Role of vitamin A metabolism in IIH: Results from the idiopathic intracranial hypertension treatment trial

INTRODUCTION

Vitamin A and its metabolites (called retinoids) have been thought to play a role in the development of idiopathic intracranial hypertension (IIH). The IIH Treatment Trial (IIHTT) showed the efficacy of acetazolamide (ACZ) in improving visual field function, papilledema grade, quality of life and cerebrospinal fluid (CSF) pressure. We postulated that IIH patients would demonstrate elevated measures of vitamin A metabolites in the serum and CSF.

METHODS

Comprehensive measures of serum vitamin A and its metabolites were obtained from 96 IIHTT subjects, randomly assigned to treatment with ACZ or placebo, and 25 controls with similar gender, age and body mass index (BMI). These included retinol, retinol binding protein, all-trans retinoic acid (ATRA), alpha- and beta-carotenes, and beta-cryptoxanthin. The IIHTT subjects also had CSF and serum vitamin A and metabolite measurements obtained at study entry and at six months.

RESULTS

At study entry, of the vitamin A metabolites only serum ATRA was significantly different in IIHTT subjects (median 4.33nM) and controls (median 5.04nM, p=0.02). The BMI of IIHTT subjects showed mild significant negative correlations with serum ATRA, alpha- and beta-carotene, and beta-cryptoxanthin. In contrast, the control subject BMI correlated only with serum ATRA. At six months, the serum retinol, alpha-carotene, beta-carotene, and CSF retinol were increased from baseline in the ACZ treated group, but only increases in alpha-carotene (p=0.02) and CSF ATRA (p=0.04) were significantly greater in the ACZ group compared with the placebo group. No other vitamin A measures were significantly altered over the six months in either treatment group. Weight loss correlated with only with the change in serum beta-carotene (r=-0.44, p=0.006) and the change in CSF retinol (r=-0.61, p=0.02).

CONCLUSION

Vitamin A toxicity is unlikely a contributory factor in the causation of IIH. Our findings differ from those of prior reports in part because of our use of more accurate quantitative methods and measuring vitamin A metabolites in both serum and CSF. ACZ may alter retinoid metabolism in IIH patients.

Validity and Responsiveness of Generic Preference-based HRQOL Instruments in Chronic Epilepsy

Generic, preference-based instruments are recommended for assessing health-related quality of life (HRQOL) in cost-utility analyses (CUA). We aimed to determine which instrument is the most appropriate for CUA of epilepsy care, using established psychometric criteria. We compared validity and responsiveness of EQ5D (using both UK and US preferences), visual analog scale (VAS), Health Utilities Index Mark II (HUI-2) and Mark III (HUI-3) and SF6D in 165 adults evaluated for epilepsy surgery. SF6D had the strongest or next-strongest associations with seizure severity and seizure control. It was not associated with education or IQ. Only SF6D and HUI-3 discriminated between patients with and without seizures 2 years after baseline evaluation. SF6D was most or next-most responsive to being seizure-free for 2 years, in most responsiveness analyses. VAS was also responsive, but showed less evidence of validity. The QOLIE-89, an epilepsy-targeted profile instrument, had stronger evidence for validity and responsiveness than the preference instruments. SF6D has several key psychometric advantages over four other preference instruments in CUAs of epilepsy care. This may reflect better coverage of HRQOL dimensions affected by epilepsy, greater sensitivity at the upper end of the HRQOL continuum, or both. These findings may not generalize to other chronic conditions.

A randomized, double-blind, placebo-controlled trial of antidepressants in Parkinson disease

OBJECTIVE

To evaluate the efficacy and safety of a selective serotonin reuptake inhibitor (SSRI) and a serotonin and norepinephrine reuptake inhibitor (SNRI) in the treatment of depression in Parkinson disease (PD).

METHODS

A total of 115 subjects with PD were enrolled at 20 sites. Subjects were randomized to receive an SSRI (paroxetine; n = 42), an SNRI (venlafaxine extended release [XR]; n = 34), or placebo (n = 39). Subjects met DSM-IV criteria for a depressive disorder, or operationally defined subsyndromal depression, and scored >12 on the first 17 items of the Hamilton Rating Scale for Depression (HAM-D). Subjects were followed for 12 weeks (6-week dosage adjustment, 6-week maintenance). Maximum daily dosages were 40 mg for paroxetine and 225 mg for venlafaxine XR. The primary outcome measure was change in the HAM-D score from baseline to week 12.

RESULTS

Treatment effects (relative to placebo), expressed as mean 12-week reductions in HAM-D score, were 6.2 points (97.5% confidence interval [CI] 2.2 to 10.3, p = 0.0007) in the paroxetine group and 4.2 points (97.5% CI 0.1 to 8.4, p = 0.02) in the venlafaxine XR group. No treatment effects were seen on motor function.

CONCLUSIONS

Both paroxetine and venlafaxine XR significantly improved depression in subjects with PD. Both medications were generally safe and well tolerated and did not worsen motor function.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that paroxetine and venlafaxine XR are effective in treating depression in patients with PD.

Outcome measures in placebo-controlled trials of osteoarthritis: responsiveness to treatment effects in the REPORT database

INTRODUCTION

Treatment response in randomized clinical trials (RCT) of osteoarthritis (OA) has been assessed by multiple primary and secondary outcomes, including pain, function, patient and clinician global measures of status and response to treatment, and various composite and responder measures. Identifying outcome measures with greater responsiveness to treatment is important to increase the assay sensitivity of RCTs.

OBJECTIVE

To assess and compare the responsiveness of different outcome measures used in placebo-controlled RCTs of OA.

SEARCH STRATEGY

The Resource for Evaluating Procedures and Outcomes of Randomized Trials database includes placebo-controlled clinical trials of pharmacologic treatments (oral, topical, or transdermal) for OA identified from a systematic literature search of RCTs published or publicly available before August 5, 2009, which was conducted using PubMed, the Cochrane collaboration, publicly-available websites, and reference lists of retrieved publications.

DATA COLLECTION AND ANALYSIS

Data collected included: (1) pain assessed with single-item ratings and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale; (2) patient and clinician global measures of status, improvement, and treatment response; (3) function assessed by the WOMAC function subscale; (4) stiffness assessed by the WOMAC stiffness subscale; and (5) the WOMAC and Lequesne Algofunctional Index composite outcomes. Measures were grouped according to the total number of response categories (i.e., <10 categories or ≥10 categories). The treatment effect (difference in mean change from baseline between the placebo and active therapy arms) and standardized effect size (SES) were estimated for each measure in a meta-analysis using a random effects model.

