Inflammatory-Demyelinating Polyneuropathies

Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) causes progressive or relapsing weakness and numbness of the limbs, which lasts for at least two months. Uncontrolled studies have suggested that intravenous immunoglobulin (IVIg) could help to reduce symptoms. This is an update of a review first published in 2002 and last updated in 2013.

OBJECTIVES

To assess the efficacy and safety of intravenous immunoglobulin in people with chronic inflammatory demyelinating polyradiculoneuropathy.

SEARCH METHODS

We searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, and two trials registers on 8 March 2023.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) and quasi-RCTs that tested any dose of IVIg versus placebo, plasma exchange, or corticosteroids in people with definite or probable CIDP.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcome was significant improvement in disability within six weeks after the start of treatment, as determined and defined by the study authors. Our secondary outcomes were change in mean disability score within six weeks, change in muscle strength (Medical Research Council (MRC) sum score) within six weeks, change in mean disability score at 24 weeks or later, frequency of serious adverse events, and frequency of any adverse events. We used GRADE to assess the certainty of evidence for our main outcomes.

MAIN RESULTS

We included nine RCTs with 372 participants (235 male) from Europe, North America, South America, and Israel. There was low statistical heterogeneity between the trial results, and the overall risk of bias was low for all trials that contributed data to the analysis. Five trials (235 participants) compared IVIg with placebo, one trial (20 participants) compared IVIg with plasma exchange, two trials (72 participants) compared IVIg with prednisolone, and one trial (45 participants) compared IVIg with intravenous methylprednisolone (IVMP). We included one new trial in this update, though it contributed no data to any meta-analyses. IVIg compared with placebo increases the probability of significant improvement in disability within six weeks of the start of treatment (risk ratio (RR) 2.40, 95% confidence interval (CI) 1.72 to 3.36; number needed to treat for an additional beneficial outcome (NNTB) 4, 95% CI 3 to 5; 5 trials, 269 participants; high-certainty evidence). Since each trial used a different disability scale and definition of significant improvement, we were unable to evaluate the clinical relevance of the pooled effect. IVIg compared with placebo improves disability measured on the Rankin scale (0 to 6, lower is better) two to six weeks after the start of treatment (mean difference (MD) -0.26 points, 95% CI -0.48 to -0.05; 3 trials, 90 participants; high-certainty evidence). IVIg compared with placebo probably improves disability measured on the Inflammatory Neuropathy Cause and Treatment (INCAT) scale (1 to 10, lower is better) after 24 weeks (MD 0.80 points, 95% CI 0.23 to 1.37; 1 trial, 117 participants; moderate-certainty evidence). There is probably little or no difference between IVIg and placebo in the frequency of serious adverse events (RR 0.82, 95% CI 0.36 to 1.87; 3 trials, 315 participants; moderate-certainty evidence). The trial comparing IVIg with plasma exchange reported none of our main outcomes. IVIg compared with prednisolone probably has little or no effect on the probability of significant improvement in disability four weeks after the start of treatment (RR 0.91, 95% CI 0.50 to 1.68; 1 trial, 29 participants; moderate-certainty evidence), and little or no effect on change in mean disability measured on the Rankin scale (MD 0.21 points, 95% CI -0.19 to 0.61; 1 trial, 24 participants; moderate-certainty evidence). There is probably little or no difference between IVIg and prednisolone in the frequency of serious adverse events (RR 0.45, 95% CI 0.04 to 4.69; 1 cross-over trial, 32 participants; moderate-certainty evidence). IVIg compared with IVMP probably increases the likelihood of significant improvement in disability two weeks after starting treatment (RR 1.46, 95% CI 0.40 to 5.38; 1 trial, 45 participants; moderate-certainty evidence). IVIg compared with IVMP probably has little or no effect on change in disability measured on the Rankin scale two weeks after the start of treatment (MD 0.24 points, 95% CI -0.15 to 0.63; 1 trial, 45 participants; moderate-certainty evidence) or on change in mean disability measured with the Overall Neuropathy Limitation Scale (ONLS, 1 to 12, lower is better) 24 weeks after the start of treatment (MD 0.03 points, 95% CI -0.91 to 0.97; 1 trial, 45 participants; moderate-certainty evidence). The frequency of serious adverse events may be higher with IVIg compared with IVMP (RR 4.40, 95% CI 0.22 to 86.78; 1 trial, 45 participants, moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Evidence from RCTs shows that IVIg improves disability for at least two to six weeks compared with placebo, with an NNTB of 4. During this period, IVIg probably has similar efficacy to oral prednisolone and IVMP. Further placebo-controlled trials are unlikely to change these conclusions. In one large trial, the benefit of IVIg compared with placebo in terms of improved disability score persisted for 24 weeks. Further research is needed to assess the long-term benefits and harms of IVIg relative to other treatments.

