Parsonage-Turner syndrome, affecting suprascapular nerve and especially to infraspinatus muscles after COVID-19 vaccination in a professional wrestler, a case report and literature review of causes and treatments

Background Acute peripheral neuropathy, also known as Parsonage-Turner syndrome or neuralgic amyotrophy, mostly affects the upper brachial plexus trunks, which include the shoulder girdle. It is typically accompanied by abrupt, intense pain, weakness, and sensory disruption. The etiology and causes of this disease are still unknown because of its low prevalence, however viral reactions-induced inflammation is one of its frequent causes. Case presentation Here, we introduce a professional wrestler patient who was diagnosed with PTS after vaccination and was treated, and we review some articles in this field. Conclusion When it comes to shoulder-girdle complaints and pain, Parsonage-Turner syndrome can be a differential diagnosis. Corticosteroids during the acute period, followed by physical therapy, appear to be an efficient way to manage pain, inflammation, muscular atrophy, and the process of recovering to full nerve regeneration.


Introduction
As a differential diagnosis, nerve injuries are frequently disregarded as a possible cause of unusual shoulder discomfort and can be challenging to diagnose clinically, which can leave the patient with a protracted impairment [1].Lesions of the anterior horn of the spinal cord, nerve root [2], plexus such as acute brachial plexus neuritis (BN) [3], peripheral nerve lesion such as Quadrilateral space syndrome [4,5] and suprascapular entrapment [6] can all lead to these injuries.The causes of entrapment can include arteriovenous malformation such as those found in the spinoglenoid notch that impinge on the suprascapular nerve and cause atrophy of the infraspinatus muscle., or some cyst that compress the nerves [7], thickened or ossified ligaments [8] and massive rotator cuff tears [9].
Because there is a wide range of illnesses that can cause these injuries, a correct diagnosis may be challenging.Julius Dreschfeld originally described Parsonage-Turner syndrome (PTS) [10], an uncommon upper extremity condition that is often referred to as idiopathic brachial plexopathy or neuralgic amyotrophy (NA) [11].The first set of "localized shoulder girdle neuritis" cases was reported by Spillane in 1943 [12], but in 1948, M.J. Parsonage and John W. Alden Turner introduced the condition with specifics regarding its clinical features [13].Extreme neuropathic pain episodes, fast multifocal weakening, and upper limb atrophy are the hallmarks of PTS, a unique peripheral nervous system illness [13,14].Two different kinds of neuralgic amyotrophy-idiopathic and hereditary-exist, with an immune-mediated mechanism [15,16].Autosomal-dominant recurrent neuropathy affecting the brachial plexus due to abnormalities in a septin family gene characterizes the hereditary form of the illness.The hereditary form of the illness has been identified in multiple families with mutations in the gene septin 9 on chromosome 17q23 [16].
Its prevalence is 1.64 per 100,000 subjects [17], while two to three subjects per 100,000 individuals [18] and one per 1000 people were reported in some earlier investigations [19].Taking into account possible misdiagnoses, the actual annual incidence seems to be at least 20-30 cases per 100,000 subjects [20].Men are more likely than women to experience it [21] and the second or third decade of life is when it occurs most frequently [14].It may be bilateral in 30% of cases [22].Regretfully, data indicates that, in three out of four cases, this ailment is identified within 28 weeks of the sickness beginning [19].Health care providers, particularly those who see patients directly, are therefore in a crucial position to detect this illness as soon as feasible.
A six-month-old infant was described as the youngest patient with PTS.One week following a viral illness, the infant experienced right upper extremity weakness, primarily in abduction and elevation, with the C5-C7 nerve roots showing the most involvement.Following a primary and neurologic examination, the brachial plexus showed no aberrant signals or discernible mass effect.With a diagnosis of BN, the infant was given prednisolone treatment and directed to an occupational therapist.Over the course of ten months, the youngster received an intensive therapy regimen, and her right upper extremity function significantly improved [23].
According to Parsonage and Turner, the pathological process in many PTS cases was in one or more peripheral nerves, and they proposed that the syndrome be referred to as NA until its etiology and pathophysiology are known [13,24].Put another way, PTS usually affects upper brachial plexus trunk with or without long thoracic nerve involevement [13,22,25] and middle brachial plexus trunks [26], not the entire plexus [24].While PTS sequel can impact any nerve or nerves within the brachial plexus, data indicate that the major nerve affected in these cases is the suprascapular, axillary, musculocutaneous, long thoracic, and radial nerves.[27,28].Up to 78% of subjects with PTS also have involvement of the sensory nerves in addition to motor nerve complaints, with paresthesia and hypoesthesia being the most typical symptoms [22].Persistent, severe, mostly unilateral shoulder girdle pain that originates at the top of the shoulder blade and may extend down the outside side of the upper arm or into the neck is the typical definition of PTS [13,26].Pain, may last for two hours to eight weeks, followed by sporadic paresis of the upper limb and shoulder girdle [22,26,29].
The prognosis is generally better for patients with upper trunk involvement than for those with lower trunk involvement [28].Within one month from the start of weakness, two thirds of patients exhibit the first signs of motor function recovery [47].When this syndrome first manifests, the patient's symptoms will gradually get better over the course of a few weeks to months, and three years later, they will totally disappear [25,26], nonetheless, supplemental therapies like oral or intravenous corticosteroids and physical therapy can be helpful during this time with as a multidisciplinary approach [11,17,43,44,[48][49][50][51].To put it another way, it was suggested that while most patients are treated conservatively, supportive pain management techniques such opiates and non-steroidal anti-inflammatory medications are helpful during acute periods.Early oral prednisone administration has been suggested by some researchers as a way to slow the disease's progression and promote an early recovery [14].Some advise utilizing co-analgesics (amitriptyline, carbamazepine, gabapentin) in place of steroids after severe neuropathic pain to avoid the side effects of steroids [52,53].Furthermore, by maintaining muscle strength and range of motion, physical rehabilitation therapy also assisted in managing muscle weakness [52].Patients who don't respond to conservative treatment have access to surgical alternatives [11].During the first 12 to 18 months after the onset of symptoms, tendon transfers might be a good alternative to restore motion if no meaningful recovery is made [37].However, it appears that more research is required in this area, given that the majority of studies have only reported on and looked at one case.In this study, we describe a case with similar symptoms, evaluation, treatments performed, treatment results, and a review of similar studies in this field.

