What Is Akinesia?
Akinesia is defined as the loss of the ability to move one’s muscles voluntarily. Akinesia is one of the most common symptoms of Parkinson’s disease (PD) [1, 2]. However, it can be present in other diseases as well.
Definition of Akinesia
The medical definition of akinesia is the loss of the ability to move your muscles voluntarily. In a non-medical definition, it is often described as "absent movement” [3]. It occurs when the movement is not executed due to an excessive amount of time it takes to initiate it or because the amplitude of the movement is small.
Akinesia vs Dyskinesia
Akinesia and dyskinesia are often mistaken. While akinesia refers to the inability to initiate movement, dyskinesia is a term used for involuntary uncontrolled movement. Both can be seen in Parkinson’s disease. However, akinesia is a symptom of Parkinson’s disease whereas dyskinesia is a side effect of Parkinson’s medications.
Akinesia vs Bradykinesia
Akinesia and bradykinesia are two distinct phenomena which can be distinguished by understanding their manifestation. Akinesia is a term to describe the loss of the ability to voluntarily move muscles, while bradykinesia refers to the reduction in the speed of movements.
Akinesia Symptoms
The symptoms of akinesia may vary as akinesia can be manifested in multiple ways[2, 3]. However, we usually observe:
- Delayed response - Patients have often delays in movement execution, resulting in not executing the movement at all.
- Freezing of muscles - Patients experiencing akinesia can feel having one or more muscle groups stiff. Additionally, it may result in a phenomenon called “gait freezing” (also known as postural instability, a special type of walk observed in patients with Parkinson’s disease or Progressive Supranuclear Palsy(PSP)).
- Inability to execute multiple actions at once - Patients struggle to perform multiple tasks at once, for example, buttoning clothes while answering a question
- Complete abolition of movement - Patients are completely unable to execute a wished movement.
Causes of Akinesia
The causes of akinesia all include dysfunction of the nervous system involving dopamine [2]. In particular, akinesia has been linked to the dysfunction of the basal ganglia [4] The etiology of Akinesia can vary. We can either observe an adult-onset akinesia or fetal akinesia [2, 3].
Adult onset akinesia
Adult onset of akinesia usually occur as a consequence of neurodegenerative disease [1, 2]. These most commonly include PD and PSP.
Fetal akinesia
Fetal akinesia refers to a term used to describe reduced or completely absent movements for babies in the womb. It has been proposed, that fetal akinesia can lead to various abnormalities. These may include malformation and maldevelopment of the lungs or may cause the baby to be born with facial abnormalities [5, 6, 7].
Akinesia and Neurodegenerative Diseases
In fact, akinesia is considered a psychomotor syndrome of diseases such as Parkinson’s disease or Progressive Supranuclear Palsy[1, 8, 9].
Akinesia and Parkinson’s Disease
Akinesia is a common symptom of Parkinson’s disease and manifests as the loss of voluntary muscle movement [1]. Acute akinesia in Parkinson's disease contributes to a worsening of motor symptoms in PD [9].
Akinesia and Progressive Supranuclear Palsy
Akinesia present in PSP is a distinct form of the one is PD and we refer to it as pure akinesia. In PSP, it is characterized by freezing of gait and prominent speech disturbance. However, we do not observe rigidity or tremor in PSP patients with pure akinesia [9].
Treatment for Akinesia
Akinesia does not have a cure yet. A general recommendation is to keep active, exercise and stretch. However, there are some treatments which can help us to manage the symptoms. These include medical and surgical treatments.
- Medical treatment - Drugs that can improve akinesia include dopaminergic drugs such as L-Dopa, dopamine agonists, and monoamine oxidase B inhibitors such as selegiline and rasagiline [2]. For acute akinesia the use of amantadine sulfate infusion as a first line of treatment. The second line of treatment is apomorphine or bolus infusion [9].
- Surgical Treatment - Surgical treatment for akinesia has also been shown to be beneficial. In particular, deep brain stimulation has been suggested to improve gait freezing [2].
- Physiotherapy - A regular physiotherapy can manage the symptoms of akinesia. This involves activation of the muscles, thus preventing muscle stiffness and improving mobility. Physiotherapy includes exercises and massages. In addition, walker aids can lead to easing down of the symptoms of akinesia[2].