Guillain-Barré syndrome and Crohn disease: a case report

Development of both Crohn disease and Guillain-Barré syndrome likely involves autoimmunity associated with excessive inflammatory cytokines. We treated a girl who developed Guillain-Barré syndrome during the course of Crohn disease. Although high-dose γ-globulin therapy administered initially for Guillain-Barré syndrome was ineffective, plasmapheresis ameliorated her acute neuropathic symptoms. Crohn disease was managed with Salazopyrin administration and enteral feeding. Chronic inflammation of the intestinal mucosa caused by Crohn disease can allow presentation of microbial intestinal antigens normally hidden from the immune system. Such presentation could incite an extraintestinal immune response on the basis of molecular mimicry, leading to activation of systemic autoimmunity against the nervous system. Accordingly, concurrence of Guillain-Barré syndrome and Crohn disease in our patient appeared to result from shared autoimmune mechanisms and systemic and local increases in cytokine concentrations. The patient also developed erythema nodosum and gall stones, relatively common complications of Crohn disease. However, Guillain-Barré syndrome is rare.

Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) causes progressive or relapsing weakness and numbness of the limbs, developing over at least two months. Uncontrolled studies suggest that intravenous immunoglobulin (IVIg) helps. This review was first published in 2002 and has since been updated, most recently in 2013.

OBJECTIVES

To review systematically the evidence from randomised controlled trials (RCTs) concerning the efficacy and safety of IVIg in CIDP.

SEARCH METHODS

On 4 December 2012, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL (2012, issue 11 in the Cochrane Library), MEDLINE and EMBASE to December 2012 and ISI from January 1985 to May 2008. We searched for ongoing trials through two metaRegistries (World Health Organization International Clinical Trials Registry Platform Search Portal and Current Controlled Trials).

SELECTION CRITERIA

We selected RCTs testing any dose of IVIg versus placebo, plasma exchange or corticosteroids in definite or probable CIDP.

DATA COLLECTION AND ANALYSIS

Two authors reviewed literature searches to identify potentially relevant RCTs, scored their quality and extracted data independently. We contacted authors for additional information.

MAIN RESULTS

We considered eight RCTs, including 332 participants, to be eligible for inclusion in the review. These trials were homogeneous and the overall risk of bias low. Five studies, in a total of 235 participants compared IVIg against placebo. One trial with 20 participants compared IVIg with plasma exchange, one trial compared IVIg with prednisolone in 32 participants, and one trial, newly included at this update, compared IVIg with intravenous methylprednisolone in 46 participants.A significantly higher proportion of participants improved in disability within one month after IVIg treatment as compared with placebo (risk ratio (RR) 2.40, 95% confidence interval (CI) 1.72 to 3.36; number needed to treat for an additional beneficial outcome 3.03 (95% CI 2.33 to 4.55), high quality evidence). Whether all these improvements are equally clinically relevant cannot be deduced from this analysis because each trial used different disability scales and definitions of significant improvement. In three trials, including 84 participants, the disability score could be transformed to the modified Rankin score, on which improvement of one point after IVIg treatment compared to placebo was barely significant (RR 2.40, 95% CI 0.98 to 5.83) (moderate quality evidence). Only one placebo-controlled study included in this review had a long-term follow-up. The results of this study suggest that IVIg improves disability more than placebo over 24 and 48 weeks.The mean disability score revealed no significant difference between IVIg and plasma exchange at six weeks (moderate quality evidence). There was no significant difference in improvement in disability on prednisolone compared with IVIg after two or six weeks, or on methylprednisolone compared to IVIg after two weeks or six months (moderate quality evidence).There were no statistically significant differences in frequencies of side effects between the three types of treatment for which data were available (IVg versus placebo or steroids). (moderate or high quality evidence) Mild and transient adverse events were found in 49% of participants treated with IVIg, while serious adverse events were found in six per cent.

