Gerstmann syndrome is a cluster of neurological symptoms that includes difficulty writing (dysgraphia or agraphia), difficulty with arithmetic (dyscalculia or acalculia), an inability to distinguish left from right, and difficulty identifying fingers (finger agnosia).
Two types of Gerstmann syndrome have been identified: an acquired form that occurs in adults who have suffered brain injury through stroke or trauma, and a developmental form that has been noted in children.
The brain area that seems to be primarily responsible for the deficits seen in Gerstmann syndrome appears to be the parietal lobe, which is located behind the frontal lobe. Current research has not identified a tendency for the developmental form of Gerstmann syndrome to be inherited.
Although both adults and children with Gerstmann syndrome may have considerable impairment, they do not necessarily have abnormal intelligence.
Gerstmann syndrome is usually identified in adult patients who have a history of brain injury or stroke. A very small group of children have also been identified as having the developmental form of the condition. Although the diagnosis tends to be made in school-aged children (usually at the point when writing and calculating become central classroom tasks), the condition may well be congenital. There are no reports clarifying the frequency or incidence of either the acquired or the developmental forms of Gerstmann syndrome.
Causes and symptoms
In adults, Gerstmann syndrome may be acquired when bleeding into the brain during a stroke or after a traumatic head injury occurs in an area of the left parietal lobe called the angular gyrus. A few adult cases of Gerstmann syndrome have also been described after viral encephalitis, tumor, or toxic exposure has caused injury to this same area of the brain. A specific cause for developmental Gerstmann syndrome has not been identified, although the fact that both parietal lobes are affected suggests that the problem occurs some time during early brain development.
The core symptoms in Gerstmann syndrome include:
- dysgraphia or agraphia: an inability or impairment in the ability to express oneself through the written word.
- dyscalculia or acalculia: an inability to perform basic calculations.
- left-right confusion: difficulty identifying the left or right of one's body or of other objects.
- finger agnosia: an inability to identify one's own or someone else's finger on the basis of a verbal command to hold up a particular finger.
Adults with Gerstmann syndrome may also display some degree of aphasia, which is an impaired ability to communicate verbally, to understand verbal communication, and to understand written language. Children with developmental Gerstmann syndrome may also exhibit poor handwriting, difficulty spelling, reading problems, and difficulty copying simple drawings (called constructional apraxia).
Diagnosis is through a comprehensive neurological exam and through psychoeducational testing.
There is no cure for Gerstmann syndrome. Neither children nor adults with this disorder will recover completely from its effects. Instead, supportive therapy may teach some skills, but will also help identify bypass strategies that can be used. For example, if the arithmetic facts cannot be learned, then the use of calculators and other resources should be encouraged. Word processing programs
Gerstmann syndrome is a permanent disorder. It will last an individual's lifetime. However, the prognosis can be very good if the patient is helped to understand his or her deficits, supported in using effective bypass strategies, and encouraged to continue developing his or her areas of strength.
Good diagnosis and support is necessary so that individuals with Gerstmann syndrome can maintain the strongest possible self-esteem. Care must be taken not to suggest that the individual's failed efforts are due to laziness or lack of caring. Instead, the neurological basis of the disorder should be clearly explained, and reasonable bypass strategies should be immediately identified and implemented.
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Rosalyn Carson-Dewitt, MD