Magnetic resonance imaging at the demyelinative foci in chronic inflammatory demyelinating polyneuropathy

Abstract

Using MRI, we investigated the morphology and blood-nerve barrier function of the peripheral nerve trunk in 10 patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Eight patients had a focal demyelinative segment in the median or ulnar nerve trunk that was defined by conduction block or abnormal temporal dispersion over a short distance. These demyelinative foci showed nerve enlargement with high signal intensity on proton or T2-weighted images. In four patients with progressive illness or relapse, the enlarged segment showed gadolinium enhancement that disappeared during remission induced by immune therapies. The other four were in the steady phase and showed no gadolinium enhancement of the enlarged nerves. The two patients who showed conduction slowing, but no focal demyelinative focus, had neither nerve enlargement nor gadolinium enhancement. In CIDP, focal conduction abnormalities correlate well with anatomic changes that suggest intermittent, repeated inflammation associated with the breakdown of the blood-nerve barrier.

Quantification of L5 radiculopathy due to foraminal stenosis using three-dimensional magnetic resonance myelography

“…Regardless of the cause, physical or chemical stimulation of the nerve root causes reflexive swelling of the root. Considering the both the present results and previous reports, nerve root enlargement observed on MRM images in the present study depicts secondary inflammation of the nerve root and especially the DRG due to either nerve root compression, entrapment, or both [9][10][11] . MRM-based diagnostic criteria reported for foraminal stenosis consist of the lateral course of the nerve root or spinal nerves, unclear morphology of DRG, and spinal nerve entrapment 3) .…”

“…This type of pathology appears on MRM as a secondary DRG enlargement accompanying radiculopathy. Nerve root enlargement is attributable to infiltration of inflammatory cells, interstitial edema, and onion-bulb formation due to repeated demyelination and remyelination and frequently produces conduction block [9][10][11] . If such DRG enlargement can be quantitatively assessed and a high correlation with the clinical symptoms can be established, this can lead to the reduction of failed back surgery syndrome.…”

Chronic Inflammatory Demyelinating Polyneuropathy with Multiple Hypertrophic Nerves in Intracranial, and Intra- and Extra-Spinal Segments.

“…In our case, cranial nerves V, VI, VII and VIII were thickened, with Gd-DTPAenhancement of the cranial nerves III, V, VI and VIII. The mechanism for enhancement seen with inflammatory processes is considered to be due to breakdown of the blood-nerve barrier (15,16). In 66% of patients with CIDP, a slow monophasic progressive course was observed (17), as seen in our case.…”

Spinal Nerve Root Hypertrophy on MRI: Clinical Significance in the Diagnosis of Chronic Inflammatory Demyelinating Polyradiculoneuropathy

“…We studied 14 MRI o f a c o n t r o l ( A, B ) a n d a r e p r e s e n t a t i v e c a s e ( c a s e 2 i n T a b l e 1 (9,22), and frequently produces conduction block (7,9). Total protein in CSF has been reported to show a significantly positive correlation with diameters of spinal nerve roots (10) …”