Education and propagation of intravascular surgery in okinawa

SUMMARY

Okinawa is an island located on the southwest edge of the Japanese Islands in which about 1,300,000 people live, and is an area where selfconclusion type medical treatment is desired. In this area, intravascular surgery was only performed for several cases per year until 1998. From May 1999, intravascular surgery started being performed in earnest, and 140 or more cases of intravascular surgery per year were performed in 2002. In the meantime, various measures for the propagation and development of intravascular surgery that we undertook led to the increase in the number of cases. As a result, the choice of medical treatment has increased by propagating these medical treatments, and it seems that this has contributed to the welfare of the people of Okinawa.

Low-dose tissue plasminogen activator followed by planned rescue angioplasty reduces time to reperfusion for acute myocardial infarction treated at community hospitals

The time from admission to reperfusion in patients with acute myocardial infarction (AMI) was compared according to the type of hospital and treatment strategy. A total of 164 patients with a first AMI within 12h of onset were enrolled at one tertiary emergency center (TEC) and 6 community hospitals (CHs). The subjects were randomly assigned to receive either primary percutaneous transluminal coronary angioplasty (PTCA) (TEC-primary PTCA and CHs-primary PTCA groups) or 800,000 units of intravenous monteplase, half the standard dose of a mutant tissue plasminogen activator (t-PA), followed by rescue PTCA if the Thrombolysis in Myocardial Infarction (TIMI) flow grade was 2 or less (TEC-monteplase and CHs-monteplase groups) on the first coronary angiogram. Sixty minutes after admission, TIMI flow grade 3 rates of the study groups were as follows, in descending order: TEC-monteplase group, CHs-monteplase group, TEC-primary PTCA group, and CHs-primary PTCA group (56%, 41%, 36%, and 8%, respectively; p<0.01). However, there was no significant difference in the final TIMI flow grade 3 rate among the 4 groups. In the CHs, the peak creatine kinase tended to be lower in the monteplase group than in the primary PTCA group. The results suggest that low-dose monteplase followed by rescue PTCA is an effective strategy for promoting early reperfusion in patients with AMI, especially those who are treated at CHs.

[Schwannoma of the cervical spinal cord with cervical angina: a case report]

A case of schwannoma of the cervical spinal cord presenting with cervical angina is reported. A 49-year-old man was admitted to our hospital with severe chest pain, cold sweats, and unconsciousness. Extensive cardiac examination showed no abnormal findings. Neurological deficits were muscular weakness and atrophy of the left arm, bilateral hypersthesia of the arms, and hyporeflexia of the left biceps. MRI revealed a tumor in the left side of the spinal canal between C4 and C5. The diagnosis was neurinoma of the left nerve root in C5. The tumor was completely removed surgically by laminectomy. Surgery confirmed that the tumor had originated from the left posterior root of C5 and that, histologically, it was schwannoma. The severe chest pain immediately disappeared after removal of the tumor with only dull post-operative chest pain remaining. We hypothesized that the severe chest pain was protopathic pain caused by compression of the anterior C5 root by the tumor and/or disturbance of the inhibitory pain mechanisms of the sympathetic nerve located in the posterior horn of the spinal cord. It must be kept in mind that cervical angina caused by spinal schwannoma is one of the differential diagnoses of chest pain.

Intravascular neurosurgery for cerebral aneurysm using interlocking detachable coils

SUMMARY

Instead of the Guglielmi detachable coil (GDC; Target Therapeutics, Fremont, California), the interlocking detachable coil (IDC; Target Therapeutics, Fremont, California) was the only available detachable and retractable coil in Japan until February 1997. From October 1993 to February 1997, endovascular treatment with IDCs were attempted for 25 cases of cerebral aneurysm. Within 25 trials, 15 cases were treated by intraaneurysmal coil embolization, 9 cases by parent artery or proximal occlusion using IDCs and one case could not be treated due to anatomical problems of the aneurysm. As for 15 cases of intraaneurysmal coil packing, complete occlusion was performed in 9 cases, subtotal occlusion in 4 cases and partial occlusion in 2 cases. In one of the partial occluded cases, a coil compaction occurred 6 months after embolization. Distal emboli were recognized on CT after embolization in 3 cases, however, only one case was symptomatic. Intraoperative bleeding occurred in one case, but no obvious hemorrhage after coil embolization in any case. From our experiences, treatment for poor-grade ruptured aneurysm is still difficult, but intravascular surgery for cerebral aneurysms using IDC is possible and a useful alternative, especially for surgically difficult aneurysm.

