Subarachnoid hemorrhageSubarachnoid hemorrhage (SAH) is bleeding into the subarachnoid space—the area between the arachnoid membrane and the pia mater surrounding the brain. Symptoms may include a severe headache of rapid onset, vomiting, decreased level of consciousness, fever, weakness, numbness, and sometimes seizures. Neck stiffness or neck pain are also relatively common. In about a quarter of people a small bleed with resolving symptoms occurs within a month of a larger bleed.
MeningesIn anatomy, the meninges (məˈnɪndʒiːz, : meninx (ˈmiːnɪŋks or ˈmɛnɪŋks), ) are the three membranes that envelop the brain and spinal cord. In mammals, the meninges are the dura mater, the arachnoid mater, and the pia mater. Cerebrospinal fluid is located in the subarachnoid space between the arachnoid mater and the pia mater. The primary function of the meninges is to protect the central nervous system. Dura mater The dura mater (tough mother) (also rarely called meninx fibrosa or pachymeninx) is a thick, durable membrane, closest to the skull and vertebrae.
Cerebrospinal fluidCerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the brain, and absorbed in the arachnoid granulations. There is about 125 mL of CSF at any one time, and about 500 mL is generated every day. CSF acts as a shock absorber, cushion or buffer, providing basic mechanical and immunological protection to the brain inside the skull.
Chiari malformationChiari malformation (CM) is a structural defect in the cerebellum, characterized by a downward displacement of one or both cerebellar tonsils through the foramen magnum (the opening at the base of the skull). CMs can cause headaches, difficulty swallowing, vomiting, dizziness, neck pain, unsteady gait, poor hand coordination, numbness and tingling of the hands and feet, and speech problems.
Lumbar punctureLumbar puncture (LP), also known as a spinal tap, is a medical procedure in which a needle is inserted into the spinal canal, most commonly to collect cerebrospinal fluid (CSF) for diagnostic testing. The main reason for a lumbar puncture is to help diagnose diseases of the central nervous system, including the brain and spine. Examples of these conditions include meningitis and subarachnoid hemorrhage. It may also be used therapeutically in some conditions.
Spinal anaesthesiaSpinal anaesthesia (or spinal anesthesia), also called spinal block, subarachnoid block, intradural block and intrathecal block, is a form of neuraxial regional anaesthesia involving the injection of a local anaesthetic or opioid into the subarachnoid space, generally through a fine needle, usually long. It is a safe and effective form of anesthesia usually performed by anesthesiologists that can be used as an alternative to general anesthesia commonly in surgeries involving the lower extremities and surgeries below the umbilicus.
Spinal cordThe spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the spinal cord, which contains cerebrospinal fluid. The brain and spinal cord together make up the central nervous system (CNS). In humans, the spinal cord begins at the occipital bone, passing through the foramen magnum and then enters the spinal canal at the beginning of the cervical vertebrae.
Pia materPia mater (ˈpaɪ.ə_ˈmeɪtər or ˈpiːə_ˈmɑːtər), often referred to as simply the pia, is the delicate innermost layer of the meninges, the membranes surrounding the brain and spinal cord. Pia mater is medieval Latin meaning "tender mother". The other two meningeal membranes are the dura mater and the arachnoid mater. Both the pia and arachnoid mater are derivatives of the neural crest while the dura is derived from embryonic mesoderm. The pia mater is a thin fibrous tissue that is permeable to water and small solutes.
Combined spinal and epidural anaesthesiaCombined spinal and epidural anaesthesia is a regional anaesthetic technique, which combines the benefits of both spinal anaesthesia and epidural anaesthesia and analgesia. The spinal component gives a rapid onset of a predictable block. The indwelling epidural catheter gives the ability to provide long lasting analgesia and to titrate the dose given to the desired effect. This technique also allows for better post operative pain relief. The epidural catheter may be left in place for up to 72 hours if required.
Requirements analysisIn systems engineering and software engineering, requirements analysis focuses on the tasks that determine the needs or conditions to meet the new or altered product or project, taking account of the possibly conflicting requirements of the various stakeholders, analyzing, documenting, validating and managing software or system requirements. Requirements analysis is critical to the success or failure of a systems or software project.cite book |editor1= Alain Abran |editor2=James W.