Jinn-Rung Kuo

Neurological improvement after cranioplasty - analysis by transcranial doppler ultrasonography

Cranioplasty can improve neurological status in patients with skull bone defects. The mechanism of postoperative improvement in neurologic status might be increased cerebral blood flow (CBF) velocity due to elimination of the effects of atmospheric pressure. Between May 2001 and June 2002, 13 patients (8 men and 5 women; average age, 46 years; range, 21-65 years) were studied. Postoperative changes in neurological status and blood flow velocity were examined and compared using transcranial Doppler (TCD) sonography. The mean interval between craniectomy and cranioplasty was 122.3+/-100.4 days. The mean interval between cranioplasty and performance of TCD examination was 15.2+/-2.8 days. The results showed significant improvements after cranioplasty in GCS, arm muscle power, and Barthel Index. While the CBF velocities tended to increase after cranioplasty, only the increase in the non-lesion side middle cerebral artery (MCA) was statistically significant. The interval from decompressive craniectomy to cranioplasty and neurological status change before and after cranioplasty was significantly negatively correlated. We conclude that cranioplasty can improve neurological status, and it should be performed as earlier as edema has resolved.

Beneficial effect of agmatine on brain apoptosis, astrogliosis, and edema after rat transient cerebral ischemia

BackgroundAlthough agmatine therapy in a mouse model of transient focal cerebral ischemia is highly protective against neurological injury, the mechanisms underlying the protective effects of agmatine are not fully elucidated. This study aimed to investigate the effects of agmatine on brain apoptosis, astrogliosis and edema in the rats with transient cerebral ischemia.MethodsFollowing surgical induction of middle cerebral artery occlusion (MCAO) for 90 min, agmatine (100 mg/kg, i.p.) was injected 5 min after beginning of reperfusion and again once daily for the next 3 post-operative days. Four days after reperfusion, both motor and proprioception functions were assessed and then all rats were sacrificed for determination of brain infarct volume (2, 3, 5-triphenyltetrazolium chloride staining), apoptosis (TUNEL staining), edema (both cerebral water content and amounts of aquaporin-4 positive cells), gliosis (glial fibrillary acidic protein [GFAP]-positive cells), and neurotoxicity (inducible nitric oxide synthase [iNOS] expression).ResultsThe results showed that agmatine treatment was found to accelerate recovery of motor (from 55 degrees to 62 degrees) and proprioception (from 54% maximal possible effect to 10% maximal possible effect) deficits and to prevent brain infarction (from 370 mm3 to 50 mm3), gliosis (from 80 GFAP-positive cells to 30 GFAP-positive cells), edema (cerebral water contents decreased from 82.5% to 79.4%; AQP4 positive cells decreased from 140 to 84 per section), apoptosis (neuronal apoptotic cells decreased from 100 to 20 per section), and neurotoxicity (iNOS expression cells decreased from 64 to 7 per section) during MCAO ischemic injury in rats.ConclusionsThe data suggest that agmatine may improve outcomes of transient cerebral ischemia in rats by reducing brain apoptosis, astrogliosis and edema.

Prognostic predictors of outcome in an operative series in traumatic brain injury patients.

BACKGROUND Although several prognostic factors for traumatic brain injury (TBI) have been evaluated, a useful predictive scoring model for outcome has yet to be developed for TBI patients. The aim of this study was to determine independent predictors and develop a multivariate logistic regression equation to determine prognosis in TBI patients. METHODS A total of 13 different variables were evaluated. All 84 patients in this study were retrospectively evaluated between October 2003 and January 2008 and all underwent craniectomy or craniotomy for hematoma removal and were fitted with intracranial pressure (ICP) microsensor monitors. By using univariate, multiple logistic regression and prognostic regression scoring equations it was possible to draw Receiver-Operating Characteristic curves (ROC) to predict Glasgow Outcome Scale (GOS) 6 months after TBI. RESULTS We found that patients over 40 years of age (p < 0.001), unresponsive pre-op pupil reaction (p =0.001), pre-op midline shift (p =0.008), higher injury severity score (ISS; p=0.007), and craniectomy (p < 0.05) were associated with poor outcome in patients with TBI. Using ROC curve to predict the probability of unfavorable outcome, the sensitivity was 97.5% and the specificity was 90.7%. CONCLUSION In our preliminary findings, five variables to predict poor outcomes 6 months after TBI were useful. These sensitive variables can be used as a referential guideline in our daily practice to decide whether or not to perform advanced management or avoid decompressive craniectomy.

Intraoperative applications of intracranial pressure monitoring in patients with severe head injury

From December 2002 to January 2004, 30 patients (20 men and 10 women; mean age 36.8 years [+/- 14.9 years]) with preoperative Glasgow Coma Scale scores of 8 or less underwent emergency haematoma evacuation surgery and continuous intracranial pressure (ICP), cerebral perfusion pressure (CPP) and mean arterial blood pressure monitoring to determine ICP and CPP thresholds to predict patient outcomes. Receiver-operating characteristic (ROC) curves were plotted. Using the ROC curve, the diagnostic accuracy is given by the area under the curve and at the point on the curve farthest from the diagonal, which indicates the threshold value. The results showed that the initial ICP for unfavourable outcomes was 47.4 +/- 21.4 mmHg, resulting in a CPP of 22.8 +/- 12.83 mmHg. The initial ICP for favourable outcomes was 26.4 +/- 10.1 mmHg, resulting in a CPP of 48.8 +/- 13.4 mmHg. The CPP had the largest area under the ROC curve in all stages of the operation, corresponding to intraoperative CPP thresholds of 37 mmHg (initial), 51.8 mmHg (intraoperative) and 52 mmHg (after scalp closure). The ROC curve analysis showed that CPP was a better predictor of outcome than ICP.

