Neuralgic amyotrophy: an underrecognized entity

Abstract

Neuralgic amyotrophy (NA) is markedly underdiagnosed in clinical practice, and its actual incidence rate is about 1 per 1000 per year. In the current article, we provide an overview of essential information about NA, including the etiology, clinical manifestations, diagnostic investigations, differential diagnosis, treatment, and prognosis. The causes of NA are multifactorial and include immunological, mechanical, or genetic factors. Typical clinical findings are a sudden onset of pain in the shoulder region, followed by patchy flaccid paralysis of muscles in the shoulder and/or arm. A diagnosis of NA is based on a patient’s clinical history and physical examination. Gadolinium-enhanced magnetic resonance imaging and high-resolution magnetic resonance neurography are useful for confirming the diagnosis and choosing the appropriate treatment. However, before a diagnosis of NA is confirmed, other disorders with similar symptoms, such as cervical radiculopathy or rotator cuff tear, need to be ruled out. The prognosis of NA depends on the degree of axonal damage. In conclusion, many patients with motor weakness and pain are encountered in clinical practice, and some of these patients will exhibit NA. It is important that clinicians understand the key features of this disorder to avoid misdiagnosis.

Leg paralysis after AstraZeneca COVID-19 vaccination diagnosed as neuralgic amyotrophy of the lumbosacral plexus: a case report

“…The exact pathophysiology of NA remains unclear, and it may be associated with multiple etiologies, including immunological, mechanical, and genetic factors. 5 Rapid inflammation, also known as plexitis, is considered as an important cause of NA. 5 Over 50% of patients with NA have an inciting event, such as infection, vaccination, surgery, pregnancy, or stress, which triggers the immune system.…”

“… 5 Rapid inflammation, also known as plexitis, is considered as an important cause of NA. 5 Over 50% of patients with NA have an inciting event, such as infection, vaccination, surgery, pregnancy, or stress, which triggers the immune system. 7 However, post-vaccination-related NA, as in the current patient, is thought to be very rare, although its precise incidence is unknown.…”

“… 9 Before establishing a diagnosis of NA, clinicians should rule out other disorders such as radiculopathy, entrapment neuropathy, mononeuritis multiplex, multifocal motor neuropathy, and hereditary neuropathy. 5 In the present case, we also excluded infectious neuritis, including human immunodeficiency virus infection and Lyme disease.…”

“…NA is characterized by the sudden onset of pain, followed by patchy flaccid paralysis, muscle atrophy, and sensory deficits. 5,6 Most patients with NA typically present with paralysis preceded by pain; however, atypical cases may suffer painless attacks. 6,7 Most cases of NA involve the brachial plexus and, less frequently, the lumbosacral plexus, peripheral nerves, and nerve roots.…”

“… 3 , 4 NA has less frequently been attributed to immunological factors, such as vaccination. 5 Here, we describe the case of a patient diagnosed with NA after developing leg paralysis following administration of a COVID-19 vaccine. There are currently no published reports of NA involving the lumbosacral plexus occurring after COVID-19 vaccination.…”