Conservative Management of Brachial Plexus Injury Through a Structured Rehabilitation Protocol: A Case Report

Introduction

Severe brachial plexus injuries may include avulsion, traction or rupture of a cervical nerve root, which leads to loss of function and disability of upper limb.¹ Brachial plexus injuries are commonly classified as traumatic or obstetric injuries. The traumatic injuries can be further classified as closed or open depending on the mechanism. Closed injuries are typically associated with a stretching or traction force where the head and neck are forced away from the shoulder, whereas open injuries are typically seen in gunshot and stab wounds.²

Traumatic brachial plexus affects upper limb function and disability. A good upper limb function requires good stability if the involved shoulder and elbow flexion is of adequate strength and range of motion.³

Adult classification is based on lesion site i.e. supraclavicular, retro-clavicular and infra-clavicular, whereas in children, classification is based on the rootlets involved.³ Brachial plexus injuries (BPI) commonly presents with weakness in the muscles, loss of sensation and chronic neuropathic pain in the upper limb. There will be also marked wasting and atrophy of involved muscles in the upper limb.⁴ Few studies have looked at creating a specific treatment protocol for patients with traumatic BPI. The purpose of this study was to determine the effectiveness of a structured rehabilitation program for a 23 year old male referred to Physical Medicine and rehabilitation for upper limb weakness.

Case Report

A 21-year-old male gave an alleged history of road traffic accident and had a fall on to his right shoulder. He became unconscious and was immediately taken to a nearby hospital. As per the records obtained from the patient, he had multiple bleeding areas on the forehead and bruises over the right shoulder. Contrast Tomography (CT) scan was taken immediately and a week later with findings of bi-frontal, left anterior temporal extradural hematoma and bilateral basi-frontal contusion.

Then the patient was referred to Government Medical College, Kottayam. Patient was admitted in the neurosurgery unit where he regained consciousness and had history of vomiting episodes. Later subject noticed that he was unable to move his right arm. On clinical examination, the right side passive range of motion was full and active range of motion was nil. Sensation was reduced in the area over right shoulder. Management of extradural hematoma and anterior cranial fossa repair was done. Postoperative period was uneventful.

Patient was reviewed in plastic surgery department after one month. A detailed sensory evaluation was done there. Clinically it was diagnosed to be brachial plexus traction injury involving the upper trunk. As per the magnetic resonance scan (MRI) report, there was loss of normal morphology of cords of right brachial plexus with hyper intense signals on Short Tau Inversion Recovery (STIR) image which was suggestive of traction injury. There was hyper intense signal on STIR in right supraspinatus, infraspinatus muscle suggestive of oedema and post denervation changes. Later the patient was referred to Physical Medicine and rehabilitation department.

Patient was reviewed by Physiatrist in Physical Medicine department after five weeks. Detailed motor examination was done and initial muscle strength was as follows: deltoid, supra and infraspinatous grade 0, biceps grade 2 and rest all muscles had grade 5. Patient had sensory loss over right shoulder. Initially, arm sling was advised to support shoulder and elbow joints. Nerve conduction studies (NCV) were performed after 2 months. Right axillary nerve amplitude was 2.42 millivolts, whereas on the left side, it was 30.98 millivolts. The latency on the right side was 3.33 milliseconds (mS) and on the left side was 3.65 mS. The amplitude was not recordable for supraspinatus and infraspinatus muscles. All the other parameters were normal.

Patient reported to physiotherapy section for motor reeducation. Within eight months after the injury, patient regained nearly normal power of grade 5 with full active range of motion of shoulder flexion, abduction and external rotation and elbow flexion. (Table 1)

Physiotherapy assessment

Physiotherapist performed two electro-diagnostic tests for this subject: faradic galvanic test and strength duration curve. Faradic galvanic test was administered for the patient initially for the deltoid muscle. Results showed that there was no response to faradic current and sluggish response to galvanic current. A strength duration curve was plotted for deltoid, supraspinatus and biceps. Curve obtained for deltoid and supraspinatus was typical curve for denervated muscle and curve obtained for biceps was that of partial denervated nerve with kink. Chronaxie and utilisation time was plotted for deltoid, supraspinatus and biceps. Based on these test results, 30 mS duration for biceps and 100 mS for deltoid and supraspinatus were chosen for neuro muscular electrical stimulation.