Case description
A 24-year-old right-handed professional wrestler with no medical history suddenly developed severe left shoulder pain during sleep two weeks after Sinopharm [Vero Cell]inactivated COVID-19 vaccine 2 st dose.He experienced severe left shoulder pain and weakness after it for one week, which continued with less intensity after months.After two months, the infraspinatus muscle started to atrophy, and at the time of initial presentation to us, about three months from onset (Fig. 1), all active and passive ROMs were full, and the patient's pain had largely resolved, but muscle strength decreased in abduction and more in external rotation movements.He had no sensory change in his upper extremity.The subject complained of increasing weakness during the competition.His shoulder MRI was normal with no findings of tendinopathy, ganglion cyst, or rotator cuff tear.The first EMG demonstrated a left suprascapular nerve lesion with fair reinnervation in supraspinatus and no reinnervation in infraspinatus (Lt suprasoinatus: ↓ Amplitude, Polyphasic: 2 + , Partial motor unit, and Lt infraspinatus: ↑Insertional activity, Fibrillation: 6/10, Positive Sharp Wave: 6/10, Amplitude: absent, no motor unit.).
The question raised here was: if the suprascapular nerve is under pressure in the scapular notch, why is the infraspinatus muscle atrophied more than the supraspinatus?In addition, there was no evidence of nerve compression in the suprascapular notch or spinoglenoid notch in the patient's MRI.Therefore, for the second time, the subject was referred to a physical medicine and rehabilitation specialist for a more accurate EMG.The findings in the new EMG were: in left supraspinatus muscle: ↑Insertional activity, Fibrillation and Positive Sharp Wave: 2 + and partial voluntary activity; in left infraspinatus muscle: ↑Insertional activity, Fibrillation 2 + , Positive Sharp Wave: 3 + and partial voluntary activity.According to the opinion of the relevant specialist, the subject's history, and his clinical findings, all findings were compatible with the left PTS that affected the upper trunk, mostly the suprascapular nerve, especially the infraspinatus muscle.In order to ensure the desired diagnosis, the subject was referred to a peripheral neurologist for consultation, who also confirmed the desired diagnosis and the planned treatment.-NL ECG: -Revealing a sinus rhythm, Pneumological examination: -NL lung function: Muscle strength: -NL Neurological examination: -NL EMG: -NL NCS: -  So he was referred to a physiotherapist to maintain ROM and increase muscle strength through electrical stimulation and therapeutic exercises to prevent further muscle atrophy until full nerve regeneration.Exercises to strengthen the muscles include strengthening the supraspinatus and infraspinatus, first actively without weight in the direction of abduction and external rotation three times a day and each time 20 exercises for up to four weeks, then based on the patient's tolerance, using Traband with different elasticity up to three months.Then weight training started with 50% of 1RM and 5% was added to the weight every week or every two weeks according to the patient's ability and continued until the fifth month.In addition, aquatic therapy was suggested to the patient twice a week.After six months, the patient started specialized exercises related to his field under the supervision of the Specialized physiotherapist and the relevant trainer.During this time, he was under our supervision by phone because he lived in another city.According to the patient's statements, five months after the onset of symptoms, muscle strength began to return and the atrophied muscles bulk were gradually filled, and he was able to start specialized wrestling training well and participate in Asian competitions in April 2023, about 11 months after onset.Currently, the subject does his daily activities and professional sports and does not complain of pain or muscle weakness.In the two pictures below, the difference in the atrophic area is evident in about three months (Fig. 1) and almost one year (Fig. 2) after the onset of symptoms.

