The thalamus is a mass at the top of the brain stem that works with the cerebrum to control muscle coordination. It also acts as a relay station for the cerebrum's sensory centre. Malignant tumours within this area of the brain are often considered inoperable.
Thalamic tumours are diagnosed through a CT scan. Tumours of the thalamus account for up to 5 per cent of all brain tumours.
A tumour in the thalamus presents with a decreased or impaired sense of touch, often on one side of the body, and is accompanied by headaches due to increased intracranial pressure. Symptoms also include abnormal involuntary eye movement (nystagmus), swollen optic nerves and speech difficulties.
Tumours of the thalamus affect muscle movements. A person might experience difficulty walking, speaking and performing day-to-day functions. Tumours can be benign (noncancerous) or malignant (cancerous).
Tumour size varies. The larger the tumour is, the more intracranial pressure presents within the brain. A patient experiences more symptoms as pressure increases.
Treatment depends on the size, scope and location of the tumour. Noncancerous tumours can be surgically removed to relieve symptoms. Cancerous thalamic tumours generally are not removed surgically; instead, they are treated with chemotherapy and radiation.