Physiotherapy management

A one month in-patient rehabilitation program followed by out-patient rehabilitation program was planned till the patient showed good recovery. Short term goals were set to prevent further subluxation and strengthening of functional muscles. An arm sling was advised to support shoulder and elbow joints. In the outpatient rehabilitation program, patient was followed up by Physiatrist biweekly, reported for physiotherapy sessions weekly once and home exercises program was also advised.

Structured physiotherapy protocol was administered for him (Protocol as listed in table 2). This protocol was progressed based on the patient’s improvement in muscle grade. Strengthening of scapular stabilisers were also done initially and progressed throughout the course. As the muscles were in grade zero power, active movements were given on the non-affected side which was followed by passive movements on the affected side. Then electrical stimulation was administered (Technomed model: Electrostim-DT) and was followed by the application of facilitation techniques. The parameters chosen were of 100 mS duration for deltoid and supraspinatus and 30 mS for biceps, with 1 pulse in 2 seconds, a total of 30 contractions for biceps, supraspinatus, infraspinatus, anterior middle and posterior deltoid. Muscle facilitation techniques were given in the following order: fast brushing, quick icing, vibrations, muscle tapping. This was followed by quick stretch and voluntary command and patient tried to abduct the shoulder along with the command.

Once the muscle power attained grade 1, gravity assisted movements for shoulder were given with pendular suspension and wedge (Figure 1). Skate roller (Figure 2) with re-education board (Figure 3) was also given for biceps and supraspinatus muscles in addition to the above techniques. Once the patient initiated the movement, remaining range of motion was completed with the help of gravity. A wedge was also used for this purpose by putting inclination slope away from the body. Once the patient initiated the movement on a wedge, remaining sliding up to 90 degree was completed with the help of gravity. Tilt of the re-education board (Figure 4) was adjusted with tilting towards the patient so that elbow flexion was gravity assisted and extension was gravity resisted.

As the power reached to grade 2, gravity eliminated exercises were given without any assistance or resistance from the gravity. Pendular suspension was changed to axial suspension, Skate roller exercise were performed without tilt on a re-education board for biceps and supraspinatus. Exercises were performed on a mat without wedge for shoulder abduction in supine lying and shoulder flexion in side lying.

From grade two to three, the patient had to initiate and complete movement against slight resistance of gravity. Pendular suspension, wedge and skate roller with re-education board were used for the same purpose but positioning was in the opposite way as described previously during grade 1-2. A wedge also was used for this purpose by putting inclination slope towards the body. Tilt of the re-education board was adjusted with tilting away from the patient so that elbow flexion was gravity resisted and extension was gravity assisted.

As the subject reached grade 3 power, free exercises were incorporated for shoulder and elbow muscles. These exercises were performed in lying, standing and sitting positions. Once the muscle grade attained 3+ power, brief resisted isometric exercise regimes (BRIME) was performed followed by administration of isometric exercises at multiple angles. Later, resisted exercises were performed using weight cuffs and theraband on alternate days and progressed accordingly.

Discussion

There is scarcity of literature available on the effectiveness of physiotherapy in patients with brachial plexus injuries. Therefore, this case report is projected to describe the type of injury and level with relevance to physiotherapists, electro-diagnosis made by physiotherapists and implementing a structured physiotherapy protocol for earlier recovery in patients with traumatic brachial plexus injuries. This case report has been discussed under the following headings - type of injury and its mechanism, investigations, electrodiagnosis, electrical stimulation, facilitation techniques and muscle re-education.

