Functional Localization of the Supplementary Motor Area

The supplementary motor area (SMA) is a key structure involved in behavioral planning and execution. Although many reports have indicated that SMA is organized somatotopically, its exact organization remains still unclear. This study aimed to functionally map SMA using functional magnetic resonance imaging (fMRI) and validate the fMRI-SMA by electrocortical stimulation (ECS) and postsurgical symptoms. Total 32 healthy volunteers and 24 patients participated in this study. Motor tasks were right and left finger tapping and language tasks included simple reading, lexical decision for presented words, and verb generating tasks. SPM8 was used to conduct individual and group analyses. In all subjects, the lexical decision task induced the greatest number of active fMRI pixels in SMA. fMRI during the language tasks showed anterior part of SMA compared to finger tapping tasks. We found an overlap spot with all different tasks in posterior part of SMA, which we termed SMA core. Six patients underwent awake craniotomy for ECS mapping for primary regions and SMA. During awake craniotomy, ECS to posterior part of SMA, which might involve the possible SMA core consistently, evoked both speech arrest and flaccid hemiparesis. The SMA mapping suggested posterior part of SMA might play more important roles in any executions, which might involve the SMA core.     

Comparison of <Superscript>11</Superscript>C-4DST and <Superscript>18</Superscript>F-FDG PET/CT imaging for advanced renal cell carcinoma: preliminary study

Purpose

4′-[Methyl-¹¹C]-thiothymidine (4DST) has been developed as an in vivo cell proliferation marker based on its DNA incorporation mechanism. This study evaluated the potential of 4DST PET/CT for imaging cellular proliferation in advanced clear cell renal cell carcinoma (RCC), compared with FDG PET/CT. Both 4DST and FDG uptake were compared with biological findings based on surgical pathology.

Methods

Five patients (3 men and 2 women; mean (±SD) age 64.8 ± 11.0 years) with a single RCC (mean diameter: 9.3 ± 3.2 cm) were examined by PET/CT using 4DST and FDG. The dynamic emission scan of 4DST for RCC over 35 min followed by a static emission scan of the body for 4DST and FDG. Then we compared the maximum standardized uptake value (SUVmax) of 20 areas of RCC on both 4DST and FDG images with (1) the Ki-67 index of cellular proliferation (2) Fuhrman grade system for nuclear grade (G) in RCC and (3) pathological phosphorylated grade of mammalian target of rapamycin (pmTOR).

Results

All patient cases showed clear uptake of FDG and 4DST in RCC tumors, with mean 4DST SUVmax of 7.3 ± 2.2 (range 4.3–9.4) and mean FDG SUVmax of 6.0 ± 2.8 (range 3.4–10.4). The correlation coefficient between SUVmax and Ki-67 index was higher with 4DST (r = 0.61) than with FDG (r = 0.43). Tumor 4DST uptake (G0: 1.4, G2: 2.6, G2 5.6, G4: 5.7) and tumor FDG uptake (G0: 1.8, G2: 2.9, G2 3.7, G4: 4.1) were both related to Fuhrman grade system. The 4DST uptake increased as the pmTOR grade increases (G0: 3.1, G1: 4.8, G2: 4.7, G3: 6.2); in contrast FDG uptake was unrelated to pmTOR grade (G0: 2.8, G2: 4.0, G2 3.3, G4: 3.6).

Conclusion

A higher correlation with the proliferation of RCC was observed for 4DST than for FDG. The 4DST uptake exhibits the possibility to predict pmTOR grade, indicating that 4DST has potential for the evaluation of therapeutic effect with mTOR inhibitor in patients with RCC.

     

Effectiveness of brain hypothermia treatment in patients with severe subarachnoid hemorrhage: comparisons at a single facility

The effectiveness of hypothermia treatment for severe subarachnoid hemorrhage (SAH) was evaluated at the same facility under the same director. A total of 187 patients with SAH, 67 admitted before the introduction of hypothermia treatment in May 1999 (early cases) and 120 treated thereafter (late cases), were transported to the National Cardiovascular Center and treated in the acute phase between November 1997 and September 2001. Brain hypothermia treatment was performed in 19 patients of the 120 late cases, 10 males and 9 females aged 33-72 years (mean 57. 6 years), treated by direct surgery in 15 and endovascular surgery in 4. The indications for hypothermia treatment were age of 75 years or younger, SAH due to rupture of a cerebral aneurysm, Japan Coma Scale score of 100 or higher, and initiation of treatment within 24 hours after the onset. The body core temperature was sustained at 34°C for 48 hours, rewarming was performed over 48 hours, and normothermia was maintained thereafter. The outcome, evaluated according to the modified Rankin scale (m-RS) on transfer to another hospital or after 3 months, was m-RS 3 in 1 patient, m-RS 4 in 4, m-RS 5 in 3, and death in 11. Before the introduction of hypothermia treatment (early period), 16 patients showed the indications for the treatment, and their outcomes were m-RS 3 in 2, m-RS 4 in 3, m-RS 5 in 2, and death in 9. Cerebral vasospasm was important as a prognostic factor, markedly deteriorating the outcome. Hyperthermia after therapeutic hypothermia induced brain swelling and markedly affecting the outcome. Brain hypothermia treatment did not improve the outcome of severe SAH compared with the period before its introduction. The emphasis in treating severe SAH should be placed on the maintenance of normothermia to prevent brain swelling and elimination of factors that may induce cerebral vasospasm, rather than interventional hypothermia for aggressive brain protection.     