[Efficacy of low-dose mutant tissue-type plasminogen activator followed by planned rescue percutaneous transluminal coronary angioplasty as reperfusion therapy for acute myocardial infarction]

OBJECTIVES

The efficacy of injection of a low-dose mutant tissue-type plasminogen activator (mt-PA), monteplase, followed by planned rescue percutaneous transluminal coronary angioplasty (PTCA) was compared with that of primary PTCA.

METHODS

A total of 164 patients with acute myocardial infarction within 12 hr from onset were randomly assigned to a treatment with 80 x 10(4) U bolus of monteplase (Group M) or no administration (Group P) by the envelope method, followed by immediate angiography with angioplasty in patients with Thombolysis in Myocardial Infarction (TIMI) flow grade 0, 1 or 2.

RESULTS

There were no differences in baseline characteristics between the two groups. Initial angiography showed a higher reperfusion rate (TIMI 2 + 3: 21% + 38% vs 13% + 9%, p < 0.001) and the median time to TIMI 3 was shorter (63 vs 78 min, p < 0.005) in Group M than in Group P, but the final TIMI 3 rate was similar (93% vs 96%). Peak creatine kinase was lower, and predischarge left ventricular ejection fraction measured in 70% of all patients was higher (59 +/- 9% vs 54 +/- 14%, p = 0.02) in Group M than in Group P. Recurrent ischemia with ST elevation occurred in three patients in Group M, but death, re-acute myocardial infarction or stroke did not occur in either group and the rate of bleeding complication was similar (4.9% vs 3.7%). PTCA was performed less frequently in Group M, but medical expenses were comparable in both groups.

CONCLUSIONS

Low-dose mt-PA followed by rescue PTCA is effective for early recanalization and preservation of left ventricular function without increases in bleeding complications or medical expenses. These results suggest that low-dose mt-PA should be given to all patients with acute myocardial infarction who are scheduled to undergo primary PTCA.

Expression of enzymes and oncogene induced after radiotherapy and/or chemotherapy in patients with brain tumors

The relationship between the degree of the expression of Cu/Zn SOD, GST-pi and bcl-2 in the initial and recurrent tumor tissue after radiotherapy and/or chemotherapy and the cellular heterogeneity obtained from DNA content by image cytometry was investigated. Subjects were 7 patients who had glial tumors which were surgically removed at onset and removed a second time at recurrence. Radiotherapy and chemotherapy were also administered after initial resection. Immunoreactivity for copper/zinc super oxide dismutase (Cu/Zn SOD), GST (glutathione-S-transferase)-pi, and bcl-2 were evaluated from routinely prepared tissue blocks. Tumors were classified into two groups by cytometric analysis of DNA ploidy in the G2M cell cycle phase. One tumor group consisted of single clonal cells in both the initial and recurrent tumors and the other group consisted of tumors with polyclonal cells in the initial and recurrent tumor. In this study, one patient (case 3) with single clonal cell glioblastoma at recurrence did not show high Cu/Zn SOD activity after radiotherapy and chemotherapy but showed a short survival time after recurrence. In three patients (cases 1, 2, 3) with single clonal-cell glioblastoma, the recurrent tumor cells showed high GST-pi immunoreactivity and survival time was short after recurrence. Tumor cells in two patients (cases 5, 7) with single clonal cell anaplastic glioma at recurrence, showed high GST-pi immunoreactivity and had a short survival time after recurrence. In three single clonal glioblastomas (cases 1, 2, 3), the recurrent tumor showed the increased bcl-2 immunoreactivity and showed a short survival time after recurrence. In two patients (case 5, 7) with single clonal cell anaplastic glioma at recurrence, tumor cells showed a high bcl-2 immunoreactivity and these patients showed a short survival time after recurrence. Although the number of subjects is very small, our study shows that the immunoreactivity of bcl-2 and GST-pi in malignant gliomas may be very important factors in radio- and chemosensitivity, and shows that GST-pi is induced by radiation and anti-cancer drugs.