Type of injury and its mechanism

Based on the history, assessment, investigations (Nerve conduction studies, Electro myography (EMG) findings & MRI), this subject had a traction injury of upper trunk with predominant involvement of C5-C6. In traction injuries (also known as stretch injury), the nerves of the brachial plexus were damaged due to the forced pull by the widening of shoulder & neck or upper arm & trunk. In a motorcycle accident where the head is side flexed and the shoulder girdle is depressed, traction occurs from severe movement and causes a pull or tension among the nerves. There are two types of traction injuries: downward traction and upward traction. In downward traction, there is tension in the arm which forces the angle of the neck and shoulder to become broader. This tension is forced and can cause lesions of the upper roots and trunk of the nerves of the brachial plexus. Upward traction results in the broadening of the angle between the arm and chest as it occurs when the arm and shoulder are forced upwards, and this is the time the nerves of T1 and C8 are torn away.^5,6

In traction injury, the injury is usually diffuse from nerve roots through terminal branches and disruption of brachial plexus can be found at more than one site compared with the report. Abrasions on the ipsilateral shoulder and cheek is suggestive of traction of brachial plexus incurred in motor cycle accidents, whereas contusion and echymosis at supra scapular or deltopectoral area indicate that the site of injury is direct due to compression (direct blow to supraclavicular fossa over erb’s point). In this case, subject had bruises over right shoulder and fracture of mandible suggestive of traction injury of downward traction type.

Investigations

Nerve conduction studies performed after three weeks showed that right nerve amplitude was less compared to left side. However, latency was near normal for both the sides. After 3-4 weeks following injury, conduction of potential stops along a nerve due to Wallerian degeneration. In post-traumatic brachial plexus injuries, the amplitude of compound muscle action potential is generally low as seen in this case. Sensory nerve action potential (SNAP) is very important in localizing a lesion as pre-ganglionic or post-ganglionic. In pre-ganglionic lesions, SNAP at that dermatome will be preserved in lesions proximal to dorsal root ganglion due to the fact that the sensory nerve cell bodies are intact with the dorsal root ganglion.

Early signs of muscle recovery may be detected on EMG such as nascent potential (in complete axonal loss) and decreased number of fibrillation potential or increased number of motor unit potential (in partial axonal loss). In this patient, EMG was not done. Clinical recovery is much earlier than signs showed in EMG studies. As per the MRI findings which was done five weeks later, there was loss of normal morphology of upper trunk of right brachial plexus with hyper intense signals on STIR image suggestive of traction injury. Hyper intense signals on STIR seen in right supraspinatus, infraspinatus muscle was suggestive of oedema and post denervation changes. MRI may be performed to assess the anatomical continuity and site of the lesion and it is normally done after 3-4 weeks after trauma to ensure that there is enough time for blood clots to be absorbed and for the formation of pseudomeningocele which is an indicative sign of root avulsion injury. In this patient, there was no evidence of pseudomeningocele. This indicates that this case was not of root avulsion. If the investigations are suggestive of neuropraxia, treatment is usually conservative. However, in this case there were no signs of recovery after two months. As signs of recovery may start appearing by three months, we planned to have a structured physiotherapy protocol for the patient with regular follow up and progression. A good recovery in terms of active range of motion and muscle strength was observed with this conservative management approach. Previous studies have showed that complete recovery is achieved by twelve to eighteen months. In the present case report, full functional recovery was achieved by six months (after 8 months of injury). This indicates that a structured rehabilitation programme has impact on full functional recovery of brachial plexus injuries.

Electrodiagnostic tests

Two electrodiagnostic tests were performed for the patient - F-G test & S-D curve. Routine electro diagnostic tests were commonly performed by physiotherapist to find out whether muscle is innervated or denervated, proportion of denervation/re-innervation and to find out the chronaxie. In F-G test, the strength of the muscle contraction to faradic current is checked first by the comparing with same muscle on the unaffected side i.e. same strength, reduced strength or no response. Later response to galvanic current is noted; brisk contraction, sluggish contraction or slightly sluggish contraction. Then the interpretation is made. In this subject, there was no response to faradic current and sluggish response to galvanic current was noted. This indicated that deltoid muscle was denervated.⁷

