Neuralgic amyotrophy: variable expression in 40 patients

Abstract

This study looks at disease diversity, location of lesions, and progression of neuralgic amyotrophy (NA). Forty patients (28 male and 12 female, age range 15 to 70 years) were clinically examined. Muscle atrophy, weakness, and sensory impairment were assessed. Needle EMG and conduction velocities were performed. Careful clinical, electrophysiological, laboratory, and radiological studies excluded other illness. Twenty-two patients were followed for 2 years. Antecedent fever and upper-respiratory tract infection was seen in 22 cases. Pain of sudden onset was always the initial symptom, followed by weakness, mainly in the proximal muscles of shoulder. The affectation was bilateral in 7 cases. Seven cases had a recurrent form of the disease. Clinical and electrophysiological findings suggest axonal lesions of the peripheral nerves, occurring singly (mononeuritis) or in various combinations (mononeuropathy multiplex). Unusual features, such as VII and XI cranial nerves, phrenic nerve, and lateral antebrachial cutaneous nerve affectation, were found. Follow-up showed good function recovery at variable times, even in 1 case with associated myotonic dystrophy (MD). NA is a well-defined entity, with variable clinical expression and data consistent with mononeuropathy or mononeuropathy multiplex, axonal in type. The overall prognosis is good. The progression in a patient with MD suggests that the capability of muscle fiber membrane to accept regenerating nerve sprouts remains in dystrophic muscles.

Idiopathic Neuralgic Amyotrophy: An Illustrative Case Report

“…Those that have provided data suggest a mononeuropathy multiplex. 3,18 In this case, there was no electromyographic evidence of spontaneous paraspinal activity confirming the clinical impression that radiculopathy was unlikely. For this patient, nerve conduction studies and electromyography categorized the lesion to a likely combined mononeuropathy and plexopathy as opposed to a plexopathy alone or mononeuropathy.…”

Intravenous Immunoglobulin (IVIg) with Methylprednisolone Pulse Therapy for Motor Impairment of Neuralgic Amyotrophy: Clinical Observations in 10 Cases

“…In 2002, Cruz-Martínez et al reported 40 patients with NA (28 males and 12 females, age: 15-70 years) and described that the overall prognosis of NA is good in general, despite the severity and extent of the lesions. In follow-up studies in 22 of 40 patients (43 affected nerves), the muscles innervated by 41 of 43 (95.3%) nerves reached good function within the 2-year follow-up period (7).…”

“…Except for the classical presentation of NA, there are some phenotypic variations including involvement of nerves outside the brachial plexus (cranial nerves, phrenic nerve, or lumbosacral plexus), mononeuropathic form, bilateral symptoms, prominent sensory symptoms, or painless attack (17). For instance, Cruz-Martínez reported 7 bilateral impairment, 4 accessory nerve, 4 facial nerve, and 1 phrenic nerve involvement in the above-mentioned report (7). Moreover, the severity of an episode can vary hugely between patients, and even between different attacks in the same patient (17).…”

“…In over half of the families investigated, causal mutations of the septin-9 (SEPT9) gene on chromosome 17q25.3 have been demonstrated (4). NA has been considered to be a selflimiting, benign disorder showing good recovery without specific treatment (5)(6)(7). However, recent studies have indi- cated that the long-term prognosis of NA is less favourable than has been assumed (3,(8)(9)(10).…”

Neuroradiologic and Neurophysiologic Findings of Neuralgic Amyotrophy

“…Use of corticosteroids reduces the time until the start of paresis recovery but does not improve longterm outcome 19,22) . Most patients will generally have good recovery after 2-3 years with supportive management 3,19,20) . We managed all patients conservatively by initiating early physiotherapy, analgesics, and/or steroids, and the pain and motor weakness of all 10 patients improved significantly.…”