Dictionary

migraine, classic A migraine with an aura. Such migraines account for no more than 20 percent of migraines. See also migraine.

migraine, common A migraine without an aura. This is the most frequent type of migraine, accounting for about 80 to 85 percent of migraines. See also migraine.

migraine, ocular A migraine involving the eyes that results in distortion of visual images, accompanied or followed by headache. An ocular migraine usually affects only one eye at a time. Image distortion generally begins in the center of the image and then moves to one side. Images “gray out” or look wavy, and sight may…

migraine, ophthalmoplegic A rare condition observed most commonly in children and young adults characterized by headache of relatively long duration (up to one week) and paralysis or weakness of the muscles that control eye movement. Rather than a true migraine, the condition is believed to represent a cranial neuralgia (nerve problem).

migraine aura A sensory phenomenon that may occur before a migraine. Visual auras may include flashing lights, geometric patterns, or distorted vision. Some people may have aural auras that involve hearing sounds (usually buzzing) that are not actually present, olfactory auras that involve smelling odors that are not actually present, or tactile auras that appear…

migraine headache The most common type of vascular headache, thought to be caused by abnormal sensitivity of arteries in the brain to various triggers that result in arterial spasms. Other arteries in the brain and scalp then open, and throbbing pain is perceived in the head. The tendency to migraine is inherited and appears to…

migrainous neuralgia See cluster headache.

miliary aneurysm A tiny aneurysm. Miliary aneurysms tend to affect minute arteries in the brain or in the retina of the eye. They can bleed and lead to impaired function of the brain or eye. See also aneurysm.

miliary tuberculosis The presence of numerous sites of tuberculosis infection, each of which is minute, due to dissemination of infected material through the bloodstream in a process somewhat like the metastasis of a malignancy.

mineralocorticoid A group of hormones that regulate the balance of water and electrolytes (ions such as sodium and potassium) in the body. The mineralocorticoid hormones act on the tubules of the kidney. The most important mineralocorticoid hormone is aldosterone.

minimally invasive surgery A type of surgery that is done through small incisions through which instruments and imaging devices are passed; sometimes called laparoscopic surgery. Minimally invasive surgery is performed in many different surgical specialties. For patients, minimally invasive surgery has the advantages of a lower rate of blood loss and other complications, smaller surgical…

mini-stroke See transient ischemic attack.