AUTHORS' CONCLUSIONS

The evidence from RCTs shows that IVIg improves disability for at least two to six weeks compared with placebo, with an NNTB of three. During this period it has similar efficacy to plasma exchange, oral prednisolone and intravenous methylprednisolone. In one large trial, the benefit of IVIg persisted for 24 and possibly 48 weeks. Further research is needed to compare the long-term benefits as well as side effects of IVIg with other treatments.

Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) causes progressive or relapsing weakness and numbness of the limbs, developing over at least two months. Uncontrolled studies suggest that intravenous immunoglobulin (IVIg) helps.

OBJECTIVES

To review systematically the evidence from randomised controlled trials concerning the efficacy and safety of IVIg in CIDP.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Trials Register, MEDLINE, EMBASE and ISI from January 1985 to May 2008.

SELECTION CRITERIA

Randomised controlled studies testing any dose of IVIg versus placebo, plasma exchange or corticosteroids in definite or probable CIDP.

DATA COLLECTION AND ANALYSIS

Two authors reviewed literature searches to identify potentially relevant trials, scored their quality and extracted data independently. We contacted authors for additional information.

MAIN RESULTS

Seven randomised controlled trials were considered eligible including 287 participants. These trials were homogeneous and overall quality was high. Five studies on 235 participants compared IVIg against placebo. One trial with 20 participants compared IVIg with plasma exchange and one trial compared IVIg with prednisolone in 32 participants. A significantly higher proportion of participants improved in disability within one month after IVIg treatment as compared with placebo (relative risk 2.40, 95% confidence interval 1.72 to 3.36). Whether all these improvements are equally clinically relevant cannot be deduced from this analysis because each trial used different disability scales and definitions of significant improvement. In three trials including 84 participants the disability could be transformed to the modified Rankin score, on which significantly more patients improved one point after IVIg treatment compared to placebo (relative risk 2.40, 95% confidence interval 0.98 to 5.83). Only one study included in this review had a long-term follow-up. The results of this study suggest that intravenous immunoglobulin improves disability more than placebo over 24 and 48 weeks. The mean disability score revealed no significant difference between IVIg and plasma exchange at six weeks. There was no significant difference in improvement in disability on prednisolone compared with IVIg after two or six weeks. There were no statistically significant differences in frequencies of side effects between the three types of treatment.

AUTHORS' CONCLUSIONS

The evidence from randomised controlled trials shows that intravenous immunoglobulin improves disability for at least two to six weeks compared with placebo, with a number needed to treat of 3.00. During this period it has similar efficacy to plasma exchange and oral prednisolone. In one large trial, benefit of IVIg persisted for 24 and possibly 48 weeks.