RESULTS

There were 125 RCTs with data to compute the treatment effect for at least one measure; the majority evaluated non-steroidal anti-inflammatory drugs (NSAIDs), followed by opioids, glucosamine and/or chondroitin, and acetaminophen. In general, the patient-reported pain outcome measures had comparable responsiveness to treatment as shown by the estimates of treatment effects and SES. Treatment effects and SESs were generally higher for patient-reported global measures compared with clinician-rated global measures but generally similar for the WOMAC and Lequesne composite measures.

CONCLUSIONS

Comparing different outcome measures using meta-analysis and selecting those that have the greatest ability to identify efficacious treatments may increase the efficiency of clinical trials of treatments for OA. Improvements in the quality of the reporting of clinical trial results are needed to facilitate meta-analyses to evaluate the responsiveness of outcome measures and to also address other issues related to assay sensitivity.

Mexiletine is an effective antimyotonia treatment in myotonic dystrophy type 1

OBJECTIVE

To determine if mexiletine is safe and effective in reducing myotonia in myotonic dystrophy type 1 (DM1).

BACKGROUND

Myotonia is an early, prominent symptom in DM1 and contributes to decreased dexterity, gait instability, difficulty with speech/swallowing, and muscle pain. A few preliminary trials have suggested that the antiarrhythmic drug mexiletine is useful, symptomatic treatment for nondystrophic myotonic disorders and DM1.

METHODS

We performed 2 randomized, double-blind, placebo-controlled crossover trials, each involving 20 ambulatory DM1 participants with grip or percussion myotonia on examination. The initial trial compared 150 mg of mexiletine 3 times daily to placebo, and the second trial compared 200 mg of mexiletine 3 times daily to placebo. Treatment periods were 7 weeks in duration separated by a 4- to 8-week washout period. The primary measure of myotonia was time for isometric grip force to relax from 90% to 5% of peak force after a 3-second maximum grip contraction. EKG measurements and adverse events were monitored in both trials.

RESULTS

There was a significant reduction in grip relaxation time with both 150 and 200 mg dosages of mexiletine. Treatment with mexiletine at either dosage was not associated with any serious adverse events, or with prolongation of the PR or QTc intervals or of QRS duration. Mild adverse events were observed with both placebo and mexiletine treatment.

CONCLUSIONS

Mexiletine at dosages of 150 and 200 mg 3 times daily is effective, safe, and well-tolerated over 7 weeks as an antimyotonia treatment in DM1.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that mexiletine at dosages of 150 and 200 mg 3 times daily over 7 weeks is well-tolerated and effective in reducing handgrip relaxation time in DM1.

Six-Minute Walk Test demonstrates motor fatigue in spinal muscular atrophy

BACKGROUND

In spinal muscular atrophy (SMA), weakness, decreased endurance, and fatigue limit mobility. Scales have been developed to measure function across the wide spectrum of disease severity. However, these scales typically are observer dependent, and scores are based on sums across Likert-scaled items. The Six-Minute Walk Test (6MWT) is an objective, easily administered, and standardized evaluation of functional exercise capacity that has been proven reliable in other neurologic disorders and in children.

METHODS

To study the performance of the 6MWT in SMA, 18 ambulatory participants were evaluated in a cross-sectional study. Clinical measures were 6MWT, 10-m walk/run, Hammersmith Functional Motor Scale-Expanded (HFMSE), forced vital capacity, and handheld dynamometry. Associations between the 6MWT total distance and other outcomes were analyzed using Spearman correlation coefficients. A paired t test was used to compare the mean distance walked in the first and sixth minutes.

RESULTS

The 6MWT was associated with the HFMSE score (r = 0.83, p < 0.0001), 10-m walk/run (r = -0.87, p < 0.0001), and knee flexor strength (r = 0.62, p = 0.01). Gait velocity decreased during successive minutes in nearly all participants. The average first minute distance (57.5 m) was significantly more than the sixth minute distance (48 m) (p = 0.0003).

CONCLUSION

The Six-Minute Walk Test (6MWT) can be safely performed in ambulatory patients with spinal muscular atrophy (SMA), correlates with established outcome measures, and is sensitive to fatigue-related changes. The 6MWT is a promising candidate outcome measure for clinical trials in ambulatory subjects with SMA.

A randomized controlled trial of telephone peer support's influence on breastfeeding duration in adolescent mothers

PURPOSE

Adolescent mothers breastfeed less often and for a shorter duration than adult mothers. This randomized controlled trial was designed to evaluate the effect of telephone peer support on breastfeeding duration among adolescents.

METHODS

Five adolescents who had previously breastfed were trained to provide peer support. Seventy-eight breastfeeding mothers were randomly assigned to an intervention group that received telephone calls from the peer support persons (n = 38) or to a control group that did not receive support (n = 40). An independent interviewer telephoned all new mothers weekly to document feeding patterns. Peer support persons, subjects, and the interviewer were all blinded to the research hypothesis and to group assignment. The primary outcome variable was "any breastfeeding" duration, i.e., the age at complete breastfeeding cessation. A secondary outcome variable was exclusive breastfeeding, i.e., the age at first introduction of any supplement.

RESULTS

"Any breastfeeding" duration did not differ significantly between the groups (median 75 days in the intervention group vs. 35 days in the control group, p = 0.26). Among the 13 intervention and 11 control mothers who were exclusively breastfeeding at the time of hospital discharge, the duration of exclusive breastfeeding was increased in the intervention group (median 35 days vs. 10 days, p = 0.004).

CONCLUSIONS

This study did not demonstrate a significant effect of peer support on "any breastfeeding" duration. In contrast, exclusive breastfeeding duration appeared to be extended by peer support. This latter finding would benefit from confirmation in future studies. However, unless better methods are developed for retaining peers, this is likely to be a labor-intensive approach to extending exclusive breastfeeding duration among adolescent mothers.

Incidence of and risk factors for cognitive impairment in an early Parkinson disease clinical trial cohort

OBJECTIVE

To investigate the incidence of and risk factors for cognitive impairment in a large, well-defined clinical trial cohort of patients with early Parkinson disease (PD).

METHODS

The Mini-Mental State Examination (MMSE) was administered periodically over a median follow-up period of 6.5 years to participants in the Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism trial and its extension studies. Cognitive impairment was defined as scoring 2 standard deviations below age- and education-adjusted MMSE norms.

