Acute and chronic neuropathies: new aspects of Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy, an overview and an update

Guillain-Barré syndrome associated with myasthenia gravis: Three cases report and a literature review

RATIONALE

Myasthenia gravis (MG) and Guillain-Barré syndrome (GBS) are 2 common neurologic autoimmune diseases. Although both the diseases can present with acute or subacute onset of muscular weakness involving the limbs and bulb, the coexistence in the same patient is unusual and rarely described in the literature.

PATIENT CONCERNS

Three cases of combined MG and GBS at the department of Neurology were described. All the 3 patients developed GBS, who had had MG for 30 years, 6 years, and 6 months, respectively.

DIAGNOSES

The newly developed GBS was clinically confirmed by the clinical features, electromyographic (EMG) studies, typical albumino-cytologic dissociation in cerebrospinal fluid (CSF), and positive anti-ganglioside antibodies in serum.

INTERVENTIONS

The 3 patients had been treated with intravenous immunoglobulin (IVIG), or plasma-exchange (PE), or IVIG combined with PE in the acute stage of severe muscle weakness. In light of the MG symptoms, they have received glucocorticoids, oral pyridostigmine, and immunosuppressive agents.

OUTCOMES

The patient 1 was able to walk longer than 5 m with assistance (Hughes 3). The patient 2 had significantly improved, and completely recovered at the 1-year follow-up (Hughes 0). But unfortunately, the patient 3 was severely disabled and chair-bound at the last interview (Hughes 4).

LESSONS

The combination of MG and GBS is quite rare. Limbs and oculo-bulbar weakness are the cardinal manifestations of both the diseases. Although their characteristics are quite different, there are still some difficulties in diagnosing them when they occur in the same patient. Early diagnosis and proper treatment will yield satisfactory prognosis. Further researches are needed to elucidate the pathogenesis of the coexistence.

Pyrexia-associated Relapse in Chronic Inflammatory Demyelinating Polyradiculoneuropathy

Chronic inflammatory demyelinating polyradiculoneuropathy is a relapsing-remitting or chronic progressive demyelinating polyradiculoneuropathy. We report the case of a patient with chronic inflammatory demyelinating polyradiculoneuropathy who experienced relapses on four occasions after experiencing pyrexia and flu-like symptoms. Our patient showed characteristic features, such as relapse after pyrexia and flu-like symptoms, remission after pyretolysis without treatment, and the absence of remarkable improvement in a nerve conduction study in the remission phase. The serum level of tumor necrosis factor-α was elevated in the relapse phase and reduced in the remission phase; thus, the induction of cytokine release by viral infection might have caused the relapses.

Chronic Inflammatory Demyelinating Polyneuropathy (CIDP): An Uncommon Manifestation of Systemic Lupus Erythematosus (SLE)

BACKGROUND Chronic inflammatory demyelinating polyneuropathy (CIDP) is an uncommon manifestation of systemic lupus erythematosus (SLE). We report a case of SLE presenting as CIDP and discuss the diagnosis, management, and prognosis of CIDP. CASE REPORT A 40-year-old woman with a past medical history of SLE treated with hydroxychloroquine presented with bilateral, progressive, ascending, sensory and motor neuropathy. Physical examination showed weakness and reduced temperature of all extremities, reduced pinprick and vibration sense of the distal extremities, loss of reflexes, and walking with a wide-based unsteady gait. Laboratory investigations showed positive antinuclear antibodies (ANA), anti-(smooth muscle (SM) antibody, anti-RNP antibody, anti-SSA antibody, anti-ds-DNA antibody, and an erythrocyte sedimentation rate (ESR) of 75 mm/hr, low C4, leukopenia, and anemia. Electromyography (EMG) confirmed the diagnosis of CIDP. The patient's neuropathy and muscle weakness improved on treatment with intravenous immunoglobulin (IVIG) and high-dose steroids. CONCLUSIONS The early clinical diagnosis of CIDP, supported by serological autoantibody profiles associated with SLE, can predict a good response to steroids. Most patients with CIDP are treated successfully with steroids if the diagnosis is made early. IVIG, plasmapheresis, or immunosuppressive therapy should be considered if there is no response to steroids.

