Neuroanatomical associations of the Edinburgh cognitive and Behavioural ALS screen (ECAS)

Brain Imaging and Behavior - Cognitive impairment is now recognized in a subset of patients with amyotrophic lateral sclerosis (ALS). The objective of the study was to identify group differences...     

Thrust during ambulation and the progression of knee osteoarthritis

OBJECTIVE: To determine whether the presence of varus thrust at baseline increases the risk of progression of medial tibiofemoral osteoarthritis (OA), whether knees with thrust have a greater adduction moment, whether thrust has any additional impact on top of static varus, and whether thrust is associated with poor physical function outcome. METHODS: Two hundred thirty-seven patients with knee OA (definite osteophytes and symptoms) underwent baseline gait observation to assess varus thrust and full-limb radiography to assess alignment. Sixty-four of these 237 patients also underwent quantitative gait analysis to determine the maximum knee adduction moment. Two hundred thirty patients (97%) returned for followup at 18 months. At baseline and 18 months, the 230 participants had semiflexed, fluoroscopically confirmed knee radiographs (with progression defined as worsening of medial joint space grade); self-reported and performance-based measures of function were also assessed. Logistic regression with generalized estimating equations was used to estimate odds ratios (ORs) for medial OA progression, after excluding knees that were not at risk for progression. RESULTS: Varus thrust was present in 67 of 401 knees. Thrust increased 4-fold (age-, sex-, body mass index-, and pain-adjusted OR 3.96, 95% confidence interval [95% CI] 2.11-7.43) the odds of medial progression, with some reduction after further adjustment for varus alignment severity. In varus-aligned knees, thrust increased the odds of OA progression 3-fold (adjusted OR 3.17, 95% CI 1.60-6.31). In the gait substudy, the adduction moment was greater in knees with a thrust compared with knees without a thrust. Having a thrust in both knees versus neither knee was associated with a 2-fold increase in the OR for poor physical function outcome (P not significant). CONCLUSION: Varus thrust is a potent risk factor, identifiable by simple gait observation, for disease progression in the medial compartment, the most common site of OA involvement at the knee. Varus thrust may also predict poor physical function outcome. Varus thrust increased the odds of progression among varus-aligned knees considered separately, suggesting that knees with a thrust are a subset of varus-aligned knees at particularly high risk for progression of OA.     

Gabapentin therapy for amyotrophic lateral sclerosis: lack of improvement in neuronal integrity shown by MR spectroscopy

BACKGROUND AND PURPOSE: Proton MR spectroscopy has revealed impaired neuronal integrity in the motor cortex of patients with amyotrophic lateral sclerosis (ALS). We hypothesized that the N-acetylaspartate (NAA)-creatine (Cr) ratios in the motor cortex and adjacent brain could reflect the therapeutic effectiveness of gabapentin (GBP) treatment in ALS. METHODS: Eight patients with ALS underwent MR spectroscopy before and 26.5 days +/- 8.8 after starting GBP. In 10 patients with ALS who were not treated with GBP, paired spectra were obtained 21.4 days +/- 7.2 apart. Fourteen healthy subjects underwent a single MR spectroscopic examination. The NAA/Cr ratio was measured in the precentral gyrus, the postcentral gyrus, the superior parietal lobule, the supplementary motor area, and the premotor cortex. RESULTS: The NAA/Cr ratio was decreased in the precentral and postcentral gyri of patients with ALS compared with healthy controls. In those with ALS, the change in the NAA/Cr ratio was not different between treated patients and untreated patients in any of the regions studied. CONCLUSION: No improvement in neuronal integrity was detected in motor and nonmotor cerebral regions after GBP treatment. This result agrees with that of prior investigations showing the equivocal clinical effectiveness of GBP for ALS and supports the validity of the NAA/Cr ratio as a surrogate of therapeutic effectiveness.     