RESULTS

Cumulative incidence of cognitive impairment in the 740 participants with clinically confirmed PD (baseline age 61.0 +/- 9.6 years, Hoehn-Yahr stage 1-2.5) was 2.4% (95% confidence interval: 1.2%-3.5%) at 2 years and 5.8% (3.7%-7.7%) at 5 years. Subjects who developed cognitive impairment (n = 46) showed significant progressive decline on neuropsychological tests measuring verbal learning and memory, visuospatial working memory, visuomotor speed, and attention, while the performance of the nonimpaired subjects (n = 694) stayed stable. Cognitive impairment was associated with older age, hallucinations, male gender, increased symmetry of parkinsonism, increased severity of motor impairment (except for tremor), speech and swallowing impairments, dexterity loss, and presence of gastroenterologic/urologic disorders at baseline.

CONCLUSIONS

The relatively low incidence of cognitive impairment in the Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism study may reflect recruitment bias inherent to clinical trial volunteers (e.g., younger age) or limitations of the Mini-Mental State Examination-based criterion. Besides confirming known risk factors for cognitive impairment, we identified potentially novel predictors such as bulbar dysfunction and gastroenterologic/urologic disorders (suggestive of autonomic dysfunction) early in the course of the disease.

Neuropathy progression in Charcot-Marie-Tooth disease type 1A

OBJECTIVE

To determine the rate of disease progression in Charcot-Marie-Tooth disease type 1A (CMT1A).

BACKGROUND

CMT1A is the most common inherited peripheral neuropathy, affecting approximately 1:5,000 people irrespective of ethnic background or gender. There is no cure for CMT1A. Clinical trials are being initiated that use the CMT Neuropathy Score (CMTNS), a composite score based on patient symptoms, signs, and neurophysiologic abnormalities, as the primary outcome variable. The sensitivity of the CMTNS or any other score to change over time, as a measure of CMT1A progression, has yet to be determined.

METHODS

We determined the CMTNS as well as the Neuropathy Impairment Score (NIS) on 72 patients followed for up to 8 years. The rate of disease progression was evaluated for the CMTNS and NIS using mixed effects linear regression models, adjusting for age and gender.

RESULTS

Both CMTNS and NIS showed changes over time. The CMTNS increased an average of 0.686 points per year (95% CI 0.461 to 0.911, p <or= 0.0001). The NIS increased 1.368 points per year on average (95% CI 0.616 to 2.121, p = 0.0005). There was a suggestion that the rate of progression increased with age.

CONCLUSION

Progression of CMT1A can be detected by both the CMT Neuropathy Score (CMTNS) and the Neuropathy Impairment Score (NIS). This supports the feasibility of clinical trials to detect a slowing of disease progression using either or both of these scales as outcome measures. Since the CMTNS combines symptoms, signs, and electrophysiology and the NIS is based solely on the neurologic examination, the two scales may be complementary.

Health care costs decline after successful epilepsy surgery

BACKGROUND

Surgery is an effective, high-cost procedure used increasingly to treat refractory epilepsy. For surgery to be cost-effective, long-term cost savings from reduced health care use should provide some offset to the initial costs of evaluation and surgery. There is little information about how health care costs are affected by evaluation and surgery.

OBJECTIVE

To determine whether health care costs change when seizures become controlled after surgery.

METHODS

Health care costs for the 2 years prior to surgical evaluation and for 2 years afterward were calculated from medical records of 68 subjects with temporal lobe epilepsy (TLE) participating in a multicenter observational study. Costs were compared among patients who did not have surgery, patients who had persisting seizures after surgery, and patients who were seizure free after surgery.

RESULTS

Antiepileptic drugs (AEDs) accounted for more than half of the costs of care in the pre-evaluation period. Total costs for seizure-free patients had declined 32% by 2 years following surgery due to less use of AEDs and inpatient care. Costs did not change in patients with persisting seizures, whether they had surgery or not. In the 18 to 24 months following evaluation, epilepsy-related costs were $2,068 to $2,094 in patients with persisting seizures vs $582 in seizure-free patients.

CONCLUSIONS

Costs remain stable over 2 years post-evaluation in patients with temporal lobe epilepsy whose seizures persist, but patients who become seizure free after surgery use substantially less health care than before surgery. Further cost reductions in seizure-free patients can be expected as antiepileptic drugs are successfully eliminated.

Is skin biopsy a predictor of transition to symptomatic HIV neuropathy?: A longitudinal study

OBJECTIVE

To investigate whether serially assessed epidermal nerve fiber (ENF) density and quantitative sensory thresholds (QSTs) are associated with the clinical transition from HIV infection with no neuropathy or asymptomatic neuropathy to symptomatic distal sensory neuropathy (SDSP).

BACKGROUND

Identifying predictors of transition to SDSP would enable identification of subjects at enhanced risk for development of HIV-SDSP and facilitate intervention studies with the ultimate goal of disease prevention. Asymptomatic signs of sensory dysfunction in the feet have been shown to be weakly predictive of SDSP; however, bedside evaluation of small sensory fibers is limited. Abnormality of these fibers may play an important role in the genesis of SDSP.

METHODS

Fifty-eight HIV-infected subjects underwent serial clinical, virologic, immunologic, skin biopsy, and QST assessments. Cox proportional hazards modeling was used to examine the associations of serial ENF density and QST assessments with the risk of development of SDSP among the subset of 26 subjects who had asymptomatic or no neuropathy at study entry.

RESULTS

Median follow-up was 2.9 years (range 6 months to 4.5 years) during which 19 of 26 subjects transitioned to SDSP. Using a model where ENF density and QST measures from the study visit before potential transition were examined, a lower leg ENF density, a higher cooling threshold, and a higher heat pain threshold for minimal pain (HP 0.5) were associated with a greater risk of SDSP in univariate analyses. In multiple regression analyses, leg ENF density but not QST measures were significantly associated with SDSP. A leg ENF density of 10 fibers/mm or less conferred a 14-fold greater risk of SDSP than a leg ENF density greater than 10 fibers/mm.

CONCLUSIONS

Measures of small sensory fibers (leg epidermal nerve fiber density, cooling and heat pain thresholds) seem to be associated with transition to symptomatic HIV-associated distal sensory neuropathy 6 to 12 months later.

Markers of immune activation and viral load in HIV-associated sensory neuropathy

BACKGROUND

HIV infection is associated with a painful distal sensory polyneuropathy (DSP) that can severely limit the quality of life of affected subjects. The pathogenesis of DSP is unknown, although both HIV proteins and products of immune activation triggered by HIV infection have been implicated.

OBJECTIVE

To assess the association between baseline markers of immune activation and HIV RNA levels (viral load) and time to symptomatic DSP (SDSP).

METHODS

A cohort of 376 subjects, most receiving highly active antiretroviral therapy (HAART), were followed semiannually for up to 48 months. Blood and CSF levels of HIV viral load, monocyte chemotactic protein-1, macrophage colony-stimulating factor (M-CSF), matrix metalloproteinase-2, and tumor necrosis factor-alpha were measured in addition to CD4 lymphocyte cell count.

