Clinical utility and safety of a trapezoid-shaped electrode placement for evaluating the mesio-basal temporal lobe during epilepsy surgery

A trapezoid-shaped electrode (TSE) is used for detecting epileptogenicity in patients with temporal lobe epilepsy (TLE). However, the utility and safety associated with TSE placement have not been reported. In this study, we evaluated the safety and usefulness of TSE by analyzing the seizure detection, surgical outcomes and complications in patients with TLE who underwent intracranial electrodes (ICE) placement. Between April 2000 and August 2019, 50 patients with TLE who underwent 51 ICE placement procedures were examined. A TSE with eight contacts covering the parahippocampal gyrus and basal temporal lobe was used. Among the 37 patients who underwent TSE placement, 26 and 11 patients were diagnosed with mesial TLE (mTLE) and extra-mTLE, respectively. The 14 remaining patients without TSE placement were diagnosed with extra-mTLE. Seizure freedom was achieved in 73% (19/26) of mTLE patients detected by TSE and 50% (14/24) of extra-mTLE patients.Good seizure outcomes (Engel class I and II) were observed in 81% (21/26) patients with mTLE and 67% (16/24) patients with extra-mTLE. Radiographic complications were observed in 20% (10/50) patients who underwent ICE placement. Although 6% (3/50) patients showed transient neurological deficits, none were permanent. The electrodes responsible for the occurrence of complications included nine grid electrodes and one TSE. The complication rate after TSE placement was 3% (1/37). More than 64 electrode contacts and male sex, not TSE placement, were identified as significant risk factors for developing complications. This study demonstrated the usefulness and safety of TSE for evaluating mTLE in patients undergoing ICE placement.

Mechanical Thrombectomy and Parent Artery Occlusion for Acute Basilar Artery Occlusion Due to Vertebral Fracture and Artery Dissection: A Case Report

Objective

Basilar artery occlusion (BAO) secondary to traumatic vertebral artery (VA) dissection caused by vertebral fracture is a rare cause of acute ischemic stroke, and optimal management, such as antithrombotic agents, surgical fixation, and parent artery occlusion (PAO), has been controversial. We report a case in which mechanical thrombectomy and PAO were performed for a BAO due to right VA dissection caused by a transverse foramen fracture of the axis vertebra.

Case Presentation

A patient in her 80s suffered from a backward fall, and a neck CT revealed a fracture and dislocation of the right lateral mass of the axis and a compressed transverse foramen. The patient was instructed to admit and to remain in bed rest; however, she suddenly lost consciousness the following day. The CTA revealed right VA occlusion and BAO; therefore, the patient underwent mechanical thrombectomy and the BAO was successfully reperfused but the VA stenotic dissection remained. PAO of the right VA was performed on the fifth day after the accident to prevent BAO recurrence.

Conclusion

Mechanical thrombectomy is an effective treatment for BAO caused by VA dissection, and PAO may contribute to the prevention of stroke recurrence.

[Electrocorticography for the Evaluation of Focus Resection]

Electrocorticography(ECoG)with intracranial electrodes has a higher spatial resolution and higher sensitivity than conventional electroencephagrahy. Chronic VIDEO-ECoG with subdural grid electrodes has been used to determine the resection border of epileptic focus, and to evaluate cortical function prior to resective surgery. Recording multiple seizures is necessary to determine whether they are the same as habitual seizures and whether they are reproducible, to allow subsequent identification of the seizure onset zone. It is also necessary to understand the ictal ECoG patterns of various seizure onsets. Recent advances in engineering technology have made wideband(0.01 Hz-600Hz)analysis possible. The resection of the area with the ictal DC shift and high frequency oscillation is reported to improve surgical outcome. Although the procedure of subdural grid insertion is technically easy, high rates of complications, such as infections and bleeding, have been reported. Intraoperative acute ECoG was used to validate the extent of resection area. Overall, intraoperative ECoG is greatly affected by anesthetics, and the interictal epileptic discharge should be evaluated carefully.