[Recent progress in intravascular neurosurgery for the treatment of cerebrovascular disease]

With the recent advances in the devices and techniques in intravascular neurosurgery such as microcatheters or a digital subtraction angiography, intravascular neurosurgery plays an important role for the treatment of cerebrovascular disease. We describe here, a recent progress in intravascular neurosurgery for the treatment of cerebrovascular disease. As a treatment of cerebrovascular disease, we discuss the treatment of cerebral aneurysm using Guglielmi detachable coils (GDC), and the treatment of ischemic cerebrovascular disease such as the thrombolytic therapy for the acute embolic occlusion of the cerebral artery, and a percutaneous transluminal angioplasty (PTA) or a stenting for the stenotic lesion of the cerebral arteries. Embolization of the cerebral aneurysm using GDC is less invasive method compare to the standard neurosurgical clipping of aneurysm. So, recently it becomes one of standard methods of the treatment of cerebral aneurysm. Thrombolytic therapy, PTA and stenting also become an important treatment for the ischemic cerebrovascular disease.

Brain metastasis of epithelioid sarcoma--case report

A 20-year-old-female first presented with an epithelioid sarcoma of the right thumb, and the right thumb was amputated. Five years later, a metastasis was found in the right lower lung and a partial lobectomy was performed. Three years later, computed tomography showed a metastatic brain tumor in the left frontal lobe, which was removed surgically. Adjuvant radiotherapy and chemotherapy were given after all operations. Histological examination showed all resected tumors were epithelioid sarcoma. She has maintained a good activity of daily living level as an outpatient for 2 years, although subcutaneous metastases and bronchial lymph node metastases have been observed. Such intensive treatment of slowly growing tumors often prolongs survival time, even in patients with multiple metastases.

Symptomatic arachnoid cyst of the left frontal convexity presenting with memory disturbance--case report

A 48-year-old female presented with vertiginous feeling and behavior disturbance. Computed tomography showed an arachnoid cyst on the left cerebral convexity. Single photon emission computed tomography revealed decreased cerebral blood flow (CBF) in the left frontal lobe. The Wechsler Memory Scale-Revised test demonstrated memory dysfunction. The arachnoid cyst was partially removed. Disturbances in CBF and behavior disappeared postoperatively. Local ischemia induced by compression due to arachnoid cyst may cause memory dysfunction and behavior disturbance. Neuropsychometric examination is useful for the evaluation of such symptoms.

Shunt tube problems due to placement of valves on the chest wall--three case reports

Programmable valves are often used for ventriculoperitoneal (VP) shunts with the shunt valve positioned on the chest wall. Three cases of shunt problems occurred due to placement of the valve on the chest wall. A 43-year-old male was treated with a VP shunt, and suffered shunt malfunction due to dislocation of the ventricular tube. A 21-year-old male was treated with a VP shunt, and suffered shunt malfunction due to disconnection of the shunt tube. A 4-day-old female neonate was treated with a VP shunt, and suffered migration of the shunt valve. The shunt system has two anchor sites on the head and chest wall, with the neck between the two anchor sites. High tension is sometimes caused in the shunt tube between the two points due to movement of the neck or growth, and may induce such dislocation and disconnection of the shunt tube. We recommend a longer shunt tube in such cases.

Probing the Site for r-Process Nucleosynthesis with Abundances of Barium and Magnesium in Extremely Metal-poor Stars

We suggest that if the astrophysical site for r-process nucleosynthesis in the early Galaxy is confined to a narrow mass range of Type II supernova (SN II) progenitors, with a lower mass limit of Mms=20 M middle dot in circle, a unique feature in the observed distribution of [Ba/Mg] versus [Mg/H] for extremely metal-poor stars can be adequately reproduced. We associate this feature, a bifurcation of the observed elemental ratios into two branches in the Mg abundance interval -3.7</=&sqbl0;Mg&solm0;H&sqbr0;</=-2.3, with two distinct processes. The first branch, which we call the y-branch, is associated with the production of Ba and Mg from individual massive supernovae. The derived mass of Ba synthesized in SNe II is 8.5x10-6 M middle dot in circle for Mms=20 M middle dot in circle and 4.5x10-8 M middle dot in circle for Mms=25 M middle dot in circle. We conclude that SNe II with Mms approximately 20 M middle dot in circle are the dominant source of r-process nucleosynthesis in the early Galaxy. An SN-induced chemical evolution model with this Mms-dependent Ba yield creates the y-branch, reflecting the different nucleosynthesis yields of [Ba/Mg] for each SN II with Mms greater, similar20 M middle dot in circle. The second branch, which we call the i-branch, is associated with the elemental abundance ratios of stars which were formed in the dense shells of the interstellar medium swept up by SNe II with Mms<20 M middle dot in circle that do not synthesize r-process elements, and it applies to stars with observed Mg abundances in the range &sqbl0;Mg&solm0;H&sqbr0;<-2.7. The Ba abundances in these stars reflect those of the interstellar gas at the (later) time of their formation. The existence of a [Ba/Mg] i-branch strongly suggests that SNe II that are associated with stars of progenitor mass Mms</=20 M middle dot in circle are infertile sources for the production of r-process elements. We predict the existence of this i-branch for other r-process elements, such as europium (Eu), to the extent that their production site is in common with Ba.

