Projections from the dorsal peduncular cortex to the trigeminal subnucleus caudalis (medullary dorsal horn) and other lower brainstem areas in rats

This study has revealed direct projections from the dorsal peduncular cortex (DP) in the medial prefrontal cortex (mPfC) to the trigeminal brainstem sensory nuclear complex and other lower brainstem areas in rats. We first examined the distribution of mPfC neurons projecting directly to the medullary dorsal horn (trigeminal subnucleus caudalis [Vc]) and trigeminal subnucleus oralis (Vo) which are known to receive direct projections from the lateral prefrontal cortex (insular cortex). After injections of the retrograde tracer Fluorogold (FG) into the rostro-dorsomedial part of laminae I/II of Vc (rdm-I/II-Vc), many neurons were labeled bilaterally (with an ipsilateral predominance) in the rostrocaudal middle level of DP (mid-DP) and not in other mPfC areas. After FG injections into the lateral and caudal parts of laminae I/II of Vc, or the Vo, no neurons were labeled in the mPfC. We then examined projections from the mid-DP by using the anterograde tracer biotinylated dextranamine (BDA). After BDA injections into the mid-DP, many axons and terminals were labeled bilaterally (with an ipsilateral predominance) in the rdm-I/II-Vc, periaqueductal gray and solitary tract nucleus, and ipsilaterally in the parabrachial nucleus and trigeminal mesencephalic nucleus. In addition, the connections of the mid-DP with the insular cortex were examined. Many BDA-labeled axons and terminals from the mid-DP were also found ipsilaterally in the caudalmost level of the granular and dysgranular insular cortex (GI/DI). After BDA injections into the caudalmost GI/DI, many axons and terminals were labeled ipsilaterally in the mid-DP. The projections from the mid-DP to the rdm-I/II-Vc and other brainstem nuclei suggest that mid-DP neurons may regulate intraoral and perioral sensory processing (including nociceptive processing) of rdm-I/II-Vc neurons directly or indirectly through the brainstem nuclei. The reciprocal connections between the mid-DP and caudalmost GI/DI suggest that this regulation may involve mid-DP interactions with the caudalmost GI/DI neurons.

Subtle structural change demonstrated on T2-weighted images after clipping of unruptured intracranial aneurysm: negative effects on cognitive performance

OBJECT

The mechanisms underlying neurocognitive changes after surgical clipping of unruptured intracranial aneurysms (UIAs) are poorly understood. The aim of this study was to investigate factors that determine postoperative cognitive decline after UIA surgery.

METHODS

Data from 109 patients who underwent surgical clipping of a UIA were retrospectively evaluated. These patients underwent neuropsychological examinations (NPEs), including assessment by the Wechsler Adult Intelligence Scale-Third Edition and the Wechsler Memory Scale-Revised before and 6 months after surgical clipping of the UIA. Results of NPEs were converted into z scores, from which pre- and postoperative cognitive composite scores (CSpre and CSpost) were obtained. The association between the change in CS between pre- and postoperative NPEs (that is, CSpost - CSpre [CSpost - pre]) and various variables was assessed. These latter variables included surgical approach (anterior interhemispheric approach or other approach), structural change evidenced on T2-weighted imaging at 6 months, somatosensory evoked potential amplitude decrease greater than 50% during aneurysm manipulation, preexisting multiple ischemic lesions in the lacunar region detected on preoperative T2-weighted imaging, and total microsurgical time. Paired t-tests of the NPE scores were performed to determine the net effect of these factors on neurocognitive function at 6 months.

RESULTS

A significant CSpost - pre decrease was observed in patients with a structural change on postoperative T2-weighted imaging when compared with those without such a change on postoperative T2-weighted imaging (-0.181 vs 0.043, p = 0.012). Multiple regression analysis demonstrated that postoperative T2-weighted imaging change independently and negatively correlated with CSpost - pre (p = 0.0005). In group-rate analysis, postoperative NPE scores were significantly improved relative to preoperative scores.

