Kinetic mutism is a syndrome characterized by a reduction in the frequency of movement, including verbal behavior, associated with motivational deficits resulting from brain damage.
In this article we will describe what is kinetic mutism and what are its main symptoms, causes and types.
What is kinetic mutism
In 1941 Cairns, Oldfield, Pennybacker and Whitteridge described the case of Elsie Nicks, a 14 year old girl with a cyst in her right lateral ventricle. As Elsie got older, the malformation caused increasingly severe headaches that prompted doctors to initiate treatment with morphine.
The patient began to show signs of listlessness as well as significant alterations in her ability to speak and control her movements. The symptoms evolved into a condition Cairns and colleagues dubbed “kinetic mutism.”
These authors described the disorder as a state in which the person remains stillSo that you can fix your gaze on objects and follow the movements. Statism also affects the movements necessary for speech and other vocalizations. Although actions are sometimes taken and sounds are made, these are usually not intentional.
As we will see below, the Cairns team’s proposal has been updated over the years and the scientific advancements that follow. Today, the term “kinetic mutism” is often used to describe any case that shows the absence of motor and verbal behavior which give it its name, and which can also consist of less severe deficits.
Main symptoms and signs
Cairns et al. (1941) point out five key signs for the diagnosis of kinetic mutism: the presence of states of alert, the ability to fix the gaze on other people, the execution of eye movements in response to auditory stimuli, actions in response to recurring orders and difficulties. speak and communicate in general.
However, we currently have more specific knowledge about kinetic mutism. In their review of the relevant scientific literature, Rodríguez-Bailón et al. (2012) conclude that a significant reduction in the number of verbal behaviors and the ability to follow objects with the gaze are the two basic diagnostic criteria.
The authors of this work highlight the variability of emotional alterations in these cases. Thus, patients with obvious deficiencies in the expression of emotions have been identified, but also others with signs of disinhibition. This clinical diversity is linked to the specific location of the brain lesions at the origin of acinetic mutism.
The immobility characteristic of this impairment manifests itself in all facets of motor skills, so that those with kinetic mutism they cannot speak, gesture or form facial expressions, Or have serious difficulty doing so. When successful, movements tend to be slow and sparse, and responses monosyllabic.
People with kinetic mutism are not paralyzed at the motor level, but the alterations that cause it appear to affect the willingness and motivation to adopt behaviors, including verbal ones. Many patients with this disorder have reported noticing resistance that prevents them from moving when they try to do so.
Types of kinetic mutism and their causes
The symptoms and signs of each case of kinetic mutism depend on the areas of the brain damaged by the causative factor of the disorder. Generally speaking, we can distinguish two variants of kinetic mutism: frontal and mesencephalic, which are associated with lesions of the frontal lobe of the brain and midbrain, respectively.
Frontal kinetic mutism is often due to alterations in the blood supply, especially to the anterior cerebral artery. Disorders and strokes are the most common causes kinetic mutism, although it can also appear as a result of infections, contact with toxic substances and neurodegenerative diseases.
When kinetic mutism occurs as a result of frontal injury, it often appears in conjunction with signs of disinhibition typical of frontal syndrome. Thus, in these cases, impulsive emotional responses are often given mainly related to passivity.
The midbrain is a subcortical structure that contains brain nuclei as relevant as colic, involved in visual and auditory perception, and substantia nigra, fundamental in the production of dopamine and therefore in strengthening. This kind of kinetic mutism is associated with hypersomnolence and motivational deficits.
Kinetic mutism can also be caused by respiratory arrest (which can cause cerebral hypoxia), traumatic brain injury, tumors, meningitis, hydrocephalus, thalamus damage, destruction of the cingulate gyrus, and Creuztfeldt’s disease. Jakob, a neurodegenerative disease caused by prion infections.
Cairns, H .; Oldfield, RC; Pennybacker, JB and Whitteridge, D. (1941). Acinetic mutism with epidermoid cyst of the 3rd ventricle. Brain, 64 (4): 273-90.
Rodríguez-Bailón, M .; Triviño-Mosquera, M .; Ruiz-Pérez, R. and Arnedo-Montoro, M. (2012). Acinetic mutism: review, proposal for a neuropsychological protocol and application to a case. Annals of Psychology, 28 (3): 834-41.