CMI may cause specific symptoms related to CMI, and generalized symptoms that are often hard to associate only with CMI. Headaches and or neck pain, particularly precipitated by and exacerbated by coughing, straining, sneezing, are a very classic, specific symptom of CMI [2]. These headaches are called “tussive” headaches and can easily be distinguished from migraine headaches, which are unilateral and aggravated by light or noise. Frontal headaches occur in people without CMI and headaches associated with stress are not usual the result of this condition. Millions of Americans get headaches more than once a month, so physicians are cautious to avoid over diagnosing CMI based on headache symptoms that are not specifically tussive or in a person whose MRI that is not diagnostic for CMI but suffers headaches. Another less common symptom is a problem with balance and coordination, which may affect walking or other activities (See Table 7.1). CMI patients may complain about dizziness or vertigo (the room is spinning). Eye symptoms, most commonly jerky to-and-fro movements of the eyes, called nystagmus can be a complaint of CMI patients or be discovered on exam. CMI patients may complain about swallowing issues, sleep disturbances and general malaise in which they feel fatigued all the time. Some of that fatigue may be attributed from the incessant pain associated with headaches that start whenever the patient strains. It is important to note that a significant percentage of people with CMI suffer no symptoms and are diagnosed following an MRI for an unrelated clinical reason. These patients may remain asymptomatic for much of their life and the “natural history” (i.e., do they get symptoms later) of patients who do not receive treatment is still being studied.

Patients with syringomyelia associated with CMI can have severe symptoms, which include motor, sensory, pain and major dysfunction of their nervous system (See Table 7.2). The motor symptoms range from mild weakness to wasting of muscles. It is common for children with syringomyelia to have scoliosis as well. Syringomyelia can cause loss of feeling in the hands and feet or even the opposite. Patients can suffer exaggerated, hypersensitivity to touch, which is painful. The pain quality may be burning and occur in the arms and trunk. There may be joint pain in the shoulders that occurs from slow destruction of the joint. The major dysfunction of the nervous system may include incontinence of the bladder or bowel. There may be “autonomic” symptoms, which include wide swings in blood pressure, fainting or sweating. CMI patients with associated syringomyelia are rarely asymptomatic but their natural history is often one of progressively worse symptoms slowly over time.