CONCLUSIONS

Minimal structural damage visualized on T2-weighted images at 6 months as a result of factors such as pial/microvascular injury and excessive retraction during surgical manipulation could cause subtle but significant negative effects on postoperative neurocognitive function after surgical clipping of a UIA. However, this detrimental effect was small, and based on the group-rate analysis, the authors conclude that successful and meticulous surgical clipping of a UIA does not adversely affect postoperative cognitive function.

Carotid endarterectomy for treatment of tandem carotid stenosis in the presence of the anomalous origin of the occipital artery arising from the cervical internal carotid artery: a case report

Introduction

Branches from the cervical portion of the internal carotid artery are rare. In most cases, atherosclerotic stenosis is found at the bifurcation of the internal and external carotid arteries. However, when associated with atherosclerotic carotid artery disease, the origin of the rare branches arising from the internal carotid artery can be another site of stenosis. This report describes a rare case of such tandem carotid stenosis treated by carotid endarterectomy and the importance of the possibility of stenosis at the origin of the anomalous branch from the internal carotid artery.

Case presentation

A 73-year-old Japanese woman presented with transient left hemiparesis and vertigo. Magnetic resonance angiography seemed to indicate two stenotic lesions distal to the right internal carotid artery in addition to the origin of the right internal carotid artery, and angiography indicated tandem stenotic lesions of the internal carotid artery. The patient was successfully treated with right carotid endarterectomy, including the distal stenotic lesion of internal carotid artery, and postoperative angiography indicated that the occipital artery arose from the internal carotid artery.

Conclusion

It is important to recognize rare cases of the anomalous origin of the occipital artery from the internal carotid artery and the possibility that the origin of such an anomalous occipital artery may be the cause of stenosis.

Scrotal migration of lumboperitoneal shunt catheter in an adult--case report

A 57-year-old man presented with recurrent parasagittal anaplastic meningioma of frontoparietal region. The tumor was extensively removed, and the dura was repaired with Gore-Tex surgical membrane. After the operation, subcutaneous cerebrospinal fluid (CSF) collection was observed in the fronto-parietal area and a lumboperitoneal shunt was placed. Four weeks after the shunt procedure, he complained of right scrotal swelling and recurrence of the CSF collection. Radiography revealed the coiled catheter in the scrotum. The catheter was surgically removed through a small incision in the skin of the scrotum under local anesthesia. Lumboperitoneal shunt is a simple and useful procedure to control CSF pressure, but catheter migration has been reported in infants and children. Shunt catheter can migrate into the scrotum even in an adult, as the vaginal process, through which the catheter seemed to have entered the scrotum, is patent in 5% of the adult population. In these cases, direct removal through a small incision is appropriate to remove the catheter.

Subclinical ischemia verified by somatosensory evoked potential amplitude reduction during carotid endarterectomy: negative effects on cognitive performance

OBJECT

Although the mechanisms underlying neurocognitive changes after carotid endarterectomy (CEA) are poorly understood, intraoperative ischemia and postoperative hemodynamic changes may play a role.

METHODS

Data from 81 patients who underwent unilateral CEA with routine shunt use for carotid artery stenosis were retrospectively evaluated. These patients underwent neuropsychological examinations (NPEs), including assessment by the Wechsler Adult Intelligence Scale-Third Edition and the Wechsler Memory Scale-Revised before and 6 months after CEA. results of NPEs were converted into z scores, from which pre- and postoperative cognitive composite scores (CSpre and CSpost) were obtained. The association between the change of CS between pre- and postoperative NPEs (that is, CSpost - CSpre [CSpost - pre]) and various variables was assessed. These latter variables included ischemic or hemodynamic parameters such as 1) intraoperative hypoperfusion detected by somatosensory evoked potential (SSEP) change-that is, an SSEP amplitude reduction more than 50% and longer than 5 minutes (SSEP< 50%, > 5 min); 2) new lesions on postoperative diffusion-weighted imaging studies; and 3) preexisting hemodynamic impairment. Paired t-tests of the NPE scores were performed to determine the net effect of these factors on neurocognitive function at 6 months.