Analysis of the US Safety Data for Edaravone (Radicava®) From the Third Year After Launch

BackgroundAmyotrophic lateral sclerosis (ALS) is a progressive and fatal neuromuscular disease with no curative therapies. Edaravone (Radicava^®) (Mitsubishi Tanabe Pharma Corporation, Tokyo, Japan), approved in the United States (US) for ALS in adults in 2017, was shown in a clinical trial to slow the rate of physical functional decline in ALS and is administered intravenously. The aim of this paper is to summarize the observed safety profile from real-world patient use during the first 3 years of edaravone availability in the US.MethodsEdaravone usage data were collected, and adverse events (AEs) were identified from a postmarketing safety database from August 8, 2017 through August 7, 2020 (cutoff date).ResultsAs of October 3, 2020, 5207 ALS patients had been treated with edaravone. As of August 7, 2020, the most commonly reported AEs included death (not specified), drug ineffective, disease progression, therapeutic response unexpected, fall, asthenia, fatigue, muscular weakness, gait disturbance, and dyspnea. The most commonly reported serious AEs (SAEs) included death (not specified), pneumonia, disease progression, ALS, fall, dyspnea, respiratory failure, device-related infection, hospitalization, and injection-site infection. There were 687 deaths, with 494 reported as death without specifying the cause. Deaths were most commonly attributed to ALS, disease progression, respiratory failure, or pneumonia. Review for administration-site reactions revealed 95 AEs, including 34 site infections, with 22 SAEs (all non-fatal). Five non-fatal SAEs of anaphylaxis were reported.ConclusionIn the postmarketing reporting to date, no new safety signals were identified beyond those already known from the edaravone clinical trial program.     

Cerebral degeneration predicts survival in amyotrophic lateral sclerosis

Objective

To determine the relationship of cerebral degeneration with survival in amyotrophic lateral sclerosis (ALS).

Methods

Patients with probable or definite ALS underwent magnetic resonance spectroscopic imaging (MRSI) of the brain between July 1996 and May 2002, and were followed prospectively until March 2004. Creatine (Cr), choline (Cho) and the neuronal marker N‐acetylaspartate (NAA) were quantified as ratios in the motor cortex.

Results

In 63 patients compared with 18 healthy people, NAA/Cho was reduced by 13% (p<0.001), NAA/Cr was reduced by 5% (p = 0.01) and Cho/Cr was increased by 8% (p = 0.01). NAA/Cho was used for survival analysis, given its larger effect size and superior test accuracy (a sensitivity of 67% and a specificity of 83%). Median survival after MRSI was 24 months. Multivariate analysis showed reduced survival for lower NAA/Cho (hazard ratio (HR) 0.24, 95% confidence interval (CI) 0.08 to 0.72, p = 0.01), older age (HR 1.03, 95% CI 1.00 to 1.06, p = 0.04) and shorter symptom duration (HR 0.96, 95% CI 0.93 to 0.99, p = 0.01). Patients with NAA/Cho <2.11 had a reduced survival of 19.4 v 31.9 months (HR 2.05, 95% CI 1.12 to 4.03, p = 0.02).

Conclusions

Cerebral degeneration is predictive of reduced survival in ALS.The extent to which cerebral involvement contributes to shortened life expectancy in amyotrophic lateral sclerosis (ALS) has been difficult to elucidate. The clinical evaluation of upper motor neurone (UMN) integrity as an index of motor cortex degeneration falls short owing to the possible masking of UMN signs by the loss of lower motor neurones (LMNs). Indeed, autopsy series have shown UMN degeneration in cases of LMN‐predominant motor neurone disease that would not have otherwise met the clinical criteria for ALS.¹ The identification of prognostic indicators would aid in selecting patients for clinical trials who are predicted to behave in a homogeneous manner with respect to disease progression and, potentially, pathogenesis. Prognostic indicators would also have clinical value in counselling patients.Proton magnetic resonance spectroscopy (MRS) studies in ALS have consistently shown evidence of neuronal loss or dysfunction in the motor cortex by the finding of decreased N‐acetylaspartate (NAA), a neuronal marker.^2,3We aimed to determine whether cerebral neurochemical abnormalities quantified by MRS correlated with survival.     

Diagnostic delay in amyotrophic lateral sclerosis

Background

Amyotrophic lateral sclerosis (ALS) is a progressive, fatal neurodegenerative disease, and the time from symptom onset to diagnosis remains long. With the advent of disease-modifying treatments, the need to identify and diagnose ALS in a timely fashion has never been greater.

Methods

We reviewed the literature to define the severity of ALS diagnostic delay, the various factors that contribute to this delay (including patient and physician factors), and the role that site of symptom onset plays in a patient's diagnostic journey.

Results

Diagnostic delay is influenced by general practitioners’ lack of recognition of ALS due to disease rarity and heterogenous presentations. As a result, patients are referred to non-neurologists, have unnecessary diagnostic testing, and may ultimately be misdiagnosed. Patient factors include their illness behavior—which impacts diagnostic delay—and their site of symptom onset. Limb-onset patients have the greatest diagnostic delay because they are frequently misdiagnosed with degenerative spine disease or peripheral neuropathy.

