Cognitive Impairment: Causes

What causes cognitive impairment?

Cognitive impairment can result from conditions that occur during fetal development, at birth, shortly after birth, or at any point in life. Sometimes, the cause of cognitive impairment cannot be determined, especially in a newborn or small child.

Congenital causes of cognitive impairment

Cognitive impairment may be present at birth and may be genetic or chromosomal or result from complications of pregnancy. Congenital causes of cognitive impairment include:

• Chromosomal abnormalities such as Down syndrome, fragile X syndrome, cri du chat syndrome, Prader-Willi syndrome, and others
• Congenital hypothyroidism (underactive thyroid)
• Genetic abnormalities such as phenylketonuria, Tay-Sachs disease, galactosemia, Hunter syndrome, Hurler syndrome, adrenoleukodystrophy, and others
• Intrauterine growth retardation (poor growth of fetus)
• Prenatal drug or alcohol exposure
• Prenatal infections

Birth-related causes of cognitive impairment

Cognitive impairment can also be caused by complications related to delivery including:

• Infection
• Lack of oxygen during labor or birth
• Preterm birth or its complications such as intracranial hemorrhage (uncontrolled bleeding in the brain)

Causes of cognitive impairment that occur after birth or during childhood and adolescence

Cognitive impairment can also be caused by conditions that occur after birth or during childhood and adolescence including:

• Autism (abnormal development of communication and social skills)
• Head injury
• Heavy metal poisoning such as lead poisoning
• Infection
• Kidney disease (which includes any type of kidney problem such as kidney stones, kidney failure, and kidney anomalies)
• Malnutrition
• Metabolic conditions
• Neonatal jaundice (yellowing of the skin and whites of the eyes occurring after birth)
• Side effects of cancer therapy
• Systemic lupus erythematosus (a disorder in which the body attacks its own healthy cells and tissues)

Causes of cognitive impairment that occur in adults

Cognitive impairment can also be caused by conditions that occur in adulthood including:

• Alcohol or drug abuse
• Brain or spinal cord injury
• Certain vitamin deficiencies
• Congestive heart failure (deterioration of the heart’s ability to pump blood)
• Dementia
• Infections
• Kidney disease (which includes any type of kidney problem such as kidney stones, kidney failure, and kidney anomalies)
• Liver disease (which includes any type of liver problem such as hepatitis, cirrhosis, and liver failure)
• Medication side effects

Serious or life-threatening causes of cognitive impairment

In some cases, cognitive impairment may be a symptom of a serious or life-threatening condition that should be immediately evaluated in an emergency setting. These include:

• Brain tumor
• Encephalitis (inflammation and swelling of the brain due to a viral infection or other causes)
• Heat stroke
• Kidney failure
• Meningitis (infection of the membranes that cover the brain and spinal cord)
• Profound dehydration
• Sepsis (severe infection of the bloodstream)
• Spinal cord injury or tumor
• Stroke
• Traumatic head injury

Questions for diagnosing the cause of cognitive impairment

To diagnose your condition, your doctor or licensed health care practitioner will ask you several questions related to your cognitive impairment including:

• When did you first notice symptoms of cognitive impairment?
• What specific symptoms have you noticed?
• Did anything such as an injury or illness precede the symptoms?
• Were there any prenatal complications or complications of birth?
• Do you have any other medical conditions?
• What medications are you taking? Are you taking any new medications?
• Have you taken any street drugs?
• Do you drink alcohol?

What are the potential complications of cognitive impairment?

Because cognitive impairment can be due to serious diseases, failure to seek treatment can result in serious complications and permanent damage. Once the underlying cause is diagnosed, it is important for you to follow the treatment plan that you and your health care professional design specifically for you to reduce the risk of potential complications including:

• Developmental delays and failure to thrive
• Learning disability
• Paralysis or inability to move a body part
• Permanent cognitive impairment
• Permanent loss of sensation
• Personality changes
• Physical disability

References:

NINDS traumatic brain injury information page. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/tbi/tbi.htm. Accessed May 2, 2011.

Mental retardation. PubMed Health. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002491/. Accessed May 2, 2011.