The 'Dropped shoulder'

57 yo male patient presented in their words with a ‘dropped shoulder’ on their dominant side with insidious onset and their main issue was difficulty lifting the arm overhead occurring gradually over several months. They did not report an episode of debilitating pain nor could recall any recent viral infection. Generally fit and well with a history of shoulder stabilisation on the same side many years ago and excellent recovery (able to play badminton/lift weights without issue). The patient had no red flags (night pain, recent weight loss, history of cancer, non smoker)

Examination revealed marked wasting to upper fibres of trapezius and levator scapulae with a depressed and protracted shoulder girdle. They had intact sensation and upper limb motor power along with reflexes. Neck range revealed tightness of upper trapezius and levator scapular but when shoulder position was restored it was full with no reproduction of any arm symptoms. Shoulder joint range of movement was restricted due to reduced scapula mobility, when this was restored he had full shoulder pain free range. Rotator cuff testing was intact once the scapula stabilised. There was no upper limb adverse nerve tension and thoracic outlet testing was negative.

After advising the patient of the suspected diagnosis he was referred for investigation under a shoulder specialist with scans completed of his neck, brachial plexus, axilla (armpit) and shoulder. Management was centred around information provision and prognosis, guidance on movements and support for shoulder musculature, mobility and alternative exercise movements to consider.

What is Brachial Neuritis/Parsonage Turner Syndrome

A rare neurological issue affecting the brachial plexus, the network of nerves originating in the neck and controlling the function (movement and sensation) of the arm and hand. Typically the condition involves sudden onset of shoulder pain and arm in the absence of an injury. This can last for several hours to a few weeks. It is thought to be caused by the immune system, often after a viral illness. As the pain resolves it is replaced by weakness in the affected muscles and wasting will be evident (amyotrophy) on examination, you may notice the shoulder has changed ‘shape’. Each person can be affected differently depending on the specific nerves involved and recovery can vary from person to person, most often occurring over months to years.

Pain in the initial or acute phase is continuous, severe and can be worse at night or in the evening. In some instances it can be excruciating and very debilitating. Moving out of this phase the pain often settled but some movements can be problematic/restricted or painful depending to the extend of the associated weakness. Nerves can remain more sensitised for some time and any stretch or compression can cause pain and discomfort.

Weakness then becomes the predominant issue and can range from slight to pronounced depending on the number of nerves affected. This is accompanied by muscle wasting due to lack of nerve signalling and use. Reflexes can be affected along with experiencing altered sensation (numbness/ tingling/pins and needles or hypersensitivity.

Due to the weakness people can be more prone to shoulder and neck pain, due to overload of other muscles, positional changes or stiffness due to lack of use. Some may experience issues with circulation, changes to hair and nail growth or swelling.

Some individuals recover full strength and function with most regaining 70-90% of their strength and function at the 2 year point with 10-20% being left with some residual pain, decreased exercise tolerance and strength of the affected arm. It is suggested that recurrence can range from 5-25%

Treatment from a physio perspective is aimed at ensuring this is not an alternative diagnosis (cervical radiculopathy/ rotator cuff issue, frozen shoulder, guillain-barre, thoracic outlet syndrome). This will involve referral to a specialist and consideration of imaging of the shoulder, neck and brachial plexus. The focus is then on protecting any affected joints, maintaining range of movement and strength as able, advice and guidance on the course of recovery.

More information is available at https://rarediseases.org/rare-diseases/parsonage-turner-syndrome/

https://pmc.ncbi.nlm.nih.gov/articles/PMC2926354/