Brain & skull base

A brain tumour is an abnormal growth of cells inside the skull. Some start in the brain or its coverings (primary tumours, such as gliomas and meningiomas); others spread to the brain from a cancer elsewhere in the body (brain metastases). Many are not cancerous, and some are found by chance on a scan done for another reason.

Symptoms depend on where the tumour is and how quickly it grows. They may include headaches that are new or getting worse, seizures, weakness or numbness on one side, changes in speech, vision, memory or personality, and problems with balance. The neurosurgeon examines you and reviews MRI or CT scans, and may arrange further imaging or a biopsy to confirm the diagnosis.

Not every brain tumour needs an operation. Depending on the tumour type, its location and your general health, management may involve observation with serial imaging, medicines to control swelling or seizures, biopsy, microsurgical removal by craniotomy, or treatment planned together with oncologists, radiologists and other specialists.

The pituitary is a small gland at the base of the brain that controls many of the body's hormones. Most pituitary tumours (pituitary adenomas) are not cancerous. Other growths can also occur in the same area, known as the sellar region, such as cysts and craniopharyngiomas.

A pituitary tumour may cause symptoms by producing too much of a hormone, by reducing normal hormone production, or by pressing on nearby structures. This can lead to headaches, changes in vision (often loss of the outer field of vision), tiredness, changes in periods or sexual function, or changes in appearance and weight. Some are found by chance on a scan.

Assessment usually includes MRI of the pituitary, blood tests for hormone levels and, where vision may be affected, an eye and visual field check. Depending on the condition, management may involve observation, medicines arranged with an endocrinologist, or surgery, often by a transsphenoidal approach through the nose.

The skull base is the floor of the skull, where the brain, brainstem, major blood vessels and cranial nerves pass through. Tumours here include acoustic neuromas (vestibular schwannomas) on the hearing and balance nerve, meningiomas, and other tumours in the cerebellopontine angle, the space between the brainstem and the inner ear.

Symptoms depend on which nerves or structures are affected. They may include hearing loss or ringing in one ear, imbalance, facial numbness or weakness, double vision, difficulty swallowing, or headaches. Assessment includes a neurological examination, MRI and, depending on the tumour, hearing tests and other investigations.

Depending on the condition, management may involve observation with repeat MRI, microsurgical removal, or radiosurgery arranged with partner centres. The approach is tailored to the tumour's anatomy, with particular attention to preserving cranial nerve function, such as hearing and facial movement, where possible.

A head injury can range from a mild knock or concussion to a serious traumatic brain injury with bleeding in or around the brain. Some problems, such as a chronic subdural haematoma, may develop days or weeks after what seemed a minor injury, particularly in older adults and people taking blood-thinning medicines.

Symptoms after a head injury may include headache, dizziness, nausea, poor concentration, memory problems, tiredness, irritability and sleep changes. Worsening headache, drowsiness, confusion, weakness or repeated vomiting need urgent hospital assessment.

The neurosurgeon examines you and reviews CT or MRI scans. Depending on the injury, management may involve observation, advice on gradual return to activity, medicines, follow-up imaging or surgery. Emergency surgery, such as removal of a blood clot or decompression of the brain, takes place in hospital.

Cerebrospinal fluid (CSF) is the clear fluid that surrounds and cushions the brain and spinal cord. Hydrocephalus is a build-up of this fluid inside the brain's fluid spaces (ventricles), which can raise pressure on the brain. It may be present from birth, or develop at any age because of a tumour, bleeding, infection, injury or, in older adults, normal pressure hydrocephalus.

In babies, signs may include a rapidly growing head, a tense soft spot (fontanelle), vomiting, irritability and poor feeding. Older children and adults may have headaches, nausea, drowsiness and blurred vision. Normal pressure hydrocephalus typically causes a slow, shuffling walk, bladder control problems and memory difficulties.

Assessment includes a neurological examination and CT or MRI of the brain, and sometimes tests that measure or drain CSF. Depending on the cause, treatment may include observation, a shunt that drains fluid to another part of the body, an endoscopic procedure such as endoscopic third ventriculostomy, or treatment of the underlying cause. Surgery takes place in hospital.

In a Chiari malformation, the lowest part of the brain (the cerebellar tonsils) sits lower than usual and extends into the opening at the base of the skull. This can crowd the brainstem and block the normal flow of cerebrospinal fluid. Syringomyelia is a fluid-filled cavity (syrinx) within the spinal cord, which is often linked to a Chiari malformation.

Some people have no symptoms and are diagnosed on a scan done for another reason. Others may have headaches at the back of the head that are worse with coughing or straining, neck pain, dizziness, imbalance, numbness or weakness in the arms or hands, or, in children, scoliosis. Assessment includes a neurological examination and MRI of the brain and spine.

Depending on the condition, management may involve observation with repeat MRI, treatment of symptoms, or surgery such as posterior fossa decompression to make more room at the base of the skull and improve CSF flow. Surgery takes place in hospital.

Skull lesions are abnormal areas in the bone of the skull. They may be found as a lump on the head or by chance on a scan, and include benign bone growths, cysts and tumours that start in or spread to the skull. Most are not dangerous, but some need further investigation or treatment.

A skull defect is a gap in the skull, for example after a decompressive craniectomy for brain swelling, after removal of a tumour involving the bone, or after an injury. Cranioplasty is an operation to repair the defect using the patient's own bone or a custom-made implant, to protect the brain and restore the shape of the head.

Assessment includes examination and CT or MRI. Depending on the condition, management may involve observation, biopsy, surgical removal of the lesion with reconstruction, or cranioplasty at a suitable time after earlier surgery. Surgery takes place in hospital.

Infections can occasionally affect the brain, the spine or the spaces around them. A brain abscess is a collection of pus within the brain. Spinal infections include infection of the vertebrae and discs (discitis and osteomyelitis) and a spinal epidural abscess, a collection of pus that can press on the spinal cord or nerves. Infection can also occur after brain or spine surgery, or around a shunt or implant.

Symptoms may include fever, headache, confusion, seizures, severe or worsening back or neck pain, weakness or numbness in the arms or legs, and loss of bladder or bowel control. These conditions need urgent hospital care.

Assessment includes blood tests, MRI or CT and, where possible, a sample to identify the organism. Treatment is usually a course of antibiotics, planned with infectious diseases specialists, and may include surgery to drain an abscess, relieve pressure on the brain or spinal cord, or remove infected material. Treatment takes place in hospital.