Symptoms of DAVF

A dural arteriovenous fistula (DAVF) creates an abnormal connection between high-pressure arteries and low-pressure veins, bypassing the normal capillary network. This abnormal shunting of blood can cause a number of problems. The entry of arterial blood into the venous system raises venous pressure, and since veins are not designed to handle such force, they may stretch, dilate or even rupture, which can lead to bleeding in or around the brain. In some cases, blood flows backwards within the veins, a process known as venous reflux. This congestion reduces normal blood flow in parts of the brain or spinal cord, which over time can injure tissue and produce symptoms such as weakness, numbness or seizures. A DAVF may also divert blood away from healthy brain or spinal tissue, depriving it of oxygen and nutrients and thereby causing further neurological problems. The exact effects depend on the location of the fistula. For example, when a DAVF occurs near the ear, patients may develop pulsatile tinnitus, a rhythmic whooshing sound that follows the heartbeat.

Not everyone with a DAVF develops symptoms. When symptoms do occur, they can vary widely depending on the location of the DAVF and the way it affects blood flow. Some people develop symptoms gradually, while others may notice them suddenly.

Neurological Symptoms

Headaches – New or persistent headaches, often different in pattern or severity from previous ones.

Visual disturbances – Blurred vision, double vision, or partial loss of sight.

Balance and coordination problems – Difficulty walking or clumsiness.

Weakness or numbness – Often affecting one side of the body.

Cognitive decline – Gradual problems with memory, thinking or behaviour that can resemble dementia.

Auditory Symptoms

Pulsatile tinnitus – A rhythmic whooshing or ringing sound in the ear, in sync with the heartbeat.

Severe Symptoms (Emergency)

Bleeding in or around the brain (intracranial haemorrhage) – May present with sudden severe headache (“worst ever”), vomiting, loss of consciousness, or neurological deficits such as weakness or difficulty speaking.

Seizures – Sudden, uncontrolled electrical activity in the brain. This may cause collapse, loss of consciousness and convulsions.

Stroke-like symptoms – Sudden weakness on one side, facial drooping or difficulty speaking.