AVMs are usually diagnosed with medical imaging studies which are often requested by neurologists after a patient has developed symptoms. Symptoms of an AVM may include headache, numbness, seizures, weakness, or often the abrupt onset of a stroke. To find out more about symptoms and abrupt onset visit the ‘Treatment’ section.

The first investigations carried out on a patient suspected of having an AVM is usually a CT scan or an MRI scan. These studies are effective methods of identifying an AVM and are non invasive, requiring only an injection of contrast material into a small vein during the examination.

Further identification of the abnormal vessels involved in the AVM requires a test called an angiogram. An angiogram is the only test currently available which can provide sufficiently detailed information on which a neurologist or surgeon can plan and carry out treatment on most AVMs.