Answer for CoW 29 Oct 2017
Neuropraxic injury of right brachial plexus.
Findings
Comminuted fracture is noted in the middle 1/3rd of right clavicle. Sharp edge of the free fragment is seen indenting the cords of right brachial plexus. Thickened trunks, divisions and cords of right brachial plexus with diffuse T2 / STIR hyperintensity is noted No evidence of nerve discontinuity. No evidence of preganglionic injury to the brachial plexus. MR features suggestive of postganglionic neuropraxic injury of right brachial plexus.
Discussion
Brachial plexus injuries can be divided into pre- and postganglionic lesions. The preganglionic lesions are avulsion of the nerve roots at their origin while postganglionic lesions may be lesions in continuity or nerve ruptures . The patient may have a combination of both pre- and postganglionic lesions. It is important to differentiate between pre and postganglionic lesions to determine the prognosis and plan further management. Postganglionic lesions in continuity without disruption of nerve fibers have good prognosis and recover spontaneously with conservative management. Postganglionic lesions with disruption of nerve fibers are treated with surgical repair, that is, nerve grafting with good results . Preganglionic lesions are usually treated with nerve transfers to restore function of the denervated muscles Pseudomeningoceles are formed due to extravasation of cerebrospinal fluid through tear of the perineural sheath. Neuropraxic injury is seen as T2 hyperintense signal in the roots, trunks, or cords with or without enlargement Nerve ruptures are seen as discontinuity in the neural structures Associated findings of denervation edema in the muscles may be seen.
Ref: Pictorial essay: Role of magnetic resonance imaging in evaluation of brachial plexus pathologies Indian J Radiol Imaging. 2012 Oct-Dec; 22(4): 344–349
Findings
Comminuted fracture is noted in the middle 1/3rd of right clavicle. Sharp edge of the free fragment is seen indenting the cords of right brachial plexus. Thickened trunks, divisions and cords of right brachial plexus with diffuse T2 / STIR hyperintensity is noted No evidence of nerve discontinuity. No evidence of preganglionic injury to the brachial plexus. MR features suggestive of postganglionic neuropraxic injury of right brachial plexus.
Discussion
Brachial plexus injuries can be divided into pre- and postganglionic lesions. The preganglionic lesions are avulsion of the nerve roots at their origin while postganglionic lesions may be lesions in continuity or nerve ruptures . The patient may have a combination of both pre- and postganglionic lesions. It is important to differentiate between pre and postganglionic lesions to determine the prognosis and plan further management. Postganglionic lesions in continuity without disruption of nerve fibers have good prognosis and recover spontaneously with conservative management. Postganglionic lesions with disruption of nerve fibers are treated with surgical repair, that is, nerve grafting with good results . Preganglionic lesions are usually treated with nerve transfers to restore function of the denervated muscles Pseudomeningoceles are formed due to extravasation of cerebrospinal fluid through tear of the perineural sheath. Neuropraxic injury is seen as T2 hyperintense signal in the roots, trunks, or cords with or without enlargement Nerve ruptures are seen as discontinuity in the neural structures Associated findings of denervation edema in the muscles may be seen.
Ref: Pictorial essay: Role of magnetic resonance imaging in evaluation of brachial plexus pathologies Indian J Radiol Imaging. 2012 Oct-Dec; 22(4): 344–349
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!