Electrodiagnosis of peripheral neuropathy

Electrodiagnostic studies are an important component of the evaluation of patients with suspected peripheral nerve disorders. The pattern of findings and the features that are seen on the motor and sensory nerve conduction studies and needle electromyography can help to identify the type of neuropathy, define the underlying pathophysiology (axonal or demyelinating), and ultimately help to narrow the list of possible causes. This article reviews the electrodiagnostic approach to and interpretation of findings in patients with peripheral neuropathies.

Analyses of transthyretin concentration in the cerebrospinal fluid of patients with Guillain-Barré syndrome and other neurological disorders

BACKGROUND

Guillain-Barré syndrome (GBS) is an autoimmune inflammatory polyradiculoneuropathy that causes acute areflexic paralysis with a high risk of respiratory failure. Previously, using two-dimensional gel electrophoresis and mass spectrometry, we found that the transthyretin level was altered in the cerebrospinal fluid (CSF) of GBS patients when compared to that in CSF of control patients.

METHODS

We used enzyme-linked immunosorbent assay (ELISA) to measure the transthyretin levels in the CSF and serum from 22 GBS, 4 Miller-Fisher syndrome (MFS), 9 chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), 22 multiple sclerosis (MS), 10 Alzheimer's disease (AD), and 6 viral meningitis (VM) patients, and 18 controls.

RESULTS

The results show that CSF transthyretin concentration of the GBS patients is significantly higher than that of the control, MS, AD and VM patients (p<0.05), although not significantly different from that of MFS and CIDP patients.

CONCLUSION

The increased CSF transthyretin level may be explained by barrier dysfunction or decreased CSF flow in the GBS patients along with increased intrathecal synthesis of transthyretin that might be a protective response to nerve damage.

An experimental model of peripheral neuropathy induced in rats by Karwinskia humboldtiana (buckthorn) fruit

Intoxication by Karwinskia humboldtiana (buckthorn) fruit presents a neurological picture similar to that of Guillain-Barré syndrome. In this report, we describe an experimental animal model of peripheral neuropathy induced by buckthorn fruit. Four groups of Wistar rats received one oral dose of 1.5 g/kg followed by oral doses of 0.5 g/kg at days 3, 7, 10, and 14 of dried and ground buckthorn fruit in aqueous suspension. Rats were sacrificed at 24, 48, 58, and 112 days after initial dose. Treated animals developed progressive paralysis through 58 days, then completely recovered by 112 days. Sciatic nerves showed segmental demyelination and cellular infiltrates until 58 days after exposure and then remyelinating changes at 112 days. This experimental model for peripheral neuropathy is reproducible and easy to handle. Its manipulation is relatively innocuous and allows us to study reversible peripheral nerve damage. This model can be developed in other animal species and may be useful to test new therapies for peripheral neuropathy.

Chronic inflammatory demyelinating polyneuropathy in patients with systemic lupus erythematosus: prognosis and outcome

OBJECTIVES

To identify clinical characteristics, laboratory features, approaches to management, and predictors of outcome of chronic inflammatory demyelinating polyneuropathy (CIDP) in patients with systemic lupus erythematosus (SLE).

METHODS

An analysis of 6 adults with the concurrent diagnosis of CIDP and SLE seen at a SLE Clinic from 1994 to 2004 with a review of 13 patients with SLE and CIDP reported in the medical literature from 1950 through 2004.

RESULTS

Among our 6 patients with SLE and CIDP, 3 (50%) achieved a substantial clinical response to intravenous immunoglobulin (IVIg) and the remainder had a minimal response. The improved patients were more likely to have received treatment earlier (within 1 year of CIDP onset) and to respond faster (<1 to 3 months) than minimally improved patients. They tended to have CIDP features of weakness of all extremities, hyporeflexia of the upper extremities, and slowed nerve conduction velocity of the motor median nerve. Compared with minimal responders, responders had more serious internal organ manifestations and multiple autoantibodies associated with SLE. Review of the literature identified 13 previously reported CIDP patients with SLE. Many had neurological involvement of all extremities, nerve biopsies showing demyelination, and serious SLE internal organ manifestations. Most were treated with steroids, but the 1 treated with IVIg had similar characteristics to our subset of patients who improved with IVIg.