An initial strength duration curve was plotted for deltoid, supraspinatus and biceps for the patient. Curve obtained for deltoid and supraspinatus was typical curve for denervated muscle and curve obtained for biceps was that of partial denervated nerve with kink. Chronaxie and utilisation time was plotted for deltoid, supraspinatus and biceps. Based on these test results, 30 mS duration for biceps and 100 mS for deltoid and supraspinatus were chosen for neuro muscular electrical stimulation initially. SD curves were plotted at regular intervals and based on these results, the duration of pulse was reduced to a shorter duration.⁷

Neuromuscular electrical stimulation (NMES) Initially galvanic currents were given for long duration (30 mS duration for biceps and 100 mS for deltoid and supra/infraspinatus). Duration for neuro muscular electrical stimulation was further reduced based on the results of SD curve plotted at regular intervals. Once the patient was able to get satisfactory contraction with one millisecond, galvanic currents were withdrawn and faradic currents were administered. This was continued till the muscle grade improved to grade 2. The purpose of electrical stimulation was to maintain the properties of muscle i.e. elasticity, extensibility, irritability and contractility, thereby preventing muscle atrophy till the nerve re-innervates to the muscle.8 Another possible effect is that it facilitates the growth and assists in acceleration of nerve regeneration itself.^9,10 Some studies in the literature suggest that NMES may reduce axonal sprouting and motor unit enlargement, inhibit nerve regeneration.^11,12 Compared to voluntary contraction, in electrical stimulation there will be synchronous firing, force of contraction is not graded, type II fibres are recruited first compared to type I fibres; hence fatigue is more and large motor units are recruited compared to small motor units.⁸ Due to this reason, electrical stimulation was withdrawn once muscle attained grade 2. In order to prevent unwanted contraction of nearby innervated muscles, slow rising galvanic currents are preferred over fast rising galvanic current. Since nerve has the property of accommodation, all the innervated muscle gets adapted to fast rising current. Slow rising galvanic currents can selectively stimulate denervated muscle with less current and sensory stimulation.⁸ Large indifferent electrode was placed over the nape of the neck and pen electrode was placed at motor point in case of galvanic currents and were given little away from motor point in case of faradic currents in order to prevent its effect on axonal sprouting.

Muscle re-education

Muscle re-education is the regaining of normal or near normal functioning of an injured or denervated muscle or muscle with lack of control by appropriate therapeutic techniques. Re-education should be done at outer to middle range in the earlier stage and from middle into inner range during later stage.¹³

Facilitation

To initiate a movement response, one should try to increase the neuronal activity, which is called as facilitation. Following techniques were used to initiate movement response from grade 0-1 and continued till grade 2.

Brushing is a therapeutic preparatory facilitatory technique presented originally by Margeret Rood to increase the excitability of motor neurons which supply inhibited muscle, thereby facilitating movement responses. Application can be done manually by an artistic brush or by using battery-operated brush over the skin. A criterion for this technique is that myotome and dermatome should be same and skin overlying the muscle should share its root supply. It is applied for 3 to 5 times followed by 30 second pause and repeated. Brushing should be applied for up to three seconds at one place. There is a delay of 20 minutes to get response. This technique increases modulation of muscle spindle sensitivity presumably through complex gamma motor neuron reflexes. Brief ice or excitatory cold can be used to facilitate a muscle response, which uses a combination of coolness and pain sensation to produce the desired response. Vibration was applied followed by icing.

The high frequency vibration is driven from vibrator that optimally operates at a frequency of 100 – 200 Hz and at amplitude of 1 – 2 mA. This type of vibration produces facilitation of muscle contraction through what is known as tonic vibration reflex. This facilitatory effect is sustained for a brief time after application. Therefore, it can be used for stimulating muscles whose primary function is one of tonic holding.

