Acalculia is an acquired impairment in which people have difficulty performing simple mathematical tasks, such as adding, subtracting, multiplying, and even simply stating which of two numbers is larger.
Calculation impairments include the inability to perform simple mathematical operations, such as addition, subtraction, division, and multiplication.
Conversely, patients with lesions in the region of the intraparietal sulcus tend to have greater deficits in subtraction, with preserved multiplication abilities.
However, damage to various but not necessarily identified areas of the brain can cause computational difficulties, as various cognitive functions are necessary to execute mathematical calculations.
"Provided that general mental impairment and significant aphasic disorder can be excluded as primary factors, the presentation of deficits such as agraphia, acalculia, and right-left confusion should alert the clinician to the possibility of focal posterior parietal lobe disease.
[7] A basic examination of numerical abilities in brain-damaged patients should include both verbal and non-verbal aspects of number processing.
[9] At the same time that these number reconstruction technique is used, spatial orientation exercises, comprehension of the right-to-left relationship, and visual analysis of geometrical objects and forms should be developed.
[1] In a more basic form, the method used was rote practice: the retrieval of simple arithmetical facts through drill[10] or through conceptual training,[10][11] or the creation of strategies for solving concrete problems.
[12] Sohlberg and Mateer have said that "treatment should then include exercises that permit spatial analysis and visual motor ability training."
[13] In a case study, Rosselli and Ardila describe the rehabilitation of a 58-year-old woman with spatial alexia, agraphia, and acalculia associated to a vascular injury in the right hemisphere.
In a special test of written arithmetical operations (addition, subtraction, multiplication, and division), and initial score of 0/20 was obtained.
[7] Another case study published in 1990 described the condition and management of a former female accountant who had "suffered a small circumscribed left parietal subdural hematoma in an auto accident."
[6] The term acalculia was coined by Salomon Eberhard Henschen in 1925; it refers to the decrease in cognitive capacity for calculation that results from damage to the brain.
Earlier, in 1908, researchers Max Lewandowsky and Stadelmann published the first report of an individual with calculation impairment due to brain damage.