Acute combined central and peripheral nervous system demyelination in children

Reports of acute combined central and peripheral nervous system acquired inflammatory demyelination are rare in children. This study aimed to (1) define the clinical features and prognoses of patients with this entity; and (2) compare these patients with children presenting isolated acute central or peripheral nervous system demyelination. A retrospective chart review of 523 children with central or peripheral nervous system demyelination hospitalized between 1993-2006 was undertaken. Among these, 93 fulfilled criteria (clinical features and positive magnetic resonance imaging or electromyography/nerve conduction studies) for either acute central (n = 37; 39.8%) or peripheral (n = 43; 46%) nervous system demyelination, or a combination of the two (n = 13; 14%). Significant differences between groups were evident for age (median, 10 versus 7 versus 11 years, respectively; P = 0.047), admission to pediatric intensive care unit (8% versus 30% versus 58%, respectively; P = 0.001), length of hospital stay (median, 8 versus 9 versus 29 days, respectively; P < 0.001), treatment with steroids (52% versus 7% versus 75%, respectively; P < 0.001) and immunoglobulins (11% versus 81% versus 75%, respectively; P < 0.001), and poor evolution (3% versus 12% versus 54%, respectively; P = 0.002). This entity in children is not rare, and has a poorer outcome than isolated central or peripheral nervous system demyelination. Assessment is needed for a better understanding of risk factors, etiologies, management, and prognosis.

Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy: a systematic review

This review discusses the efficacy and safety in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) of intravenous immunoglobulin and compares this treatment with plasma exchange and prednisolone. We searched publications from 1985 onwards for randomised controlled studies examining the effects of intravenous immunoglobulin in patients with this immune-mediated neuromuscular disorder. Six trials, with 170 patients in total, were judged eligible. A significantly higher proportion of patients improved in disability within a month after the start of treatment with intravenous immunoglobulin than with placebo (relative risk 3.17 [95% CI 1.74 to 5.75]). During this period, intravenous immunoglobulin has similar efficacy to plasma exchange and oral prednisolone; therefore which of these treatments should be the first choice is currently uncertain. An algorithm on treatment approaches for CIDP is proposed.

Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy

BACKGROUND

Chronic inflammatory demyelinating polyradiculoneuropathy is an immune mediated disorder characterised by progressive or relapsing symmetrical motor or sensory symptoms and signs in more than one limb, developing over at least two months. It may cause prolonged periods of disability and even death. Several uncontrolled studies have suggested a beneficial effect of intravenous immunoglobulin.

OBJECTIVES

To review systematically the evidence from randomised controlled trials concerning the efficacy and safety of intravenous immunoglobulin in chronic inflammatory demyelinating polyradiculoneuropathy.

SEARCH STRATEGY

We used the Search Strategy of the Cochrane Neuromuscular Disease Review Group to search the Disease Group register and other databases for randomised controlled trials from 1985 onwards.

SELECTION CRITERIA

Randomised controlled studies examining the effects of any dose of intravenous immunoglobulin versus placebo, plasma exchange or corticosteroids in patients with definite or probable chronic inflammatory demyelinating polyradiculoneuropathy. Outcome measures had to include one of the following: a disability score, the Medical Research Council sum score, electrophysiological data or walking distance. Studies which reported the frequency of adverse effects were used to assess the safety of treatment.

DATA COLLECTION AND ANALYSIS

Two reviewers independently reviewed literature searches to identify potentially relevant trials, scored their quality and extracted data independently. For dichotomous data, we calculated relative risks, and for continuous data, effect sizes (for definition see statistical analysis section) and weighted pooled effect sizes. Statistical uncertainty was expressed in 95% confidence intervals. Sensitivity analysis excluding studies with quality scores below A 0.50 and below B 0.75 was planned but not performed as all studies had quality scores above 0.75.

MAIN RESULTS

Six randomised controlled trials were considered eligible including 170 patients. Four studies on 113 patients compared intravenous immunoglobulin against placebo. One trial with 17 patients compared intravenous immunoglobulin with plasma exchange in a cross-over design and one trial compared intravenous immunoglobulin with prednisolone in 32 patients. A significantly higher proportion of patients improved in disability within one month after the onset of intravenous immunoglobulin treatment as compared with placebo (relative risk 3.17, 95% confidence interval 1.74 to 5.75). Whether all these improvements are equally clinically relevant cannot be deduced from this analysis because each trial used a different disability scale with a unique definition of a significant improvement. To overcome this problem an attempt was made to transform the various disability scales to the modified Rankin score. In three trials including 87 patients this transformation could be carried out. A significantly higher proportion of patients improved one point after intravenous immunoglobulin treatment compared to placebo (relative risk 2.47, 95% confidence interval 1.02 to 6.01). The effect size for change of mean disability score at six weeks comparing intravenous immunoglobulin with plasma exchange revealed no difference between the two therapies (effect size -0.07, 95% confidence interval -0.76 to 0.63.) The proportion of patients with a significant improvement did not differ significantly between prednisolone and intravenous immunoglobulin (relative risk of 0.91 (95% CI 0.50 to 1.68). Also, no difference in mean improvement on the disability scale was found at two weeks (effect size -0.12, 95% confidence interval -0.68 to 0.45) or six weeks (effect size -0.07, 95% confidence interval -0.63 to 0.50) between prednisolone and intravenous immunoglobulin. There were no statistically significant differences in frequencies of side effects between the three types of treatment.