Cytotoxic effect through fas/APO-1 expression due to vitamin K in human glioma cells

Congeners of vitamin K have been found to inhibit growth in various rodent and human tumor cells, but the mechanisms of the inhibitory action are still not well understood. To investigate the modes of actions of vitamin K, we used several vitamin K analogs and examined their cytotoxic effect for human glioma cell lines RBR17T and U251. The analogs included vitamin K1 (VK1), vitamin K2 (VK2), vitamin K3 (VK3), and geranylgeraniol (GGO) which form an unsaturated side chain of VK2. Cell viability was estimated by MTT assay. DNA fragmentation was demonstrated by gel electrophoresis and flow cytometry. In order to study the mechanism of apoptosis, we measured the changes of intracellular reactive oxygen intermediates (ROI) and Fas/APO-1 expression by flow cytometry. The results showed: (1) VK2, VK3, and GGO inhibited cell growth; (2) VK3 had a more potent cytotoxic effect than VK2, and VK3 enhanced the cytotoxic effect of antitumor agents (ACNU and IFN-beta) in RBR17T cells; (3) VK2, VK3, and GGO induce apoptosis: (4) VK3 increased the expression of Fas/APO-1 although VK2 and GGO did not increase its expression in glioma cells; (5) VK3 increased the production of intracellular ROI. Catalase and reduced glutathione (GSH) inhibited production of intracellular ROI and antagonized inhibition of cell-growth induced by VK3, but failed to antagonize that of VK2 and GGO. We hypothesize that VK3 induces apoptosis by promoting the generation of intracellular ROI and Fas/APO-1 expression. On the other hand, VK2 and GGO induce apoptosis but most likely by some other unknown pathway.

Palliative radiation therapy for brain metastases from endometrial carcinoma: report of two cases

Although endometrial carcinoma is a common invasive neoplasm of the female genital tract, brain metastases are extremely rare and few reports exist of their treatment with radiation therapy. We report two patients with manifest clinical signs of brain metastases from endometrial carcinoma on computed tomography (CT) or magnetic resonance imaging (MRI). These two patients had multiple brain metastases, with widespread dissemination late in the course of the disease and received palliative whole-brain radiation therapy to a total dose of 50 Gy in 25 fractions (case 1) and 30 Gy in 10 fractions (case 2). After radiation therapy, improvement of neurological function (NF) was observed in both patients. The duration of improvement of NF was 9 weeks in case 1 and 12 weeks in case 2. The patients died 5 months and 3 months after the diagnosis of brain metastases, respectively. In these two cases, palliative radiation therapy was effective in improving the quality of the remaining lifetime and appears to be the best treatment for brain metastases from endometrial carcinoma as well as those frequently seen from other primaries.

A patient with improvement in short-term memory disturbance brought about by radiation therapy for germinoma involving Papez circuit

A 27-year-old male presented with memory loss. With magnetic resonance imaging (MRI), enhanced masses on the right side of hypothalamus, right side of anterior basal ganglia, and left side of hypothalamus were found. Histological analysis of the tumor by stereotactic biopsy proved it to be a germinoma. When related to the map of the thalamic nuclei, the tumor involved anterior column of the fornix and anterior nuclei of the thalamus. Neuropsychological tests prior to radiation therapy disclosed only short-term memory disturbance. The patient received radiation therapy to a total dose of 55 Gy to the primary lesion. After the completion of radiation therapy, the enhanced effect disappeared on gadolinium enhanced T1-weighted MRI. Single photon emission computed tomography indicated improvement in blood flow in the anterior portion of the bilateral thalami. Neuropsychological tests after radiation therapy showed improvement in short-term memory compared with baseline. Test results have remained stable for two and half years. This case indicates the possibility of improvement in memory function by treatment for tumor when it involves part of Papez circuit. Nevertheless, a decrease in intellectual ability by irradiation remains the major problem. Better approaches not only for cure but also to reduce the late effects should be undertaken when radiation therapy is the treatment of choice.

