From 2013 to 2015, patients participated in the first part of the study. Pain was assessed prior to the study.
It should be noted that the majority of patients with a duration of phantom pain persistence for more than one year assessed pain as less pronounced in comparison with patients in whom amputation occurred recently (Fig. 1).
Fig. 1 Assessment of the severity of phantom pain and the duration of symptom persistence in patients before the start of the MVF course
However, in the course of a survey on the effect of phantom pain on self-care and quality of life, it was found that the elements of self-care, social functioning and quality of life are equally reduced in all patients.
To conduct the MVF session, the intact limb was positioned on one side of the mirror so that the reflection created the illusion of the second intact limb located on the opposite side, after which the patients were asked to squeeze and unclench the fingers, flexion and extension in the wrist and elbow joints (for the upper extremities) (Fig. 2-a) or ankle and knee joints (for the lower extremities), and rotational movements were also performed (Fig. 2-b).
Fig. 2-a Example of upper limb movements
Fig. 2-b An example of movements in the lower limb
The duration of the session was, on average, 20 minutes, 3 times a day; the duration of the course was 15 days. The group showed significant positive dynamics (p <0.001) (Fig. 3).
Fig. 3 Analysis of the dynamics of the severity of phantom pain in the process of using MVF (Sign-test)
Stable positive dynamics were observed in 8 patients. In 6 patients, there were no dynamics, and in 8 cases, phantom pain increased significantly 6-8 days after the completion of the MVF course (p <0.05).
A detailed study of the anamnesis, symptoms, and the underlying disease, revealed that in all cases with persistent positive dynamics, the time interval between amputation and MVF sessions did not exceed 1 month. In patients without dynamics, it was found that the position of the reflected limb did not correspond to the position of the phantom and, in the process of work, led to a discrepancy in the sensory perception of the limb in the mirror, and in some cases, after the first sessions, an increase in pain was noted (Fig. 4). In addition, it was found that the position of the phantom was often described as atypical, with a pronounced uncontrolled tone of the flexor muscles.
Fig. 4 Inconsistency of the phantom with the sensory response (on the left - the location of the intact limb and an attempt to give an identical position to the phantom; on the right - the perception of the location of the phantom at the sensory level)
Also, in some cases, a discrepancy at the level of sensory perception occurred due to the fact that the reflection in the mirror was distorted by an increase or decrease in the angle of the mirror on the surface (Fig. 5).
Fig. 5 Inconsistency of the ratio of reflection in the mirror with the real environment
The information obtained at the first stage of the study made it possible to form a hypothesis that the effectiveness of MVF depends not only on the performance of simultaneous movements in the limb and the phantom, but also on other important factors, such as the duration and severity of the pain syndrome, the discrepancy between the location of the phantom at the level of sensations. and in reflection.
In the second part of the study, 18 patients took part, of which 9 patients were participants in the first part of the study, without positive dynamics or in whom pain in the phantom returned after a short time (Fig. 6).
Fig. 6 Assessment of the severity of phantom pain and the duration of the symptom persistence in patients before the start of the MVF course (on the left - the ratio of the duration of the symptom and the severity of pain; on the right - the duration of the persistence of pain, expressed in weeks)
Also, in the second part of the study, patients with phantom pain lasting more than ten years took part.
Before starting work, the position of the phantom was determined. Subsequently, this information was used by a specialist to correct the position of the limb with the patient's confirmation of the presence of a sensory response. Correction was carried out by giving the intact limb a position identical to the phantom with muscle tension (Fig. 7).
Fig. 7 Giving the intact limb an identical phantom position with muscle tension
After that, the specialist grasped the intact limb with one hand from the visible side of the mirror, the other hand was positioned so that the illusion of grasping the second limb was created in the reflected side of the mirror (Fig. 8).
Fig. 8 Grabbing of a limb by a specialist before starting MVF training (on the left - the location of the limbs in reality; on the right - the location of the limbs in the reflection)
Then, under the control of sensations, kneading of the intact limb in the initial position was carried out, followed by slow extension in the joints. In the process of extending the limb, it is necessary to clarify with the patient whether the phantom feels identical to the reflection. If the sensations in the phantom do not correspond to the reflection, it is necessary to correlate the intact limb in such a way that the sensations of the phantom's position in space correspond to the position of the reflection of the intact limb. After giving the limb and the phantom a position accessible for work, it is necessary to once again clarify the correspondence of sensations to the observed reflection in the patient and then proceed to perform movements: flexion-extension in the joints, pronation-supination, in which the most pronounced pain sensations were previously observed (Fig. 8).
The duration of the initial sessions was selected individually and depended on the initial state of the patient and the feeling of fatigue in the trained limb, but subsequently increased to a time of no less than 15 minutes and no more than 30 minutes 3 times a day. The duration of the course was 2 weeks.
After completion of the study, positive dynamics were established in all patients (p <0.0001) (Fig. 9).
Fig. 9 Analysis of the dynamics of the severity of phantom pain in the process of using MVF (Sign-test)
One week after the completion of the rehabilitation course, three patients showed a slight increase in phantom pain. After a second two-week course, after a 10-day break, the pain was significantly relieved.
It was found that the use of MVF in patients in the first days after amputation prevents the formation of phantom pain, and in one patient, MVF showed positive results in the process of adaptation to a bionic prosthesis.