Immunotherapy for diabetic amyotrophy

Immunotherapy for diabetic amyotrophy

BACKGROUND

People with diabetes mellitus (DM) sometimes present with acute or subacute, progressive, asymmetrical pain and weakness of the proximal lower limb muscles. The various names for the condition include diabetic amyotrophy, diabetic lumbosacral radiculoplexus neuropathies, diabetic femoral neuropathy or Bruns-Garland syndrome. Some studies suggest that diabetic amyotrophy may be an immune-mediated inflammatory microvasculitis causing ischaemic damage of the nerves. Immunotherapies would therefore be expected to be beneficial. This is the second update of a review first published in 2009.

OBJECTIVES

To review the evidence from randomised trials for the efficacy of any form of immunotherapy in the treatment of diabetic amyotrophy.

SEARCH METHODS

On 5 September 2016 we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE and Embase. We also contacted authors of relevant publications and other experts to obtain additional references, unpublished trials, and ongoing trials.

SELECTION CRITERIA

We intended to include all randomised and quasi-randomised trials of any immunotherapy in participants with the condition fulfilling all the following: diabetes mellitus as defined by internationally recognised criteria; acute or subacute onset of pain and lower motor neuron weakness involving predominantly the proximal muscles of the lower limbs; weakness that is not confined to one nerve or nerve root distribution; and exclusion of other causes of lumbosacral radiculopathies and plexopathy.

DATA COLLECTION AND ANALYSIS

Two authors independently examined all references retrieved by the search to select those meeting the inclusion criteria.

MAIN RESULTS

We found only one completed placebo-controlled trial (N = 75) using intravenous methylprednisolone in diabetic amyotrophy (Dyck 2006). The results have not been fully published and were not available for analysis. The risk of bias was unclear because there was too little information to make a judgement, but we considered the trial at high risk of selective reporting. The published abstract did not report adverse events. We found no additional trials when the searches were updated in September 2016.

AUTHORS' CONCLUSIONS

There is presently no evidence from randomised trials to support a positive or negative effect of any immunotherapy in the treatment in diabetic amyotrophy.

Immunotherapy for idiopathic lumbosacral plexopathy

BACKGROUND

Idiopathic lumbosacral plexopathy (ILSP), also called lumbosacral plexitis or non-diabetic lumbosacral (radiculo)plexus neuropathy is a rare clinical entity. The core features are (sub)acute, severe, asymmetrical leg pain, followed by asymmetrical multifocal weakness and atrophy in the subsequent weeks or months. Sensory symptoms include paresthesias, hypesthesia, allodynia, and autonomic dysfunction. ILSP generally runs a monophasic and self limiting course. Recovery starts slowly over months to several years and is nearly always incomplete. Some studies suggest that the condition has an immune-mediated etiology. Biopsies of distal cutaneous nerve segments have shown features suggestive of an inflammatory microvasculitis causing ischemic damage of the nerves. The clinical and pathological findings are similar to those found in diabetic lumbosacral plexus neuropathy and suggest that inflammation may form part of the final common pathway in both conditions.

OBJECTIVES

To assess the effects of any form of immunotherapy in the treatment of ILSP.

SEARCH METHODS

On 15 October 2013, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL, MEDLINE, EMBASE, LILACS, and Index to Theses. We scanned conference abstracts, and searched trials databases for ongoing trials. We checked all references in the identified trials and contacted authors to identify any additional published or unpublished data.

SELECTION CRITERIA

We intended to include all randomized controlled trials (RCTs) or quasi-RCTs of any immunotherapy given within six weeks of disease onset, in participants with conditions fulfilling all the following: acute or subacute onset of pain and lower motor neuron weakness involving predominantly the proximal muscles of the lower limbs, weakness that is not confined to one nerve or nerve root distribution, electrophysiological tests showing predominantly axonal neuropathies, exclusion of other causes of lumbosacral radiculopathy and plexopathy as well as patients with plasma sugar in the diabetic range (fasting greater than 7.0 mmol/L, random greater than 11.1 mmol/L).

DATA COLLECTION AND ANALYSIS

Two authors independently examined all references retrieved by the search to select those meeting the inclusion criteria, according to standard Cochrane methodology.

MAIN RESULTS

We identified no RCTs of any immunotherapy for ILSP.

AUTHORS' CONCLUSIONS

There is at present no evidence from randomized trials to support any recommendation on the use of any immunotherapy treatment in ILSP.

Treatment of diabetic and nondiabetic lumbosacral radiculoplexus neuropathy

OPINION STATEMENT

Lumbosacral radiculoplexus neuropathy (LRPN) is a multifocal, asymmetric, painful neuropathic disorder affecting multiple levels of lumbosacral plexus, nerve roots, and distal nerves that emerge from the plexus. The disorder was first described in diabetic patients (DLRPN) and was later found to occur in nondiabetic patients as well. There have been debates as to the pathogenesis of DLRPN and LRPN. Recent detailed and extensive pathologic studies, however, have shown that the main pathogenesis is inflammation and microvasculitis affecting various components in the peripheral nerves, resulting in ischemic injury to the nerves. Even though studies on the natural history of this disorder have shown that the majority of patients recover within a few years after the attack without any treatment (although recovery is incomplete in many cases), it is a common practice, based on the pathophysiology and case series, to administer immunotherapy. Preliminary data from a controlled clinical trial failed to show significant improvement in outcomes measured by neurologic deficits (as judged by the Neuropathy Impairment Score) but did show improvement in symptoms (pain and positive sensory symptoms). Choices of immunotherapy include corticosteroids, intravenous immunoglobulin, plasma exchange, or a combination. Pain management, physical therapy, and treatment of depression remain mainstays for managing this disorder.