Reduction of end-stage malignant glioma by injection with autologous cytotoxic T lymphocytes

Autologous cytotoxic T lymphocytes (CTL) against primary-cultured malignant gliomas were generated from peripheral blood mononuclear cells in vitro in 4 patients. Activities of the CTL were highly specific to the corresponding autologous glioma and were inhibited, in one patient, with antibodies against CD3, CD8 and MHC-class I molecules. When the CTL were injected 3 times into the primary-tumor-resected cavity via an Ommaya tube, reduction of the recurrent tumors with magnetic resonance imaging (MRI)-measured volumes exceeding 45 cm3 was observed in 3 patients. In a patient with glioblastoma multiforme (GBM), the tumor volume (estimated, 130 cm3) was rapidly reduced to 1/3, although re-recurrence of the tumor followed 40 days later. A slight but distinct rapid reduction of the tumor volume was observed in another GBM patient and in an anaplastic astrocytoma patient; essentially no change was observed in a further GBM patient. These results suggest that adoptive immunotherapy with autologous CTL will be clinically effective against end-stage malignant gliomas.

Chronic progressive hematomyelia: case reports and review of the literature

BACKGROUND

Hematomyelia usually has an acute onset and rapid progression, which results in a poor prognosis. However, there have been a few cases in which the clinical symptoms have progressed chronically, with a good prognosis. These two different clinical courses should be analyzed separately. The differential diagnosis of spinal tumor and other chronic progressive diseases due to the similarity of the clinical courses is also important.

CASE DESCRIPTION

Two cases of hematomyelia with slowly progressive symptoms are reported. Unlike the acute onset and rapid progression or recurrent episodic deterioration usually seen in hematomyelia, the symptoms of chronic hematomyelia progressed over months and resulted in a better clinical prognosis than the acute course. The cases of "chronic progressive hematomyelia" from the literature are briefly summarized.

CONCLUSIONS

Chronic progressive hematomyelia should be considered as a different clinical entity from the acute version because of its slowly progressive clinical course and good outcome. Magnetic resonance imaging is the procedure of choice to exclude spinal tumors or other slowly progressive intraspinal diseases.

Copper/zinc superoxide dismutase, nuclear DNA content, and progression in human gliomas

To our knowledge, there have been no previous reports regarding the immunohistochemistry and image cytometry to demonstrate elevated Copper/zinc superoxide dismutase (Cu/Zn SOD) expression and numbers of the clonal cells in human gliomas. In 30 well-studied patients with gliomas, immunoreactivity for Cu/Zn SOD and cytometric evidence of DNA ploidy in the G2M cell cycle phase were evaluated from routinely prepared tissue blocks. Cu/Zn SOD positive tumor cells were shown in 8 of 13 glioblastomas (mean quantitative immunoreactivity SOD score; 1), 3 of 8 anaplastic gliomas (score; 0.6), and none of 9 low-grade gliomas. The differences in SOD score was not significant. In hypertetraploid glioblastomas, time to progression was shorter than for hypertetraploid of anaplastic gliomas, while SOD scores were not significantly different. The same relationship held for tetraploid specimens. Considering variables in combination, hypertetraploid gliomas with high SOD immunoreactivity showed a significantly short time to progression (p < 0.05) (1-5 months after radiotherapy and chemotherapy) compared with hypertetraploid, low-SOD immunoreactivity gliomas or tetraploid, low-SOD immunoreactivity gliomas. The tumor cells with high SOD activity also tended to be resistant for radiotherapy and anticancer drugs. Those results were suggested that the high grade glioma with a single clone and low SOD activity were effective for radiotherapy associated with oxidative stress, and that the high grade gliomas with more than two clones and high SOD activity were very less effective for same therapy. Cu/Zn SOD activity and the degree of the clonality in human gliomas should be very important factors influencing a choice of oxidative cytotoxic treatment.

