Ming-Hsueh Lee

Factors affecting graft infection after cranioplasty.

The aim of this study was to identify the risk factors associated with bone grafts infection after cranioplasty. Eighty-four cranioplasties were performed on 75 patients between 2002 and 2006. Cryopreserved bone grafts were used as graft material in group 1 and polymethylmethacrylate (PMMA) was used in group 2. Risk factors including age, gender, time intervals between craniectomy and cranioplasty, mechanism of injury, number of procedures, graft material, and the Glasgow Coma Scale score were compared between groups. Swab culture results and bone graft infection were assessed in group 1. Multiple procedures before cranioplasty and an inadequate time interval between craniectomy and cranioplasty increase the risk of infection after cranioplasty. Swab culture results, age, gender, mechanism of injury, graft material and Glasgow Coma Scale score are not related to infection. The use of PMMA was associated with a relatively low risk of infection (6.25%). Risk of graft infection was not associated with the choice of graft material in the present study. Multiple procedures and insufficient time intervals increase the risk of infection. Interrupting the wound healing process may be the cause of infection. PMMA is a safe material for cranioplasty regardless of previous infection.

Foramen ovale cannulation guided by intra-operative computed tomography with integrated neuronavigation for the treatment of trigeminal neuralgia

BackgroundRadiofrequency rhizotomy of the Gasserian ganglion for the treatment of trigeminal neuralgia via percutaneous cannulation of the foramen ovale is facilitated by various localization modalities. In our preliminary study, we described the feasibility of computed tomography (CT) using an integrated neuronavigation system to cannulate the foramen ovale.MethodsAnalysis was performed on 42 consecutive patients who underwent cannulation of the foramen ovale for radiofrequency trigeminal rhizotomy guided by CT using an integrated neuronavigation system. The reproducibility and safety of the neuronavigation-guided procedure were evaluated.ResultsOverall, the average dimension of the foramen ovale was 7.1 (1.5) × 4.7 (1.1) mm, and it was successfully cannulated by neuronavigation guidance in 31 (73.8%) patients with a mean cannulation time of 3.1 (0.7) min and an overall procedure time of 68.2 (16.4) min. The remaining 11 (26.2%) patients required subsequent CT guidance for successful puncture of the foramen ovale.ConclusionsThese data demonstrate that neuronavigation-guided cannulation of the foramen ovale can be executed both quickly and safely on an outpatient basis. Additionally, the use of CT with integrated neuronavigation technology provides superior visual-spatial information compared to conventional fluoroscopy, the process of CT scanning, object planning, and neuronavigation-guided intervention can be completed in the same locale, and its application is easy to master and has the potential to enhance procedure tolerability of awake patients.

Dexamethasone reduces brain cell apoptosis and inhibits inflammatory response in rats with intracerebral hemorrhage.

Spontaneous intracerebral hemorrhage (ICH) is associated with high rates of mortality and morbidity. Thus, the identification of novel therapeutic agents for preventing strokes and attenuating poststroke brain damage is crucial. Dexamethasone (DEX) is used clinically to reduce edema formation in patients with spinal cord injury and brain tumors. In this study, we sought to elucidate the effects of DEX treatment on apoptosis and inflammation following ICH in rats. A high dose of DEX (15 mg/kg) was administered immediately following ICH induction and again 3 days later. The inflammatory and apoptotic responses in the rat brains were evaluated by using hematoxylin‐eosin, terminal deoxynucleotidyl transferase dUTP nick end labeling, Nissl, and neurofilament‐H staining. Levels of phosphorylated neurofilaments and apoptosis‐related proteins such as B‐cell lymphoma 2 (Bcl‐2), Bcl‐2 associated X protein (Bax), caspase‐3, and P53 were analyzed by Western blotting. This study shows that rats without ICH that received DEX treatment had a fourfold higher expression of Bcl‐2 than sham‐operated rats. ICH causes an increase in Bax, cleaved caspase‐3, and P53 proteins from 4 hr to 7 days following ICH induction. In comparison with the ICH rats, the ICH/DEX rats showed significantly decreased apoptotic cell death and increased neuron survival and maintained neurofilament integrity in the perihematomal region. DEX increased the Bcl‐2/Bax ratio and lowered the expression of cleaved caspase‐3 at 12 hr and 5 days. The ICH rats were accompanied by activation of the inflammatory response, and DEX treatment modulated the expression of a variety of cell types and then decreased ICH‐induced apoptosis.

