The cause of an epileptic seizure should always be sought.
Headache alone is rarely the sole symptom of a brain tumour.
Central nervous system (CNS) tumours can be treated surgically but also by radiotherapy and cytostatic chemotherapy.
Prognosis varies greatly depending on the type of tumour and the patient's age.
Decisions on how to treat brain tumours should be made by multidisciplinary teams.
Epidemiology
The incidence of primary CNS tumours in Finland is 11-14/100 000/year. About 10% of these are spinal cord tumours. Tumours of the nervous system account for 3-4% of all tumours.
CNS tumours may occur in any age group but they are most common in the elderly.
Aetiology
The cause of most CNS tumours is unknown.
Immunosuppression and immunological deficiency as well as prior radiotherapy increase the risk of tumours.
Neurofibromatosis type 2 and tuberous sclerosis are associated with an increased risk of developing CNS tumours.
Signs and symptoms
The symptoms are determined by the location of the tumour, not by the type of tumour.
Epileptic seizure
Focal, or generalized after focal onset
Primary symptom in 30 to 50% of patients
Changes in cognitive performance
The functioning of more extensive neural networks, particularly in the frontal lobe, can easily be deranged. This may, for instance, appear as weakening of initiative and judgment or of the ability to structure and organize situations, as impaired concentration and attention, or as slowness and disturbed emotional regulation particularly in patients with frontotemporal tumours. The patients may also gradually lose their ability to behave in accordance with their personality.
Disturbances associated with memory, language and visuospatial perception may remain unidentified or may be interpreted as resulting from depression or exhaustion.
Impaired regulation of alertness may cause exceptional tiredness, hypersomnia, restlessness or sleep disturbances in various combinations.
Motor symptoms
Caused by tumours affecting the pyramidal tract either in the motor cortex, in certain deeper areas of the brain or the brain stem.
Cerebellar tumours may cause ataxia and dizziness.
Headache
Visual field defects may be associated with tumours in the occipital lobe.
Tumours of the sella turcica area Pituitary Tumours cause hormonal disturbances and visual field defects due to compression of the optic nerve.
At an early stage, headache and nausea beginning in the early hours
Coughing or straining may accentuate the pain.
Posterior fossa tumours may initially present with hydrocephalus (obstruction of cerebrospinal fluid flow in the brain stem area).
Tumours in the spinal cord area cause paralysis and sensory symptoms as well as pain (see Diseases of the Spinal Cord).
The symptoms may become slowly worse until the tumour reaches a sufficient size or extends to an area where damage or disturbance causes symptoms that are easy to recognize. Tumour-associated bleeding may cause a sudden symptom picture.
Diagnosis
It is essential for the physician to be alert to the possibility of a tumour. History and status are important. Findings related to the patient's status are significant, as are combinations of various symptoms.
MRI is a basic examination. CT may be required in an emergency. The scan should be contrast-enhanced.
The possibility of a tumour should be considered particularly as the cause of neuropsychiatric symptoms in patients with no background of explanatory psychiatric causes or in cases that otherwise appear atypical.
Investigation of focal or non-motor epileptic seizures, in particular, requires skill and accuracy.
The character of the headaches is often different from any headaches in the past, and the headaches are associated with other symptoms and findings.
Increased intracranial pressure and papilloedema are rarely encountered; tumours are mostly diagnosed before these develop.
CSF examination, skull x-ray or EEG are not needed for the diagnosis of brain tumours.
Early signs of an acoustic neurinoma (vestibulocochlear nerve tumour) usually become evident in otological examinations.
The most common tumours affecting the central nervous system
There are almost a hundred different histological types of CNS tumours. Gliomas, meningiomas and neurinomas are the most common types.
Gliomas or supportive cell tumours
Gliomas form the largest group of primary CNS tumours, accounting for approximately 50% of all cases.
Earlier the classification of gliomas was based solely on cell type and degree of malignancy. Since 2016, knowledge of certain chromosomal changes, mutations and other prognostic factors have changed and added to this classification.
The significance of the previous classification based primarily on degree of malignancy, i.e. grade, is decreasing specifically in Grade II and III astrocytomas and oligodendrogliomas.
Grade I: Pilocytic astrocytoma and ganglioglioma
The majority occur in children and young adults; approximately 75% of patients are aged less than 20 years; the most prevalent tumours in children
Benign and can usually be completely resected by surgery but may cause troublesome epilepsy.
After partial excision, however, follow-up should be continued for more than 10 years.
Grade II: Astrocytoma and oligodendrogliomas
Occur in young and middle-aged people.
