Gerstmann Syndrome: Causes, Symptoms And Treatment
At the beginning of the last century, Josef Gerstmann encountered a patient who, after a brain injury, was unable to name the fingers on his hand, or even recognize them. Motivated by the interest of this curious symptom, he found a constellation of symptoms that accompanied this phenomenon.
Let’s see below the Gerstmann syndrome, a clinical condition that occurs after an injury to the parietal lobes. We will describe what its symptoms are, where the injury is and why it may occur.
When we talk about Gerstmann’s original patient, we always mention the four classic symptoms: digital agnosia, agraphia, acalculia, and laterality problems.
If these four cardinal points occur at the same time in a patient, we say that he suffers from Gerstmann syndrome.
1. Digital agnosia
It is a form of asomatognosia, that is, the inability to recognize parts of one’s own body. This symptom can affect either side of the body depending on which brain hemisphere is affected. Interestingly, the inability to recognize fingers is closely related to the presence of dyscalculia. Those children who, due to an injury or malformation, are unable to recognize their own fingers, have much more difficulty learning to calculate.
2. Agraphia
The patient with Gerstmann syndrome is unable to communicate in writing. Agraphia can occur for two different reasons: either due to an injury that causes linguistic deficits or due to an injury where linguistic ability is fine, but motor skills are affected.
In the case of Gerstmann syndrome, the reason for this is not clear. Although some patients also present other language disorders such as inability to read or aphasias that could be related, we also know that a common denominator in the syndrome is the inability to mentally manipulate images. Both hypotheses remain up in the air.
3. Dyscalculia
This is the name given to difficulties in performing arithmetic operations in the head. Patients with Gerstmann syndrome have difficulty with even the simplest addition and subtraction. It remains to be elucidated exactly at what point in the arithmetic operations the inability occurs. Perhaps it is in the retention of numbers in consciousness, as a kind of working memory for arithmetic operations.
4. Laterality problems
Gerstmann’s patient was completely unable to differentiate left from right. This is not crossed laterality, where both directions are confused, but rather the loss of the notion of laterality. For this person left and right do not exist and they respond randomly to the tests that are done in this regard.
To this classic tetralogy, other symptoms are added that may or may not be present depending on the patient. The injuries in each case are unique and will result in a different clinical picture, although all (or almost all) will present these four key points. Many of the patients show a fifth symptom not included in tetralogy, but which throughout the century has become more and more relevant in case descriptions.
5. Aphasia
The inability to articulate language can be seen in many patients with Gerstmann syndrome, indicating that rather than an impairment of specific abilities, what could actually be affected is symbolic thinking. What’s more, it could even be that the inability to understand abstract concepts explains why patients do not know what to answer when asked where their right hand is or what their index finger is, confusing digital agnosia with receptive aphasia.
The syndrome occurs due to injury to the left parietal region of the brain, specifically the angular gyrus. The parietal is responsible for motor skills and sensitivity, space, calculation and part of language. It is normal, then, that an injury somewhere in the parietal lobe, due to geographical and also functional proximity, affects this entire group.
It is common for regions close to each other to carry out similar functions or to complement each other, as if each had specialized in a specific aspect of a more general function. For example, motor skills and sensitivity are closely related and one is next to the other. Thus, an injury to motor skills can also alter sensitivity and vice versa. This is why an apparently focal lesion can affect an entire subsystem of interrelated components.
The reasons why someone could suffer damage to the parietal lobe are multiple. Head trauma, through the blow itself or the edema that is generated afterwards, brain tumors or even strokes are common causes of this syndrome. It is very common to find people who have lost blood supply to this area of the brain, losing the neurons in charge of these functions.
Treatment
The treatment of Gerstmann syndrome is symptomatic. There is nothing that can be done to automatically restore the damage, but this does not mean that the individual cannot be rehabilitated and relearn all those skills you’ve lost. Depending on the injury, its severity and the age of the individual, the prognosis is different.
To get an idea, we must think that the brain is very plastic and has the ability to reorganize itself to assume the functions that have been lost. As if the workers of a company assumed the responsibilities of an entire department that has just been fired, but at no cost. The younger the brain, the greater its ability to adapt.
With progressive training it is possible to restore functions. It will not always be possible to return to the functioning prior to the syndrome, especially if the affected area is very large or the lesions are deep, but the disability is ruled out if cognitive rehabilitation is followed exhaustively.