RESULTS

In subjects without SDSP at baseline (62.5% of the cohort), among the virologic and immunologic markers, only baseline CSF M-CSF levels were associated with time to SDSP (hazard ratio = 2.97, p = 0.05). The Kaplan-Meier estimate of the 1-year incidence of SDSP was 21%, a 15% decrease from that observed in the Dana cohort, a pre-HAART cohort enrolled with the same inclusion/exclusion criteria.

CONCLUSION

Highly active retroviral therapy (HAART) has changed the natural history of HIV-associated symptomatic distal sensory polyneuropathy (SDSP), which may explain, in contrast with studies from the pre-HAART era, the lack of association between SDSP and baseline HIV viral load and CD4 cell count.

Evaluation of HIV RNA and markers of immune activation as predictors of HIV-associated dementia

OBJECTIVE

To evaluate whether baseline levels of plasma and CSF HIV RNA, tumor necrosis factor alpha (TNFalpha), monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinase-2 (MMP-2), or macrophage colony stimulating factor (M-CSF) are predictors of incident HIV-associated dementia (HIVD) in a cohort with advanced HIV infection.

METHODS

A total of 203 nondemented subjects with CD4 lymphocyte counts less than 200/muL, or <300/microL but with cognitive impairment, underwent semiannual neurologic, cognitive, functional, and laboratory assessments. HIVD and minor cognitive motor disorder (MCMD) were defined using American Academy of Neurology criteria. The cumulative incidence of HIVD was estimated using Kaplan-Meier curves. Cox proportional hazards regression models were used to examine the associations between biologic variables and time to HIVD, adjusting for age, sex, years of education, duration of HIV infection, type of antiretroviral use, premorbid IQ score, and presence of MCMD.

RESULTS

After a median follow-up time of 20.7 months, 74 (36%) subjects reached the HIVD endpoint. The dementia was mild in 70% of cases. The cumulative incidence of HIVD was 20% at 1 year and 33% at 2 years. Highly active antiretroviral therapy (HAART) was used by 73% of subjects at baseline. A plasma HIV RNA level was undetectable in 23% of subjects and a CSF HIV RNA level was undetectable in 48% of subjects. In adjusted analyses, neither plasma nor CSF HIV RNA levels (log10) were associated with time to HIVD; log10 levels of plasma TNFalpha (HR 3.07, p = 0.03) and CSF MCP-1 (HR = 3.36, p = 0.06) tended to be associated with time to HIVD.

CONCLUSION

The lack of association between baseline plasma and CSF HIV RNA levels and incident dementia suggests highly active antiretroviral therapy may be affecting CNS viral dynamics, leading to lower HIV RNA levels, and therefore weakening the utility of baseline HIV RNA levels as predictors of HIV-associated dementia.

The prevalence of PD in a nutritionally deficient rural population in China

OBJECTIVES

In most reports, the prevalence of PD in mainland China is lower than in western populations. To estimate PD prevalence in China, we performed a cross-sectional study in a rural population in Linxian County, China.

PRIMARY OUTCOMES

Clinical diagnosis of PD.

RESULTS

Among the 16,488 participants examined, the overall age- and gender-adjusted prevalence rate of PD was 522/100,000 (95% CI: 477-567) assuming no cases of PD would be found among those younger than 50 years of age. The gender-adjusted prevalence rates were 103 (95% CI: 83-123), 621 (95% CI: 572-670), 902 (95% CI: 843-961), and 1744 (95% CI: 1662-1826) per 100,000 in age groups 50-59, 60-69, 70-79, and 80 and above, respectively.

CONCLUSIONS

The estimated prevalence of PD in Linxian, China is higher than most of those reported from other areas in China, and similar to those reported from non-Asian populations.

Survival in Parkinson disease: Thirteen-year follow-up of the DATATOP cohort

OBJECTIVE

To investigate predictors of survival in Parkinson disease (PD).

METHODS

Vital status was determined in 800 subjects enrolled in a clinical trial of deprenyl (selegiline) and tocopherol 13 years earlier.

RESULTS

Two hundred ninety-six deaths were recorded. There was no difference in the standardized mortality ratios across gender or age group. In univariate analyses, PD-specific variables associated with mortality were increased symmetry of parkinsonism, gait dysfunction as an initial symptom, severity of parkinsonism, and rate of worsening of parkinsonism prior to study enrollment. Cumulative exposure to deprenyl was not associated with mortality. In multivariable analysis, severity of parkinsonism and rate of worsening of parkinsonism remained associated with mortality. A poorer response to levodopa was associated with increased mortality independent of disease severity or dosage of levodopa. Results were unchanged when the analysis was restricted to 747 subjects maintaining a most likely diagnosis of PD throughout 6 years of active follow-up.

CONCLUSIONS

Parkinson disease did not affect survival differently across gender or age groups in this selected group of otherwise healthy clinical trial participants. Severity and rate of worsening of parkinsonism and response to levodopa are strongly related to survival.

Inter-rater reliability of a clinical staging of HIV-associated cognitive impairment

OBJECTIVE

To determine the inter-rater reliability of a modification of the Memorial Sloan-Kettering (MSK) Staging for HIV-associated cognitive impairment.

METHODS

Data were abstracted on neurologic, neuropsychological, and functional status on 100 individuals participating at four sites in the Northeast AIDS Dementia (NEAD) Consortium cohort study, a longitudinal study of predictors of cognitive impairment in HIV-infected individuals. Neuropsychological performance was defined 1) based on the neuropsychologist's global impression and 2) solely based on neuropsychological test scores. Raters at each site used the abstracted data to assign an MSK stage to each subject blind to any identifying information. Inter-rater reliability was assessed using kappa statistics. Agreement between computer-generated ratings and site-generated ratings was also assessed.

RESULTS

Kappa statistics for pair-wise agreement among the sites regarding MSK stage ranged from 0.70-0.91, representing good to excellent agreement between sites. Agreement between computer-generated ratings and site-generated ratings was in the good to excellent range (0.62-0.79).

CONCLUSIONS

The authors have modified the MSK rating scale and developed a reliable instrument that can be used in multicenter studies. This instrument will be useful in staging HIV-dementia in future longitudinal studies and will be valuable in increasing accuracy of clinicopathologic studies.

A randomized clinical trial of CPI-1189 for HIV-associated cognitive-motor impairment

BACKGROUND

CPI-1189 is a compound with antioxidant properties that blocks tumor necrosis factor-alpha (TNFalpha) effects in animal models. It has neuroprotective properties in model systems for HIV-associated neurotoxicity and thus is a candidate for neuroprotective therapy in humans with HIV-associated CNS disease.