Literature review and discussion
NA frequently corresponds to a recent viral upper respiratory tract illness [11,20].It is thought that infection causes an abnormal rise in the quantity of antibodies directed against peripheral nerve myelin, which in turn causes inflammation [29].There is substantial evidence of post-Covid-19 respiratory complications [20].An increasing number of case reports identified neurological manifestations [54,55], central [56] and peripheral [57,58], traumatic [59] and atraumatic [39,60], as prodromal signs and Covid-19 side effects [61].According to one theory, the COVID-19 virus may directly infiltrate cells to cause neuropathogens in cases of atraumatic NA.Direct cytotoxic effects on nerves or molecular mimicry are two other potential pathways [62].There have already been reports of PTS in certain individuals who received the COVID-19 vaccination [17,42,44,48,50,63].As of right now, there's no test that can definitively confirm or rule out PTS on its own.Other differential diagnoses can be ruled out with the use of imaging modalities (MRI, ultrasound) and electrodiagnostic investigation.[52].We have presented some of related studies in the following titles.

PTS and COVID-19 infection PTS following COVID-19 vaccination
According to the Table 1, with vaccination and the corona virus, PTS became more common.As a result, while treating both acute and severe shoulder pain, it appears to be regarded as a crucial differential diagnosis.The therapist can make an accurate diagnosis in this case with the aid of a clinical examination, MRI, and EMG [52].Given the lack of positive findings for tendinopathy, other soft tissue damage, entrapment or nerve damage, and other relevant instances in our case's MRI and EMG results, PTS is the most plausible diagnosis, which may have resulted from an inflammatory response to the vaccine injection.[17].Though the small number of patients has hampered these investigations, it appears that more research is needed to understand the pathophysiology of this disease.

Conclusion
According to the research listed in the Tables 1 and 2, it appears that using corticosteroids during the acute phase, is beneficial in reducing the pain and inflammation brought on by lesions after thorough inspection and the rollout of more lesions with comparable symptoms It is also necessary for the patient to be under the supervision of a physiotherapist until complete recovery and to maintain muscles and daily function with the help of therapeutic exercise and electrical stimulation until complete nerve regeneration.What happened to our subject was pleasant, and he returned to his daily and professional life with a full recovery.

Table 1 (
continued) F female, M male, Lt Left, RT Right, UL Upper Limb, NCS Nerve Conduction Study, EMG Electromyography, NA Neuralgic amyotrophy, MRI Magnetic Resonance Imaging, CMAP Compound Muscle Action Potential, SAN Spinal Accessory Nerve, PTS Parsonage-Turner, SyndromeTmin Teres Minor, Tmaj Teres Major, CRP C-Reactive Protein, Bid Two times a day, ROM Range Of Motion, PT Physical Therapy, ECG Electrocardiogram, GHJ OA Glenohumeral Joint Osteoarthritis, IV Intravenous, SM Serratus Major, LTN Long Thoracic Nerve, CT-Scan Computerized Tomography, LHBT Long Head Biceps Tendon, NPRS Numerical Rating Scale