Tumours that are found in the brain, are part of the brain, and may develop slowly or may progress fairly rapidly.
Other tumours may spread to the brain from a cancer elsewhere in the body.
There are also tumours that may develop inside the skull but outside the brain. These tumours press into the brain as they expand but strictly speaking they are not in the brain, they are not part of the brain. They may develop from the coverings of the brain, nerves leaving the brain or the pituitay gland.
brain tumours are diagnosed on clinical presentation
WAYS THEY PRESENT
This may manifest as evidence of an increase of pressure inside the head causing a new experience of headache.
Disturbance in Brain Function
Any of the countless functions of the brain may be disturbed by a developing brain tumour. The particular disturbance in neurological function would depend upon the position of the tumour in the brain and the effect it has on the brain.
Brain tumours may initiate abnormal activity within the brain that manifests as any one of the very many different forms of epilepsy.
DIAGNOSING A BRAIN TUMOUR
The diagnosis of a brain tumour should begin with a very thorough enquiry into the persons general health and the new symptoms experienced. This leads on to a careful physical examination that may confirm the complaints described by the patient.
The gold standard radiological investigation of the brain is the MRI scan. This amazing invention gives us exquisite pictures of the brain as it lurks hidden behind the skull. We can get a very good idea of the type of tumour we are dealing with and its position in the brain. Specialised scans such as the functional MRI, or fMRI, can tell us about selected brain functions such as the ability to talk (language fMRI) or move (motor fMRI.) We can also see nerve fibers (fibre tracts) as they are affected by the tumour, by employing other advanced MRI techniques such as diffusion tensor imaging. MRI spectroscopy may be used to help us differentiate between abnormalities that may or may not be a real tmour. We neurosurgeons are very lucky to have specialist radiologists who devote all their working lives to understanding the intricacies of MRI of the nervous system. The modern neurosurgeon cannot work without this marvelous tool.
SURGERY FOR BRAIN TUMOURS
there are two main reasons for offering an operation to a person
who has been diagnosed as harbouring a brain tumour
In many instances the presenting complaint may be relieved if the tumour is affecting brain function. Removing the tumour may relieve the abnormal pressure and to relieve the complaint of headache. Epilepsy caused by the tumour may also be relieved by paying particular attention to the way the tumour is causing the epilepsy. It goes without saying that whatever the surgeon is planning to do must be planned in such a way as to avoid all possible risks to the patients function and future quality of life.
The surgery must be planned so as to cause the least possible risk to the patient. We do everything we can to avoid causing harm to important brain structures. To this end neuronavigation is used to assist and guide the surgeon during the operation. The MRI images are displayed on a computer screen while the surgeon uses a detection device that is projected onto the MRI image. The surgeon may use ultrasound during the operation or perhaps waken the patient to test for those all important vital brain areas such as language and movement. On these occasions the neurosurgeon will plan to have the patient awake during a particularly delicate aspect of the surgery. This may sound very frightening but it is remarkable how often patients come through the experience without any difficulty. Most patients do not even remember waking during the operation.
Establishing a Diagnosis
The surgeon is able to obtain a specimen of the tumour. This can be subjected to extensive pathological tests that include a visual assessment down a microscope. Nowadays the genetic makeup of the tumour is also assessed. This information is of vital importance in the next phase of tumour treatment. That phase may well include adjuvant therapy that is directed by yet another specialist, the neuro-oncologist, who plans radiotherapy and chemotherapy tumour therapy.
An untreated brain tumour is likely to continue to grow and eventually lead to the death of the patient. There are occasions when the tumour can be removed completely with the expectation that the problem has been solved. There are also occasions when a safe and lasting tumour removal is not possible.
THE SURGEONS DILEMMA & INFORMED CONSENT
The neurosurgeon, when advising and treating a patient, must weigh up the benefits of surgical intervention and the particular risks presented by the particular tumour. A very important part of the surgeons advice involves what is known as informed consent. During this meeting the patient must be given enough information about what is known of the tumour and the advice on treatment options. This must include the hoped-for outcome, realistic expectations, and the risks of the planned surgical intervention. The term “shared decision making” has entered the lexicon of the patients informed consent.
Neurourgeons live in fear of causing harm when operating on the brain. We are constrained by the type of tumour and its particular position in the brain. It may be too close to vital brain structures, or involve arteries and veins that prevent a thorough tumour removal. There are tumours we know we cannot remove, tumours we may hope to remove and tumours we can be confident of removing.
There is always the fear of causing permanent harm and destroying the quality of life we are trying to preserve.
Caring for the patient with a brain tumour is very much a team effort. We rely very heavily on our colleagues, the neuroradiologists, anaesthetists, neurologists, electrophysiologists and neuropsychologists; but nothing could be achieved without the dedicated nursing staff in our Neurosciences Ward, the nursing experts at the bedside in the Intensive Care Units and the many wonderful nurses who devote their working lives to the closed confines of the windowless operating rooms. Last, but far from least, are the physiotherapists, speech therapists, occupational therapists and dieticians. The neurosurgeon plays a transient role in the difficult journey the patient must take, and hope beyond hope that he will not be the cause of a stumble.