OBJECTIVE

To assess the tolerability and safety of CPI-1189 in treating HIV-associated cognitive-motor impairment.

METHODS

Sixty-four subjects with mild to moderate HIV-associated cognitive-motor impairment were randomized to receive either placebo or 50 or 100 mg daily of CPI-1189 in addition to optimal HIV therapy. Subjects were followed prospectively in a double-masked study for 10 weeks. The primary assessment was tolerability and safety of the compound. Secondary objectives examined neuropsychological and functional change associated with this treatment.

RESULTS

The study compound was well tolerated, with 91% of CPI-1189-treated subjects and 76% of placebo-treated subjects completing the trial. Skin rash was seen equally in placebo and active arms, but the only study withdrawals due to skin rash occurred in CPI-1189-treated subjects (n = 2). One subject developed a cataract on drug (100 mg/day). CD4 lymphocyte counts and plasma HIV viral load remained stable in all groups throughout the trial. No significant treatment effects were observed on the change in composite Z-scores for eight neuropsychologic measures (NPZ-8). The Grooved Pegboard Test (nondominant) showed improved performance with CPI-1189 at 100 mg/day (p = 0.01), but no other neuropsychometric or functional measures demonstrated significant improvement.

CONCLUSIONS

CPI-1189 was well tolerated in HIV subjects with cognitive-motor disorder. This study was not powered to conclusively determine efficacy and showed no consistent treatment-associated improvement in cognitive or functional measures.

The behavioral spectrum of tic disorders: a community-based study

BACKGROUND

Tourette syndrome (TS) and related tic disorders are commonly associated with obsessive-compulsive disorder (OCD) and attention deficit hyperactivity disorder (ADHD). It has been argued, however, that any observed association between TS and these and other psychopathologies may be due to ascertainment bias in that individuals with multiple problems are more likely to be referred for medical evaluation.

METHODS

In order to overcome the potential confounding by ascertainment bias, the authors conducted a community-based study of school children using direct interviews to determine the prevalence of tic disorders and any comorbid psychopathology. A standard psychiatric interview and standardized rating scales were utilized to diagnose childhood behavioral disorders.

RESULTS

Of the 1,596 children interviewed, 339 were identified as having tics. The following psychopathologies were found more commonly (p < 0.05) in the children with tics: OCD, ADHD, separation anxiety, overanxious disorder, simple phobia, social phobia, agoraphobia, mania, major depression, and oppositional defiant behavior.

CONCLUSION

The behavioral spectrum of tic disorders includes OCD, other anxiety disorders, a mood disorder, and attention-deficit and disruptive behavior disorders.

Incidence of and risk factors for HIV-associated distal sensory polyneuropathy

OBJECTIVE

To assess the incidence of and risk factors for distal sensory polyneuropathy (DSP) in a cohort of HIV-infected subjects.

METHODS

We followed 272 subjects semiannually for up to 30 months. DSP was diagnosed if subjects had decreased or absent ankle jerks, decreased or absent vibratory perception at the toes, or decreased pinprick or temperature in a stocking distribution. Subjects were further classified at each visit as having asymptomatic DSP (ADSP) (signs only) or symptomatic DSP (SDSP) if, in addition to the neurologic signs, paresthesias or pain was reported.

RESULTS

At baseline, 45% of the subjects did not meet criteria for DSP, 20% met criteria for ADSP, and 35% met criteria for SDSP. Dideoxynucleoside therapy was used by 23% of the patients, and this treatment was independent of their neuropathy status. In longitudinal univariate analyses, history of AIDS diagnoses (hazard ratio [HR] = 1.89; p = 0.02) and lower CD4 cell count (HR = 0.69; p = 0.0006) were risk factors for incident DSP (ADSP or SDSP). However, for incident SDSP only, in addition to history of AIDS diagnoses, mood and neurologic (other than DSP) and functional abnormalities were significant risk factors. Functional abnormalities remained a significant risk factor in a multiple regression analysis. The presence of ADSP and the use of dideoxynucleosides at baseline were not significant risk factors for incident SDSP. The Kaplan-Meier estimate of the 1-year incidence of SDSP was 36%.

CONCLUSION

Subjects with moderate-to-severe immunosuppression from HIV infection commonly have SDSP. However, sex, use of dideoxynucleosides, and presence of ADSP were not significant risk factors for SDSP.

Quantitative functional measures in MS: what is a reliable change?

As a first step toward understanding which changes should be considered as meaningful, the authors assessed the reliability of quantitative functional tests on 5 consecutive days in 63 patients with MS, determining the range of measurement variability present when patients are clinically stable. Time to walk 25 feet (T25FW) and the 9-hole peg test (9HPT) varied by <20% of individual mean scores on repeated testing. Therefore, a 20% change on these tests can be considered to be the threshold that reliably indicates a true change in function for an individual.

Prevalence of tics in schoolchildren and association with placement in special education

BACKGROUND

Based on the knowledge that Tourette's syndrome (TS) is associated with several clinical features that can impair school function and growing evidence that the disorder is much more common than previously thought, the authors hypothesized that TS and related tic disorders would be associated with school problems in the childhood population at large.

METHODS

Direct, blinded (to educational placement) interviews of 1,596 schoolchildren in Monroe County, Rochester, NY, were conducted.

RESULTS

Twenty-seven percent of 341 students classified as receiving special education (SpEd) had tics compared with 19.7% (p = 0.008) of 1,255 students in regular classroom programs (RegEd). The weighted prevalence estimates for tics were 23.4% in SpEd and 18.5% in RegEd. A higher percentage of students in SpEd (7.0%) met diagnostic criteria for TS than students in RegEd (3.8%; p = 0.01).

CONCLUSIONS

Although possibly influenced by selection bias, our results indicate that tic disorders are common in children and are highly associated with school dysfunction. Tics may represent an identifiable sign of an underlying brain developmental disorder that contributes to academic difficulties.

Randomized, double-blind, placebo-controlled trial of albuterol in facioscapulohumeral dystrophy

BACKGROUND/OBJECTIVES

Animal and human studies suggest that beta(2)-adrenergic agonists exert anabolic effects on muscles, inducing and preventing atrophy after a variety of insults. Based on data from an open-label trial of albuterol in 15 patients with facioscapulohumeral dystrophy (FSHD), the authors conducted a randomized, double-blind, placebo-controlled trial of sustained-release albuterol in this disease.

