Introduction
Acquired Brain Injury (ABI) is one of the leading causes of death and disability in the world. It is defined as brain damage after birth, which is not related to congenital disorders, developmental disabilities and progressive brain damage processes [1]. There are many types of ABI that can be divided into traumatic and non-traumatic. Common traumatic causes include motor vehicle accidents, falls, assaults, gunshot wounds, and sporting injuries, while non-traumatic causes include brain damage, lack or shortage of oxygen, tumors, aneurysms, vascular malformations, and brain infections [2-5]. 
The global incidence of traumatic ABI is 349 per 100,000 people [5] and in Tehran, 15.3-144 people per 100,000 people [6]. The findings show an increase in the incidence of patients with non-traumatic ABI due to anoxia, and a decrease in the incidence of non-traumatic ABI due to cerebral and vascular tumors [7]. People with ABI, depending on the location of the injury, may have mobility problems such as spasticity, limited range of motion, abnormal gait, ataxia, instability and weakness, and impaired upper limb function [8]. 
These people have many executive and motor problems in functional areas such as daily living activities and personal care [9]. Therefore, patients with ABI experience long-term defects, and their treatment requires many health care resources. Inpatient rehabilitation has higher therapeutic costs, and these costs are significantly higher even after three years. Therefore, patients with non-traumatic ABI suffer from longer-term problems and require more intensive and intensive care than patients with traumatic ABI [10]. The primary concern in the rehabilitation of ABI is the recovery of motor ability, because the improvement in mobility and the motor function of the upper limbs leads to improving the patient’s independence in performing daily living activities and reducing the amount of day care [11, 12].
Therapeutic restriction is one of the approaches used to restore mobility based on the neurological flexibility of the brain, followed by improved upper limb function with greater involvement [13]. It is difficult to implement therapeutic restriction in clinical situations, as studies have reported that patients are reluctant to follow treatment and wear restraining devices. On the other hand, therapists have acknowledged that the resources and facilities necessary to implement therapeutic restriction are not available [14]. Patients often prefer few treatment sessions and less hours of use of restrictive devices. Therefore, Page et al. proposed a shorter protocol called Constraint-Induced Movement Therapy (CIMT) [13].
Given that the evidence for intervention strategies including upper limb rehabilitation, used in the rehabilitation of people with ABI is not sufficient [4, 15], and there is a paucity of studies on the effect of modified CIMT in patients with chronic and severe ABI, this study aimed to investigate the effect of this method on upper extremity function of a patient with severe ABI.
Case Presentation
Patient was a 33-year-old right-handed woman admitted to Rofeideh Rehabilitation center with a hypoxia diagnosis due to suicidal ideation and having no complaints of pain in the upper extremities near affected area. After the suicide, all four organs of the patient were involved, where the upper left side was more affected. The patient had always used the lower extremity with less damage and had difficulty performing daily living activities that required bilateral upper limb movements. 
The left arm was able to reach objects but was unable to pick up and carry them. Immediately after discharge from the hospital and admission to the rehabilitation center, the patient had received occupational therapy and physiotherapy services from four years ago during 13 hospitalizations and had not been able to use the upper left limb during all this time. First, the purpose of the study was explained to the authorities, and after obtaining consent from the patient, an initial assessment was made. The inclusion criteria were: active wrist extension of at least 20 degrees, maintaining balance for two minutes, Ashworth scale score <3 and Mini-Mental State Examination (MMSE) score>24. In addition to receiving the intervention provided in this study, the patient received physiotherapy interventions. Her main complaint was the inability to use the more involved upper limbs and the difficulty in performing daily activities independently.
The intervention was performed for two weeks, five sessions a week, each for three hours [16]. Sling and gloves were used as constraints for at least six hours a day. In each session, upper extremity preparation was performed by reducing the spasticity of upper limb muscles [17], followed by motor activities and tasks [18]. Shaping technique was used during the intervention (Table 1). For assessment of patients, Fugl-Meyer Assessment (FMA) scale, Functional Independence Measure (FIM), Motor Activity Log (MAL), and Box and Block Test (BBT) were used. The evaluation was performed before, and 2, 4 and 6 weeks after the intervention.
FMA is a quantitative measure for sensory-motor evaluation of patients with central nervous system damage. The total score for the upper limb is 66. The reliability of this test on patients with stroke was reported by Karimi et al. and Toluee et al. as 0.97 and 0.98, respectively [19, 20]. FIM tool includes 13 motor items and 3 cognitive items. The validity and reliability of this test in Iran were investigated by Naghdi et al. on people with stroke [21] and Rezaei et al. on people with traumatic brain injury. MAL test is for assessing the use and quality of movements of the injured arm in 30 daily living activities. This test has a very good validity and reliability [22] and has been used in various studies in Iran [23-25]. Finally, BBT measures unilateral gross manual dexterity. This test has high validity and reliability [26, 27].