CONCLUSIONS

CIDP is an uncommon, but not rare, manifestation of SLE. Certain characteristics including early CIDP diagnosis, involvement of all 4 extremities, hyporeflexia of the upper extremities, and slowed motor nerve conduction velocity of the median nerve in addition to SLE involvement of critical internal organs and the presence of multiple antibodies associated with SLE all appear to predict a good response to IVIg.

Recurrent polyradiculoneuropathy and PMP22 defects

BACKGROUND

Although immunologic factors play an important role in the pathogenesis of the inflammatory neuropathies, the mechanisms of recurrent episodes of Guillain-Barré syndrome (GBS) and chronic relapsing polyneuropathies (CRP) are not known. Hereditary neuropathy with liability to pressure palsy (HNPP) is an inherited disease caused by a deletion or point mutation in the peripheral myelin protein 22 (PMP22) gene, which may manifest as a recurrent polyradiculoneuropathy. This study tried to elucidate the relationship between PMP22 and recurrent GBS and CRP.

METHODS

Between 1993 and 2003, we saw 114 patients with polyradiculoneuropathies or their variants. Only 4 patients had recurrent episodes: 2 had recurrent GBS and 2 had CRP. We analyzed the PMP22 gene to determine its genetic role in these 4 patients. Genomic DNA was extracted from peripheral lymphocytes of all 4 patients using a previously described procedure, and molecular detection of PMP22 deletion was performed.

RESULTS

The results showed no duplication, deletion or point mutation in the PMP22 gene.

CONCLUSION

PMP22 gene deletion did not play a role in our patients with recurrent GBS and CRP.

F-waves: neurophysiology and clinical value

This review deals with F responses, which are late responses obtained by supramaximal stimulation of virtually all the motor and mixed peripheral nerves. They are recorded over a muscle innervated by the stimulated nerve. The first description of F-waves was published in the fifties. Their neurophysiological mechanisms have been abundantly discussed in the literature leading to a current consensus, whereby F-waves are considered as antidromic responses produced by a pool of motoneurons activated by peripheral nerve stimulation. In the first part of this review, the neurophysiological mechanisms of F-waves as well as the distinction between these and H reflexes are described from a historical point of view. Other late responses are intentionally not reported; nevertheless A-waves are discussed since they are frequently ill-described in a number of conditions. Stimulation and recording procedures as well as F-wave parameters analysis are detailed, with emphasis on measures most useful for clinical purposes. A rigorous F-wave recording method is mandatory for reliable and meaningful analyses. Physiological factors, which influence F-waves such as ageing, drugs and sleep, must be known and their effects discussed. Also, as maturation is an important factor in clinical neurophysiology, data on F-wave ontogenesis are reviewed and discussed. Finally, the different F-wave alterations described so far in the literature, in either peripheral or central disorders, are listed and commented. It is emphasised that F-waves are particularly useful for the diagnosis of polyneuropathies at a very early stage and for the diagnosis of proximal nerve lesions. F-wave recording is indeed one of the rare methods in routine examination allowing at the same time the functional assessment of motor fibres on their proximal segment, and contributing to the evaluation of motoneuronal excitability.

Acquisitions récentes dans le traitement des polyneuropathies dysimmunitaires chroniques

Chronic immune-mediated polyneuropathies encompass chronic inflammatory demyelinating polyneuropathies, polyneuropathies associated with monoclonal gammopathy and multifocal motor neuropathy with persistent conduction blocks. Their diagnosis is made on clinical, electrophysiological and sometimes immunochemical and pathological criteria. The efficacy of intravenous immunoglobulins has been reported in the short-term treatment of these neuropathies in the same way than corticosteroids and plasma exchanges, depending on the type of the polyneuropathy. The efficacy of long-term treatments needs further evaluation.

