Phase II screening trial of lithium carbonate in amyotrophic lateral sclerosis: examining a more efficient trial design.

OBJECTIVE: To use a historical placebo control design to determine whether lithium carbonate slows progression of amyotrophic lateral sclerosis (ALS). METHODS: A phase II trial was conducted at 10 sites in the Western ALS Study Group using similar dosages (300-450 mg/day), target blood levels (0.3-0.8 mEq/L), outcome measures, and trial duration (13 months) as the positive trial. However, taking riluzole was not a requirement for study entry. Placebo outcomes in patients matched for baseline features from a large database of recent clinical trials, showing stable rates of decline over the past 9 years, were used as historical controls. RESULTS: The mean rate of decline of the ALS Functional Rating Scale-Revised was greater in 107 patients taking lithium carbonate (-1.20/month, 95% confidence interval [CI] -1.41 to -0.98) than that in 249 control patients (-1.01/month, 95% CI -1.11 to -0.92, p = 0.04). There were no differences in secondary outcome measures (forced vital capacity, time to failure, and quality of life), but there were more adverse events in the treated group. CONCLUSIONS: The lack of therapeutic benefit and safety concerns, taken together with similar results from 2 other recent trials, weighs against the use of lithium carbonate in patients with ALS. The absence of drift over time and the availability of a large database of patients for selecting a matched historical control group suggest that use of historical controls may result in more efficient phase II trials for screening putative ALS therapeutic agents. CLASSIFICATION OF EVIDENCE: This study provided Class IV evidence that lithium carbonate does not slow the rate of decline of function in patients with ALS over 13 months.

Congenital muscular dystrophy with rigid spine syndrome: a clinical, pathological, radiological, and genetic study.

Rigid spine syndrome is a term first proposed by Dubowitz to describe a subset of patients affected by myopathy with early spinal contractures as a prominent feature. While spinal rigidity is a nonspecific feature, found in Emery-Dreifuss muscular dystrophy and in some congenital myopathies, it is also a prominent feature in a group of patients with merosin-positive congenital muscular dystrophy, where it is generally associated with stable or only slowly progressive weakness and early respiratory insufficiency. Recently, the first locus for congenital muscular dystrophy in association with rigid spine syndrome was mapped to chromosome 1p35-p36 in consanguineous Moroccan, Turkish, and Iranian families. We present here a detailed phenotypic description of the familial syndrome linked to this locus, describing 4 siblings (3 boys and 1 girl) of Northern European-American heritage who are the offspring of a nonconsanguineous marriage. All 4 siblings were affected by hypotonia and prominent neck weakness in infancy, early spinal rigidity, and early scoliosis. After initial improvement, muscle strength stabilizes or slowly declines, and skeletal deformities and respiratory insufficiency supervene. Muscle biopsy in an affected child at age 9 months revealed minimal, nonspecific myopathic changes, leading to a diagnosis of "minimal change myopathy." Muscle biopsy in his sibling, at the age of 14 years, revealed chronic and severe myopathic (dystrophic) changes, with normal staining for laminin-2 and for proteins of the dystrophin-glycoprotein complex. A possible explanation for these biopsy findings is that magnetic resonance imaging of the thighs reveals stereotyped selective muscle involvement, with the selectivity more pronounced early in the disease course followed by widespread muscular signal abnormalities in the late stages of the disease. In this family, linkage to the chromosome 1p rigid spine syndrome locus (RSMD1) is supported by maximum LOD scores for several markers of 1.81 at theta = 0, representing the maximum statistical power possible for this family. In combination with the previous report, this syndrome is linked to the RSMD1 locus with a summated maximum LOD score of 6.29, and analysis of recombination events in our family narrows the previously reported RSMD1 locus to 3 centiMorgans.

Agreement between symptom surveys, physical examination procedures and electrodiagnostic findings for the carpal tunnel syndrome.