Recovery of Visual Loss Following Internal Trapping of Anterior Cerebral Artery (A1 Segment) for Partially Thrombosed Large Anterior Communicating Artery Aneurysm: A Case Report

A 60-year-old woman, who experienced progressive right visual loss, was diagnosed with an unruptured large cerebral aneurysm. Magnetic resonance imaging (MRI) and angiography revealed a large partially thrombosed anterior communicating artery (Acom) aneurysm. The aneurysmal neck was located at the junction of the left A1–A2 segments, and the aneurysmal dome communicated with the right A1–A2 junction by the Acom. Endovascular treatment using the flow alteration technique was selected. Following an oral antiplatelet therapy for 9 days, balloon test occlusion (BTO) of the medial portion of the left A1 segment was performed under local anesthesia. After confirming the tolerance of the BTO, internal trapping of the medial portion of the left A1 segment by detachable coils was performed following intra-aneurysmal coil embolization. Oral antiplatelet treatment was continued for 19 days postoperatively. Within 3 months following the operation, her right visual acuity dramatically improved to the original level. Owing to aneurysmal recanalization and the disappearance of the thrombus, the second and third embolization was performed through the Acom route, 4 months and 3 years following the first embolization, respectively, and followed up for an additional 7 years by MRI; no deterioration of her visual acuity and no aneurysmal recanalization was observed. Thus, endosaccular embolization combined with flow alteration is considered a useful alternative treatment for large and partially thrombosed Acom aneurysms.

Neurodegenerative processes accelerated by protein malnutrition and decelerated by essential amino acids in a tauopathy mouse model

Protein malnutrition is epidemiologically suggested as a potential risk factor for senile dementia, although molecular mechanisms linking dietary proteins and amino acids to neurodegeneration remain unknown. Here, we show that a low-protein diet resulted in down-regulated expression of synaptic components and a modest acceleration of brain atrophy in mice modeling neurodegenerative tauopathies. Notably, these abnormal phenotypes were robustly rescued by the administration of seven selected essential amino acids. The up-regulation of inflammation-associated gene expression and progressive brain atrophy in the tauopathy model were profoundly suppressed by treatment with these essential amino acids without modifications of tau depositions. Moreover, the levels of kynurenine, an initiator of a pathway inducing neuroinflammatory gliosis and neurotoxicity in the brain, were lowered by treatment through inhibition of kynurenine uptake in the brain. Our findings highlight the importance of specific amino acids as systemic mediators of brain homeostasis against neurodegenerative processes.

Rab27a targeting to melanosomes requires nucleotide exchange but not effector binding

Rab GTPases are important determinants of organelle identity and regulators of vesicular transport pathways. Consequently, each Rab occupies a highly specific subcellular localization. However, the precise mechanisms governing Rab targeting remain unclear. Guanine nucleotide exchange factors (GEFs), putative membrane-resident targeting factors and effector binding have all been implicated as critical regulators of Rab targeting. Here, we address these issues using Rab27a targeting to melanosomes as a model system. Rab27a regulates motility of lysosome-related organelles and secretory granules. Its effectors have been characterized extensively, and we have identified Rab3GEP as the non-redundant Rab27a GEF in melanocytes (Figueiredo AC et al. Rab3GEP is the non-redundant guanine nucleotide exchange factor for Rab27a in melanocytes. J Biol Chem 2008;283:23209–23216). Using Rab27a mutants that show impaired binding to representatives of all four Rab27a effector subgroups, we present evidence that effector binding is not essential for targeting of Rab27a to melanosomes. In contrast, we observed that knockdown of Rab3GEP resulted in mis-targeting of Rab27a, suggesting that Rab3GEP activity is required for correct targeting of Rab27a. However, the identification of Rab27a mutants that undergo efficient GDP/GTP exchange in the presence of Rab3GEP in vitro but are mis-targeted in a cellular context indicates that nucleotide loading is not the sole determinant of subcellular targeting of Rab27a. Our data support a model in which exchange activity, but not effector binding, represents one essential factor that contributes to membrane targeting of Rab proteins.

