Background: Revision of the guidelines on the use of skin biopsy in the diagnosis of peripheral neuropathy, published in 2005, has become appropriate owing to publication of more relevant articles. Most of the new studies focused on small fiber neuropathy (SFN), a subtype of neuropathy for which the diagnosis was first developed through skin biopsy examination. This revision focuses on the use of this technique to diagnose SFN. Methods: Task force members searched the Medline database from 2005, the year of the publication of the first EFNS guideline, to June 30th, 2009. All pertinent articles were rated according to the EFNS and PNS guidance. After a consensus meeting, the task force members created a manuscript that was subsequently revised by two experts (JML and JVS) in the field of peripheral neuropathy and clinical neurophysiology, who were not previously involved in the use of skin biopsy. Results and Conclusions: Distal leg skin biopsy with quantification of the linear density of intraepidermal nerve fibers (IENF), using generally agreed upon counting rules, is a reliable and efficient technique to assess the diagnosis of SFN (Recommendation Level A). Normative reference values are available for bright-field immunohistochemistry (Recommendation Level A) but not yet for confocal immunofluorescence or the blister technique. The morphometric analysis of IENF density, either performed with bright-field or immunofluorescence microscopy, should always refer to normative values matched for age (Recommendation Level A). Newly established laboratories should undergo adequate training in a well-established skin biopsy laboratory and provide their own stratified for age and gender normative values, intra-and interobserver reliability, and interlaboratory agreement. Quality control of the procedure at all levels is mandatory (Good Practice Point). Procedures to quantify subepidermal nerve fibers and autonomic innervated structures, including erector pili muscles, and skin vessels, are under development but need to be confirmed by further studies. Sweat gland innervation can be examined using an unbiased stereologic technique recently proposed (Recommendation Level B).

We conducted a double-blind, placebo-controlled, study of 19 patients fulfilling eligibility criteria for multifocal motor neuropathy with persistent conduction block. They were enrolled and divided into two groups: those who had never been treated previously with intravenous immunoglobulins (IVIg) (Group 1: 10 patients) and those who presented recurrent symptoms after previously successful treatment with IVIg (Group 2: nine patients). They were randomized prospectively to receive either IVIg or placebo at a dose of 500 mg/kg/day for 5 consecutive days, once a month for 3 months. At month 4, patients found to be responders remained on the same treatment for the 3 following months, while non-responders were switched to the alternative study drug for the 3 following months. Clinical assessment was conducted with the MRC score in 28 muscles and a self-evaluation scale (five daily motor activities scored from 0 to 5). In Group 1, nine patients completed the study, of whom initially four received IVIg and five placebo; four patients responded to IVIg (two at months 4 and 7, and a further two at month 7 after switching treatment at month 4), two patients responded to placebo at months 4 and 7, and three patients did not respond to either treatment. In Group 2, nine patients completed the study. Five patients first received IVIg and all responded at months 4 and 7. Four patients first received placebo and none responded at month 4; all were then switched to IVIg and three responded at month 7. When the 18 patients were considered together, seven out of the nine patients who received IVIg first were responders at month 4, compared with two of the nine patients who received placebo first, a difference that was statistically significant (P = 0.03). On the other hand, there was no significant difference in MRC score but a significant difference in the self-evaluation score, at month 4, between IVIg patients and placebo patients. Electrophysiological studies did not show significant differences at month 4 in motor parameters between IVIg patients and placebo patients. IgM anti-GM1 titres did not change significantly in patients treated with IVIg compared with those who received placebo, between baseline, month 4 and month 7. However, of five patients who had significantly high anti-GM1 titres (>3200) at baseline, four responded to IVIg. This trial confirms that IVIg is a promising therapeutic option for multifocal motor neuropathy.

Type I cryoglobulinemia vasculitis (CryoVas) is considered a life-threatening condition; however, data on the characteristics and outcome are scarce. To analyze the presentation, prognosis, and efficacy and safety of treatments of type I CryoVas, we conducted a French nationwide survey that included 64 patients with type I CryoVas between January 1995 and July 2010: 28 patients with monoclonal gammopathy of unknown significance (MGUS) and 36 with hematologic malignancy.Type I monoclonal CryoVas was characterized by severe cutaneous involvement (necrosis and ulcers) in almost half the patients and high serum cryoglobulin levels, contrasting with a lower frequency of glomerulonephritis than expected. The 1-, 3-, 5-, and 10-year survival rates were 97%, 94%, 94%, and 87%, respectively. Compared to MGUS, type I CryoVas related to hematologic malignancy tended to be associated with a poorer prognosis. Therapeutic regimens based on alkylating agents, rituximab, thalidomide or lenalinomide, and bortezomib showed similar efficacy on vasculitis manifestations, with clinical response rates from 80% to 86%.Data from the CryoVas survey show that the prognosis of type I CryoVas does not seem to be as poor as previously suggested. Besides alkylating agents, the use of regimens based on rituximab, thalidomide or lenalinomide, and bortezomib are interesting alternative options, although the exact role of each strategy remains to be defined.