Dural metastasis from prostatic adenocarcinoma mimicking chronic subdural hematoma

Dural metastasis is rare. In most reported cases, brain CT scan findings are mistaken for subdural hematoma or meningioma. We present here a 72-year-old male with a history of headache and progressive mental status changes. Brain CT scans suggested chronic subdural hematoma. However, the only surgical findings were diffuse thickening of the dura and sclerosis of the temporal bone. Histopathology revealed metastatic prostatic carcinoma. As the surgical approach and prognosis of chronic subdural hematoma and metastatic tumors are completely different, the differential diagnosis of these diseases is very important. A contrast-enhanced brain CT scan is recommended for patients who could possibly have dural metastases.

Hydrocephalus following decompressive craniectomy for malignant middle cerebral artery infarction

OBJECTIVE The aim of this study was to evaluate the incidence of hydrocephalus and understand the influence of hydrocephalus on the functional outcome of patients undergoing decompressive craniectomy for malignant middle cerebral artery (MCA) infarction. METHODS We retrospectively analyzed data of consecutive patients who underwent decompressive craniectomy for malignant MCA infarction. Clinical and imaging data were reviewed to confirm the incidence of hydrocephalus and evaluate the impact of hydrocephalus on functional outcome. The functional outcomes of patients were estimated with the Glasgow outcome score at 1year after stroke onset. RESULTS Seventeen patients who received decompressive craniectomy for malignant MCA infarction from January 2003 to December 2006 were enrolled. Persistent hydrocephalus developed in 5 patients. The functional outcomes in these patients were uniformly poor regardless of cerebrospinal fluid diversion surgery. Our data revealed that functional outcome was related to patient age and the duration from infarction to craniectomy. CONCLUSIONS Persistent hydrocephalus is common in patients who receive decompressive craniectomy for malignant MCA infarction. However, the shunt procedure does not significantly improve the patients clinical condition. The timing of operation in relation to the functional outcome may be critical.

Feasibility of Intraoperative Computed Tomography Navigation System for Pedicle Screw Insertion of the Thoracolumbar Spine

Study Design: A retrospective analysis of feasibility of intraoperative computed tomography (iCT) navigation for pedicle screw insertion of the thoracolumbar spine. Objectives: This study assessed the feasibility of an iCT navigation system by evaluating the screw insertion time, screw revision time, and learning curve of the iCT surgical team in patients who underwent thoracolumbar pedicle screw surgery using this navigation system. Summary of Background Data: The iCT navigation system has been reported to improve the accuracy and safety of pedicle screw insertion. However, the assessment of the feasibility of spinal instrumentation guided by iCT navigation system is limited. Materials and Methods: From the time iCT navigation system was set-up to a period covering 16 months, consecutive patients who underwent thoracic or lumbar spinal pedicle screw surgery were enrolled. The screw insertion and screw revision times were estimated using the system’s automatic time recording between the iCT scans. The insertion time per screw of the first 50 patients not requiring screw revision was also analyzed to evaluate the learning curve of the iCT surgical team. Results: There were 178 patients with a total of 932 pedicle screws. The cortical breach rate was 3.2% and the screw revision rate was 1.4%. The insertion time per screw was 10.2±6.3 minutes and the screw revision time was 13.8±9.9 minutes. The learning curve of the iCT surgical team for pedicle screw insertion guided by this navigation system was not steep, and experience from <10 patients was adequate to provide familiarity with this system. Conclusions: The iCT navigation system is clinically feasible for thoracolumbar pedicle screw surgery. It provides high-level safety and accuracy, as well as ease of screw revision when required.

Fate of Diffusion Restricted Lesions in Acute Intracerebral Hemorrhage

Background Diffusion-restricted lesions on diffusion-weighted imaging (DWI) are detected in patients with intracerebral hemorrhage (ICH). In this study, we aimed to determine the fate of DWI lesions in ICH patients and whether the presence of DWI lesions is associated with functional outcome in patients with ICH. Methods This prospective study enrolled 153 patients with acute ICH. Baseline MRI scans were performed within 2 weeks after ICH to detect DWI lesions and imaging markers for small vessel disease (SVD). Follow-up MRI scans were performed at 3 months after ICH to assess the fate of the DWI lesions. We analyzed the associations between the characteristics of DWI lesions with clinical features and functional outcome. Results Seventeen of the 153 patients (11.1%) had a total of 25 DWI lesions. Factors associated with DWI lesions were high initial systolic and mean arterial blood pressure (MAP) at the emergency room, additional lowering of MAP within 24 hours, and the presence of white matter hyperintensity and cerebral microbleeds. Thirteen of the 25 DWI lesions (52%) were not visible on follow-up T2-weighted or fluid-attenuated inversion recovery images and were associated with high apparent diffusion coefficient value and a sharper decease in MAP. The regression of DWI lesions was associated with good functional outcome. Conclusions More than half of the DWI lesions in the ICH patients did not transition to visible, long-term infarction. Only if the DWI lesion finally transitioned to final infarction was a poor functional outcome predicted. A DWI lesion may be regarded as an ischemic change of SVD and does not always indicate certain cerebral infarction or permanent tissue injury.