Grow slowly within the brain tissue, infiltrating the surroundings.
Can rarely be completely removed. May become malignant.
The median period of survival is 7 years or more.
IDH-mutated Grade II astrocytomas: median survival time is approximately 10 years.
Oligodendrogliomas are identified by deletions of chromosomes 1p and 19q.
The prognosis is good, median survival time is even over 14 years.
Grade III: Anaplastic astrocytoma and oligodendroglioma
The clinical picture is varied, as some of these tumours behave like Grade II gliomas and some like glioblastoma.
Grade III (anaplastic) astrocytoma
IDH-mutated: median survival time is approximately 4 years.
IDH wild type (wt): rare, prognosis like in glioblastoma, median survival time is approximately 20 months.
Grade III (anaplastic) oligodendrogliomas: median survival time is approximately 8-9 years.
The most common and malignant of all gliomas; approximately half of all gliomas in adults belong to this group.
Most common in the elderly.
Most tumours recur within one year.
About 30% of patients survive for more than 2 years. However, long-term survival (beyond 5 years) does occur. On average, older age weakens the prognosis.
Absence of the favourable IDH1 mutation is common.
Ependymoma
Ependymoma originates from the ependymic tissue. It accounts for 3-9% of all gliomas and about 50% of spinal cord gliomas.
The prognosis is good if surgical removal is macroscopically complete. Spinal cord ependymomas often fall into this category.
Meningioma
Originates from the cerebral meninges (arachnoid).
The second most common CNS tumour
Usually (approx. 95%) a benign (Grade I), well circumscribed, slow-growing tumour
More common in women and in middle aged and older people
Can often be totally resected. However, both primary and recurring tumours may cause invalidity.
If surgical treatment is not possible (difficult anatomic location), radiotherapy should be given for either primary or recurrent tumours; for Grade II and III meningiomas, postsurgical radiotherapy is often given primarily because of the tendency to recur.
Follow-up in accordance with regional care pathway
Other tumours affecting the central nervous system
Neurinomas, or schwannomas, are benign and slow-growing. They account for approximately 10% of all central nervous system tumours.
Neurinomas can be located anywhere in the nervous system. The site of origin within the intracranial space is in the cranial nerves, most commonly the 8th cranial nerve (acoustic neurinoma).
The majority of pituitary tumours are pituitary adenomas Pituitary Tumours. Also located in the same region are craniopharyngiomas, congenital tumours that can cause pituitary insufficiency or visual and severe cognitive symptoms.
Primary cerebral lymphomas have been diagnosed in increasing numbers, especially among the elderly population. Cerebral lymphomas respond well to treatment in the initial phase but later often recur. In approximately 20% of the patients, tumour tissue is also found in the eye. Spread to the meninges may occur.
Treatment
Individual therapeutic recommendations should be made by a multidisciplinary team.
Pressure-induced symptoms or significant neurological deficits may be alleviated by oral or intravenous dexamethasone (in doses of up to 10 mg 2-3 times daily). The effect can be seen as soon as within a few hours.
If pressure-induced symptoms are life-threatening (unconsciousness, pupillary dilatation), 1.5-2 g/kg of mannitol may be administered by infusion. This will improve the patient's condition for a few hours, during which time they can be transferred to a neurosurgical unit.
Hydrocephalus can be treated with a shunt or, depending on the location of the tumour, only with tumour resection.
Histological diagnosis based on a sample obtained by biopsy or resection must always be sought.
Neuroradiological imaging provides a histologically erroneous diagnosis in about 10% of cases.
It is mandatory to consult a neurosurgeon to determine the treatment. Even if the tumour would be impossible to remove by surgery, it is important for patients and their families to know that a specialist has considered all treatment possibilities.
The extent of the resection will affect the prognosis and recurrence of the tumour.
The possibility of surgical treatment depends primarily on the location, size, growth pattern and nature of the tumour as well as the age, general condition and functional capacity of the patient.
Complete removal is often possible if the tumour originates from outside the brain tissue (e.g. meningiomas and neurinomas), as well as if it is a pilocytic astrocytoma or ganglioglioma.
Cytostatic chemotherapy administered during and after radiotherapy has significantly improved the prognosis of glioblastomas. A combination of radio- and chemotherapy is also used to treat glioblastoma and certain aggressive Grade III gliomas.
cytostatic chemotherapy for a period of 6 months is given after radiotherapy.
