The clinical manifestations of neurologic disease are as varied as the disease processes themselves. Symptoms can be subtle or in-tense, fluctuating or permanent, an inconvenience or devastating. An introduction to some of the most common symptoms associated with neurologic disease follows; detailed discussions regard-ing how specific symptoms relate to a particular disorder.
Pain is considered an unpleasant sensory perception and emo-tional experience associated with actual or potential tissue damage or described in terms of such damage. Pain is therefore considered multidimensional and entirely subjective (Loeser, 2001). Pain can be acute or chronic. In general, acute pain lasts for a relatively short period of time and remits as the pathology resolves. In neurologic disease, this type of pain is often associated with spinal disc disease, trigeminal neuralgia, or other neuropathic pathology (eg, post-herpetic neuralgia, or painful neuropathies). In contrast, chronic pain extends for long periods of time and may represent a low level of pathology. This type of pain might also occur with discogenic disease.
Seizures are the result of abnormal paroxysmal discharges in the cerebral cortex, which then manifest as an alteration in sensation, behavior, movement, perception, or consciousness (Hickey, 2003). The alteration may be short, as in a blank stare lasting only a second, or of longer duration, such as a tonic-clonic grand mal seizure that can last several minutes. The type of seizure activity is a direct result of the area of the brain affected. Seizures can occur as isolated events, such as when induced by a high fever, alcohol or drug withdrawal, or hypoglycemia. A seizure may also be the first obvious sign of a brain lesion.
Dizziness is an abnormal sensation of imbalance or movement. It is fairly common in the elderly and one of the most common com-plaints encountered by health professionals. Dizziness can have a variety of causes, including viral syndromes, hot weather, roller coaster rides, and middle ear infections, to name a few. One diffi-culty confronting health care providers when assessing dizziness is the vague and varied terms patients use to describe the sensation. Vertigo, a specific form of dizziness, is defined as a sensation thatis usually a manifestation of vestibular dysfunction. It can be so se-vere as to result in spatial disorientation, loss of equilibrium, and nausea and vomiting (Greenberg, Aminoff, & Simon, 2002).
Visual defects that cause people to seek health care can range from the decreased visual acuity associated with aging to sudden blind-ness caused by glaucoma. Normal vision depends upon func-tioning visual pathways through the retina and optic chiasm and the radiations into the visual cortex in the occipital lobes. Lesions of the eye itself (eg, cataract), lesions along the pathway (eg, tumor), or lesions in the visual cortex (from stroke) interfere with normal visual acuity. Abnormalities of eye movement (as in the nystagmus associated with multiple sclerosis) can also compro-mise vision by causing diplopia or double vision.
Weakness, specifically muscle weakness, is a common manifesta-tion of neurologic disease. Weakness frequently coexists with other symptoms of disease and can affect a variety of muscles, causing a wide range of disability. Weakness can be sudden and permanent, as in stroke, or progressive, as in many neuromuscular diseases such as amyotrophic lateral sclerosis. Any muscle group can be affected.
Numbness, abnormal sensation, or loss of sensation is a neuro-logic manifestation of both central and peripheral nervous system disease. Altered sensation can affect small or large areas of the body. It is frequently associated with weakness or pain and is po-tentially disabling. Both numbness and weakness can significantly affect balance and coordination.