Age / Sex : 75 / M

M/75

CC: Flaccid paralysis, both legs (onset: 7 days ago)

1) What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

* Send Application Answers to In Sook Lee, MD ([email protected])

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Guillain-Barre syndrome

Discussion

Findings:

Postcontrast sagittal and axial T1-WIs show enhancement of ventral roots of the cauda equina. Clinical symptoms and signs are symmetric, progressive motor weakness and hyporeflexia and no sensory change. Electrophysiologic findings show motor axonal polyradiculoneuropathy, very severe axonotmesis state. The clinical diagnosis was Guillain-Barre syndrome.

Differential diagnosis:

AIDS-related polyradiculopathy with cytomegalovirus infection, arachnoiditis, CIDP

Discussion:

Guillain-Barre syndrome (GBS) is a clinical entity that exhibits an acute, predominantly demyelinating polyneuropathy. The diagnosis is established on the basis of the characteristic clinical signs and symptoms, aided by laboratory and electrophysiologic results. The characteristic laboratory finding is an increased protein level without pleocytosis in the CSF. Electrophysiologic features include nerve-conduction slowing, conduction block, prolonged distal latencies, and prolonged or absent F waves. Typical symptoms and signs are symmetric, progressive motor weakness and hyporeflexia or areflexia; and little or no sensory change.

In GBS, there is lymphocytic and macrophagic infiltration around endoneural vessels that is associated with demyelination of the affected nerves. Macrophages penetrate the basement membrane around the nerve fibers and strip the myelin away from the axons. The abnormal enhancement of intrathecal nerve roots in GBS seen on MR images is suggestive of the breakdown of the blood-nerve barrier and is correlated with perivascular disease.

In several reports, patients with GBS demonstrated various degrees of gadolinium enhancement of the spinal nerve roots. They stated that enhanced spinal MR imaging is useful in revealing the involved nerve roots and the degree of illness in patients with GBS. According to the reports, the majority of the patients had weakness of the lower limbs but no definite sensory change, which are correlated with enhancement of the anterior nerve roots only. Some patients with sensory change show enhancement of both anterior and posterior nerve roots. Therefore, in GBS, the most common site of enhancement on MR images of the spine may be the anterior nerve roots rather than the posterior nerve roots. Follow-up MR imaging in some patients with slight improvement of symptoms showed that the thickness and the degree of enhancement of the spinal nerve roots were diminished. Therefore, serial imaging may be useful in monitoring the response to therapy and assessing new treatment regimens. It may also yield

a better understanding of the disease process.

Reference:

Byun WM, et al. Guillain-Barre syndrome: MR imaging findings of the spine in eight patients. Radiology. 1998 Jul;208(1):137-41.