FDG-PET of patients with suspected renal failure: standardized uptake values in normal tissues

Objective This study aims to clarify the effect of renal function on 2-[¹⁸F] fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) imaging and determine the clinical significance of renal function in this setting. We compared FDG distribution between normal volunteers and patients with suspected renal failure. Methods Twenty healthy volunteers and 20 patients with suspected renal failure who underwent FDG-PET between November 2002 and May 2005 were selected for this study. We define “patients with suspected renal failure” as having a blood serum creatinine level in excess of 1.1 mg/dl. The serum creatinine level was examined once in 2 weeks of the FDG-PET study. Regions of interest were placed over 15 regions for semi-quantitative analysis: the white matter, cortex, both upper lung fields, both middle lung fields, both lower lung fields, mediastinum, myocardium of the left ventricle, the left atrium as a cardiac blood pool, central region of the right lobe of the liver, left kidney, and both femoris muscles. Results The mean standardized uptake values (SUVs) of brain cortex and white matter were higher in healthy volunteers than in renal patients. The mean SUVs of the mediastinum at the level of the aortic arch and left atrium as a cardiac blood pool were lower in healthy volunteers than in patients with suspected renal failure. These regions differed between healthy volunteers and patients with suspected renal failure (P < 0.05). Conclusions We found decreasing brain accumulation and increasing blood pool accumulation of FDG in patients with high plasma creatinine. Although the difference is small, this phenomenon will not have a huge effect on the assessment of FDG-PET imaging in patients with suspected renal failure.     

Goal-directed,serial and synchronous activation of neurons in the primate striatum

To study roles of cortico-basal ganglia loops in action planning, we examined interactions between the activities of simultaneously recorded neurons in the striatum of monkeys performing sequence motor tasks by cross-correlation analysis. Serial activation occurred between projection neurons in a motor sequence-dependent manner, and was in the direction of a neuron encoding an early event in the sequence to a neuron encoding the same event or later, but closer event to the reward. Synchronous activation occurred between pairs of interneurons. The serial activation seems to originate through the cortico-basal ganglia loops, because projection neurons are inhibitory. We propose that the task-dependent serial and synchronous activation of striate neurons may be a neural substrate for goal-directed planning through the basal ganglia.     

Do all patients with mandibular hypoplasia present difficulty in endotracheal intubation?

On 7 patients with Pierre-Robin syndrome (PR), 8 patients with first and second brachial arch syndrome (BA) and 7 patients with Treacher Collins syndrome (TC), we examined retrospectively the number of patients whom anesthesiologists found difficult to perform laryngoscopy and intubation, the number of attempt necessary for proper insertion of the tracheal tube, the number of patients in whom the endotracheal intubation with laryngoscopy was given up and the time necessary for endotracheal intubation. We compared these with those from 22 control patients. Our results suggest that the difficult laryngoscopy and intubation are more frequent in TC. On the other hand, most of PR and BA may not present difficulty in intubation.     

Use of sulfur hexafluoride, SF6, in the management of the postpneumonectomy pleural space

After a pneumonectomy in patients of advanced age with lung cancer, overinflation of the contralateral lung causes a further emphysematous change. This aggravation of emphysematous disturbances occasionally leads to serious cardiopulmonary dysfunctions. Therefore, we have devised a new therapeutic method which consists in injecting sulfur hexafluoride, SF6, an inert gas, into the postpneumonectomy pleural space so as to maintain the chest cavity. As SF6 gas is slowly absorbed through the pleura, gas injection at intervals of 6 months can maintain a clear pleural space with neither retention of pleural effusion nor deformity of the thorax. As a result, in 23 patients who were treated by this method, overinflation of the contralateral lung after unilateral pneumonectomy could be prevented, and respiratory functions could be improved, i.e., the vital capacity increased about 20% and the residual volume decreased over 20% after SF6 gas injection. All patients have been in good condition of their performance status, and it was not disadvantageous to continue the SF6 gas injection for a long term such as several years.