REVIEWER'S CONCLUSIONS

The evidence from randomised controlled trials shows that intravenous immunoglobulin improves disability for at least two to six weeks compared with placebo, with a number needed to treat of three. During this period it has similar efficacy to plasma exchange and oral prednisolone. Since intravenous immunoglobulin, plasma exchange and prednisolone seem to be equally effective, it is currently uncertain which of these treatments should be the first choice. Cost, side effects, duration of treatment, dependency on regular hospital visits and ease of administration all have to be considered before such a decision can be made.

GUILLAIN-BARRE SYNDROME IN ORGAN AND BONE MARROW TRANSPLANT PATIENTS

BACKGROUND

Guillain-Barre Syndrome (GBS) is believed to be caused by autoimmune mechanisms that are predominantly T-cell mediated. We report GBS in organ transplant patients and bone marrow transplant patients, both of whom have iatrogenically suppressed T-cell function.

METHODS

We reviewed the Duke University Medical Center database from 1989-1999 for all patients who met the criteria for GBS. There were a total of 212 patients. Of these patients, two had undergone organ transplantation and two had undergone autologous bone marrow transplantation.

RESULTS

Our report supports the notion that the humoral immune system is involved in the pathogenesis of GBS. Contrary to previous reports, however, functional recovery can occur without return of T-cell function.

CONCLUSIONS

This suggests that in organ transplant patients, GBS may be humorally mediated and, even more importantly, responds well to treatment.

Impact of plasma exchange on indices of demyelination in chronic inflammatory demyelinating polyradiculoneuropathy

We studied the impact of plasma exchange (PE) on indices of primary demyelination in patients of the Canadian multicenter trial of PE in chronic inflammatory demyelinating polyneuropathy (CIDP). Individual motor nerves (median, ulnar, peroneal, tibial) were studied: distal motor latencies (DMLs), proximal and distal compound muscle action potential (M-wave) amplitudes, negative peak areas and durations, and motor conduction velocities (CVs). Proximal M-wave amplitudes in individual motor territories, particularly in the ulnar nerve (from below elbow, above elbow, and axillary stimulating sites) demonstrated significant improvement with PE, but not sham exchange. Proximal ulnar M-wave areas also had significant improvement with PE. Trends toward improvement of individual nerve motor CVs, M-wave durations, and DMLs did not achieve statistical significance. Proximal M-wave amplitudes, particularly in the ulnar motor territory, and proximal M-wave areas (providing a measure of conduction block) were the most sensitive indices of improvement conferred by PE in CIDP. In individual patients, these indices may help judge the efficacy of therapy.

Childhood chronic inflammatory demyelinating polyneuropathy

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a chronic disorder of the peripheral nervous system with sensory and motor involvement, and insidious onset over a period of months. In children and adults, both proximal and distal muscles are affected. Muscle stretch reflexes are absent or depressed. Laboratory findings include elevated cerebrospinal fluid protein with no increase of mononuclear cells. Electrophysiological and pathological studies show evidence of demyelination. No control studies of the efficacy of immunomodulating therapy in childhood CIDP are available. However, several studies have indicated clinical improvement after treatment with prednisolone, plasmapheresis and intravenous immunoglobulin, but disappointing results with other immunosuppressive agents. While some children have a monophasic course, with complete recovery, others have a protracted course, with either a slowly progressive or a relapsing-remitting course, resulting in prolonged morbidity and disability.