OBJECTIVES: The goal of this study was to evaluate the concordance between various clinical screening procedures for carpal tunnel syndrome. METHODS: The subject population consisted of 824 workers from 6 facilities. The evaluated procedures included bilateral sensory nerve conduction testing, physical examinations, and symptom surveys, including hand diagrams. The agreement between the outcomes of various combinations of these procedures was assessed by determining the kappa coefficient. RESULTS: There was relatively poor overlap between the reported symptoms, the physical examination findings, and the electrodiagnostic results consistent with carpal tunnel syndrome. Overall, only 23 out of 449 subjects (5%) with at least 1 positive finding met all 3 criteria (symptoms, physical examination findings, and electrophysiological results consistent with carpal tunnel syndrome) for the dominant hand. The screening procedures showed poor or no agreement with kappa values ranging between 0.00 and 0.18 for all the case definitions evaluated for carpal tunnel syndrome. CONCLUSIONS: The poor overlap between the various screening procedures warns against the use of electrodiagnostic findings alone without the symptom presentation being considered. The results of this study also point to a need for the further development and evaluation of methods for detecting carpal tunnel syndrome.

Calciphylaxis mimicking dermatomyositis: ischemic myopathy complicating renal failure.

BACKGROUND: Among the complications of chronic renal failure is a syndrome of medial calcification of small- to medium-sized arteries associated with ischemic necrosis of the skin and other organ systems, leading to gangrene and a poor prognosis. The syndrome has been reviewed in the renal, dermatologic, and surgical literature under the term calciphylaxis, which describes a postulated pathogenetic mechanism whereby sensitization to an endogenous or exogenous substance (such as parathyroid hormone) predisposes to calcium deposition after exposure to a challenging agent. Myopathy has rarely been reported as the presenting feature, and the syndrome has not been discussed in the neurologic literature. METHODS: We report two patients with renal failure and systemic calciphylaxis who presented to our hospital with myopathic complaints and signs suggesting dermatomyositis. We also discuss possible disease mechanisms and treatment. CONCLUSIONS: Because early treatment (including aggressively lowering the calcium and phosphate levels and parathyroidectomy) may improve the outcome, early recognition of the syndrome of calciphylaxis is essential.

Peripheral neuropathy in the nondiabetic patient.

The differential diagnosis includes an array of acquired and hereditary disorders. The history often offers the richest source of information, which can then direct the physical examination and electrodiagnostic testing. Further studies may include nerve biopsy and, most recently, blood testing for genetic disorders. Some neuropathies may respond to treatment; indeed, the response to treatment may be diagnostic.

Randomized trial of azathioprine or prednisone for initial immunosuppressive treatment of myasthenia gravis.

Ten patients with myasthenia gravis were randomized to azathioprine or prednisone as the initial immunomodulating drug and followed for over one year. Of five patients randomized to azathioprine, two had idiosyncratic reactions and were immediately crossed over to prednisone. Two patients completed one year on azathioprine with little or no change in level of function and were crossed over to prednisone and showed greater improvement. The fifth patient on azathioprine had a satisfactory improvement and continued on it during the second year. All patients initially randomized to prednisone improved, but the degree varied among patients. The side effects of azathioprine were idiosyncratic reactions. The side effects of prednisone were manageable.

The low incidence of suprascapular nerve injury after primary repair of massive rotator cuff tears.

We measured the incidence of cuff retear and injury to the suprascapular nerve after mobilization and repair of a massive rotator cuff tear. Of one hundred four rotator cuff repairs performed over a 5-year period, 10 patients (7 men and 3 women, age range 22 to 68 years) had primary repairs of massive rotator cuff tears requiring cuff mobilization and an acromioplasty as their only procedure. These patients were evaluated at a mean of 2.5 years (range 2.0 to 3.0 years) after surgery. At follow-up electromyographic examination confirmed that 1 of the 10 patients had an iatrogenic suprascapular nerve injury, whereas ultrasound evaluation revealed that 2 of 10 repairs failed. Pain relief was achieved in the eight patients with intact repairs and not in the two with recurrent tears. All patients had some limitation of active motion or strength, especially in external rotation. Thus 7 of 10 patients had neither evidence of nerve injury nor recurrent rotator cuff tears yet still showed limited active motion or weakness. It appears that operative injury to the suprascapular nerve during cuff mobilization can occur, but other factors such as inadequate cuff muscle function are more frequently responsible for the poor functional outcomes seen after successful repairs of massive rotator cuff tears.