Extracranial metastasis of anaplastic ganglioglioma through a ventriculoperitoneal shunt: a case report

Extracranial metastasis of an intracranial anaplastic ganglioglioma through a ventriculoperitoneal shunt is reported. A 53-year-old woman was treated by surgery, radiation and chemotherapy and died 2 years later. At autopsy, multiple metastatic lesions were found in the spinal cord, and the abdominal and pleural cavities. Histologically, all the metastatic lesions were composed of atypical cells which resembled primitive glial elements found in intracranial anaplastic ganglioglioma, suggesting that anaplastic glial elements have a metastatic potential. Extracranial metastasis of ganglioglioma is a rare occurrence; however, the spread of glial elements through the shunt further suggests that caution is required in therapy and indicates a need for protective filters in the shunt system.

[Proliferation inhibition of glioma cells by vitamin K2]

The antitumor effects of vitamin K2 were studied using three glioma cell lines: C6 (rat glioma cell), RBR17T and T98G (human glioma cell). The antitumor effects were estimated by count assay. The results was that vitamin K2 induced growth inhibition in a dose-dependent manner. The RBR 17T cells exposed to vitamin K2 for 72 hours resulted in oligonucleosomal DNA fragmentation and formed a ladder on agarose gel electrophoresis. Furthermore, the RBR17T cells exposed to vitamin K2 for 24 hours were significantly accumulated in the G0G1 phase of the cell cycle. Those results suggested that vitamin K2 can inhibit the proliferation of cells through the induction of cell cycle arrest and apoptosis for tumor cells. The combined treatment of vitamin K2 with ACNU or 5-FU or INF-beta or 1,25-dihydroxyvitamin D3 enhanced growth inhibition significantly. In conclusion, vitamin K2 can be a useful drug for the treatment of glioma.

Neutron capture therapy with a new boron-porphyrin compound in the rat 9L glioma model

Neutron capture therapy with a new boron-porphyrin compound was tested in a rat brain tumor model. Although the concentration of boron in the tumor was too low to elicit a therapeutic effect, prominent histopathologic changes, such as necrosis, congestion and bleeding were observed in the tumors of the rats which were administered the boron neutron capture therapy.

Endothelial nitric oxide synthase gene polymorphism and acute myocardial infarction

Recently a point mutation of guanine to thymine at nucleotide position 1917 in the endothelial nitric oxide synthase (eNOS) gene has been reported to be associated with coronary artery spasm. In addition, a significant association of the 4a/b polymorphism in intron 4 of the eNOS gene with coronary artery disease has been reported. However, the implications of these polymorphisms with respect to acute myocardial infarction (AMI) remain to be established. We conducted a case-control study of 226 patients with AMI and 357 healthy gender- and age-matched control subjects. In the former group, coronary angiograms were evaluated according to angiographic criteria based on the number of diseased vessels (>/=75%) and the number of stenotic lesions (>/=50%). Homozygosity for the Glu-Asp298 polymorphism existed in 5 of 226 patients with AMI (2.2%) but not in any of the 357 control subjects (P=.0085). However, when we evaluated the coronary angiograms of 226 case patients, there was no difference in the number of diseased vessels or the number of stenotic lesions between the patients with this homozygote and those without it. By contrast, there was no evidence of a significant increase in the risk of AMI or the severity of coronary atherosclerosis among individuals with the a/a genotype of the eNOS4a/b polymorphism. Our results imply that patients who are homozygous for the Glu-Asp298 polymorphism may be genetically predisposed to AMI; however, this mutation apparently is not related to the severity of coronary atherosclerosis. Further studies are needed to confirm our results and characterize the molecular mechanisms by which eNOS is involved in susceptibility to AMI.

Characteristics of neurons with high-frequency discharge in the central nervous system and their relationship to chronic pain. Experimental and clinical investigations

High-frequency extracellular unitary activity was recorded mainly in the ventral caudal nucleus of the thalamus in chronic-pain patients. These high-frequency discharge (hyperactive) neurons shows three types of discharge pattern with different interval histograms. Some of these hyperactive neurons were suppressed by the administration of a calcium antagonist (nicardipine). In an experimental study, chronic-pain models were made in rats according to the method of Lombard et al. (1979). From these animals, hyperactive neurons were recorded from the contralateral thalamic nuclei, lemniscus medialis. Hyperactive neurons were examined via electrical stimulation of and/or iontophoretic application. The results suggest that there is some relationship to the glutamatergic and GABAergic (probably GABAA) fibers or receptors.