Finger agnosia is the inability to recognize and distinguish your fingers or someone else’s. It may appear alone or it may be combined with other conditions as part of Gerstmann syndrome.

Agnosia is the loss of ability to recognize things, people, or even voices. Fewer than 1% of neurological patients have agnosia and even fewer will experience a form of agnosia that prevents them from recognizing and distinguishing body parts. When people are unable to distinguish fingers, it’s known as finger agnosia.

Finger agnosia may appear alone or grouped with other neurological disorders in a condition known as Gerstmann syndrome. In addition to addressing any underlying issues, treatment may include specialized therapies.

Symptoms of finger agnosia can include:

  • the inability to recognize and name your fingers
  • being unable to distinguish or name other’s fingers
  • struggling to move specific fingers when asked to

In some cases, people may also be unable to name and distinguish their toes. This is known as digit agnosia.

Finger agnosia may appear on its own or in combination with other conditions. If you have finger agnosia, it’s important to determine if it’s part of a bigger condition like Gerstmann syndrome.

Gerstmann syndrome is a rare neurological condition where individuals experience the loss of several functions. It includes:

  • Acalculia (difficulty performing mathematical calculations)
  • Finger agnosia
  • Left-right disorientation (inability to tell the difference between the left and right sides of the body)
  • Dysgraphia or agraphia (writing impairment)

True Gerstmann syndrome where all these conditions are present without other cognitive irregularities is extremely rare, but people may also experience various combinations of two or three of these symptoms with cognitive irregularities.

Finger agnosia is typically caused by damage to brain pathways. It’s often seen in people with damage to the left posterior parietal cortex of the brain.

Gerstmann syndrome is also seen in people with lesions in this area of the brain, but damage to other regions may also be involved. In fact, some research on Gerstmann syndrome indicates a lesion in the left middle frontal lobe of the dominant hemisphere of the brain is involved.

The brain damage responsible for finger agnosia may be due to a number of things including:

People may also experience damage to the brain as a result of a cognitive developmental disorder or a progressing degenerative brain disease.

A variety of simple tests can be performed to diagnose finger agnosia.

For example, after covering your eyes and having you stretch out all your fingers, your doctor or another examiner may lightly touch your fingers, having you identify them as soon as each finger is touched.

This test is done first with open eyes to prevent any misunderstandings. At least a 20% false recognition is needed for a finger agnosia diagnosis.

Another test that may be used to diagnose finger agnosia involves participants guessing the number of fingers in between two fingers they touch. An examiner may also touch one finger on one hand and ask you to move the same finger on the other hand.

If you test positively for finger agnosia, it’s important to have a brain MRI or CT scan done to learn all of the areas of the brain that are affected and rule out certain medical conditions like tumors that may be causing the agnosia.

Specialized therapies and counseling may help with finger agnosia.

Treatment of any underlying neurological conditions is also important. For example, if finger agnosia is related to tumors in the brain, surgery may help to alleviate it.

Normal life may never be possible if a person has Gerstmann syndrome, but when treatment begins at a young age, there’s a chance for improvement.

Having finger agnosia means that a person is unable to identify and distinguish between their fingers or other people’s fingers. Along with other neurological impairments, it may be a part of Gerstmann syndrome.

If it’s suspected you have finger agnosia, your doctor can perform simple tests to confirm it. Treating any underlying neurological conditions may help along with specialized therapy and counseling.