Schwannoma in an accessory branch of the posterior cord of the brachial plexus: a rare case report

BACKGROUND

Variation in the posterior cord of the brachial plexus is complicated and creates a risky relationship with the neighbouring structures. This is of importance to the surgeons, anaesthetists who must deal with the region in surgeries and procedures. Moreover, any benign tumour like Schwannoma is rare in the plexus comprising 5 % of total head and neck schwannomas.

METHODS

We present a case of Schwannoma of the brachial plexus in a cadaver during routine anatomy dissection for the medical students. The origin and order of branching of the posterior cord were recorded and photographs were taken. The tumour was present in an accessory branch of the posterior cord and removal was made in-toto. An immunohistochemistry study was done for confirmation of diagnosis.

RESULTS

The classical branching of the posterior cord was present. Additionally, a branch existed that was supplying the triceps muscle and emerged directly from the posterior cord. Tumour having the dimension of 2 x 1.8x 0.5 cm was present.

CONCLUSIONS

Schwannomas are indolent but may cause compression of the nerve and resulting neurological symptoms. They might mimic nodules of supraclavicular fossa in breast carcinoma. Variations of the brachial plexus can also make the surgeons confused during surgery due to which anatomical knowledge of the possible variations is important. Pre- and Post-operative complications can be easily predicted from it. Follow-up of the tumour is essential to track its progress and differentiation.

Role of positioning posterior cord on coracoid approach brachial plexus block guided by nerve stimulator: Compared with guided by ultrasound

BACKGROUND

Coracoid approach is efficient and safe for brachial plexus block, and is guided by nerve stimulator or ultrasound in general. Many trials have proved that ultrasonic guidance was more efficacious than nerve stimulator guidance. We hypothesized that positioning posterior cord could enhance the anesthesia effect of coracoid approach brachial plexus block (CABPB) guided by nerve stimulator.

METHODS

Eighty patients were randomized into 2 groups to receive CABPB with positioning posterior cord guided by nerve stimulator (group A) or CABPB guided by ultrasound (group B). Success rate, procedure time, and onset time of sensory or motor block were recorded.

RESULTS

Success rate was similar in 2 groups (89.7% in group A vs 87.5% in group B, P > .05). Procedure time was longer in group A (8 minutes), as compared with group B (4 minutes; P < .05). The difference of onset time of sensory and motor block was not significant between the 2 groups. The onset time of sensory and motor block for musculocutaneous nerve was significantly shorter in group A, as compared with group B (P < .05).

CONCLUSION

The 2 technologies are equivalent regarding success rate, safety, and onset time of sensory or motor block. Positioning posterior cord in CABPB guided by nerve stimulator is efficacious for upper extremity surgery.(URL: http://www.chictr.org.cn/listbycreater.aspx ID: ChiCTR-INR-16009091 DATE: 25/8/2016).

Neuroimaging in Sensory Neuronopathy

Sensory neuronopathies (SN) are a group of disorders characterized by primary damage to the dorsal root ganglia neurons. Clinical features include multifocal areas of hypoaesthesia, pain, dysautonomia, and sensory ataxia, which is the major source of disability. Diagnosis relies upon clinical assessment and nerve conductions studies, but sometimes it is difficult to distinguish SN from similar conditions, such as axonal polyneuropathies and some myelopathies. In this scenario, underdiagnosis is certainly an important issue for SN patients and additional diagnostic tools are needed. MRI is able to evaluate the dorsal columns of the spinal cord and has proven useful in the workup of SN patients. Although T2 weighted hyperintensity restricted to the posterior fasciculi without contrast enhancement is the typical finding, additional abnormalities have been recently reported. The aim of this review is to gather available information on neuroimaging findings of SN, discuss their clinical correlates and the potential impact of novel MRI-based techniques.