Fortification Spectra

Fortification Spectra, also known as Scintillating Scotoma, is a medical term relating to the visual disturbance that one may experience before the onset of a migraine. It is one part of what is called, Migraine With Aura.

Fortification Spectra is perceived at first as a tiny flickering of light in the central field of vision. The flickering visual disturbance then moves to the peripheral vision where it expands and becomes much more noticeable. The flickering dot stretches and inside, zig zag lines or shimmering patterns may be perceived. The visual disturbance can be either bilateral or unilateral. Normal vision should return within an hour from the onset of the scintillating scotoma.

Functioning MRI imaging (Imaging which displays brain activity), has shown that this symptom arises out of abnormal functioning of the occipital cortex; located at the back of the brain. The exact causes and mechanisms of action are still not known, although cortical spreading depression sounds the most likely. The eye itself is not the cause. It does not damage the eye in any way.

Cortical Spreading Depression is, in a nutshell, abnormal electrical activity in the brain. It more than usually involves the occipital cortex, the part of the brain that controls sight. It is a wave of electrophysiological hyperactivity, followed by a wave of inhibition. A surge of abnormal electrical functioning travels up through the occipital lobe in around three minutes. This may cause inappropriate messages or signals to be sent to the parts of the visual cortex that process what we are seeing, resulting in the fortification spectra or scintillating scotoma.

In the majority of cases, this condition is benign and normally in direct relation to migraine headaches. This visual disturbance can happen spontaneously with no head pain and is referred to as an acephalgic migraine.

It is important for first time sufferers to rule out other, more serious conditions such as epilepsy or stroke (particularly Transient Ischemic Attacks). Some epileptics experience an aura, similar to migraine sufferers, that can sometimes indicate to them when a seizure is about to occur. Also, stroke patients can experience visual disturbances similar to migraine patients.

I have had migraines with aura since I was thirteen years old (I'm twenty-four now!). The vision problems that one may experience due to the condition can be extremely frightening. But, to reassure you, I have had visual aura's for eleven years now and I am still here! I have had brain scans and neurological exams and all is good! (so they tell me!).

It will not kill you or cause you to go blind.