NeuroCogFX--a computer-based neuropsychological assessment battery for the follow-up examination of neurological patients

Many neurological therapeutic trials require a longitudinal assessment of cognitive functions. An ideal instrument for that purpose should be in accordance to the criteria of classical testing theory and, furthermore, it should be repeatable and economic in administration and interpretation. We developed NeuroCogFX, a computerized assessment battery, according to these criteria. NeuroCogFX comprises subtests for short term memory, working memory, psychomotor speed, selective attention, verbal and figural memory and verbal fluency (mean duration: 25 minutes). Age-related normative data was obtained from 244 subjects without history of neurological or psychiatric disease (age range 16 - 75 years). Forty-two subjects were re-tested after an average of 8 weeks (range: 6 - 10 weeks) in order to assess retest reliability and training effects. Retest-reliabilities were middle-sized in all but one subtest, ranging from r (12) = 0.5 to r (12) = 0.7 (2-back Test: r (12) = 0.37). For construct validation NeuroCogFX was administered in addition to a comprehensive neuropsychological assessment battery in a group of 40 healthy subjects and in 42 patients with chronic epilepsy. The test allows a valid assessment of short-term memory, reaction speed, memory and verbal fluency. NeuroCogFX is an economic, sufficiently reliable and valid instrument for the neuropsychological follow-up examination in single patients and study groups which can be administered if a comprehensive neuropsychological assessment is unavailable.     

Surgical aspects of infection involving osteosynthesis implants: implant design and resistance to local infection

Infection is still a major complication associated with surgery in orthopedics and traumatology. The implant design, the implant material, and the implantation technique may play essential roles in preventing infection. The goal of this paper is to discuss a series of experiments evaluating different aspects of both surgical procedures and implants. For this purpose, standardized local application of the human pathogen Staphylococcus aureus was performed in an animal model. Although these experimental results may be clinically relevant, direct extrapolation to clinical infection rates should be avoided.     

The effects of augmentation with Swine small intestine submucosa on tendon healing under tension: histologic and mechanical evaluations in sheep

BACKGROUND: Rotator cuff failure after surgery may be attributed to inferior tissue healing properties that result from repetitive cyclic loading during early rehabilitation. Enhancing the biological healing process may reduce the incidence of failures after rotator cuff repairs. HYPOTHESIS: Augmentation of rotator cuff tissue using swine small intestine submucosa in a sheep model will improve the rate and quality of tissue repair. STUDY DESIGN: Controlled laboratory study. METHODS: We resected and reattached 26 sheep infraspinatus tendons under tension, with 13 animals receiving a small intestine submucosa patch (augmented group). Animals were sacrificed at 12 weeks, and biomechanical testing and histologic evaluation were performed. Biomechanical testing was completed in 10 tendons from each group. Specimens were loaded to failure at a constant displacement to obtain the load deformation curve used to calculate load to failure and stiffness of the healed bone-tendon interface. Histologic testing addressed tissue healing at the bone-tendon interface. RESULTS: The load-to-failure data did not indicate a significant difference between the augmented and nonaugmented groups (1252 +/- 402 N vs 985 +/- 459 N, respectively; P > .05). However, the augmented group had significantly better stiffness than the nonaugmented group (215 +/- 44 N/mm vs 154 +/- 63 N/mm, respectively; P = .03). Histologic data revealed that the infraspinatus tendon in all specimens inserted into the bone through a zone of fibrocartilage, although none of the patches were intact. CONCLUSION: Although there were no differences in the load-to-failure data between the 2 groups, the statistically significant improvement in stiffness for the augmented group is clinically relevant. Stiffness is the biomechanical parameter representing the tissue response to subdestructive loads seen with early rehabilitation. Augmenting the repair with a collagen matrix improved the early healing characteristics of the repair construct. CLINICAL RELEVANCE: Enhancing the biological process of tendon healing under tension by using a collagen matrix patch may improve the ultimate success of rotator cuff repair.     