METHODS

Ninety patients were randomized to three groups: placebo; 8.0 mg albuterol twice daily; or 16.0 mg albuterol twice daily. Patients were treated for 1 year with assessments at baseline and weeks 13, 26, and 52. The primary outcome was the 52-week change in global strength by maximum voluntary isometric contraction testing (MVICT). Secondary outcomes included changes at 52 weeks in strength by manual muscle testing (MMT), grip strength, functional testing, and muscle mass assessed by dual energy x-ray absorptiometry (DEXA).

RESULTS

Eighty-four patients completed the study. The mean changes in composite MVICT scores were not significantly different between the groups (mean +/- SD: placebo 0.20 +/- 0.91; low dose -0.04 +/- 0.84; high dose 0.08 +/- 0.98). Similarly, there were no differences in the mean MMT change (placebo 0.04 +/- 0.16; low dose -0.03 +/- 0.13; high dose 0.00 +/- 0.15). Grip improved in both treatment groups compared to placebo (placebo -0.53 +/- 4.13, low dose +1.90 +/- 3.34 [p = 0.02], high dose +1.70 +/- 4.13 [p = 0.03]). The high-dose group had a significant increase in lean mass by DEXA (+1.57 +/- 1.71 kg) compared to placebo (0.25 +/- 2.24; p = 0.007). Albuterol was well tolerated; side effects included cramps, tremors, insomnia, and nervousness.

CONCLUSIONS

Although albuterol did not improve global strength or function in patients with FSHD, it did increase muscle mass and improve some measures of strength.

A multiple sclerosis cluster associated with a small, north-central Illinois community

The authors investigated a reported incidence cluster of multiple sclerosis (MS) cases in a small, north-central Illinois community to determine validity and statistical significance. DePue, Illinois--a small, north-central Illinois community--has previously been the site of significant environmental heavy-metal exposure from a zinc smelter. Significant contamination of soil and water with zinc and other metals has been documented in this community during the time period of interest. In the mid-1990s, several cases of MS were reported to the Illinois Department of Public Health within the geographic limits of this community. Available medical records from purported MS cases reported to the Illinois Department of Public Health were reviewed, and living individuals were seen and examined. Statistical analyses were conducted with clinically definite MS cases; onset dates were determined by first symptom, and expected incidence rates were determined from published epidemiologic studies. Nine new cases of clinically definite MS occurred among residents of DePue, Illinois, during the period between 1971 and 1990. Seven of the 8 living subjects included in the final analyses were examined by one author (RS). The computed incidence rate deriving from these cases within DePue Township, Illinois, represented a statistically significant excess of new MS cases over expected. During the period from 1971 through 1990, a significant excess of MS cases occurred within the population of DePue, Illinois. Significant exposure of this population to mitogenic trace metals, including zinc, was also documented during this time period.

A prospective natural history study of inclusion body myositis: implications for clinical trials

Eleven patients with untreated inclusion body myositis (IBM) were prospectively studied during a 6-month period that included muscle strength, lean body mass, and muscle mass measurements. There was an overall quantifiable mean decline in percent of predicted normal muscle strength of 4% from baseline in a 6-month period, but one third of patients showed no change or slight improvements in strength. Short-term treatment trials in IBM will require large numbers of patients to detect slowing, arrest, or even slight improvement in muscle strength.

Freezing of gait in PD: prospective assessment in the DATATOP cohort

OBJECTIVE

To study the development of freezing of gait in PD.

BACKGROUND

Freezing of gait is a common, disabling, and poorly understood symptom in PD.

METHODS

The authors analyzed data from 800 patients with early PD from the Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism (DATATOP) clinical trial who were assigned either placebo, deprenyl, tocopherol, or the combination of deprenyl and tocopherol. The primary outcome measure was the time from randomization until the freezing of gait score on the Unified Parkinson's Disease Rating Scale (UPDRS) became positive.

RESULTS

Fifty-seven patients (7.1%) had freezing of gait at study entry and 193 (26%) of the remaining patients experienced the symptom by the end of the follow-up period. Those with freezing of gait at baseline had significantly more advanced disease than those without the symptom, as measured by total UPDRS and Hoehn and Yahr stage. High baseline risk factors for developing freezing of gait during the follow-up period were the onset of PD with a gait disorder; higher scores of rigidity, postural instability, bradykinesia and speech; and longer disease duration. In contrast, tremor was strongly associated with a decreased risk for freezing of gait. At the end of follow-up, the signs most strongly associated with the freezing phenomenon were gait, balance, and speech disorders, not rigidity or bradykinesia. Deprenyl treatment was strongly associated with a decreased risk for developing freezing of gait; tocopherol had no effect.

CONCLUSIONS

Freezing of gait is directly related to duration of PD. Risk factors at onset of disease are the absence of tremor and PD beginning as a gait disorder. The development of freezing of gait in the course of the illness is strongly associated with the development of balance and speech problems, less so with the worsening of bradykinesia, and is not associated with the progression of rigidity. These results support the concept that the freezing phenomenon is distinct from bradykinesia. Deprenyl, in the absence of L-dopa, was found to be an effective prophylactic treatment and should be considered for patients with PD who have an onset of gait difficulty.

Expression of Fas (CD95) and Fas ligand on peripheral blood mononuclear cells in critical illness and association with multiorgan dysfunction severity and survival

OBJECTIVE

This was an exploratory study with three goals: a) to quantify the expression of the apoptotic receptor Fas and its ligand (FasL) on peripheral blood mononuclear cells (PBMCs) in patients with, or at risk for, multiple organ dysfunction syndrome (MODS); b) to compare this expression with the respective expression in matched controls; and c) to explore the association with MODS severity and survival.

DESIGN

Repeated-measures correlational and cross-sectional design.

SETTING

The surgical, medical, and the trauma/burn intensive care unit of an academic institution.

PATIENTS

Thirty-five adult, critically ill patients meeting the diagnostic criteria for systemic inflammatory response syndrome (SIRS) with MODS, or at risk for MODS, were followed for 14 days. Thirty-five non-SIRS controls matched with patients for age, gender, and race comprised the control group.

INTERVENTIONS

Peripheral blood sampling every 48 hrs.

MEASUREMENTS/MAIN RESULTS

T cells were considerably depleted in SIRS/MODS patients (p <.001), and Fas and FasL expression on PBMCs (flow cytometric analysis) was elevated significantly compared with controls (p <.001). In contrast to controls, non-T cells were the major sources of Fas and FasL in SIRS/MODS patients (p <.01). Expression of Fas and FasL exhibited a bimodal correlation with severity (p <.03). High severity patients demonstrated increasing Fas and FasL expression with increasing severity in contrast to declining expression in moderately severe patients. Fas and FasL measurements were significantly and positively associated with the likelihood of survival (p <.05).