Dysphagia in elderly men with myasthenia gravis.

Eight elderly men whose primary symptoms of myasthenia gravis were decreased speech and swallowing ability were seen for speech pathology evaluations and videofluoroscopic swallow studies. All patients had fatigable flaccid dysarthria and greater than expected pharyngeal phase dysphagia on videofluoroscopy; eight had decreased pharyngeal motility as demonstrated by residual material in the valleculae and pyriform sinuses bilaterally; seven had episodes of laryngeal penetration secondary to overflow of residual material; and five experienced silent aspiration despite gag reflexes and the ability to cough to command. Five patients required feeding tubes because their dysphagia responded poorly to treatment. Videofluoroscopic swallow studies revealed a common swallowing profile with pharyngeal phase dysphagia greater than expected from patient symptoms. Dysphagia did not improve at the same rate as other manifestations of myasthenia gravis.

Immune brachial plexus neuropathy: suggestive evidence for an inflammatory-immune pathogenesis.

We report brachial plexus biopsy findings from two Australian and two American patients with brachial plexus neuropathy. There were florid multifocal mononuclear inflammatory cell infiltrates. Present evidence suggests that these brachial neuropathies have an immune basis.

Long-term follow-up of patients with chronic inflammatory demyelinating polyradiculoneuropathy, without and with monoclonal gammopathy.

We previously demonstrated differences in presentation and initial clinical course between patients with idiopathic chronic inflammatory demyelinating polyradiculoneuropathy (CIDP-I) and those in whom CIDP was associated with a monoclonal gammopathy of undetermined significance (CIDP-MGUS). We now report the long-term follow-up of 69 patients with CIDP-I and 25 patients with CIDP-MGUS. (i) The clinical course was progressive in most of the CIDP-MGUS patients. CIDP-I patients were more likely to have a monophasic or relapsing course. (ii) Impairment developed more slowly in CIDP-MGUS than CIDP-I patients, with a longer time from onset of deterioration to peak impairment for each episode. (iii) Patients with CIDP-MGUS experienced less severe functional impairment and a lesser degree of measured weakness during their worst episode than did patients with CIDP-I. The primary source of functional impairment in many CIDP-MGUS patients was sensory. In contrast, the deficits in most patients with CIDP-I were primarily motor. (iv) CIDP-MGUS patients experienced a smaller degree of improvement to a poorer functional level after each episode than did patients with CIDP-I. (v) Most patients had a good outcome. However, the strength and functional scores at the time of last follow-up were significantly poorer in CIDP-MGUS than in CIDP-I patients. (vi) The disease was reclassified in seven patients; some patients with CIDP-I developed an MGUS, while some with CIDP-I or CIDP-MGUS developed multiple myeloma or a related malignant lymphoproliferative disease. These findings have implications for patient counselling and long-term prognosis, and underscore the need for long-term clinical and immunological monitoring.

X-linked bulbospinomuscular atrophy (Kennedy's disease) masquerading as lead neuropathy.

A 43-year-old male was referred by a veterinarian who evaluated his dog for a seizure and suspected a toxic lead exposure for both. He refurbished houses, removing old paint, and complained of decreased cognition, fatigue, and muscle cramps. He had a depressed affect, postural tremor, right arm weakness with partial denervation on EMG, and borderline-low sensory nerve action potential (SNAP) amplitudes. A mild anemia and elevated serum and urine lead levels supported a diagnosis of lead neuropathy. Chelation therapy increased urine lead excretion without symptomatic improvement. His brother worked part-time with him and developed similar findings, but also had difficulty chewing, dysphagia, perioral twitching, gynecomastia, and multifocal denervation of extremity and facial muscles. His lead levels were not elevated, but an androgen receptor mutation identified on the X chromosome for both brothers confirmed the diagnosis of X-linked bulbospinomuscular atrophy (Kennedy's disease).