Dissociation between titer of anti-ganglioside antibody and severity of symptoms in a case of Guillain-Barré syndrome with treatment-related fluctuation

Since plasma exchange (PE) and intravenous immunoglobulin (i.v.Ig) have been widely used in treatment for Guillain-Barré syndrome (GBS), early relapse and treatment-related fluctuation have been a potential problem, but little is known about the mechanism of relapse and fluctuation. We describe a patient who had GBS with treatment-related fluctuation. A 37-year-old Japanese man exhibited acute distal-dominant weakness in upper limbs after upper respiratory infection. His cranial nerve system was normal and muscle weakness was limited to upper limbs. Anti-GT1a IgG was strongly positive and anti-GQ1b IgG was also detected in his serum. Muscle weakness responded well to double-filtration plasmapheresis (DFPP) followed by i.v.Ig, but relapsed 45 days after the initial treatment. Although repeated treatments were effective, the patient showed additional minor deterioration twice. Motor nerve conduction velocities (MCVs) corresponded to the muscle weakness, but elevated level of cerebrospinal fluid (CSF) protein remained and anti-ganglioside antibody titers steadily decreased throughout the clinical course. These findings indicate that the clinical fluctuation was not due to changes in the production of anti-ganglioside antibodies but presumably to the transient beneficial effects of DFPP/i.v.Ig and the outlasting inflammatory response in peripheral nerves.

Proposed revised electrophysiological criteria for chronic inflammatory demyelinating polyradiculoneuropathy

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.

Huntingtin aggregate-associated axonal degeneration is an early pathological event in Huntington's disease mice

Huntington's disease (HD) is characterized by the selective loss of striatal projection neurons. In early stages of HD, neurodegeneration preferentially occurs in the lateral globus pallidus (LGP) and substantia nigra (SN), two regions in which the axons of striatal neurons terminate. Here we report that in mice expressing full-length mutant huntingtin and modeling early stages of HD, neuropil aggregates form preferentially in the LGP and SN. The progressive formation of these neuropil aggregates follows intranuclear accumulation of mutant huntingtin and becomes prominent from 11 to 27 months after birth. Neuropil aggregates, but no intranuclear inclusions, were observed in the LGP and SN, suggesting that huntingtin aggregates are formed in the axons of striatal projection neurons. In the LGP and SN, we observed degenerated axons in which huntingtin aggregates were associated with dark, swollen organelles that resemble degenerated mitochondria. Neuritic aggregates also form in cultured striatal neurons expressing mutant huntingtin, block protein transport in neurites, and cause neuritic degeneration before nuclear DNA fragmentation occurs. These findings suggest that the early neuropathology of HD originates from axonal dysfunction and degeneration associated with huntingtin aggregates.

Tissue plasminogen activator-mediated fibrinolysis protects against axonal degeneration and demyelination after sciatic nerve injury

Tissue plasminogen activator (tPA) is a serine protease that converts plasminogen to plasmin and can trigger the degradation of extracellular matrix proteins. In the nervous system, under noninflammatory conditions, tPA contributes to excitotoxic neuronal death, probably through degradation of laminin. To evaluate the contribution of extracellular proteolysis in inflammatory neuronal degeneration, we performed sciatic nerve injury in mice. Proteolytic activity was increased in the nerve after injury, and this activity was primarily because of Schwann cell-produced tPA. To identify whether tPA release after nerve damage played a beneficial or deleterious role, we crushed the sciatic nerve of mice deficient for tPA. Axonal demyelination was exacerbated in the absence of tPA or plasminogen, indicating that tPA has a protective role in nerve injury, and that this protective effect is due to its proteolytic action on plasminogen. Axonal damage was correlated with increased fibrin(ogen) deposition, suggesting that this protein might play a role in neuronal injury. Consistent with this idea, the increased axonal degeneration phenotype in tPA- or plasminogen-deficient mice was ameliorated by genetic or pharmacological depletion of fibrinogen, identifying fibrin as the plasmin substrate in the nervous system under inflammatory axonal damage. This study shows that fibrin deposition exacerbates axonal injury, and that induction of an extracellular proteolytic cascade is a beneficial response of the tissue to remove fibrin. tPA/plasmin-mediated fibrinolysis may be a widespread protective mechanism in neuroinflammatory pathologies.