Do you or your child face problems in performing simple mathematical calculations that others seem to do in a jiffy? If that is the case, it might be Acalculia at work. Find out all about this unique disorder, including its causes, symptoms, diagnosis and treatment.
It is a type of acquired impairment in which patients experience difficulties in performing basic mathematical calculations such as addition, subtraction, multiplication or just identifying which of two given numbers have the higher value.
The name is derived from the Greek word “a” which means “not” and the Latin word “calculare”, meaning “to count”. Henschen came up with the term “acalculia” in the year 1925.
Acalculia should not be considered the same as Dyscalculia, a condition characterized by reduced ability to solve mathematical problems due to dysfunction of the brain. The former is generally acquired later in life as a result of neurological injuries, such as stroke, whereas Dyscalculia is distinct form of developmental disorder that is first observed during acquisition of numerical knowledge.
Patients of acalculia demonstrate difficulty in performing simple mathematical operations, like addition, subtraction, multiplication and division.
As calculation and identification of numbers are connected with the integration of numerous cognitive skills, experts believe that an individual with this condition experiences problems in any of these four perceptions:
Young schoolchildren are usually introduced to mathematical concepts and ideas in a gradual, cumulative manner. Advancement to higher concepts requires students to grasp the basic concepts properly. The speed of grasping numerical and mathematical concepts varies among individual students. Students who find it extremely difficult to retain the basic mathematical concepts are believed to suffer from Developmental dyscalculia.
A stroke or other associated neurological injuries can cause damage to the left angular gyrus. This can give rise to signs of computational difficulties that are commonly associated with health conditions such as Anarithmetia and Primary acalculia. However, damage caused to certain other areas of the brain of an individual can also give rise to difficulties with calculations as different types of cognitive functions are required for executing mathematical calculations. Acalculia symptoms may also be observed in patients of Alzheimer’s disease. The symptoms of this condition generally arise due to stroke, brain tumor, trauma, encephalitis or cerebral infection.
The condition is linked with lesions of parietal lobe, more specifically the angular gyrus as well as the frontal lobe. Its symptoms may also be regarded as early signs of dementia. Although the disorder is occasionally considered to be a “pure” health problem, it is believed in most cases to be one of the numerous symptoms of Gerstmann’s syndrome. Gerstmann’s syndrome is a neurological condition caused by the damage of left angular gyrus. Its symptoms include agraphia, right-left confusion and finger agnosia along with the development of Acalculia.
Studies conducted in patients with parietal lobe lesions have shown the lesions of angular gyrus to be causing greater impairments in memorization of mathematical facts like multiplication tables, with rather unimpaired subtraction skills. Conversely, patients having lesions in the intraparietal sulcus region tend to experience greater difficulties in subtraction and proper multiplication abilities. These findings of double dissociations support the idea that various parts of parietal cortex are associated with different aspects of mathematical processing.
Interview sessions, where patients are asked questions about mathematical order, are among the most common screening methods for this disease. Other tests, that can accurately portray the mental condition of the patient include:
The last four of the abovementioned tests are all conducted to confirm whether or not a patient is having Gerstmann’s Syndrome. Acalculia is one among four defining symptoms of Gerstmann’s syndrome, the other three being finger agnosia, agraphia and right/left confusion. The symptoms of Acalculia are generally seen due to the presence of Gerstmann’s syndrome although it can also be linked with certain other symptoms in some cases. It is important to note that physicians face considerable difficulty in separating mathematical disorders from damages in other parts of the brain. It is due to this reason that testing of other functions apart from mathematical calculation abilities is considered important for the diagnosis of Acalculia.
More extensive tests include:
These tests have proven to be highly assistive in shedding light on some of the most important anatomical aspects for numerical calculations.
A standard examination of number-related abilities among brain-damaged patients has to include both verbal as well as non-verbal elements of number processing. Certain tests can be conducted for neurological analysis:
As acalculia is often considered to be a symptom of Gerstmann’s syndrome (GS), it is often difficult to diagnose the former separately. On the other hand, the physician may actually diagnose GS and label the signs of Acalculia as one of the four symptoms of GS. A physician also has to look for signs of posterior parietal lobe disease. Structural and functional neuro-imaging can shed more light on any other underlying neurologic abnormalities.
There are six different forms of acalculia. These are
The symptoms of Gerstmann syndrome and Acalculia are not disorders but outcomes of other neurological abnormalities. Treatment for Acalculia involves cognitive rehabilitation, which may help affected individuals deal with serious symptoms that interfere with the smooth running of daily life.
Patients of acalculia usually have a normal lifespan, unless other traumatic injuries or disabilities prevent normal living.
Acalculia is a numerical impairment that affects the patients late in their lives due to some stroke or brain trauma. Although it can seriously affect one’s ability to deal with numbers and make numerical calculations, patients of this condition are otherwise known to lead a normal, healthy life.