Minimally Invasive Augmented Fixation for Anatomical Reduction of Grade 2 and Grade 3 Listhesis in Patients with Osteoporosis

STUDY DESIGN: A retrospective study. PURPOSE: To study the efficacy of augmented fixation for anatomical reduction of grade 2 and grade 3 listhesis in patients with osteoporosis. OVERVIEW OF LITERATURE: Spondylolisthesis in osteoporotic patients requiring spinal fixation are associated with complications such as loss of surgical construct stability, screw pulling out, and screw loosening. Augmented fixation is a novel strategy to achieve necessary construct integrity. METHODS: Thirteen consecutive patients with grade 2 or grade 3 listhesis, with proven osteoporosis on dual energy X-ray absorptiometry (DEXA) scan, and who underwent augmented fixation for reduction of listhesis were retrospectively analyzed. In all patients, surgical access was achieved with a fixed 22 mm tubular retractor. A modified technique of bilateral, sequential, transforaminal decompression and discectomy, followed by reduction of listhesis using unilaterally placed augmented screws was employed in all the cases. Patients were followed up with plain X-rays at regular intervals to assess for implant stability and fusion status. All patients were started on medical treatment for osteoporosis. RESULTS: The mean age of the patients was 52.46 years, with 12 females and one male. The median T-score on DEXA scan was −3.0. Of the 13 patients, listhesis was at L4–L5 in five and at L5–S1 in eight. Nine patients had grade 2 listhesis, while four patients had grade 3 listhesis. Complete reduction was achieved in 10 patients. The median duration of follow-up was 18 months. Postoperative outcomes were satisfactory in all cases. CONCLUSIONS: Augmented fixation is a useful technique for achieving anatomical reduction of listhesis in patients with osteoporosis.

PBEF1/NAmPRTase/Visfatin: a potential malignant astrocytoma/glioblastoma serum marker with prognostic value.

Malignant astrocytomas comprise anaplastic astrocytoma (AA; grade III) and Glioblastoma (GBM; grade IV). GBM is the most malignant with a median survival of 10-12 months in patients. Using cDNA microarray based expression profiling of different grades of astrocytomas, we identified several fold increased levels of PBEF1 transcripts in GBM samples. Pre-B-cell colony enhancing factor 1 gene (PBEF1) encodes Nicotinamide phosphoribosyltransferase (NAmPRTase), which catalyses the rate limiting step in the salvage pathway of NAD metabolism in mammalian cells. Further validation using real time RT-qPCR on an independent set of tumor samples (n=91) and normal brain samples (n=9), GBM specific higher expression of PBEF1 was confirmed. Immunohistochemical staining for PBEF1 on a subset of the above samples largely reinforced our finding. We carried out ELISA analysis on serum samples of astrocytoma patients to determine whether this protein levels would correlate with the presence of tumor and tumor grade. PBEF1 serum levels were substantially elevated in many of the AA and GBM patients. Statistical analysis of these data indicates that in patients with astrocytoma, serum PBEF1 levels correlate with tumor grade and is highest in GBM. Immunohistochemical analysis of an independent set of 51 retrospective GBM cases with known survival data revealed that PBEF1 expression in the tumor tissue along with its co-expression with p53 was associated with poor survival. Thus, we have identified PBEF1 as a potential malignant astrocytoma serum marker and prognostic indicator among GBMs.

Novel glioblastoma markers with diagnostic and prognostic value identified through transcriptome analysis.

PURPOSE: Current methods of classification of astrocytoma based on histopathologic methods are often subjective and less accurate. Although patients with glioblastoma have grave prognosis, significant variability in patient outcome is observed. Therefore, the aim of this study was to identify glioblastoma diagnostic and prognostic markers through microarray analysis. EXPERIMENTAL DESIGN: We carried out transcriptome analysis of 25 diffusely infiltrating astrocytoma samples [WHO grade II--diffuse astrocytoma, grade III--anaplastic astrocytoma, and grade IV--glioblastoma (GBM)] using cDNA microarrays containing 18,981 genes. Several of the markers identified were also validated by real-time reverse transcription quantitative PCR and immunohistochemical analysis on an independent set of tumor samples (n = 100). Survival analysis was carried out for two markers on another independent set of retrospective cases (n = 51). RESULTS: We identified several differentially regulated grade-specific genes. Independent validation by real-time reverse transcription quantitative PCR analysis found growth arrest and DNA-damage-inducible alpha (GADD45alpha) and follistatin-like 1 (FSTL1) to be up-regulated in most GBMs (both primary and secondary), whereas superoxide dismutase 2 and adipocyte enhancer binding protein 1 were up-regulated in the majority of primary GBM. Further, identification of the grade-specific expression of GADD45alpha and FSTL1 by immunohistochemical staining reinforced our findings. Analysis of retrospective GBM cases with known survival data revealed that cytoplasmic overexpression of GADD45alpha conferred better survival while the coexpression of FSTL1 with p53 was associated with poor survival. CONCLUSIONS: Our study reveals that GADD45alpha and FSTLI are GBM-specific whereas superoxide dismutase 2 and adipocyte enhancer binding protein 1 are primary GBM-specific diagnostic markers. Whereas GADD45alpha overexpression confers a favorable prognosis, FSTL1 overexpression is a hallmark of poor prognosis in GBM patients.

Cerebellar abscesses in children: excision or aspiration?

OBJECT: Cerebellar abscesses are common neurosurgical emergencies in developing countries, and have a distressingly high mortality rate of 10 to 15% even today. There is still no consensus on the standard approach to these lesions, and controversy persists over whether these lesions should be treated with primary excision or aspiration. METHODS: The authors retrospectively analyzed 82 cases of cerebellar pyogenic abscesses in children treated at their institution over a period of 10 years. This represents the largest such series being described in literature. All lesions except 1 were otogenic in origin. The clinical and radiological features are discussed. RESULTS: Primary excision was undertaken in 66 patients (80%) and aspiration in 16 patients (20%). Five patients in whom the abscesses were initially treated with aspiration subsequently underwent elective excision. Nine (12.6%) of 71 patients in whom the abscesses were excised had residual abscesses on postoperative imaging; in those who had undergone aspiration as the primary treatment, 6 (54.5%) of 11 patients had recurrent abscesses. There were no deaths among the patients who underwent excision of the abscess. Also, excision of posterior fossa abscesses required fewer repeated procedures with lower recurrence rates, and statistically lower rate of complications. CONCLUSIONS: Compared to primary aspiration, the authors found that primary excision is the preferred method for treating cerebellar abscesses.