Case study of paired cadaver renal allografts from the same donor: influence of local DIC kidney and concomitant acute rejection on early graft outcome

We report the clinical course of 2 recipients whose renal allografts were obtained from the same cadaver donor after cardiac arrest. The recipients showed different outcomes after transplantation. Graft biopsy after reperfusion revealed disseminated intravascular coagulation (so-called DIC kidney) and severe acute tubular necrosis (ATN) in both recipients. While one graft showed primary nonfunction, the other graft became functional after a post-operative anuric period. Serial graft biopsies performed during the oligo-anuric period revealed recovery of ATN and no intra-glomerular fibrin thrombi, but development of acute rejection was detected in both recipients. The left kidney graft showed more severe local DIC kidney than the right kidney, as well as more severe acute rejection in the oligo-anuric period. Despite aggressive anti-rejection therapy, the left kidney graft showed primary nonfunction. Therefore, severe acute rejection leading to primary nonfunction might have been related to more severe ischemic injury and more extensive local DIC kidney in the left kidney.

Surgical significance of supernumerary parathyroid glands in renal hyperparathyroidism

In secondary hyperparathyroidism (2HPT) fundamentally all parathyroid glands, including supernumerary glands, become hyperplastic, and stimulation of parathyroid glands continues after parathyroidectomy (PTx). Therefore supernumerary glands have special significance during surgery for 2HPT, whether persistent or recurrent HPT. In the present study 570 patients underwent initial total PTx with a forearm autograft. The frequency, type, location, histopathology, and clinical significance of the supernumerary glands were evaluated. At the initial operation 90 supernumerary glands were removed from 82 to 570 patients (14.4%); 12 patients (2.1%) required extirpation of supernumerary glands for persistent/recurrent HPT. Altogether 104 supernumerary glands were identified at operation in 94 of the 570 patients (16.5%). Among these 104 glands, 25 (24.0%) were of the rudimentary, or split, type and 79 (76.0%) of the proper type. Supernumerary glands were most frequently identified in the thymic tongue (53/104, 51.0%); 32 (60.4%) of these 53 glands were identified only microscopically. In 6 of the 570 cases (1.1%), reoperation was required for persistent HPT due to supernumerary glands located in the mediastinum, and 6 patients underwent neck reexploration for recurrence. Histopathologically, 61 of 104 (58.7%) supernumerary glands, including 36 glands recognized only microscopically, showed diffuse hyperplasia, and 43 (41.3%) displayed nodular hyperplasia. Residual small supernumerary glands with diffuse hyperplasia have the potential to be transformed to nodular hyperplasia during long-term hemodialysis. Therefore all parathyroid glands including supernumerary glands should, if possible, be removed at the initial operation. Routine removal of the thymic tongue and careful examination of the regions surrounding the lower poles of the thyroid, especially on the left side, are important steps in the surgical treatment.

Beneficial effect of donor pretreatment with thromboxane A2 synthase inhibitor on the graft survival in pig liver transplantation

With a known evidence that thromboxane A2 (TxA2) is elevated in the perfusate of the liver transplant (LTx) recipient, TxA2 is likely to play a role in the pathogenesis of preservation reperfusion injury. In this study, effectiveness of donor pretreatment with TxA2 synthase inhibitor, sodium ozagrel (SO), in the prevention of primary nonfunction (PNF) was investigated. LTx was performed for eight pigs which received the grafts treated with SO during harvest surgery (treatment group). Eight other animals were the control group. All of the animals in the treatment group survived longer than 7 days, whereas 37.5% (three of eight) of the control group died from PNF within 3 days postoperative. Significantly lower serum LDH levels were noted in the treatment group than control. Serum thromboxane B2 (TxB2) and 6-keto-PGF1 alpha were both elevated in the control group. However, a significant decrease in TxB2 was noted in the treatment group after reperfusion of the liver graft. Polymorphonuclear leukocyte (PMN) infiltration in the graft after reperfusion was significantly greater in the control group than in the treatment group. Hepatocyte microsteatosis was prominent in the control group after reperfusion. Donor pretreatment with SO was effective in the prevention of PNF after LTx. The beneficial effects of this drug are improvement in microcirculation allowing better perfusion of cold preservative and the blocking effect of platelet-PMN-endothelial interaction which is thought to be a primary etiology in reperfusion injury.