We retrospectively analyzed 146 patients fulfilling the European Federation of Neurological Societies and the Peripheral Nerve Society (EFNS/PNS) criteria for definite chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) to (1) evaluate the relevance of these criteria, (2) assess the frequency of CIDP variants, and (3) determine the response to treatment and the prognosis. We found that 75% of these patients fulfilled the main EFNS/PNS clinical and electrophysiological criteria (type I). The remaining patients were diagnosed using laboratory tools as supportive criteria. The common form of CIDP represented 51% of patients. We observed a high frequency of the sensory variant (35% of patients) and the rapid onset form (18%). A positive response to treatment was observed in 87% of patients, with a similar efficacy of prednisone and IVIg. However, in the long term, 40% of treated patients remained dependent on treatment. The IVIg dependency rate was higher than the prednisone or plasma exchange dependency rate (55%, 18%, and 23%, respectively; p = 0.0054). Severe handicap was observed in 24% of patients.

Objective: To determine whether rituximab 375 mg/m 2 was efficacious in patients with immunoglobulin M (IgM) anti-myelin-associated glycoprotein antibody demyelinating neuropathy (IgM anti-MAG demyelinating neuropathy).Methods: Fifty-four patients with IgM anti-MAG demyelinating neuropathy were enrolled in this randomized, double-blind, placebo-controlled trial. The inclusion criteria were inflammatory neuropathy cause and treatment (INCAT) sensory score (ISS) $4 and visual analog pain scale .4 or ataxia score $2. The primary outcome was mean change in ISS at 12 months.Results: Twenty-six patients were randomized to a group receiving 4 weekly infusions of 375 mg/m 2 rituximab, and 28 patients to placebo. Intention-to-treat analysis, with imputation of missing ISS values by the last observation carried forward method, showed a lack of mean change in ISS at 12 months, 1.0 6 2.7 in the rituximab group, and 1.0 6 2.8 in the placebo group. However, changes were observed, in per protocol analysis at 12 months, for the number of patients with an improvement of at least 2 points in the INCAT disability scale (p 5 0.027), the self-evaluation scale (p 5 0.016), and 2 subscores of the Short Form-36 questionnaire. Within the spectrum of chronic immune-mediated neuropathies, demyelinating neuropathy associated with immunoglobulin M (IgM) monoclonal gammopathy and antibodies against myelin-associated glycoprotein (MAG) is a distinct entity that typically presents with progressive sensory ataxia and painful paresthesias.1-8 Patients present with a striking immunochemical profile, suggesting the possibility of an autoimmune mechanism: monoclonal IgM recognizes a carbohydrate MAG epitope, which is shared with a number of other glycoconjugates involved in cell adhesion, including the Po glycoprotein of myelin, peripheral myelin protein-22, sulfated sphingolipid, and other related glycolipids.9,10 The disease may progress slowly over many years in some patients, whereas others develop significant disability mostly due to dysesthesias and ataxia; thus, there is a need to develop effective treatments.

Data on the clinical spectrum and therapeutic management of noninfectious mixed cryoglobulinemia vasculitis (CryoVas) in the era of hepatitis C virus screening are lacking. We analyzed data from 242 patients with noninfectious mixed CryoVas included in the French multicenter CryoVas survey. Baseline manifestations were purpura (75%), peripheral neuropathy (52%), arthralgia or arthritis (44%), glomerulonephritis (35%), cutaneous ulcers (16%), and cutaneous necrosis (14%). A connective tissue disease was diagnosed in 30% and B-cell non-Hodgkin lymphoma in 22%, whereas the CryoVas was considered to be essential in 48%. With the use of Cox-marginal structural models, rituximab plus corticosteroids showed the greater therapeutic efficacy compared with corticosteroids alone and alkylating agents plus corticosteroids to achieve complete clinical, renal, and immunologic responses and a prednisone dosage < 10 mg/d at 6 months. However, this regimen was also associated with severe infections, particularly when high doses of corticosteroids were used, whereas death rates did not differ between the therapeutic regimens. The role of each of these strategies remains to be defined in well-designed randomized controlled trials. (Blood. 2012; 119(25):5996-6004)

Neurological complications of PSS are frequent since they were present in 40% (10/25) of patients in a consecutive series of patients from a department of Internal Medicine. Although PNS involvement predominates, complications of PSS affecting the brain or spinal cord are not rare, with subcortical dysfunction as the main finding.

Electrophysiological criteria for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) were proposed by an Ad Hoc Subcommittee of the American Academy of Neurology (AAN) in 1991. Only 60% of CIDP patients fulfilled these criteria, which therefore appear poorly sensitive. We therefore sought to revise the electrophysiological criteria. We selected 40 CIDP patients and compared them with 35 patients with axonal polyneuropathy, 116 patients with Charcot-Marie-Tooth type 1A (CMT1A) disease, and 66 patients with immunoglobulin M (IgM) monoclonal gammopathy. The proposed electrophysiological criteria identified 90% of the CIDP patients, although 3% of patients with axonal polyneuropathy were falsely identified. For the CIDP patients, sensitivity and specificity were 90% and 97%, respectively. Of the patients with IgM monoclonal gammaglobulin of undetermined significance (MGUS) and CMT1A, 100% fulfilled these new criteria, whereas 90% and 97%, respectively, fulfilled the AAN criteria. These results suggest that the AAN criteria are more appropriate for IgM MGUS and CMT1A patients than for CIDP patients. We therefore propose new electrophysiological criteria for CIDP that appear to have better sensitivity.