Non-traumatic brachial plexopathies, clinical, radiological and neurophysiological findings from a tertiary centre

Zoster-associated limb paralysis mimicking acute stroke: a case report

Background

Varicella zoster virus is a Deoxyribonucleic acid (DNA) virus exclusively affecting humans. Reactivation of varicella zoster virus causes herpes zoster with vesicular eruptions in a restricted dermatomal distribution. Peripheral motor neuropathy is a very rare complication of varicella zoster virus.

Case presentation

A 57-year-old previously well Sri Lankan female presented with acute onset painful weakness of the left upper limb with a preceding history of a febrile illness. Subsequently she developed vesicular eruptions in the dermatomal distribution of cervical 5, 6, and 7. Electromyography was suggestive of acute denervation of cervical 5, 6, and 7 myotomes. Diagnosis of zoster-associated brachial plexopathy was made, and the patient was treated with acyclovir, steroids, and analgesics. She made a good recovery.

Conclusion

Brachial plexus neuritis due to varicella zoster infection should be considered in an acute monoparesis of a limb as it is a treatable and reversible condition

A rare presentation of neuralgic amyotrophy in a child and a review of recent literature

Neuralgic amyotrophy (NA), also known as brachial neuritis and previously known as Parsonage–Turner Syndrome, has an unknown etiology. Patients with NA have a clinical pattern characterized by sudden and acute pain across the shoulder followed by flaccid paralysis. NA has an incidence of one new case per 1000 people per year with an onset of age ranging between 20 and 60 years. We describe a rare presentation of NA in a Caucasian boy who was 11 years old and did not have any other family members affected by NA. All diagnostic studies were normal and he had full recovery 5 months from the onset of symptoms. We revised the recent literature of NA. No specific diagnostic studies can confirm the diagnosis of NA, although magnetic resonance imaging or electrophysiological studies can highlight some special features. Treatment of NA is symptomatic and it is based on analgesic drugs and physical therapy, although early administration of steroids appears to improve the outcome. Prognosis of NA is generally favorable with full recovery usually within 2 years. This disease is typically an adult syndrome, but pediatricians should also be aware of this entity to avoid delays in diagnosis.

Imaging Findings in Patients with Zoster-Associated Plexopathy

Herpes zoster is a reactivation of the latent varicella zoster virus. Among the complications of herpes zoster is zoster-associated limb paresis. The clinical and imaging features of patients with zoster-associated limb paresis due to plexopathies (zoster-associated plexopathy) have had limited description in the literature. The Mayo Clinic patient data base was searched by diagnostic code for patients diagnosed with herpes zoster between January 1, 1996, and September 30, 2012. Patients who met the inclusion criteria for zoster-associated limb paresis or herpes zoster with MRIs obtained were reviewed. Ten patients with zoster-associated plexopathy were identified. Imaging abnormalities were found in 70% of patients. Secondary denervation changes in shoulder girdle muscles and nerve T2 signal hyperintensity were the most frequent abnormalities (50%), followed by nerve enlargement (20%). Enhancement was not evident in any cases despite early imaging in 80% of the cohort. These results demonstrate the clinical utility of MR imaging in confirming the diagnosis of zoster-associated plexopathy.

Effect of Co-Morbid Conditions on Persistent Neuropathic Pain after Brachial Plexus Injury in Adult Patients

Background and Purpose

Neuropathic pain (NeuP) associated with traumatic brachial plexus injury (BPI) can be severe, persistent, and resistant to treatment. Moreover, comorbidity associated with NeuP may worsen the pain and quality of life. This study compared persistent NeuP after BPI between patients with and without co-morbid conditions (psychiatric dysfunction and other painful conditions) and tramadol usage as a second-line agent in combination with an antiepileptic and/or antidepressant during a 2-year follow-up.

Methods

The medical records of patients diagnosed with BPI referred to a pain center between 2006 and 2010 were reviewed for 2 years retrospectively. Data regarding patient demographics, injury and surgical profiles, characteristics of NeuP and its severity, and treatment received were compared between patients with and without manifesting co-morbid conditions. The NeuP and pain intensity assessments were based on the DN4 questionnaire and a numerical rating scale, respectively.

