Objective: To systematically review evidence bearing on the management of patients with amyotrophic lateral sclerosis (ALS). Methods:The authors analyzed studies from 1998 to 2007 to update the 1999 practice parameter. Topics covered in this section include slowing disease progression, nutrition, and respiratory management for patients with ALS.

We report four patients with "dropped head syndrome," a recently described nonprogressive myopathy characterized by severe neck extensor weakness. This relatively benign condition may be confused with more ominous neuromuscular disorders that also present with prominent neck weakness. We compared clinical and laboratory data from the patients with dropped head syndrome with findings from patients with head drop caused by other neuromuscular conditions. Patients with "isolated neck extensor myopathy," a term we prefer to "dropped head syndrome," could be readily identified with electrophysiologic, radiographic, and histologic studies.

Inclusion body myositis, polymyositis, and dermatomyositis are three distinct categories of inflammatory myopathy. Some authorities commented on the selective early weakness of the volar forearm muscles, quadriceps, and ankle dorsiflexors in inclusion body myositis. The most important feature distinguishing inclusion body myositis from the other two inflammatory myopathies is the lack of responsiveness to immunosuppressive treatment. Although most patients with inclusion body myositis have characteristic muscle biopsy findings, some cannot be distinguished histologically early from polymyositis. Predicting responsiveness to immunosuppressive medications, independent of muscle histology, would be valuable to clinicians. We retrospectively reviewed the pattern of weakness and other clinical features of 46 patients newly diagnosed with either inclusion body myositis, polymyositis, or dermatomyositis. Asymmetrical muscle weakness with prominent wrist flexor, finger flexor, and knee extensor involvement was specific for inclusion body myositis and unresponsive polymyositis. Male sex, lower creatine kinase levels, slower rate of progression, and peripheral neuropathy were also more common in inclusion body myositis and unresponsive polymyositis than in responsive polymyositis and dermatomyositis patients. Repeat muscle biopsy in 2 patients in the unresponsive polymyositis group demonstrated histological features of inclusion body myositis. We suspect that patients with clinical features of inclusion body myositis but lacking histological confirmation may nonetheless have inclusion body myositis. Our study supports the recently proposed criteria for definite and possible inclusion body myositis.

Background Previous human clinical trials of insulin-like growth factor type I (IGF-1) in amyotrophic lateral sclerosis (ALS) have been inconsistent. This phase III, randomized, double-blind, placebo-controlled study was undertaken to address whether IGF-1 benefited patients with ALS. Methods A total of 330 patients from 20 medical centers were randomized to receive 0.05 mg/kg body weight of human recombinant IGF-1 given subcutaneously twice daily or placebo for 2 years. The primary outcome measure was change in their manual muscle testing score. Secondary outcome measures included tracheostomy-free survival and rate of change in the revised ALS functional rating scale. Intention to treat analysis was used. Results There was no difference between treatment groups in the primary or secondary outcome measures after the 2-year treatment period. Conclusions Insulin-like growth factor type I does not provide benefit for patients with amyotrophic lateral sclerosis.

The accuracy and reproducibility of magnetic resonance (MR) imaging in the determination of left ventricular mass in humans was investigated. Left ventricular wall volume was measured from ten short-axis, end-diastolic MR images that spanned the left ventricle. Mass was estimated on the basis of average left ventricular wall volume and an assumed myocardial density. To establish the accuracy of the technique, the authors imaged ten cadaver hearts and compared true left ventricular weight with the mass estimate based on MR imaging findings. In vivo determination of left ventricular mass was evaluated in 40 subjects, with resultant calculated masses of 156.4-319.3 g. Intra- and interobserver variabilities of the technique were analyzed in ten subjects. Both the intra- (r = .96, standard error of estimate [SEE] = 11.1 g) and interobserver variabilities (r = .91, SEE = 17.8 g) were excellent. Eight subjects were imaged on two separate occasions to evaluate reproducibility of the technique and confidence limits for a given measurement. For these eight, there was good correlation between the two estimates (r = .93, SEE = 21 g). The authors conclude that MR imaging yields highly accurate and reproducible estimates of left ventricular mass in humans in vivo.

Electrocardiogram-gated spin echo NMR imaging of the heart may be used for quantitating right ventricular mass in normal subjects and in patients with primary pulmonary hypertension, in whom it may also provide an alternative noninvasive technique for estimating mean pulmonary artery pressure.

Glucose labeled both in position 2 with tritium and uniformly with (glucose-2-t-U-~4c) was injected into rats. The specific activity of blood glucose and formation of labeled water were followed. The half-life of the tritium-labeled glucose was found to be 22 min and that of IC-labeled glucose, 34 min. Turnover of glucose calculated from tritium data was 3 % of the glucose pool/min, as compared to 27J rnin from 14c data. The t/14c ratios of h e r glycogen isolated 80-120 min after injection were one-third to one-half of the mean t/]T ratio during the experi-

We performed detailed electrophysiologic studies on 16 patients with clinically defined multifocal motor neuropathy and found a wide spectrum of demyelinating features. Only five patients (31%) had conduction block in one or more nerves. However, in 15 patients (94%) at least one nerve showed other features of demyelination. We also noted a significant degree of superimposed axonal degeneration in 15 patients. Eight patients (50%) had individual nerves with pure axonal injury, despite the presence of demyelinating features in other nerves. Antiganglioside antibodies were elevated in four of five patients with conduction block and five of 11 patients without conduction block. We conclude that multifocal motor neuropathy is characterized electrophysiologically by a wide spectrum of axonal and demyelinating features. Diagnostic criteria requiring conduction block may lead to underdiagnosis of this potentially treatable neuropathy.