Measuring brain temperature while maintaining brain normothermia in patients with severe traumatic brain injury

The aim of this study was to evaluate the relationship between superficial temporal artery temperature (Tt), rectal temperature (Tr) and intracranial temperature (ICT) when attempting to keep the brain in a normothermic condition in patients with severe traumatic brain injury (TBI). We also compared the incidence of temperature gradient reversal in patients who survived (survivors) and patients who did not (non-survivors) and the difference in temperature gradient reversal between survivors and non-survivors. Tr is normally lower than and ICT and temperature gradient reversal, when Tr exceeds ICT, has been demonstrated to be an early sign of brain death. A total of 28 patients with severe TBI were enrolled retrospectively in our study between November 2008 and February 2010. Each patients Tt, Tr and ICT was recorded every hour for 4 days. Our results show that the frequency of brain hyperthermia in our participants (ICT>38°C) was 17.7%. Using a paired t-test and Bland-Altman plots, it was shown that a significant temperature difference existed between Tt, Tr and ICT (p<0.001). The use of Spearmans correlation method revealed that Tt, Tr and ICT were positively correlated (p<0.001). Brain death occurred in five patients at a mean of 9.6 hours (range: 8-12 hours) after a temperature gradient reversal between Tt, Tr and ICT. Fishers exact test showed that there was a significant difference in the incidence of temperature gradient reversal between Tt, Tr and ICT in survivors and non-survivors (p<0.001). We conclude that a significant temperature difference exists between Tt, Tr and ICT when maintaining brain normothermia. The daily practice of non-invasive Tt measurement may cause doctors to underestimate ICT; reversal of the ICT and Tt and/or Tr temperatures could be an early marker of a poor prognosis for patients with severe TBI.

Radiation-induced intra- and extra-cranial high-grade myxofibrosarcoma with tumor bleeding.

Radiation-induced secondary malignant neoplasms in central nervous system tumor survivors have become a problem of increasing concern over the last 20 years because of rare but serious and potentially fatal complications. Herein, we report the case of a 28-year-old man who presented with a left fronto-temporal intra- and extra-cranial tumor with intra-tumor bleeding at the site of previous radiotherapy in May 1991. He underwent craniotomy with gross total removal of the tumor and surrounding hematoma in August 2005. The tumor was a high-grade malignant myxofibrosarcoma (Fédération Nationale des Centres de Lutte Contre le Cancer Grade III [out of III]). Radiation-induced malignant myxofibrosarcoma with tumor bleeding is an infrequent complication of radiotherapy. Although rare, it should always be kept in mind with regards to the differential diagnosis of a lesion that develops several years after radiation therapy. Also, follow-up of patients that have undergone radiation therapy should be long-term.

Acute paraplegia following chiropractic therapy

We report a 44-year-old man suffering complete paraplegia due to paraspinal and epidural abscess, following chiropractic therapy for severe back pain and whose diagnosis was delayed. He received an immediate laminectomy from T3 through T6 to decompress the full extent of the abscess and appropriate antibiotic therapy for 4 weeks postoperatively for the identified microorganism (Staphylococcus aureus). After 3 months of rehabilitation, he had recovered bladder function with moderate left lower extremity paresis. We emphasise the importance of urgent spinal gadolinium-enhanced MRI in those patients with localised back pain and raised inflammatory markers (including erythrocyte sedimentation rate). Furthermore, it is necessary to be aware of the risk of acute paraplegia after forceful massage to the back.

Malignant Astrocytoma Following Radiation for Nasopharyngeal Carcinoma: Case Report and Review of the Literature

A 32-year-old woman developed malignant astrocytoma 3 years after radiotherapy for nasopharnygeal carcinoma (NPC). Introduction of brain malignancy induction after external beam radiation for craniopharyngioma, pituitary adenoma, or meningioma has been previously reported. The theoretical risk of tumor induction in neural tissues, following radiotherapy by low-dose radiation has been verified, but the association of radiation-induced brain malignancy and NPC is extremely rare. We supposed that radiation exposure might play a promoter role in this immune-compromised patient who was previously at high risk of developing co-morbidity. We believe that the incidence of radiation-induced malignancies will increase in the future, and this warrants closer observation by physicians.

Rhabdomyolysis after cerebral perfusion pressure-guided management in severe head injury.

Intravenous infusion of norepinephrine is usually effective and safe to maintain adequate cerebral perfusion pressure for the management of posttraumatic intracranial hypertension. We report the case of a 17-year-old woman who suffered from traumatic intracranial bleeding and hypotension; she developed rhabdomyolysis, myoglobinuria and acute renal failure after receiving high dose norepinephrine postoperatively. Hemodialysis was begun 3 days after the onset of myoglobinuria when acute renal failure was noted, despite aggressive fluid supplementation and alkaline diuresis. After aggressive treatment and dialysis, the patients myoglobinuria and rhabdomyolysis gradually declined. Her kidneys eventually regained normal function. We consider that systemic hypotension may have been the leading cause for development of rhabdomyolysis, and vasoconstrictors such as norepinephrine aggravated this. We emphasise the potentially devastating consequences of rhabdomyolysis when a large dose of norepinephrine is given for the treatment of hypotension during cerebral perfusion pressure-guided management.

On the improvement of solar cell based photovoltaic charger system

Due to the energy crisis, renewable energy sources have been deeply concerned as possible solutions to remain resources on the earth. Among these energy sources, solar energy, a free conversion, non-polluted and inexhaustible energy source, has been used to generate electricity for decades. However, the efficiency of solar cell is so far still low and how to make the photovoltaic chargers achieve the maximum of efficiency becomes worthwhile to research further. This paper focuses on the analyses of loading effects between photovoltaic (hereunder as PV) array module and pattern for series of batteries