Guillain-Barré syndrome in immunocompromised patients: a report of three patients and review of the literature

Both humoral and cell-mediated autoimmune mechanisms have been implicated in the pathogenesis of Guillain-Barré syndrome (GBS). Therefore, its occurrence in severely immunocompromised patients is not expected. We identified 3 severely immunocompromised patients who developed GBS. Two of the 3 patients had acquired immunodeficiency syndrome with CD4 counts of 5 and 4 cells/mm3, respectively. One post-cardiac transplant patient was taking azathioprine and cyclosporine at the time of onset of GBS. In all 3 patients, immunocompromise was induced by infectious or chemotherapeutic agents which preferentially suppress T-lymphocyte responses. All 3 had severe lymphocytopenia and incomplete recovery. We conclude that GBS can occur in patients with severe t-cell suppression. Although no conclusion regarding prognosis can be drawn from our small group of patients, their incomplete recovery is consistent with the idea that T-cells are important for recovery.

Rehabilitation of Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is the most common cause of acute neuromuscular paralysis in developed countries. GBS is a significant cause of new long-term disability for at least 1,000 persons per year in the United States, and more elsewhere. Given the young age at which GBS sometimes occurs and the relatively long life expectancies following GBS, it is likely that at least 25,000 and perhaps 50,000 persons in the US are experiencing some residual effects of GBS. Approximately 40% of patients who are hospitalized with GBS will require admission to inpatient rehabilitation. For GBS persons necessitating admission to inpatient rehabilitation, the requirement of prior ventilator support most strongly predicts an extended length of stay on inpatient rehabilitation. Other issues that affect rehabilitation are dysautonomia, cranial nerve involvement, and various medical complications associated with GBS. Deafferent pain syndrome is common in the early stages of recovery. Multiple medical complications, including deep venous thrombosis, joint contractures, hypercalcemia of immobilization, and decubitii, may develop in the early stages of recovery and interfere with the rehabilitation program. Anemia is a frequent finding in the first few months of illness but does not appear to interfere with functional recovery. Therapy should not overfatigue the motor unit, which has been associated with paradoxical weakening. Little is known of the long-term implications of the disability caused by GBS. Work similar to that performed for postpolio syndrome and spinal cord injury should be started in the rehabilitation setting.

Chronic dysimmune demyelinating polyneuropathy: a clinical and electrophysiological study of 93 patients

OBJECTIVES

To identify clinical, electrophysiological, and immunological characteristics of chronic immune demyelinating polyneuropathy to define for each group the appropriate therapeutic strategies.

METHODS

The clinical and electrophysiological data and the response to treatment of 93 patients with an acquired chronic dysimmune demyelinating polyneuropathy (CDDP) studied over a period of 10 years were reviewed. Two groups were identified: group 1, comprising 64 patients with an idiopathic CDDP, of whom 13 had serum monoclonal or polyclonal gammopathy without detectable antibodies directed against the "myelin associated glycoprotein" (MAG), and group 2, comprising 29 patients with an IgM monoclonal gammopathy of undetermined significance (MGUS) with antibodies binding to the MAG.

RESULTS

Group 1 patients had either a progressive or relapsing course. The relapsing course had more pronounced distal slowing of motor conduction velocity. In group 1, there were no significant clinical or electrophysiological differences between patients with or without gammopathy. Patients with anti-MAG antibody (group 2) differed significantly from group 1 patients, especially on the basis of electrophysiological results. They had a more pronounced slowing of peroneal motor nerve conduction velocity, a lower frequency of conduction block, and a distal accentuation of conduction slowing, distinguishing them from those with idiopathic CDDP, Charcot-Marie-Tooth polyneuropathy type 1A, and control subjects.

CONCLUSION

The idiopathic CDDP group is heterogeneous with probably different subgroups. Patients with IgM MGUS polyneuropathy and anti-MAG antibodies have characteristics which distinguish them significantly from other CDDP and suggest different immune mechanisms and responses to treatment.