Tapping is followed by vibration. Tapping is the use of a light force applied manually over a tendon or muscle belly to facilitate a voluntary contraction. It was performed on tendon and muscle belly. Rood recommended three to five taps over the muscle belly to be facilitated. A movement can be strongly volitional and gets maximum strength if the physiotherapist’s voice is strong and instructional commands are given in brief and quick stretch was added prior to the movement. The quick stretch produces a relatively short lived contraction of the agonist muscle and short lived inhibition of the antagonist muscle. It achieves its effect via stimulation of the muscle spindle primary endings which results in reflex facilitation of the muscle via the monosynaptic reflex arc.^14,15,16

Excitatory influence may be enough to cause the lower motor neurons to conduct impulses to the muscle showing weakness. All these should be applied simultaneously to offer maximum facilitation to the patient’s voluntary effort. Misuse of timing of application of various stimuli can lead to reduced in effect. Hence techniques should be given in the following sequence to get maximum effect: quick brushing, brief icing, vibrations, tapping, quick stretch and voluntary command.

Weak muscles are provided with work suitable to their capacity by the use of Assisted-Resisted, Free or Resisted Exercises, while Objective, Recreational or Occupational activities ensure their return to “functional use”. According to the principles of mechanics, rolling frictional force is lesser than sliding frictional force. Hence during muscle re-education from grade 1-2, grade 2 and 2-3, a skate roller is better than sliding the limb on a mattress. We advised to do suspension therapy and sliding the skate roller alternatively at home. Inclination during grade 1-2 and 2-3 was increased as per the improvement and later weight cuffs were tied over the wrist for further progression. During the outpatient visits, patient used to do exercise in suspension therapy (axial at grade 2 and pendular at grade 1-2 & 2-3). He also performed skate roller exercises for shoulder flexion, abduction, external rotation and elbow flexion on a reeducation board.

Progressive resisted exercise

The resistance during training can be increased by increasing the poundage of the resistance, increasing the leverage of the resistance and speed. Increase or decrease in the speed of movement is a progression for concentric work, whereas decrease in speed is a progression for eccentric work. Lengthening of the contraction period is a progression for static holding.¹³

Bilateral arm training During earlier phase and later phase of rehabilitation, cross over therapy was done simultaneously for this subject, wherein there is emphasis of contraction of the muscle of the contralateral unaffected side to facilitate relearning on the affected side. Studies have shown that it works through irradiation based on Sherrington’s concept.^10,14 During later stages of rehabilitation, subject was encouraged to perform activities that require use of both the extremities for self-care, work, and recreation. So functional movements were added which included bilateral arm lifting with medicine ball for shoulder flexion, diagonal patterns, chopping proprioceptive neuromuscular facilitation (PNF) patterns and horizontal movements. Wand exercises were also added for shoulder abduction, flexion, external rotation and elbow flexion. Bimanual tasks will incorporate both the affected and unaffected arms and provide the opportunity for input from the contralateral cortical region and to input normal movement patterns.¹⁷

Sensory re-education was later added in the programme. There were few limitations in the present study. In the later stages of outpatient rehabilitation, physiotherapy treatment was done at home and was not supervised. A functional outcome measure was not used to assess the patient’s shoulder; rather only range of motion and manual muscle testing was measured initially and during the follow up. It is known that the majority of patients with brachial plexus injury may recover spontaneously. Hence in this study, it is not known whether spontaneous recovery has influenced the outcome of the patient. Previous studies have shown that complete recovery can be achieved in twelve to eighteen months. In the present case report, full functional recovery was achieved in six months (after 8 months of injury).

This case study concludes that a structured rehabilitation protocol and patient motivation can result in successful rehabilitation of brachial plexus injuries. Physiotherapy professionals should be aware of clinical evaluation, performing FG test and SD curve at regular intervals, changing neuro-muscular electrical stimulation settings based on the interpretation of FG test and SD curve, administering rehabilitation protocol such as modifications in exercises whenever muscle strength changes into higher grade and expected outcome of these injuries. This recommendation also enhances the intercommunication between surgeons, physiatrists and physiotherapists in improving patient’s recovery earlier than expected duration.