The BrainLab neuronavigation system has been shown to be very helpful and user-friendly for routine neurosurgical interventions. Its advantage lies in its mobility, based on wireless reflective adapters for surgical instruments, endoscopes, and the operating microscope.

The disruption of the extracellular disc matrix is a major hallmark of disc degeneration. This has previously been shown to be associated with an up-regulation of major matrix metalloproteinase (MMP) expression and activity. However, until now hardly any data are available for MMP/ TIMP regulation and thereby no concept exists as to which MMP/TIMP plays a major role in disc degeneration. The objective of this study was, therefore, to identify and quantify the putative up-regulation of MMPs/TIMPs on the mRNA and protein level and their activity in disc material in relation to clinical data and histological evidence for disc degeneration. A quantitative molecular analysis of the mRNA expression levels for the MMPs (MMPs-1, -2, -3, -7, -8, -9, -13) and the MMP inhibitors (TIMPs-1 and -2) was performed on 37 disc specimens obtained from symptomatic disc herniation or degeneration. In addition, disc specimens from patients without disc degeneration/herniation (=con-trols) were analyzed. Expression of MMPs-1, -2, -3, -7, -8, -9, -13 and TIMPs-1, -2 was analyzed using quantitative RT-PCR, normalized to the expression level of a house keeping gene (GAPDH). Gene expression patterns were correlated with MMP activity (in situ zymography), protein expression patterns (immunohistochemistry), degeneration score (routine histology) and clinical data. MMP-3 mRNA levels were consistently and substantially up-regulated in samples with histological evidence for disc degeneration. A similar but less pronounced up-regulation was observed for MMP-8. This up-regulation was paralleled by the expression of TIMP-1 and to a lesser extent TIMP-2. In general, these findings could be confirmed with regard to protein expression and enzyme activity. This study provides data on the gene and protein level, which highlights the key role of MMP-3 in the degenerative cascade leading to symptomatic disc degeneration and herniation. Control of the proteolytic activity of MMP-3 may, therefore, come into the focus when aiming to develop new treatment options for early disc degeneration.

Solitary intraneural haemangiomas are very rare. A case of intraneural capillary haemangioma involving two nerve roots of the cauda equina is reported. The patient was a 63-year-old woman with a three years history of intermittent lumbalgia and numbness of the ventral surface of the left thigh. Magnetic resonance imaging detected an intradural extramedullary nodular space occupying mass at the level of the conus medullaris. Laminectomy of T12 and complete removal of the tumour were performed. Histopathological analysis demonstrated a capillary haemangioma. The tumour was located within the sheaths of a spinal nerve root. The lesion consisted of a myriad of small and very small vessels, reticularly arranged with normal nerve fascicles dispersed within the nodules of clustered capillaries. The present case of an intraneural capillary haemangioma of the cauda equina appears to be one of the first reported examples of this entity in the world's literature. The clinical presentation, diagnostic procedures and therapeutic options of intraneural haemangiomas of the conus medullaris and cauda equina are discussed. The current literature is reviewed.