RESULTS

A significant CSpost - pre decrease was observed in patients with SSEP< 50%, > 5 min when compared with those without SSEP< 50%, > 5 min (-0.225 vs 0.018; p = 0.012). Multiple regression analysis demonstrated that SSEP< 50%, > 5 min independently and negatively correlated with CSpost - pre (p = 0.0020). In the group-rate analysis, postoperative NPE scores were significantly improved relative to preoperative scores.

CONCLUSIONS

Hypoperfusion during cross-clamping, as verified by SSEP amplitude reduction, plays a significant role in the subtle decline in cognition following CEA. However, this detrimental effect was small, and various confounding factors were present. Based on these observations and the group-rate analysis, the authors conclude that successful unilateral CEA with routine shunt use does not adversely affect postoperative cognitive function.

Acute to subacute surgical revascularization for progressing stroke in atherosclerotic vertebrobasilar occlusion

BACKGROUND

Acute vertebrobasilar artery (VBA) occlusion is catastrophic. For embolic occlusion, thrombolysis is reasonable. However, if the occlusion is atherosclerotic, the best therapeutic approach remains unclear. The aim of this study was to characterize the clinical course, case selection, techniques and complications associated with acute to subacute surgical revascularization in atherosclerotic vertebrobasilar occlusion under appropriate patient selection based on diffusion-weighted imaging (DWI) combined with careful evaluation of progressive neurological symptoms.

METHODS

We retrospectively reviewed nine consecutive patients who were scheduled to undergo acute to subacute surgical revascularization for progressing stroke in atherosclerotic VBA occlusion consisting of a relatively small DWI lesion. Clinical characteristics, radiological findings, results of revascularization, and 3-month outcomes (mRS) were assessed.

RESULTS

Seven patients underwent surgical revascularization (superficial temporal artery [STA]-superior cerebellar artery [SCA] bypass, n = 5; occipital artery [OA]-posterior inferior cerebellar artery [PICA] bypass, n = 1; vertebral endarterectomy, n = 1). Revascularization distal to the occlusion was successful in all seven patients. Two patients scheduled for STA-SCA bypass sustained irreversible confluent brainstem infarction before surgical intervention and died. The median time between admission and surgical treatment or irreversible coma was 20 h (range, 4-72 h). The modified Rankin Scale (mRS) at 3 months of seven patients who underwent surgical revascularization was good (mRS 0-2) in four patients, poor (mRS 3-6) in three patients. Mid- to long-term bypass patency was confirmed by magnetic resonance angiography (MRA) in the surviving five patients at a median follow-up of 7 months (range, 1-25 months).

CONCLUSION

Atherosclerotic vertebrobasilar artery (VBA) occlusion presented with stuttering onset of symptoms and patients developed worsening symptoms of vertebrobasilar insufficiency over hours to days. DWI was a useful modality to help guide the appropriate selection of patients for acute to subacute surgical revascularization for progressing stroke in atherosclerotic VBA occlusion. The surgical methods themselves were feasible. Poor outcomes were related to delay of treatment rather than surgical or technical failure.

[A case of a penetrating brain injury due to an explosion of a construction machine]

Penetrating brain injury caused by a high speed projectile is rather rare in Japan, known for its strict gun-control laws. We report a case of a 55-year-old male, who was transferred to our hospital with a foreign body in the brain due to penetrating head injury, which was caused by an explosion of a construction machine. Neurological examination demonstrated severe motor aphagia with no apparent motor paresis. The patient had a scalp laceration on his left forehead with exposed cerebral tissue and CSF leakage. Head CT scan and plain skull X-ray revealed a 20 mm×25 mm bolt which had penetrated due to the explosion of the machine. The anterior wall of the left frontal sinus was fractured resulting in dural laceration, and scattered bone fragments were seen along the trajectory of the bolt. Digital subtraction angiography showed no significant vascular injuries including superior sagittal sinus. We performed open surgery, and successfully removed the bolt along with the damaged frontal lobe. The patient had no infection or seizure after the surgery, and was transferred for further rehabilitation therapy. We performed a cosmetic cranioplasty six months later. Surgical debridement of the damaged cerebral tissue along the trajectory led to successful removal of the bolt with no further neurological deficit.