Effect of prolonged delayed graft function on long-term graft outcome in cadaveric kidney transplantation

One-hundred-and-twenty-six cadaveric renal transplantations were analyzed for the effect of post-transplant renal function on graft outcome. Thirty-one grafts functioned immediately after transplantation (Group 1), 54 grafts failed to function temporarily up to 8 posttransplant days as evidenced by urine output < 400 ml/day or hemodialysis support (Group 2), 33 grafts showed temporary nonfunction > 8 days (Group 3) and 8 grafts never functioned (group 4). Five-year graft failure rates were 6.5% (2/31), 13.0% (7/54), 42.4% (14/33) and 100% (8/8) for Groups 1, 2, 3 and 4, respectively. Actuarial 5-year graft survivals were 89.4%, 84.8%, 50% and 0% for Groups 1, 2, 3 and 4, respectively (p < 0.05). The most common cause of graft failure was the chronic rejection in 13, of which 9 were in Group 3. Acute rejection episodes during the first 3 months post-transplant in Group 3 (15 of 33, 45.5%) was slightly higher than that in Group 1 (10 of 30, 33.3%) or Group 2 (19 of 54, 35.2%) but the differences were not significant. Acute rejection episodes were associated with graft loss only 1 of 19 (5.3%) patients in Group 2 whereas 9 of 15 (47.4%) were seen in Group 3. The authors conclude that prolonged DGF is associated with a higher incidence of graft failure, particularly secondary to chronic rejection after 1 year posttransplant. Moreover, acute rejection based on prolonged DGF probably plays a major role in the development of chronic rejection.

Ten-year experience in the use of double balloon catheter for kidney procurement from non-heart beating donors in cadaveric kidney transplantation

One-hundred-and-twenty patients underwent first cadaveric kidney transplantation from the non-heart beating donors. All of the organs were procured with the use of double balloon catheter for in situ cooling. The mean warm ischemic time and cold ischemic time were 10.7 +/- 17.0 minutes and 18.9 +/- 11.4 hours, respectively. One- and 5-year graft survival rates were 85.0 and 72.7%, respectively. Among 120 recipients, 30 (25%) grafts functioned immediately (immediate function), 82 (68.3%) grafts functioned after varying length of oliguric periods (delayed function) and 8 (6.7%) grafts never functioned (non-function). The mean age of the donors in the group of immediate function (31.5 +/- 16.1 yr) was significantly lower than those of other two groups. The mean warm ischemic time in the group of immediate function (6.0 +/- 11.2 min) was significantly shorter than that of delayed function. However, there was no significant difference in donor hypotensive episode, types of preservation fluid and cold ischemic time between the groups. The conclusion is that the ultimate result of cadaveric kidney transplant from the non-heart beating donors with the use of double lumen catheter is acceptable despite a relatively high incidence of delayed graft function.

HLA-DRB1 matching as a recipient selection criterion in cadaveric renal transplantation

We retrospectively examined the effect of HLA-DRB1 matching at the DNA level compared with serological HLA-DR matching on acute rejection and graft survival in patients who underwent primary cadaveric renal transplantation. For patients with serological HLA-DR zero mismatch, the incidence of acute rejection in patients with zero DRB1 mismatch (3/20; 15%) was significantly lower than in those with one or two DRB1 mismatches (10/21; 48%). Five-year graft survival in patients with zero DRB1 mismatch was 100%, whereas that in those with one or two DRB1 mismatches was 76%, although the difference was not statistically significant. The fact that HLA-DRB1 matching at the DNA level influenced incidence of graft rejection after cadaveric renal transplantation is analogous to results in living-related renal transplantation. It is suggested that avoidance of mismatching for DRB1 alleles at the DNA level in recipient selection of cadaveric renal transplantation leads to an improvement of graft outcome.

Total parathyroidectomy with forearm autograft for secondary hyperparathyroidism in chronic renal failure

One hundred twenty-eight patients with chronic renal failure and secondary hyperparathyroidism underwent total parathyroidectomy with forearm autograft. Postoperative clinical improvement was remarkable. In all cases, the grafted tissue functioned well, and reimplantation of the cryopreserved parathyroid tissues was unnecessary. Intact 1-84 parathyroid hormone was more sensitive than C-terminal parathyroid hormone in parathyroid hormone level (PTH) gradient assays of grafted and nongrafted forearm. The study of hypocalcemia was also helpful in obtaining more distinct PTH gradients. Five of 119 patients had supernumerary parathyroid glands (4.2%), which preoperative noninvasive image diagnosis of parathyroid glands was helpful in detecting.