Acute idiopathic polyneuropathy in nine cats

This report describes nine unrelated cats with acute idiopathic polyneuropathy. All cats presented with acutely developing tetraparesis or tetraparalysis and loss of spinal reflexes. Seven cats recovered completely within 4 to 6 weeks, without any medication. Two years after complete recovery, none of these cats had had a relapse. In the acute stage, two cats were euthanized because of respiratory complications. Postmortem examination was performed on one of these cats and revealed generalized peripheral motor polyneuropathy. The clinical signs in these cats were identical to those of the Guillain-Barré syndrome in humans.

Chronic motor neuropathies: diagnosis, therapy, and pathogenesis

Pure motor neuropathy syndromes resemble amyotrophic lateral sclerosis variants with no upper motor neuron signs. Their identification is important, as, in contrast to amyotrophic lateral sclerosis, they are often immune mediated and treatable. Typically the immune-mediated motor neuropathy syndromes are distal and asymmetrical and progress slowly. The clinical features may help alert the clinician to the diagnosis, but other ancillary evidence such as abnormalities on electrophysiological testing and the presence of serum autoantibodies to neural antigens are helpful in making the diagnosis more secure. Electrophysiological abnormalities include not only motor conduction block but also other evidence of a demyelinative process such as prolonged distal latencies or F-wave abnormalities. High-titer anti-GM1 antibodies occur frequently but more specific patterns of reactivity may be especially helpful. Treatment of these motor neuropathy syndromes includes cyclophosphamide, which we use in combination with plasma exchange, and in some patients, human immune globulin. Clinical responses to therapy may occur within the first 2 to 4 months in patients with motor neuropathy syndromes with demyelinative features, but only become obvious 6 months or later after starting treatment in patients with predominantly axonal disorders.

Epidemic neuropathy in Cuba: morphological characterization of peripheral nerve lesions in sural nerve biopsies

More than 50,000 patients were affected in Cuba during an epidemic outbreak of peripheral neuropathy from January 1992 until September 1993. The disease presented as either a retrobulbar optic neuropathy, a predominantly sensory peripheral neuropathy, a dorsolateral myeloneuropathy, or as mixed forms. The morphological findings in sural nerve biopsies from 34 patients with various forms of the disease are presented here. Frozen, paraffin and semi-thin sections were prepared for light and electron microscopy, immunohistochemistry and morphometric analysis. Every case presented morphological alterations ranging from mild axonal dystrophy (9 cases, or 27%) to moderate and severe axonal damage (25 cases, or 73%). In 6 cases (18%), axonal damage was accompanied by perineural fibrosis and vascular abnormalities. Axonal regeneration was noted in 8 cases (23%) and remyelination in 9 (26%). Morphometric analysis showed a predominant loss of myelinated fibers in 92% of the patients. Quantification of myelinated fiber loss in 11 patients revealed a remarkable decrease in large caliber fibers. Scarce mononuclear cells were observed in 17 cases. No virus-like elements were seen. The morphological features found in this study indicate that, regardless of the clinical presentation, peripheral nerve lesions of the epidemic neuropathy in Cuba correspond to an axonal neuropathy. These lesions are compatible with nutritional, toxic, or metabolic etiologies. An inflammatory etiology would be unusual with these lesions.

Treatable gait disorder and polyneuropathy associated with high titer serum IgM binding to antigens that copurify with myelin-associated glycoprotein

We studied clinical and electrodiagnostic features of 9 patients with very high titers (> 1:10,000) of serum IgM binding to a CNS myelin antigen (CMA) preparation that copurified with myelin-associated glycoprotein (MAG). We found that 8 of the 9 patients had a combined syndrome of gait ataxia and polyneuropathy (GAPN) with late-age onset (mean = 70 years of age). In the 8 GAPN patients progressive difficulty with ambulation led to significant functional disability and frequent falling. Examination showed a wide-based unsteady gait, especially when standing still or turning. There was mild-to-moderate distal sensory loss with involvement of joint position sense only in the toes. Motor changes, when present, were mild and mainly involved distal leg musculature. Treatment of 5 GAPN patients resulted in clear improvement of 2 after intravenous human immunoglobulin and of 3 others after other immunodulating agents. Immune-mediated GAPN syndromes with high titers of serum IgM binding to CMA appear to be treatable causes of gait disorders in older patients.