Stereotactic linac-based radiosurgery in the treatment of cerebral arteriovenous malformations located deep, involving corpus callosum, motor cortex, or brainstem

PURPOSE: To evaluate patient outcome and obliteration rates after radiosurgery (RS) for cerebral arteriovenous malformations (AVM) located deep, in the motor cortex or brainstem and those involving corpus callosum. METHODS AND MATERIALS: This analysis is based on 65 patients. AVM classification according to Spetzler-Martin was 13 patients Grade 2, 39 Grade 3, 12 Grade 4, and 1 Grade 5. Median RS-based AVM score was 1.69. Median single dose was 18 Gy. Mean treatment volume was 5.2 cc (range, 0.2-26.5 cc). Forty patients (62%) experienced intracranial hemorrhage before RS. Median follow-up was 3.0 years. RESULTS: Actuarial complete obliteration rate (CO) was 50% and 65% after 3 and 5 years, respectively. CO was significantly higher in AVM <3 cm (p < 0.02) and after doses >18 Gy (p < 0.009). Annual bleeding risk after RS was 4.7%, 3.4%, and 2.7% after 1, 2, and 3 years, respectively. AVM >3 cm (p < 0.01), AVM volume >4 cc (p < 0.009), and AVM score >1.5 (p < 0.02) showed a significant higher bleeding risk. Neurologic dysfunction improved, completely dissolved, or remained stable in 94% of patients. CONCLUSIONS: Surgically inaccessible AVM can be successfully treated using RS with acceptable obliteration rates and low risk for late morbidity. The risk of intracranial hemorrhage is reduced after RS and depends on RS-based AVM score.     

Primary CNS lymphoma: clinical presentation, pathological classification, molecular pathogenesis and treatment

Primary CNS lymphomas (PCNSL) represent malignant non-Hodgkin's B cell lymphomas, which are confined to the central nervous system. They show a dramatic increase in frequency in the immunocompromised as well as in the immunocompetent population. Recent studies have identified germinal center B cells as the cellular origin of PCNSL; however, the details of their molecular pathogenesis still remain to be elucidated. Treatment recommendations are not clearly established. Radiotherapy (RT) is efficient in terms of tumor response, but not curative. Median survival after RT alone is about 1 year. According to the results of uncontrolled studies the combination of RT and chemotherapy based on high-dose methotrexate (HD-MTX) is most efficient in terms of survival rates. However, long-term neurotoxicity overshadows treatment efficacy, especially in patients over 60 years of age. The authors favor the systematic evaluation of chemotherapy alone with protocols including HD MTX, because unicenter results are promising in terms of both survival as well as quality of life in long term survivors.     

Long-term survival of glioblastoma multiforme: importance of histopathological reevaluation

The overall prognosis for patients with glioblastoma multiforme is extremely poor. However, a small proportion of patients enjoy prolonged survival. This study investigated retrospectively the extent to which erroneous histopathological classification may contribute to long-term survival of patients initially diagnosed with “glioblastoma multiforme”. We compared two age- and gender-matched patient groups with different postoperative time to tumor progression (TTP), defined as “short-term” for TTP of less than 6 months (n=54) and “long-term” for TTP of more than 12 months (n=52). Histological specimens of the corresponding tumors, all primarily diagnosed as glioblastome multiforme, were reevaluated according to the current World Health Organization (WHO) classification of central nervous system tumors, with the investigators being blinded to clinical outcome. Among the tumors from short-term TTP patients, one tumor (2%) was reclassified as anaplastic oligoastrocytoma (WHO grade III) while the remaining 53 were confirmed as glioblastoma multiforme. In contrast, 13 tumors (25%) from the long-term TTP patients were reclassified, mostly as anaplastic oligodendroglioma (WHO grade III; n=7) or anaplastic oligoastrocytoma (WHO grade III, n=2), respectively. In addition, three were reclassified as anaplastic astrocytoma (WHO grade III), and one was identified as anaplastic pilocytic astrocytoma (WHO grade III). Our data indicate that a sizable proportion of glioblastoma patients with long-term survival actually carry malignant gliomas with oligodendroglial features. The correct histopathological recognition of these tumors has not only progrostic but also therapeutic implications, since oligodendroglial tumors are more likely to respond favorably to chemotherapy. Received: 9 November 1999, Received in revised form: 13 January 2000, Accepted: 3 February 2000     

Niedriggradige Gliome

Low grade gliomas represent a group of diverse neuropathological entities that are clinically distinct from and much less aggressive than high grade gliomas. The therapy of low grade gliomas is controversial, and due to their heterogeneity a common gold standard has not been established. Here, current aspects of histopathological and molecular genetic diagnosis, indications for treatment and modern concepts in neurosurgery, chemotherapy and radiotherapy are discussed. Due to the wide neuropathological spectrum and variety of therapy options, the treatment of low grade gliomas is always interdisciplinary and based on the individual patient.