Results

Of the 45 patients studied, 24 patients presented with one of the following co-morbid conditions: myofascial pain (21%), psychiatric disorder (17%), phantom limb pain (4%), complex regional pain syndrome (21%), and insomnia (37%). Tramadol was required by 20 patients with co-morbidity and, 9 patients without co-morbidity (p<0.001). The mean pain score after 2 years was higher in patients with co-morbidity than in those without co-morbidity (p<0.05).

Conclusions

Persistent pain following BPI was more common in patients manifesting other painful conditions or psychiatric co-morbidity. A higher proportion of the patients in the co-morbid group required tramadol as a second-line of agent for pain relief.

Deformations in the Shoulder Tissues During Load Carriage: A Computational Model

Shoulder soft tissue deformations seem to be one of the limiting factors of load carriage among soldiers and recreational backpackers that are required to carry heavy loads. Yet, there are no loading limits related to the forces borne by the shoulders, and the backpacks designs are not consistent with providing pressure relief from this sensitive anatomical region. The aim of this study was to develop a model that will enable to study the biomechanical loads that develop in the shoulder under heavy loads and to help in optimizing load carriage systems design. A 3-dimensional, anatomically accurate finite element model of a human shoulder was constructed based on MRI scans. The model was developed to calculate the effective stresses on the skin below the shoulder strap (superficial loads) and the effective strain in the brachial plexus region (inner tissue deformation) for loads of up to 35 kg. The model successfully predicted deformations in the soft tissue surrounding the brachial plexus when compared with deformations measured from load-bearing MRI scans. The model yielded a skin pressure mapping, which showed pressure hotspots in the clavicle region. Inner tissue deformations mapping, as assessed by brachial plexus envelop strains, were found to peak at 30% effective strain at the lateral aspect below the pectoralis muscle. The newly developed model successfully predicted soft tissue deformations in the shoulder related to backpacks. This model can be used to optimize load carriage systems for better distribution of pressure over the shoulders and lower inner tissue deformations.

Diabetic cervical radiculoplexus neuropathy: a distinct syndrome expanding the spectrum of diabetic radiculoplexus neuropathies

Diabetic lumbosacral radiculoplexus neuropathy is a subacute painful, asymmetrical lower limb neuropathy due to ischaemic injury and microvasculitis. The occurrence of a cervical diabetic radiculoplexus neuropathy has been postulated. Our objective was to characterize the clinical features and pathological alterations of diabetic cervical radiculoplexus neuropathy, to see if they are similar to diabetic lumbosacral radiculoplexus neuropathy and due to ischaemic injury and microvasculitis. We identified patients with diabetic cervical radiculoplexus neuropathy by review of the Mayo Clinic database from 1996 to 2008. We systematically reviewed the clinical features, laboratory studies, neurophysiological findings, neuroimaging and pathological features and compared the findings with a previously published diabetic lumbosacral radiculoplexus neuropathy cohort. Eighty-five patients (56 males, 67 with Type 2 diabetes mellitus) were identified. The median age was 62 years (range 32-83). The main presenting symptom was pain (53/85). At evaluation, weakness was the most common symptom (84/85), followed by pain (69/85) and numbness (56/85). Neuropathic deficits were moderate (median motor neuropathy impairment score 10.0 points) and improved at follow-up. Upper, middle and lower brachial plexus segments were involved equally and pan-plexopathy was not unusual (25/85). Over half of patients (44/85) had at least one additional body region affected (30 contralateral cervical, 20 lumbosacral and 16 thoracic) as is found in diabetic lumbosacral radiculoplexus neuropathy. Recurrent disease occurred in 18/85. Neurophysiology showed axonal neuropathy (80/80) with paraspinal denervation (21/65), and abnormal autonomic (23/24) and sensory testing (10/13). Cerebrospinal fluid protein was elevated (median 70 mg/dl). Magnetic resonance imaging showed brachial plexus abnormality in all (38/38). Nerve biopsies (11 upper and 11 lower limbs) showed ischaemic injury (axonal degeneration, multifocal fibre loss 15/22, focal perineurial thickening 16/22, injury neuroma 5/22) and increased inflammation (epineural perivascular inflammation 22/22, haemosiderin deposition 6/22, vessel wall inflammation 14/22 and microvasculitis 5/22). We therefore conclude that (i) diabetic cervical radiculoplexus neuropathy is a predominantly monophasic, upper limb diabetic neuropathy with pain followed by weakness and involves motor, sensory and autonomic fibres; (ii) the neuropathy begins focally and often evolves into a multifocal or bilateral condition; (iii) the pathology of diabetic cervical radiculoplexus neuropathy demonstrates ischaemic injury often from microvasculitis; and (iv) diabetic cervical radiculoplexus neuropathy shares many of the clinical and pathological features of diabetic lumbosacral radiculoplexus neuropathy, providing evidence that these conditions are best categorized together within the spectrum of diabetic radiculoplexus neuropathies.

