Focal neurological deficits

Alternative names:

neurological deficits - focal

Definition:

A loss of movement, sensation, or function in a specific location; the loss is related to problems in the brain or nervous system.

Considerations:

A focal neurologic deficit involves a change in a nerve function that occurs in a specific location (as opposed to a general loss of consciousness, for example). The type, location, and severity of the neurologic change can indicate the area of the brain or nervous system that is affected.

Focal neurologic deficits affect a specific location (for example, the left face, right face, left arm, right arm, left leg, right leg, even just a small area such as just the tongue) or a specific function (for example, speech may be affected but not the ability to write).

Focal neurologic changes can include any function. Sensation changes include paresthesia (abnormal sensations), numbness, or decreases in sensation. Movement changes include paralysis, weakness, loss of muscle control, increased muscle tone, and decreased muscle tone.

Other types of focal loss of functions include:

• speech or language changes such as aphasia or dysarthria (impaired speech and language skills), poor enunciation, poor understanding of speech, impaired writing, impaired ability to read or to understand writing, inability to name objects (anomia)
• vision changes such as reduced vision, decreased visual field, sudden vision loss, double vision (diplopia)
• neglect or inattention to the surroundings on one side of the body
• loss of coordination, fine motor control, or ability to perform complex movements
• Horner's syndrome: one-sided eyelid drooping (ptosis), absent sweating on one side of the face, and retraction of one eye into the socket
• poor gag reflex, swallowing difficulty, and frequent choking

Common causes:

• stroke
• brain tumor
• cerebral palsy
• disorders of a single nerve or nerve group (for example, see carpal tunnel syndrome)

Note: There may be other causes of focal neurological deficits. This list is not all inclusive, and the causes are not presented in order of likelihood. The causes of this symptom can include unlikely diseases and medications. Furthermore, the causes may vary based on age and gender of the affected person, as well as on the specific characteristics of the symptom such as location, quality, time course, aggravating factors, relieving factors, and associated complaints. Use the Symptom Analysis option to explore the possible explanations for focal neurological deficits, occurring alone or in combination with other problems.