Low diagnostic yield of sural nerve biopsy in patients with peripheral neuropathy and primary amyloidosis.

Patients with primary amyloidosis may develop peripheral neuropathy as an early feature. Sural nerve biopsy is reported to be a sensitive method for diagnosing amyloidosis in such patients. We identified nine patients, ultimately diagnosed as having amyloidosis, who were referred for peripheral neuropathy of undetermined etiology. In six, a sural nerve biopsy demonstrated no amyloid. Subsequent examination of other tissue or of the contralateral sural nerve eventually resulted in the correct diagnosis. We conclude that sural nerve biopsy may be less sensitive than previously believed for the diagnosis of amyloidosis in patients with peripheral neuropathy secondary to amyloid. When the clinical suspicion of amyloidosis is high, a nondiagnostic sural nerve biopsy should not discourage the performance of further investigative studies.

Presentation and initial clinical course in patients with chronic inflammatory demyelinating polyradiculoneuropathy: comparison of patients without and with monoclonal gammopathy.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) may occur in association with a monoclonal gammopathy of undetermined significance (MGUS) or a variety of other systemic illnesses. It is not known if the clinical features of CIDP are altered by the presence of an MGUS. We compared demographic features, clinical presentation, improvement and outcome after initial treatment, and electrodiagnostic features of a group of 77 patients with idiopathic CIDP (CIDP-I, no associated systemic illness) with 26 patients with CIDP in whom an MGUS was found during evaluation of the neuropathy (CIDP-MGUS). Patients with CIDP-MGUS had, on average, a more indolent course and less severe weakness than patients with CIDP-I, despite similar motor conduction studies. CIDP-MGUS patients also demonstrated less functional impairment, more frequent sensory loss, and more abnormal sensory conduction studies than patients with CIDP-I. Because of the greater improvement of CIDP-I patients with treatment, both groups had similar outcomes from their initial episodes of weakness. Subgroup analysis of CIDP-MGUS patients did not demonstrate differences between groups with IgM and IgG or IgA gammopathies.

Polyneuropathy associated with IgA monoclonal gammopathy of undetermined significance.

Although polyneuropathies associated with IgM and IgG monoclonal gammopathies have been well described, polyneuropathy with IgA monoclonal gammopathy of undetermined significance (MGUS) is less commonly seen and has not been well studied. We reviewed the clinical and electrodiagnostic features of 5 such patients, and the sural nerve biopsy findings in 4 of them. One patient was diabetic, while 4 were free of other diagnoses commonly associated with neuropathy. Clinical presentations were varied. Electrodiagnostic and histological studies ranged from primary demyelination to primary axon loss to a mixed axonal/demyelinating picture. Three patients who were treated appeared to respond to prednisone or intravenous gamma globulin, despite clear clinical, electrodiagnostic, and histological differences. We conclude that the polyneuropathy associated with IgA MGUS is heterogeneous, similar to that in IgM and IgG MGUS. A trial of immunomodulating therapy appears to be warranted in such patients if the neuropathy is sufficiently severe.

Chronic inflammatory demyelinating polyradiculoneuropathy: comparison of patients with and without an associated monoclonal gammopathy.