CONCLUSIONS

Dysregulation in the expression of apoptotic receptors Fas and FasL, at least in PBMCs, may be involved in the pathophysiology of SIRS, the related lymphocytopenia, and the onset of MODS and the related morbidity and mortality rates.

Factors associated with incident human immunodeficiency virus-dementia

BACKGROUND

Antecedents to human immunodeficiency virus-dementia (HIV-D) are poorly understood.

OBJECTIVE

To identify risk factors for HIV-D.

METHODS

Subjects who are positive for HIV who have CD4+ counts either below 200/microL or below 300/microL with evidence of cognitive impairment were enrolled in this study. Neurologic, cognitive, functional, and laboratory assessments were done semiannually for up to 30 months. Human immunodeficiency virus-dementia was diagnosed using American Academy of Neurology criteria for probable HIV-1-associated dementia complex.

RESULTS

One hundred forty-six nondemented patients were enrolled, 45 of whom subsequently met criteria for incident HIV-D. In univariate analyses using the Cox proportional hazards regression model, the following variables were significantly associated with time to develop dementia: cognitive: abnormal scores on Timed Gait, Verbal Fluency, Grooved Pegboard, and Digit Symbol tests; attention-memory, psychomotor, and executive function domain scores; and the diagnosis of minor cognitive/motor disorder; neurologic and medical: increased abnormalities on the neurologic examination, extrapyramidal signs, history of HIV-related medical symptoms; functional: higher reported role or physical function difficulties. Depression was also a strong risk factor, along with sex, hematocrit, hemoglobin, and beta2-microglobulin levels. In a multivariate model that used cognitive domain scores, covariates with significant hazard ratios included depression, executive dysfunction, and the presence of minor cognitive/motor disorder.

CONCLUSION

Cognitive deficits, minor cognitive/motor disorder, and depression may be early manifestations of HIV-D.

Clinical trials in HIV-associated cognitive impairment: cognitive and functional outcomes

Cognitive and functional outcomes are of primary interest in the design of efficacy trials in HIV-associated cognitive impairment. In a longitudinal cohort study, weak associations were found between measures of cognitive performance and commonly used measures of daily functioning (mostly self-report measures) in HIV-infected individuals. Modifications of current functional scales or new functional instruments are needed to assess the clinical relevance of cognitive changes in clinical trials of HIV-associated cognitive impairment.

Release of the neuronal glycoprotein ICAM-5 in serum after hypoxic-ischemic injury

Intercellular adhesion molecule (ICAM)-5 (telencephalin) is unique among the ICAMs, because it is only expressed in somatodendritic membranes of telencephalic neurons. To investigate the fate of ICAM-5 during focal brain injury, we induced hypoxia-ischemia (HI) damage in adult mice by right common carotid artery ligation followed by hypoxia. ICAM-5 was detectable in serum within a 48-hour window after HI injury. In HI brain, dendritic ICAM-5 immunore-activity was abolished, but it was present in the neuropil and soma of hippocampal pyramidal, dentate granule, and some cortical and striatal neurons. After HI injury, levels of ICAM-5 protein and messenger RNA initially increased, and ICAM-5 messenger RNA expression then decreased, although protein levels continued to increase. Because HI injury induces microglial activation with increases in CD11a/CD18 (lymphocyte function antigen [LFA]-1) counterreceptors to ICAM-5, we investigated whether modulation of interactions between LFA-1 receptors and brain ICAM-5 during HI injury are associated with changes in levels of serum ICAM-5. Intracerebroventricular administration of lipopolysaccharide to activate microglia before HI injury resulted in elevated serum ICAM-5 levels compared with those in mice with only HI injury. Pretreatment with anti-LFA-1 antibodies before HI injury or LFA-1 receptor knockout mice with HI injury had markedly reduced levels of serum ICAM-5. Lipopolysaccharide levels increased, whereas LFA-1 receptor blockade or LFA-1 knockout decreased HI injury in the first 12 hours. These data suggest that during the necrotic phase of HI injury, serum ICAM-5 may be a potential marker for somatodendritic neuronal damage.

Soluble fas levels correlate with multiple organ dysfunction severity, survival and nitrate levels, but not with cellular apoptotic markers in critically ill patients

Apoptosis is a mode of programmed cell death (PCD). Transduction of apoptotic signals results in cellular suicide. Organ specific apoptosis has been proposed as a factor in multiple organ dysfunction syndrome (MODS). Fas is a widely occurring apoptotic signal receptor molecule expressed by almost any type of cell, which is also released in a soluble circulating form (circulating fas, sfas). In this exploratory study, we investigated the association of sfas with severity, survival, known mediators of multiple organ dysfunction, and cellular apoptotic markers on peripheral blood mononuclear cells (PBMC) in a group of 35 patients with MODS and in 35 matched controls. Critically ill patients with MODS had significantly elevated sfas levels compared to controls over time (P < .001). Increased serum concentration of circulating fas was associated with increased severity of multiple organ dysfunction. Non-survivors exhibited significantly higher sfas levels compared to survivors (P < .01) and increasing sfas was inversely associated with the likelihood of survival (P < .05). Circulating fas levels correlated highly with serum nitrate concentration, but not with fas and fasL expression on PBMC of critically ill patients. TNF-alpha and IL-6, although they appear to be mediators of both apoptosis and MODS, had no association with sfas. These results are suggestive of the need for further investigation on the role of apoptotic signaling in the development of MODS. They also suggest a potential prognostic value of sfas for SIRS/MODS clinical outcomes.

Autonomic performance and dehydroepiandrosterone sulfate levels in HIV-1-infected individuals: relationship to TH1 and TH2 cytokine profile

BACKGROUND

Products of immune activation, including cytokines and lipid membrane derivatives, have been implicated in the pathogenesis of the neurologic sequelae, including autonomic dysfunction, associated with human immunodeficiency virus 1 (HIV-1) infection. In animal models, autonomic and endocrine dysfunction are associated with an altered cytokine profile.

OBJECTIVES

To investigate the relationship between markers of immune activation (beta(2)-microglobulin), HIV-1 disease progression (CD4(+) cell count and viral load), and autonomic nervous system performance and to assess the relationship between autonomic performance, plasma levels of dehydroepiandrosterone sulfate (DHEAS), and T(H)1 and T(H)2 cytokine profile.

METHODS

Thirty-one HIV-1-infected individuals and 22 HIV-1-negative controls were evaluated with a comprehensive neurologic, neuropsychological, and autonomic examination. Interleukin 4 and interferon gamma were measured by enzyme-linked immunosorbent assay in the supernatant of stimulated peripheral blood mononuclear cells.

