Focal neurological deficits
A focal neurologic deficit is a problem with nerve, spinal cord, or brain function. It affects a specific location, such as the left side of the face, right arm, or even a small area such as the tongue. Speech, vision, and hearing problems are also considered focal neurological deficits.
The type, location, and severity of the problem can indicate which area of the brain or nervous system is affected.
In contrast, a nonfocal problem is NOT specific to a certain area of the brain. It may include a general loss of consciousness or emotional problem.
Neurological deficits - focal
A focal neurologic problem can affect any of these functions:
- Movement changes including paralysis, weakness, loss of muscle control, increased muscle tone, loss of muscle tone, or movements a person cannot control (involuntary movements, such as tremor)
- Sensation changes include paresthesia (abnormal sensations), numbness, or decreases in sensation
Other examples of focal loss of function include:
- Horner's syndrome: small pupil on one side, one-sided eyelid drooping, lack of sweating on one side of the face, and sinking of one eye into its socket
- Not paying attention to a person's surroundings or a part of the body (neglect)
- Loss of coordination or loss of fine motor control (ability to perform complex movements)
- Poor gag reflex, swallowing difficulty, and frequent choking
- Speech or language difficulties such as aphasia (a problem understanding or producing words) or dysarthria (a problem making the sounds of words), poor enunciation, poor understanding of speech, difficulty writing, lack of ability to read or understand writing, inability to name objects (anomia)
- Vision changes such as reduced vision, decreased visual field, sudden vision loss, double vision (diplopia)
Anything that damages or disrupts any part of the nervous system can cause a focal neurologic deficit. Examples include:
- Abnormal blood vessels (vascular malformation)
- Brain tumor
- Cerebral palsy
- Degenerative nerve illness
- Disorders of a single nerve or nerve group (for example, carpal tunnel syndrome)
Home care depends on the type and cause of the problem.
Call your health care provider if
If you have any loss of movement, sensation, or function, call your health care provider.
What to expect at your health care provider's office
The health care provider will take your medical history and perform a physical examination.
Medical history questions may include:
- When did the problem start and how fast is it changing?
- Was it sudden or gradual?
- Has it gotten worse over seconds, minutes, hours, days, or months?
- For how long have you had the problem?
- Where is the loss of function?
- Left arm?
- Left leg?
- Right arm?
- Right leg?
- Another location (be specific)?
- What deficits do you have?
- What other symptoms do you have?
The physical examination will include a detailed examination of your nervous system function.
Which tests are done depends on your other symptoms and the possible cause of the nerve function loss. The tests that are used try to locate the part of the nervous system that is involved. Common examples are:
- CT scan of the back, neck, or head
- Electromyogram (EMG)/nerve conduction velocities (NCV)
- MRI of the back, neck, or head
- Spinal tap
Bradley WG, Daroff RB, Fenichel GM, Jankovic J. Diagnosis of neurological disease. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann Elsevier; 2008:chap 1.
Griggs RC, Jozefowicz RF, Aminoff MJ. Approach to the patient with neurologic disease. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 403.
Last reviewed 7/31/2011 by David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by Luc Jasmin, MD, PhD, Departments of Anatomy and Neurological Surgery, University of California, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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