Zoster-associated mononeuropathies (ZAMs): a retrospective series

INTRODUCTION

Zoster-associated limb paresis is an uncommon complication of herpes zoster (HZ) and one whose precise pathophysiologic mechanism is poorly understood. Occasionally, the paresis results from a zoster-associated mononeuropathy (ZAM).

METHODS

Mayo Clinic records between 1996 and 2010 were reviewed for patients with ZAM whose clinical, electrophysiologic, and radiographic features were then abstracted.

RESULTS

Ulnar (2), median (3), femoral (1), and sciatic (2) mononeuropathies were identified. Most patients had moderate to severe weakness in affected muscles, and most had post-herpetic neuralgia (88% at 1 month and 71% at 4 months). The minimum duration of weakness was prolonged (mean, 281.9 days; range, 45-1242 days). Nerve magnetic resonance imaging (MRI) was abnormal, demonstrating nerve enlargement (4/4 cases), T2 signal hypertintensity (2/4 cases), or enhancement (1/4 cases).

CONCLUSIONS

While ZAM is an uncommon occurrence following cutaneous HZ, it is associated with significant weakness, high rates of post-herpetic neuralgia, and prolonged morbidity.

Neuroradiologic and neurophysiologic findings of neuralgic amyotrophy

OBJECTIVE

Neuralgic amyotrophy (NA) is a distinct clinical syndrome that is characterized by the acute onset of shoulder and arm pain, weakness, and sensory loss. The purpose of this study was to assess the clinical characteristics of NA and to determine appropriate diagnostic modalities.

METHODS

We reviewed the medical and radiologic records of 10 patients diagnosed with NA retrospectively. Neurophysiologic studies were performed in all patients and magnetic resonance neurography was performed in the last three patients.

RESULTS

A total of 10 patients were enrolled in our study. All patients had clinical findings compatible with NA. The most common clinical presentation was severe shoulder pain and weakness in seven patients (70%). Neurophysiologic study results were abnormal in all patients. Brachial plexus magnetic resonance neurography showed that the affected brachial plexus showed a thickened and hyper-intense trunk. All patients were managed conservatively with analgesics and physical therapy. The pain and paralysis of all patients improved clinically within 6 months of the initiation of treatment.

CONCLUSION

NA is a rare disease but the symptoms of NA can mimic those of other diseases. Neurophysiologic studies and magnetic resonance neurography are extremely useful tools for the diagnosis of NA.

Brachial plexopathy following herpes zoster infection: two cases with MRI findings

There are few reports of brachial plexopathy following the onset of a herpes zoster skin rash. Moreover, the MRI findings of zoster-induced brachial plexopathy have rarely been described. In the present study, we describe two cases of zoster brachial plexopathy and their MRI findings. MRI of the brachial plexus demonstrated T2 hyperintensity and contrast enhancement in the part of the brachial plexus that was compatible with both the clinical symptoms and the electrophysiological findings. Especially, MR imaging reflected the functional impairments more accurately than electrophysiological studies in the acute phase, during which MRI showed more extensive inflammatory involvement of the brachial plexus. MRI findings in the present cases suggest that, in addition to electrophysiological studies, MRI of the brachial plexus could provide valuable information for evaluating the location and extent of lesions and for understanding the pathophysiological mechanisms of zoster brachial plexopathy.

Neuralgic amyotrophy

Neuralgic amyotrophy is an uncommon condition characterised by the acute onset of severe pain in the shoulder and arm, followed by weakness and atrophy of the affected muscles, and sensory loss as the pain subsides. The diversity of its clinical manifestations means that it may present to a variety of different specialties within medicine. This article describes the epidemiology, aetiopathogenesis, clinical features, differential diagnoses, investigations, treatment, course and prognosis of the condition.