We reviewed our data from patients with the clinical diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Seventy patients had no demonstrable underlying disease to account for their polyneuropathy and were classified as idiopathic CIDP (CIDP-I). We detected a monoclonal gammopathy of uncertain significance (MGUS) in 30 patients who were classified as CIDP-MGUS; 17 had an IgG gammopathy, 12 an IgM gammopathy, and one an IgA gammopathy. Compared with CIDP-I patients, CIDP-MGUS patients were older and slightly more likely to be males. When compared with patients with an MGUS but without polyneuropathy reported in the literature, CIDP-MGUS patients had similar distributions of age, sex, and immunoglobulin class. There were no significant differences in motor and sensory nerve conduction measures between CIDP-I and CIDP-MGUS patients, nor between CIDP-MGUS patients with IgM and those with IgG or IgA gammopathy. Strict electrodiagnostic criteria for primary demyelination were fulfilled by 54% of CIDP-I patients and 40% of CIDP-MGUS patients, but these were not significantly different. Our study suggests that (1) the demographic features and immunoglobulin class distribution of CIDP-MGUS patients largely reflect those of patients with an MGUS, but without polyneuropathy, (2) CIDP-MGUS patients as a group cannot be distinguished from CIDP-I patients on the basis of nerve conduction studies, and (3) IgM CIDP-MGUS patients cannot be distinguished from those with other immunoglobulin classes.

The role of electrodiagnostic studies in the diagnosis and management of polymyositis.

Polymyositis is an inflammatory muscle disease preferentially affecting proximal muscles. Diagnosis is suggested by an EMG study showing abnormal spontaneous activity in proximal muscles and the presence of myopathic motor unit changes. Alternative diagnoses are eliminated by nerve conduction and neuromuscular junction studies and the EMG. Diagnosis is confirmed by muscle biopsy. Treatment requires aggressive and long term immunosuppressive therapy. Expectations for improvement in strength are good, but complete remission or cure less predictable. Polymyositis may be associated with other systemic disorders such as collagen vascular diseases and cancer, and an appropriate evaluation should include these associations.

Prognosis in long-term immunosuppressive treatment of refractory chronic inflammatory demyelinating polyradiculoneuropathy.

Treatment of chronic inflammatory demyelinating polyneuropathy (CIDP) frequently includes use of immunosuppressive agents. Controlled treatment trials demonstrating efficacy are available only for prednisone and therapeutic plasma exchange (TPE). When these fail to achieve lasting chemical improvement after reduction or cessation of therapy, subsequent regimens are empiric, often leading to prolonged immunosuppression. It is not possible to predict who will respond to which agent and when. Administered individually, immunosuppressive agents may pose an acceptable risk, but cumulative effects of multiple agents in refractory patients may suppress the immune system and contribute to increased morbidity and mortality. Treatment difficulties with refractory CIDP patients have not been emphasized, and long-term effects of immunosuppression have focused on the risk of malignancy. In reviewing our clinical experience treating over 100 CIDP patients we identified approximately 20 patients who could be considered refractory to multiple immunosuppressive therapies and dependent upon long-term intermittent TPE. Two of these patients exemplify the morbidity associated with CIDP and its associated treatment. Our review of the clinical course of these patients raised issues about the use of multiple immunosuppressive agents, long-term goals, and long-term prognosis in CIDP.

Acute pandysautonomic neuropathy.

Acute pandysautonomic neuropathy is characterized by severe postganglionic sympathetic and parasympathetic dysfunction, with relative or complete sparing of motor and sensory function. Of four reported cases with sural nerve biopsies, two were normal and two abnormal, revealing loss of small myelinated and unmyelinated fibers. We present a patient with pandysautonomic neuropathy and elevated CSF protein whose sural nerve biopsy showed active axonal degeneration.

Transient Lambert-Eaton myasthenic syndrome associated with systemic lupus erythematosus.

We present a patient who developed the Lambert-Eaton myasthenic syndrome (LEMS) in association with systemic lupus erythematosus (SLE). Severe proximal weakness with electrodiagnostic evidence of LEMS developed over 2 days during an exacerbation of cutaneous manifestations (bullous pemphigoid) associated with SLE. Following an increase in the daily dose of prednisone, there was complete clinical restitution of strength within 2 weeks and a slower resolution of electrodiagnostic abnormalities over 6 months. Marked serologic abnormalities were present at the onset and showed improvement over 6-8 months. LEMS had been infrequently described in association with SLE. The immunologic features of both SLE and LEMS suggest a linkage between the two diseases in this patient. We hypothesize that increased antibodies associated with exacerbation of SLE cross reacted with the neuromuscular junction membrane to produce LEMS.