T lymphocyte subset abnormalities in peripheral blood from patients with the Guillain-Barré syndrome

T lymphocytes are probably of pathogenic importance in many autoimmune diseases. Recently, deviations of circulating T-helper (CD4+) subpopulations have been noticed. Blood samples from 12 patients with Guillain-Barré syndrome (GBS) were studied with flow cytometry during their disease course to define circulating T cell populations. The proportion of T-helper cells (CD4+) was decreased (mean value 41 +/- 15%, P = 0.01) and the proportion of T cytotoxic/suppressor cells (CD8+) was increased (35 +/- 18%, P = 0.0006) as compared to the control group of healthy blood donors (47 +/- 8% and 26 +/- 7% respectively). The CD4+ population is divided into the helper/inducer (CD4+CD29+) and suppressor/inducer (CD4+CD45RA+) subsets, which normally are equally distributed (mean values in our control group were 45 +/- 15% and 44 +/- 15%, respectively). In patients with GBS, the helper/inducer (CD4+CD29+) subset was increased (54 +/- 10%, P = 0.05) and the suppressor/inducer (CD4+CD45RA+) subset was decreased (31 +/- 9, P = 0.005) compared to the controls. The proportion of activated HLA-DR-expressing T cells was increased (7 +/- 8%, P = 0.005) as compared to controls (3 +/- 3%). The total proportions of T cells (CD2+), B cells (CD19+) and natural killer (NK) cells (CD56+) were similar in patients and controls. The CD4+ and CD8+ populations, as well as the activated HLA-DR+ T cells, normalized during the disease course. The deviations within the CD4+ population also tended to normalize, but even at follow up after 6-33 (mean 23) months, some abnormalities remained. In conclusion, we confirm previous reports of T cell activation in peripheral blood from patients with GBS. A new finding is the deviation of T helper subpopulations with an increased helper/inducer (CD4+CD29+) subset and a decreased suppressor/inducer (CD4+CD45RA+) subset, which indicates a possible autoimmune character of GBS.

Neurologic complications of infectious mononucleosis

A review of the neurologic complications of Epstein-Barr viral (EBV) infections is presented. EBV has been associated with a wide range of acute neurologic diseases in children. Encephalitis, meningitis, cranial nerve palsies, mononeuropathies, and many other neurologic ailments have been described since the confirmation of EBV as the etiology of infectious mononucleosis. It is important to recognize that EBV can cause a myriad of neurologic illnesses with or without the stigmata of infectious mononucleosis.

Acute idiopathic axonal neuropathy (AIAN): a clinical and electrophysiological observation

Twenty patients (M:F 15:5) with electrophysiological evidence of predominant axonal lesion and fulfilling clinical criteria for Guillain Barré Syndrome were observed during a period of 6 years (1985-1990). Their mean age was 27.5 years (range 5-55). Seven patients had antecedent febrile illness. Peak motor deficit was reached at a mean period of 6.5 days (range 2-21 days). All the patients had distal muscle weakness out of proportion to proximal muscle weakness. Facial paresis (13 patients), bulbar palsy (2), respiratory failure (1), sensory deficits (7) and dysautonomia (1) were other salient features. CSF analysis revealed albumino-cytological dissociation in 12 patients. One patient died and in the remaining patients the recovery was delayed and incomplete. Presence of predominant distal muscle wasting and weakness, low amplitude CMAP or inexcitable nerves, absence of conduction block or significant temporal dispersion, normal or only slightly reduced conduction velocity and evidence of poor recovery suggest that the primary pathology in these patients may be axonal degeneration. These cases may represent a distinct entity and need to be differentiated from the more commonly observed acute idiopathic demyelinating neuropathy.