Central nervous system

Abstract

Introduction This chapter describes the management of tumours in adults in the following anatomical areas: cerebral convexity and cerebral hemispheres, the skull base, the pituitary, the pineal region and the spinal cord. Central nervous system (CNS) tumours are heterogeneous. The terms malignant and benign are not very useful because: Even small slowly growing tumours can cause severe symptoms because the brain is enclosed in a rigid skull. Surgery can be difficult because many tumours are infiltrating and often lie close to critical structures. Most of these tumours rarely, if ever, metastasise outside the CNS. Slow-growing tumours may transform into a much more aggressive variant. This chapter does not deal with metastatic disease to the CNS that is considered in other relevant chapters, although management of cerebral metastases that require specialist neuro-oncology input is discussed briefly. CNS tumours in children are considered in Chapter 37 (see p. 432). Anatomy The tentorium separates the supratentorial from the infratentorial areas of the brain. The motor and sensory cortices lie at the central sulcus. Broca's area (frontal, above the lateral sulcus) is responsible for expressive loss of speech, and Wernicke's area (temporal, posterior end of the lateral sulcus) is responsible for receptive loss of speech. The ventricular system is lined with ependyma. CSF travels from the third to the fourth ventricle through the cerebral aqueduct and from the fourth ventricle to the subarachnoid space through the foramina of Magendie (median) and Luschka (lateral). The anterior and intermediate lobes of the pituitary arise from Rathke's pouch.