What Are the Symptoms of a Brain Tumour? The Importance of Early Diagnosis

Headaches are common, and the vast majority of people with headaches do not have a brain tumour. A study of a particular group of patients urgently referred with suspected brain cancer reported that, although headache was the most common reason for referral, most final diagnoses were migraine and isolated headache was not a reliable indicator of brain cancer.^[4] This study involved a selected referral population; its rates should not be applied to everyone in the general population.

Headache features that lower the threshold for assessment include:

• A new headache that has not occurred before
• Increasing frequency or severity over days or weeks
• A marked difference from the person's established migraine or headache pattern
• Accompanying seizures, weakness, numbness or changes in speech, vision or balance
• Worsening with coughing, straining or exercise
• A marked change with position
• Additional risks such as a history of cancer, immunosuppression, fever or papilloedema

These features do not mean “there is a tumour”. In the SNNOOP10 approach, these and similar red flags prompt investigation for secondary causes of headache, including bleeding, infection, vascular disease and disorders of intracranial pressure, as well as tumours.^[3]

Nausea and vomiting can have many causes, including migraine, infection, pregnancy, medication effects and digestive disorders. However, if a headache is accompanied by repeated vomiting, blurred vision, drowsiness, marked imbalance or altered consciousness, causes such as raised intracranial pressure need to be ruled out promptly.^[5]

The idea that “morning vomiting is a definite sign of a brain tumour” is incorrect. Headache and vomiting that are more pronounced in the morning can occur with raised intracranial pressure, but this pattern is neither present in every patient nor specific to a tumour.^[5]

A first seizure in adulthood may be associated with a metabolic disorder, vascular disease, infection, trauma or other causes besides a brain tumour. Nevertheless, a first seizure requires medical assessment without delay.^[11,12]

A seizure does not always involve whole-body convulsions. Focal seizures may involve brief staring episodes, unresponsiveness, rhythmic movements of one arm or leg, repeated purposeless behaviour, an unusual smell or taste, or a brief speech disturbance. Call 112 if a seizure lasts more than five minutes, recurs before the person has fully regained consciousness, or is accompanied by breathing difficulty or serious injury. During a seizure, the person should not be restrained, nothing should be put in their mouth, and they should be turned safely onto their side.^[12]

Facial asymmetry, new weakness in one arm or leg, numbness on one side, difficulty finding words or understanding speech are focal neurological symptoms. They can occur with a brain tumour, but can also be signs of much more time-sensitive conditions such as stroke or bleeding in the brain. Particularly when symptoms start suddenly, the person should seek emergency help rather than trying to distinguish the cause themselves.^[1,11]

One-sided weakness or loss of central neurological function that progresses over hours, days or a few weeks may also require prompt imaging and specialist assessment. NICE recommends considering urgent brain MRI, or CT if MRI is unsuitable, in adults with progressive, subacute loss of central neurological function.^[1]

Loss of part of the visual field, double vision, new marked blurring, changes in eye movements, hearing loss on one side, imbalance or poor coordination can occur depending on the lesion's location. However, eye, inner ear, vascular and other neurological disorders can cause the same symptoms.

New loss of vision, marked difficulty walking or rapidly worsening imbalance should not be left unassessed, particularly when accompanied by other neurological signs. Finding papilloedema, swelling of the optic disc, during examination of the back of the eye suggests raised intracranial pressure and requires prompt investigation.^[3,5]

Much more common causes of forgetfulness include sleep deprivation, depression, stress, medications, thyroid and vitamin disorders, and age-related changes. Forgetfulness alone does not establish a diagnosis of a brain tumour.

By contrast, difficulty planning, slowed speech, a marked decline in work or everyday skills, impaired impulse control, or changes in personality and behaviour noticed by relatives that develop over a short period and progress require neurological assessment. The patient may not recognise the change, making a relative's observations valuable. Although symptoms can be related to location, a lesion's site or type cannot be determined from behavioural changes alone.^[4,6,17]

Lesions in or around the pituitary gland may cause irregular periods, changes in sexual function, milk discharge from the breasts, altered growth, excessive thirst and urination, or visual field loss. These symptoms can also occur in many hormonal disorders. Assessment often requires collaboration between endocrinology, ophthalmology, neurology and, when needed, neurosurgery.

The doctor asks about the onset and course of symptoms, the previous headache pattern, possible seizures, cancer history, medications and coexisting conditions. Muscle strength, sensation, reflexes, speech, eye movements, visual fields, coordination, walking and cognitive functions are assessed. Examination of the back of the eye may be needed if raised intracranial pressure is suspected.

In the emergency department, a non-contrast brain CT may be used for rapid assessment of conditions such as bleeding, substantial mass effect or hydrocephalus. In suitable patients, contrast-enhanced brain MRI helps assess the brain tissue and lesion characteristics in greater detail. Which method is selected first depends on urgency, examination findings, kidney function, implants and other clinical circumstances.^[2,9]

Not every headache requires routine MRI. Under the ACR appropriateness criteria, initial imaging is generally considered inappropriate for primary migraine or tension-type headache patterns without red flags; for a headache with red flags, MRI or, depending on the circumstances, CT may be appropriate.^[2] The decision to perform imaging should be based on clinical history and examination, rather than an online checklist alone.

A mass seen on MRI does not always reveal the exact tumour subtype. Depending on the clinical situation, monitoring, biopsy or the safest possible surgical removal may be considered. If tissue is obtained, neuropathological examination and the necessary molecular tests are interpreted together. The WHO 2021 classification uses an “integrated diagnosis” approach for many central nervous system tumours.^[7,8,10]

A single normal examination or a previous normal scan does not remove the need to reassess symptoms that develop or progress later. Findings can change over time; the type of test, when it was performed and the clinical question it addressed also matter. For example, a non-contrast CT performed in the emergency department to exclude bleeding does not answer the same question as a contrast-enhanced MRI planned to examine a particular brain lesion in detail.^[2,9]

Conversely, if symptoms have not changed and there are no red flags on examination, repeatedly performing scans at short intervals is not automatically safer. Incidental findings of uncertain clinical significance can lead to additional investigations, anxiety and unnecessary procedures. The follow-up plan depends on the initial suspected diagnosis, the course of symptoms and findings when the doctor examines the patient again.^[2,3]

Reassessment is appropriate in the following situations:

• A marked change or progression in a previous headache
• A new seizure, loss of strength or changes in speech, vision or balance
• The onset of vomiting, drowsiness or altered consciousness
• Unexplained rapid deterioration despite treatment
• New cognitive or behavioural decline noticed by someone close to the patient

If imaging identifies a lesion, decisions are not based solely on the wording of the report. Comparison with previous scans to assess growth, review of images in DICOM format and consistency with the clinical situation are important. Neurosurgery may be needed if surgery is a possibility; if findings support the possibility of a tumour, joint assessment by specialties such as neuroradiology, neuropathology, neuro-oncology and radiation oncology may be necessary.^[7,9,10]