Preparation of Thin Polycarbonate Film and Its Application to PIXE Analysis of Anionic Elements in Water Samples

A polycarbonate film of thin and uniform thickness was prepared. A casting solution for film-formation was made up by diluting a solution of poly (bisphenol A carbonate) in chloroform by a factor of two to three with benzene. A uniform film was created by dropping 0.2-0.3 cm3 of the casting solution slowly on a water surface within an aperture (20 mm diameter) of Mylar target frame floating on 50 wt% sucrose aqueous solution. Films of 0.14-0.27 mg/cm2 thickness thus prepared offer a good combination of mechanical strength and low continuum backgrounds. To test PIXE analysis of anionic species in water, targets containing SO 42-, Cr 2 O 72-, AsO 43-, and Ga 3+-internal standard were prepared by depositing 100 μl of the test solutions onto the polycarbonate film, and irradiated in vacuum by 3 MeV proton beams. The difference between the nominal and the analyzed concentrations seldom exceeded ± 15 % in the range from 10 to 2000 ppb.

Continuously coupled transcription-translation system for the production of rice cytoplasmic aldolase

A continuously coupled cell-free transcription-translation system was developed for the production of rice cytoplasmic aldolase, an enzyme involved in both glycolytic and gluconeogenic pathways in eukaryotic cells. The system works with a continuous flow of feeding solution containing nucleoside triphosphates and amino acids into a 1-mL reactor containing wheat-germ extract, plasmid DNA, and transcription enzyme, and continuous removal of translation product through an ultrafiltration membrane fitted in the reactor. Addition of free nucleotide primer, m(7)G(5')ppp(5')G, to this reactor was necessary for efficient transcription, thus producing biologically active mRNA for translation. The rate of aldolase synthesis was constant during the continuous translation reaction. It was observed that from 3 h onward only aldolase was synthesized by the system. After 30 h, the total amount of protein synthesized reached 205.6 microg, which is comparable with the amount synthesized (255.6 microg) in the translation system only where separately prepared capped mRNAs were added to the reactor for translation. Autoradiogram and Western blot analyses of the translated product showed a distinct band corresponding to the calculated molecular weight of the protein. These results have shown the establishment of a continuously coupled eukaryotic transcription-translation system for the expression of genes from eukaryotic cells.

Surgical repair of refractory strictures of esophagogastric anastomoses caused by leakage following esophagectomy

Refractory strictures of esophagogastric anastomosis caused by leakage following an esophagectomy are a severe complication, for which either repeated balloon dilations or bougies are not necessarily effective. In such a case, surgical repair is quite difficult because the esophageal substitute such as the stomach or colon is usually located in the mediastinum and severely adhesive to the neighboring organs. Furthermore, in case the resected stricture is too long for direct re-anastomosis to be performed, a free jejunal graft or a new esophageal substitute should be prepared. This paper proposes a procedure for the re-reconstruction of refractory stricture in the case of a retrosternal reconstruction with a gastric conduit, which frequently employs pull-up route. The anterior plate of the manubrium was divided medially from the notch to the symphysis with the sternal saw. The manubrium is then removed, bite by bite, like breaking up rocks, with a bone rongeur forceps, starting with the anterior plate, then the posterior plate, from upper median part to the lower and lateral part of the sternum until it reaches the symphysis and the sternoclavicular and the sternocostal joints. It is safer to destroy the manubrium little by little from the anterior side so that the posterior periosteum, which is likely to adhere tightly to the gastric conduit, can be preserved. After the manubrium is almost completely resected and the posterior periosteum of the manubrium is preserved, a median longitudinal incision is carefully made on the periosteum so as not to damage the gastric conduit that may be adhesive to the periosteum. The periosteum was gradually opened bilaterally separating the periostium and the gastric conduit. Although gastroenterological surgeons may hesitate to remove the manubrium, removing the manubrium and preserving the posterior periosteum make it possible to avoid injuring the gastric conduit and to provide a wide view around the stenosis for safely resecting the anastomotic stricture. Furthermore, this procedure allows direct re-anastomosis between the cervical esophagus and the gastric conduit without a complicated reconstruction such as a free jejunal graft. This procedure is strongly recommended as an alternative option so that a second reconstruction can be performed both safely and steadily.