Inflammation (neuropathy) of the brachial plexus is known as Brachial Neuritis. 
Brachial plexus is a bunch of nerves that runs through the shoulder and helps to control the hand, shoulder & arm. It is one of the reasons that trigger the severe pain in the shoulder which may be followed by weakness. 
Sometimes doctors find it difficult to diagnose this condition. Usually, pain comes suddenly and most of the times it starts in the night leading to restlessness in the patient.
Neuralgic Amyotrophy, Brachial Plexopathy, and Parsonage-Turner Syndrome are the few other medical terms given to Brachial Neuritis.
In this section, we will discuss the causes, symptoms, types, treatment options and prognosis of brachial neuritis.
Brachial Neuritis: Overview
Nerves that originate at the root of the neck and travel through axilla towards the arm and first rib of the chest are collectively called as brachial plexus.
Brachial plexus contains the cervical nerves from C5 to the C8 and 1st thoracic nerve. The major function of these nerves is to provide sensation and control the movement of the hand, arm as well as the shoulder. [02.1]
As you might know, the basic function of any nerves is to carry electric signals from one location of the body to another. The core function of the nervous system is to carry signals from the brain to the rest of the body.
In this case, brachial plexus carry massage towards the muscles, telling them to contract & relax respectively to carry out the shoulder and arm movements.
They also carry back the sensory message to the brain like temperature & touch. Inflammation of brachial plexus damages the ability of brachial nerves to carry these signals which results in the pain and muscular weakness.
- Inherited Brachial Neuritis
- Idiopathic Brachial Neuritis
Inherited Brachial Neuritis
As the name suggests, this condition is hereditary and passed on to the kids from parents. It is caused by the mutation of the SEPT9 gene on chromosome 17q. 
This condition has autosomal dominance and shows the 50% chances of transferring the mutated gene from parents to the kids.
Idiopathic Brachial Neuritis
As discussed above, most of the times medical science fails to find out an exact cause of brachial neuritis, so it is termed as idiopathic neuritis.
Though the cause is unknown, it has been considered as an immune attack on brachial nerves triggered by various preceding events like trauma, infections, vaccination, pregnancy, exposure to radiations and treatment with interferon. 
Causes of Brachial Plexopathy
Idiopathic neuritis being the most common among the two types of brachial plexopathy, the condition is mostly triggered by various preceding conditions as listed below. 
- Infections: Viral or bacterial chest infections are usually culprits. So, the patient who had an upper respiratory viral infection or suffered from pneumonia tends to show brachial neuritis symptoms. 
- Trauma: Injuries to the neck and shoulder region may cause this event.
- Pregnancy & child-birth
- Exposure to radiations
- Underlying systemic diseases like lymphoma
Brachial neuritis symptoms have an acute onset, so it comes rapidly and often begins in the night.
Acute, aching shoulder pain is the first symptom that patient notice which is followed by progressive weakness in shoulder griddle & upper extremity. The most common symptoms are:
Brachial neuritis is characterized by an acute, aching pain in the shoulder that comes rapidly and last for days to weeks.
The patient notices the sharp, burning or stabbing pain the region of neck, shoulder, arm and in some cases, it extends up to the hand.
Both shoulders can be affected by this condition but predominantly it affects the right shoulder. As pain is caused by inflammation of nerves, it tends to be increased with the movement of the arm or shoulder.
It also aggravates in the night and remains throughout the day unless and until the strong painkiller is administered to the patient.
Arm & Shoulder Weakness
Pain may subside after a few days or weeks which is followed by weakness in arm and shoulder griddle.
Most of the time muscles show the signs of atrophy leading to winging scapula and restrict the arm & shoulder movements.
The patient may experience a severe weakness for a short period which improves over time.
As nerves are affected, the sensory function gets damaged and patient experience the reduced sensation which triggers numbness in the affected area.
Though personage-turner syndrome rarely affects diaphragm, some patient may experience the difficulty in breathing. It caused by weakness of diaphragm and only up to 5% of patients shows this symptom.
It is more prevalent in the young or middle-aged people, children can be affected by the inherited genes from parents.
Idiopathic brachial plexus inflammation is more common in the males than females and ratio go like 3:1. While inherited brachial neuritis doesn’t show any difference when it comes to affecting both genders.
It’s very common to miss the diagnosis of brachial neuritis. Often the symptoms confused with the common neck problems.
To do the provisional diagnosis, your physician will ask your medical history to see if the event is triggered by any preceding factors like infections, trauma, vaccinations, etc.
Once the history taking is completed, he will examine your neck, shoulder and arm area to see the range of movements of arms and to understand the strength of shoulder muscles. Sensation and arm reflexes will also be checked.
Once your history and examination get completed, the physician will ask you to undergo certain tests and imaging studies to rule out the other possible causes of neck pain like cervical spondylitis. In some cases, an EMG test will be advised to see electrical activities of arm muscles and signal conduction capacity of nerves.
Overall, patients past medical history, physical examination, and imaging studies will help to rule out the possible causes and lead to the final diagnosis of the patient’s condition.
The main aim of treatment is to minimize pain and put the patient to ease. Once the pain is successfully relieved, the patient can be advised to undergo the physical therapy sessions to improve the strength of muscles.
Neuritis brings severe pain which is constant in nature, so strong painkillers are prescribed to provide relief from pain Opiates are usually used to provide pain relief along with the NSAIDs and hydrocodone. Few doctors also use the corticosteroids to combat the inflammation and speed up the recovery, but its use is still controversial in the medical field as few physicians questions the efficacy of corticosteroids.
In the early stage of suffering patient will be advised to take rest, but once the pain is relieved he needs to work on improving muscle strength. To achieve this, he will be advised to join physical therapy sessions at regular intervals.
- To Improve Range of Motions – In early stages, you can use your healthy arm to support and mover the affected arm passively. Your physical therapist will assist you to achieve the passive motion of arm or you can take help of your relatives. The main goal of these passive exercises is to improve the range of motions without actively involving muscles of the arm and shoulder.
As the pain subsides and you have done a few sessions of passive exercises then you can begin with the active range of motion exercises. This includes moving the affected arms actively without any external support. To learn such kind of exercises please visit our rotator cuff exercises section which will guide you to do the step by step exercises.
- Gaining the Muscles Strength: This is an important aim of exercises. Once the paid is reduced, passive and active exercises will help you to increase the core strength of rotator cuff muscles. It will also help to improve the stability of scapula & regain shoulder strength.
Some patients recover early while some struggles to get relief even after undergoing the medication and physical therapy sessions. In such cases, physician may suggest the surgery. Surgery involves removing healthy nerve or tendon graft from another place to replace the affected nerves/tendon.
Apart from medications and physical therapy, ice packs and TENS unit can also be used to provide pain relief.
Prognosis & Recovery
Most cases recover from brachial neuritis pain in several days to weeks, while muscle weakness takes few months to resolve. Usually, longer the neuritis pain lasts, the longer the recovery period.
Approximately 80% of brachial plexopathy patients shows the complete recovery within 2 yrs. while 10% of remaining cases recover in the following year. Some patients end up experiencing constant pain and weakness which eventually leads to the reduced endurance in the shoulder muscles.
Patients with inherited brachial neuritis show more recurrence than the ones with an idiopathic parsonage-turner syndrome.
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