Symptoms from the Chiari I Malformation often develop in a slow and insidious manner. Frequently, the symptoms are vague and progress over a number of years. Many people have symptoms for years before they are properly diagnosed. A few patients develop symptoms after a mild or moderate trauma. Examples include falling off a trampoline, falling off a porch or a blow to the back of the head.
The most common symptom of the Chiari I Malformation is headache. It usually begins at the back of the head and radiates behind one or both eyes, to the top of the head or to the temples. The headache is often described as a pressure sensation but can be heavy, sharp or stabbing. For many, the pain varies between these and other sensations.
The headache is often made worse by straining activities (known as valsalva maneuvers) such as coughing, sneezing or even laughing or singing. Some patients report feeling as though "my head will explode" or "my head will pop off." Bending forward or looking up can worsen the headache. When the headache is intense, some patients note dizziness, blurring of vision, nausea or a feeling of being in a "mental fog."
A variety of visual symptoms can occur with CM-I including double vision, decreased peripheral vision, seeing flickers of light ("fireflies"), visual loss, blind spots, photophobia (sensitivity to bright lights), spasm of the eyelids (blepharospasm) and jerking of the eyes (nystagmus).
Dizziness & Auditory Symptoms
Dizziness is frequently seen in persons with CM-I. It is usually intermittent, often worse with the headache, and more noticeable when changing position. A sensation of spinning (vertigo), ringing in the ears (tinnitus), poor balance (disequilibrium) and decrease or loss of hearing may also occur.
Difficulty Swallowing & Hoarseness
People with CM-I may develop difficulty swallowing (dysphagia), either with liquids or solid foods, or a feeling of "catching" in the throat when attempting to swallow. The progression of dysphagia may be rapid and result in aspiration (inhaling fluid or food products into the lungs). Change in voice character and timber are common complaints. Hoarseness is often noted first by a family member or friend. Some patients report the inability to modulate voice when singing or speaking loudly.
Persons may complain of neck or arm pain. Often the pain is worse with exertion, fatigue, or lifting. The pain may be dull and aching, or shooting and stabbing. It is usually present or worse on one side. Along with pain, some patients experience weakness of the hand or arm, or difficulty with fine movements of the fingers. If syringomyelia is present, the pain may be more widespread.
Tingling, numbness, or pins and needles sensation often occur in the same areas as the pain. Numbness can progress over months to years and involve the lower extremities and trunk. These symptoms are usually more noticeable if a person has a syringomyelia (also called syrinx).
Problems walking may be described as unsteadiness or listing to one side. Persons may report falling or bumping into walls or doors. Infrequently, patients may have spasticity (stiffness and jerkiness) of the legs, which occurs more commonly with syringomyelia.
Respiratory, Heart & Abdominal Symptoms
Effects of the CM-I on the respiratory and cardiovascular systems can cause shortness of breath, chest pain, episodes of rapid heart rate (tachycardia), black out spells, and hypertension. Abdominal symptoms may include nausea, abdominal pain, or vomiting.
General & Cognitive Symptoms
These include poor sleep (insomnia), fatigue and depression. Some note problems with memory, thinking, speech and difficulty with word finding. People may report the feeling of a "brain fog" with difficulty in thinking and concentration. Difficulty in finding the right word may occur.