Results
Table 2 shows the characteristics of patient. Figures 1, 2 and 3 demonstrates the scores of patients under performed tests at three measurement phases. According to the results in Table 3, the FMA score increased from 24 before the intervention to 56 after the intervention; BBT score increased from 5 before the intervention to 12 six weeks after the intervention; FIM score increased from 19 before the intervention to 38 six weeks after the intervention; and the subscale scores of MAL questionnaire including amount of movement (AOM) and quality of movement (QOM) increased from 0 to 1.70 and from 0 to 1.66, respectively, six weeks after the intervention.
Discussion
Upper extremity dysfunction is commonly seen in patients with ABI. The efficiency of the upper extremity in these people leads to the promotion of their participation in daily living activities and functional areas. Although several interventions have been used to improve upper extremity function, the results of this case study showed that modified CIMT with unique use of upper extremity has, quantitatively and qualitatively, increased the patient’s performance and independence more. Compared to pretest scores, the scores of FIM questionnaire as well as the BBT test increased significantly after the intervention and even continued up to four weeks after the intervention. 
These results indicate that the improvement in upper extremity function leads to an increased level of independence in self-care, ability to move, transferring, and manual dexterity. Yu et al. achieved similar results in a clinical trial on people with cerebral palsy [28]. They used BBT, FIM and a dynamometer for measuring the patient. They concluded that modified CIMT can improve hand dexterity, grip strength and activities of daily living in these patients.
Based on FMA scores reported in our study, it can be said that the motor function, the amount of hand use and the motor quality of the upper limb have increased after the intervention. The results of Takebayashi et al. also showed that the FMA and MAL scores of people with stroke increased after using modified CIMT [11]. 
Caimmi et al. [30] used kinematic and upper limb function analyses to evaluate the effect of modified CIMT. In their study, after two weeks of intervention, patients with chronic stroke significantly showed an increase in speed and coordination of upper limb movements while moving the hand to the mouth and achieving a specific goal. This is consistent with our results.
The findings of the present case study showed only a short-term improvement in upper extremity function after modified CIMT. Past studies have also reported a short-term effect of these interventions on patients with chronic and acute stroke [16]. However, Dahl et al. [31] in a study on 30 patients with chronic and subacute strokes found no significant long-term (six month) effect of modified CIMT, in spite of its short-term outcome. One of the important factors affecting long-term outcome of this treatment in people with chronic brain damage is its generalization to real life. 
The patient should use problem-solving skills and self-monitoring to transfer the interventions to daily living activities, but these patients refuse to use the affected hand due to motor and functional limitations; hence, in the long term, they will not get acceptable outcome from this intervention [29]. However, studies using transcranial magnetic stimulation have shown an increase in short-term [32] and long-term [33] activity of cerebral cortex after modified CIMT. Therefore, the long-term outcome of modified CIMT is not clear yet.
In this study, the intervention was designed and performed intensively in a short period (10 sessions for 2 weeks). The results showed an improvement in upper extremity function, especially the FMA score up to one month after the intervention, although systematic review studies have shown that the intensity of motor tasks during the intervention does not affect the therapeutic results of the modified CIMT [16]. For ethical reasons, we could not deprive the patient of receiving other services such as physiotherapy; thus, the combination of these two interventions may have led to this significant improvement [31]. 
Review and meta-analysis studies have shown that modified CIMT has the most effect on motor function in patients with acute stroke because it is possible to recover and restore nerves in this period [16, 29]. However, although four years had passed since the brain injury in the study case, there was an improvement in the qualitative and quantitative aspects of her movement and upper limb function in daily living activities. In our study, the role of learning and increased skill in using compensatory strategies to perform motor tasks may be greater than the restoration of the nervous system [34, 35]. 
More studies should be conducted to reveal the effectiveness of this intervention to increase the knowledge of recovery mechanism in people with severe chronic brain damage. Since only one patient was studied in this case study, the outcome cannot be generalized to all patients with severe chronic brain injury; it has only provided preliminary results for future studies. It is recommended that this study be performed with a larger sample size and stronger design, such as randomized controlled trial, to provide stronger evidence of the effect of modified CIMT on improving upper extremity function in patients with severe and chronic ABI.
Conclusion
There is evidence that modified CIMT can be effective in improving upper extremity function in patients with chronic and severe ABI in a short period.
Ethical Considerations
Compliance with ethical guidelines
All ethical principles were considered in this article. 
Funding
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Authors' contributions
All authors contributed in preparing this article.
Conflicts of interest
The authors declared no conflict of interest.