Depending on risk factors, in Grade II gliomas treatment alternatives include monitoring alone even for years, radiotherapy and subsequent cytostatic chemotherapy or only cytostatic chemotherapy in which case radiotherapy is postponed.
The primary treatment for cerebral lymphoma is cytostatic chemotherapy. Radiotherapy is used for recurrent lymphoma and in elderly people.
About one cancer in four causes brain metastases as it spreads. These are most common in patients with lung or breast cancer or melanoma.
Some lung cancers are diagnosed on the basis of brain metastasis.
In breast cancer, brain metastases occur later.
Solitary metastases can be removed surgically. Local radiotherapy is given after surgery.
Local radiotherapy can be used instead of surgery. If there are several foci or the patient has small cell lung carcinoma, whole brain radiotherapy should be administered.
Bone metastases may compress the spinal cord. If complete paralysis has developed, surgical treatment or radiotherapy should be urgently provided. Dexametasone to reduce oedema is started immediately. Emergency imaging (preferably MRI) and treatment will be required within 24 hours. Full restoration of function is then possible. Establishing the type of tumour is attempted before radiotherapy.
In meningeal carcinosis, malignant neoplastic cells proliferate along the meninges without forming a distinct neoplasm. The clinical picture resembles that of chronic meningitis Meningitis in Adults. Meningeal carcinosis may be associated with melanoma, leukaemia, breast or lung cancer, for example.
Follow-up
For as long as a recurrent brain tumour is being actively treated, the follow-up should take place in a neuro-oncology unit.
Follow-up requires routine MRI because it is not reasonable to just wait for 'new' symptoms. Recurrent growth is sometimes difficult to identify and possibilities for treatment may be lost. During follow-up, too, findings made on imaging may require discussion by a multidisciplinary neuro-oncological team.
Monitoring blood tests or chest x-rays are not significant for brain tumours. Primary brain tumours, with the exception of rare haemangiopericytoma, hardly ever metastasise beyond the central nervous system.
Complications
The tumour and its treatment often leave residual neurological deficits and cognitive disturbances. Patients benefit from rehabilitation regardless of the prognosis.
Many patients will benefit from shorter periods of speech therapy, occupational therapy or physiotherapy and neuropsychological rehabilitation encouraging self-guided rehabilitation and making it easier to cope with symptoms, also for the patient's relatives.
Shunts have been placed in some patients to treat obstruction of CNS flow Adult Hydrocephalus and Shunt Complications. Shunt dysfunction should be suspected if the patient develops headaches, vomiting, drowsiness, deterioration of mental capacity or gait disorders.
Suspicion of shunt dysfunction warrants CT scanning of the brain.
Many patients can easily end up as heavy users of health care services unless appropriate symptomatic treatment is arranged. Help from a social worker may be required repeatedly.
As the tumour progresses, the significance of cooperation between the hospital, home nursing services, home hospice and palliative care unit is emphasised.
Close persons are under stress in the beginning of the disease and especially at its last phases, and their ability to cope requires special attention.
Brain tumour in a family member always leaves its mark on the children. Therapy focusing on the children has a preventive effect. Informing the school or daycare is important.
Suspicion of recurrence?
Recurrence should be suspected in any patient with
worsening neurological deficits or epileptic seizures
If a recurrent tumour is to be treated, it should normally be detected by MRI before the symptoms grow significantly worse.
symptoms of increased intracranial pressure or impairment of general functional capacity
close persons report unfavourable changes in cognitive symptoms or in behaviour.
If recurrence is suspected, a neurologist, oncologist or neurosurgeon should be consulted either directly or at a neuro-oncological meeting.
Surgical reoperation of gliomas is common; repeated radiotherapy or cytostatic chemotherapy are also often considered.
Based on CT or MRI, it is often difficult to distinguish between radiation reaction and tumour growth.
Infection
Temozolomide causes lymphocytopenia predisposing to Pneumocystis infection.
Glucocorticoids and cytostatic drugs impair the immune response.
Postoperative infection (following tumour surgery) should also be kept in mind.
Thrombocytopenia
Adverse effect of cytostatic chemotherapy and some antiepileptic drugs
Epileptic seizure with any of the following underlying factors:
tumour growth
radiation reaction
life-style-associated factors, such as staying up late, forgetting to take the medication, alcohol consumption, dehydration or irregular meals.
Constipation
Both temozolomide and drugs used to alleviate the associated nausea cause severe constipation.
Back pain
Long-term glucocorticoid therapy, in particular, but also antiepileptic medication, proton pump inhibitors, SSRI and heparin products, add to the risk of osteoporotic fractures.