Focal neurologic deficitsNeurological deficits - focal
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.
A neurologic deficit refers to abnormal function of a body area due to weaker function of the brain, spinal cord, muscles, or nerves. Examples inclu...
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.
Loss of consciousness
Decreased alertness is a state of reduced awareness. A coma is a state of decreased alertness from which a person cannot be awakened. A long-term co...
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, including paresthesia (abnormal sensations), numbness, or decreases in sensation
Other examples of focal loss of function include:
- Horner 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
Horner syndrome is a rare condition that affects the nerves to the eye and face.
- Not paying attention to your surroundings or a part of the body (neglect)
- Loss of coordination or loss of fine motor control (ability to perform complex movements)
Loss of coordination
Uncoordinated movement is due to a muscle control problem that causes an inability to coordinate movements. It leads to a jerky, unsteady, to-and-fr...
- 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)
The visual field refers to the total area in which objects can be seen in the side (peripheral) vision as you focus your eyes on a central point. Thi...
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 (such as multiple sclerosis)
- Disorders of a single nerve or nerve group (for example, carpal tunnel syndrome)
- Infection of the brain (such as meningitis or encephalitis)
Home care depends on the type and cause of the problem.
When to Contact a Medical Professional
If you have any loss of movement, sensation, or function, call your health care provider.
What to Expect at Your Office Visit
Your provider will take your medical history and perform a physical examination.
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. Tests are used to 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)
Electromyography (EMG) is a test that checks the health of the muscles and the nerves that control the muscles.
- MRI of the back, neck, or head
- Spinal tap
Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL. Diagnosis of neurological disease. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice. 7th ed. Philadelphia, PA: Elsevier; 2016:chap 1.
Griggs RC, Jozefowicz RF, Aminoff MJ. Approach to the patient with neurologic disease. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 396.
Review Date: 10/24/2016
Reviewed By: Amit M. Shelat, DO, FACP, Attending Neurologist and Assistant Professor of Clinical Neurology, SUNY Stony Brook, School of Medicine, Stony Brook, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.