may at least partly be mediated via GABAergic and adenosine-dependent mechanisms. Concomitant intrathecal administration of receptor-active drugs modulating the function of the GABA and adenosine systems may both depress and enhance the effects of SCS. The first few patients with simultaneous intrathecal administration of the GABAB agonist baclofen and/or adenosine together with SCS, when the stimulation alone proved insufficient, are reported.
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Stereotact Funct Neurosurg · Jan 1996
Use of magnetic resonance imaging in stereotactic surgery. A survey of members of the American Society of Stereotactic and Functional Neurosurgery.
Members of the American Society of Stereotactic Functional Neurosurgery were surveyed to determine the current use of magnetic resonance imaging (MRI) for stereotactic coordinate determination. Of 137 respondents, 48% used MRI as the sole technique for some biopsy procedures. ⋯ Significant factors related to the use of MRI amongst individual surgeons included the performance of > or = 2 stereotactic surgeries per week, the performance of radiosurgery, and being in an academic practice (p < 0.0004). The increasing use of MRI in stereotactic surgery must be coupled with quality assurance testing from frame manufacturers, imaging manufacturers, and surgeons.