Conclusion

Prompt ALS diagnosis results in more effective clinical management, with earlier access to disease-modifying therapies, multidisciplinary care, and, if desired, clinical trial involvement. Due to lack of commercially available ALS biomarkers, alternative strategies to identify and triage patients who likely have ALS must be employed. Several diagnostic tools have been developed to encourage general practitioners to consider ALS and make an urgent referral to ALS specialists, bypassing unnecessary referrals to non-neurologists and unnecessary diagnostic workup.     

A novel heteroplasmic tRNAleu(CUN) mtDNA point mutation in a sporadic patient with mitochondrial encephalomyopathy segregates rapidly in skeletal muscle and suggests an approach to therapy

A novel mtDNA point mutation was detected in the tRNAleu(CUN) gene (G to A at position 12315) in a sporadic patient with chronic progressive external ophthalmoplegia, ptosis, limb weakness, sensorineural hearing loss and a pigmentary retinopathy. The mutation disrupts base pairing in the T psi C stem at a site which has been conserved throughout evolution. Although the other mtDNA tRNAleu gene (UUR) is a hotspot for mutation, this is the first pathogenic mutation to be reported in the gene coding for tRNAleu(CUN). MtDNAs carrying the mutation constituted 94% of total mtDNAs in two separate muscle biopsies. Single fibre analysis showed that skeletal muscle fibres without detectable cytochrome c oxidase activity (COX-ve fibres) contained predominantly mutant mtDNAs (93-98%) while fibres with apparently normal COX activity had up to 90% mutant mtDNAs, demonstrating that the G12315A mutation is functionally recessive. Immunofluorescence studies with specific antibodies to mtDNA- or nuclear-encoded subunits of COX were consistent with a defect in mitochondrial protein translation. The mutation was not present in blood cells or cultured fibroblasts and surprisingly, it could not be detected in satellite cells cultured from the patient's muscle. This pattern, which may by typical of patients who have inherited new germline pathogenic mtDNA mutations, possibly reflects loss of the mutation by random genetic drift in mitotic tissues and proliferation of mitochondria containing the mutant mtDNA in post- mitotic cells. The absence of mtDNA carrying the mutation in satellite cells suggests that regeneration of skeletal muscle fibres from satellite cells could restore a wild-type mtDNA genotype and normal muscle function.      

Contrast material-induced renal failure in patients with diabetes mellitus, renal insufficiency, or both. A prospective controlled study

To determine the risk of nephrotoxicity induced by the infusion of radiographic contrast material, we undertook a prospective study of consecutive patients undergoing radiographic procedures with intravascular contrast material. There were three study groups: patients with diabetes mellitus and normal renal function (n = 85), patients with preexisting renal insufficiency (serum creatinine level, greater than or equal to 150 mumol per liter) without diabetes (n = 101), and patients with both diabetes and renal insufficiency (n = 34). The control group consisted of patients undergoing CT scanning or abdominal imaging procedures without the infusion of contrast material who had diabetes mellitus (n = 59), preexisting renal insufficiency (n = 145), or both (n = 64). Clinically important acute renal failure (defined as an increase of greater than 50 percent in the serum creatinine level) attributable to the contrast material did not occur in nondiabetic patients with preexisting renal insufficiency or in diabetics with normal renal function. The incidence of clinically important contrast-induced renal failure among the diabetic patients with preexisting renal insufficiency was 8.8 percent (95 percent confidence interval, 1.9 to 23.7 percent), as compared with 1.6 percent for the controls. The incidence of acute renal insufficiency, more broadly defined as an increase of greater than 25 percent in the serum creatinine level after the infusion of contrast material, was 11.8 percent among all patients with preexisting renal insufficiency. After the exclusion of patients whose acute renal insufficiency could be attributed to other causes, the incidence was 7.0 percent (95 percent confidence interval, 3.2 to 12.8 percent), as compared with 1.5 percent in the control group. The risk of acute renal insufficiency attributable to the contrast material was therefore 5.5 percent, and the relative risk associated with the infusion of contrast material was 4.7. These rates were similar whether the osmolarity of the contrast material was high or low. We conclude that there is little risk of clinically important nephrotoxicity attributable to contrast material for patients with diabetes and normal renal function or for nondiabetic patients with preexisting renal insufficiency. The risk for those with both diabetes and preexisting renal insufficiency is about 9 percent, which is lower than previously reported.