Motor function improvement in patients undergoing surgery for spinal epidural abscess.

BACKGROUNDSpinal epidural abscess (SEA) is a rare and devastating clinical entity. Definitive diagnosis is usually delayed because most patients present initially with minor or variable symptoms resulting in poor outcome. The clinical outcome of SEA has been associated with various prognostic factors; however, reports on factors relating to motor function improvement after surgical treatment are limited. OBJECTIVEThe aim of this study is to elucidate which clinical factors may affect motor function recovery after surgical treatment of SEA. PATIENT AND METHODSThe clinical features of patients with SEA undergoing surgical drainage and antibiotics treatment were reviewed, and their outcomes were identified and analyzed. RESULTSThe most common presenting symptoms were neck or back pain, motor deficits, and urinary incontinence. The most common underlying medical condition was diabetes mellitus. Leukocytosis (P = .036; odds ratio [OR] = 0.754; confidence interval [CI] = 0.579–0.982), elevated C-reactive protein level (P = .017; OR 0.96; CI = 0.965–0.994), poor glycemic control (P = .012; OR = 23.33; CI = 1.992–273.29), and duration of motor deficit at the time of operation (P = .005; OR = 40.50; CI = 3.093–530.293) were found to have a strong influence on motor function improvement after surgical treatment. CONCLUSIONInfection control and the prevention of further neurological deterioration in time are paramount in the treatment of SEA for optimal recovery. Patients with rapid neurological deterioration or higher white blood cell count or C-reactive protein level on presentation warrant aggressive surgical intervention; even in those who are completely paralyzed, an improvement in muscle power may still be possible.

Brain protection by methylprednisolone in rats with spinal cord injury.

Traumatic spinal cord injury is clinically treated by high doses of methylprednisolone. However, the effect of methylprednisolone on the brain in spinal cord injury patients has been little investigated. This experimental study examined Bcl-2 and Bax protein expression and Nissl staining to evaluate an apoptosis-related intracellular signaling event and final neuron death, respectively. Spinal cord injury produced a significant apoptotic change and cell death not only in the spinal cord but also in the supraventricular cortex and hippocampal cornu ammonis 1 region in the rat brains. The treatment of methylprednisolone increased the Bcl-2/Bax ratio and prevented neuron death for 1–7 days after spinal cord injury. These findings suggest that rats with spinal cord injury show ascending brain injury that could be restricted through methylprednisolone management.

Motor outcome of deep intracerebral haemorrhage in diffusion tensor imaging: comparison of data from different locations along the corticospinal tract

Abstract Objectives: Although diffusion tensor imaging (DTI) is widely studied to assess the motor outcome after ischaemic stroke, there is paucity of data regarding outcomes of intracerebral haemorrhage (ICH). The aim of this study was to determine the DTI data from different locations along the corticospinal tract (CST) and association to motor outcome. Methods: We prospectively recruited patients with deep ICH admitted to our hospital from November 2010 to July 2012.Diffusion tensor imaging was performed within 14 days after the onset of ICH. Fractional anisotropy (FA) was measured along the CST at corona radiata, perihaematomal oedema, cerebral peduncle and pons. Corticospinal tract integrity was classified into three types by diffusion tensor tractography (DTT): type A with preserved CST, type B with partially interrupted CST and type C with completely interrupted CST. Motor outcome was assessed by Motricity index (MI) at admission, after 1 and 3 months. Results: Forty-eight patients were enrolled with a mean age of 62 years. The median time interval from onset of ICH to DTI study was 7 days. The patients in type C had significantly worse MI at admission (P < 0.001), after 1 month (P < 0.001) and after 3 months (P < 0.001) as compared to those with type A and type B. Lower rFA at the corona radiata was significantly correlated with poorer motor outcome at admission, after 1 month and after 3 months. Discussion: Clinical motor outcome of ICH within 2 weeks can be identified with a statistically significant decrease in rFA at the corona radiata.