RESULTS

A composite measure of autonomic performance (AZ score) was significantly lower (worse autonomic function) in patients compared with controls (P=.04). A lower AZ score was associated with higher beta(2)-microglobulin serum levels and a lower CD4(+) cell count. Interleukin 4 levels were significantly inversely associated with AZ score (P=.01), whereas interferon gamma levels were significantly positively associated with DHEAS levels (P=.04).

CONCLUSIONS

Our data show significant associations between markers of immune activation and disease progression and a composite measure of autonomic function in HIV-1-infected individuals. In addition, they suggest that poor autonomic function and low DHEAS plasma levels tend to be associated with an unbalanced cytokine profile.

The evolution of diagnosis in early Parkinson disease. Parkinson Study Group

CONTEXT

Since there is no diagnostic biological marker for Parkinson disease (PD), the diagnosis is based on the results of clinical assessment. The accuracy of diagnosis improves with time and repeated assessments. Studies that require only inclusion of early cases of PD present a diagnostic challenge. Previous studies concluded that initial diagnoses of PD made by general neurologists were incorrect in 24% to 35% of the cases when patients were examined at autopsy. Experts in movement disorders are expected to have greater accuracy of initial diagnosis of PD.

OBJECTIVE

To determine the evolution of clinical diagnosis in patients with early PD made initially by experts in PD.

DESIGN

Eight hundred patients with mild parkinsonian symptoms (Hoehn and Yahr stage 1 or 2) who received a diagnosis of PD less than 5 years before the beginning of the study were included in the original Deprenyl and Tocopherol Antioxidative Therapy for Parkinson's Disease study. These patients were followed up prospectively with repeated clinical assessments. The following clinical criteria were used to reassess the initial diagnosis: investigator's confidence in the diagnosis of PD, presence of atypical clinical features, findings of imaging studies, response to levodopa, and results of autopsy examinations.

RESULTS

The mean +/- SD duration of illness in the 800 cases at enrollment was 2.2+/-1.3 years, and the mean +/- SD Hoehn and Yahr stage was 1.6+/-0.5. The mean +/- SD follow-up was 6.0+/-1.4 years (range, 0.2-7.6 years). In 5 cases, PD was not confirmed at autopsy, and in 15 patients, the results of imaging studies indicated the presence of other pathological conditions. Of the 550 cases treated with levodopa, 49 (8.9%) had little or no improvement; 6 of these cases overlap with either autopsy or imaging study exclusion criteria. Two other cases had at least 4 of the 6 atypical clinical features arguing against the diagnosis of PD. Thus, of the 800 patients, 65 (8.1%) did not have PD according to the study criteria. Compared with those patients with the final diagnosis of PD, in the diagnoses of 60 patients without autopsy, the duration of symptoms (mean +/- SD, 7.2+/-2.0 years vs. 8.3+/-1.9 years; P<.001) and the duration of follow-up (5.3+/-1.6 years vs. 6.1+/-1.3 years; P<.001) were shorter.

CONCLUSIONS

We found that 65 (8.1%) of patients initially diagnosed as having PD were later found to have an alternate diagnosis based on multifactorial clinical diagnostic criteria. This alternate diagnosis indicated that experts in PD changed their diagnoses infrequently during the 7.6-year follow-up.

Transdermal selegiline in HIV-associated cognitive impairment: pilot, placebo-controlled study

The authors conducted a pilot randomized, double-blind, placebo-controlled clinical trial of the transdermal administration of selegiline in HIV+ patients to obtain preliminary data to assess its safety, tolerability, and impact on HIV-associated cognitive impairment. Both selegiline and placebo were well tolerated with few adverse events. Improvements favoring the selegiline group were suggested on single tests of verbal memory and motor/psychomotor performance, warranting a larger study.

Randomized trials of dichlorphenamide in the periodic paralyses. Working Group on Periodic Paralysis

Although the carbonic anhydrase inhibitors have been used in the treatment of the primary periodic paralyses (PPs), their efficacy has not been demonstrated in double-blind, placebo-controlled trials. Therefore, we tested the efficacy of dichlorphenamide (DCP; Daranide), a potent carbonic anhydrase inhibitor, in the treatment of episodic weakness in the primary PPs. We performed two multicenter, randomized, double-blind, placebo-controlled crossover trials, one involving 42 subjects with hypokalemic periodic paralysis (HypoPP) and the other involving 31 subjects with potassium-sensitive periodic paralysis (PSPP). In each trial, two 8-week treatment periods were separated by an active washout period of at least 9 weeks. The primary outcome variable in the HypoPP trial was the occurrence of an intolerable increase in attack severity or frequency (end point). The primary outcome variable in the PSPP trial was the number of attacks per week. In the HypoPP trial, there were 13 subjects who exhibited a preference (in terms of the end point) for either DCP or placebo, and 11 of these preferred DCP. In the PSPP trial, DCP significantly reduced attack rates relative to placebo. DCP also significantly reduced attack rates relative to placebo in the HypoPP subjects. We conclude that DCP is effective in the prevention of episodic weakness in both HypoPP and PSPP.

Primary isolate neutralization by HIV type 1-infected patient sera in the era of highly active antiretroviral therapy

Sera from highly selected HIV-1-positive patients are known to have the ability to neutralize a diverse array of primary isolates of HIV-1. The human osteosarcoma cell line that expresses CD4 and chemokine receptors (GHOST cells) was adapted to study HIV-1 neutralization in 37 HIV-1-infected individuals who were selected because of slow disease progression or nonprogression. Many of these individuals were receiving combination drug therapy. Molecularly cloned HIV-1 JR-FL and NL4-3 viruses were used as prototypes to define assay conditions. Sera were then tested at a 1:40 dilution against six additional primary isolates, three of which utilized CCR5 and three of which used both CCR5 and CXCR4. The assay was highly reproducible and independent of viral input titer, with a readout at 48 hr equivalent to that at later time points. As previously reported, neutralization sensitivity was entirely independent of coreceptor usage. Only a few sera from slow progressors were able to neutralize a broad array of primary isolates at a 1:40 dilution, and the best clinical predictor of broadly neutralizing antibody for primary isolates was the present use of antiretroviral agents. In further studies it was found that purified antibody accounted for the majority of the measured neutralization. However, experiments with exogenous addition of antiviral agents showed that the use of nucleosides also greatly contributed to the measured neutralization in some patients. Measurement of neutralization of HIV-1 primary isolates by sera from patients receiving antiretroviral therapy must be carried out with some caution.

Quantitative assessment of motor fatigue and strength in MS

OBJECTIVE

To determine the test-retest reliability of strength and fatigue measurements in patients with MS and in healthy control subjects, and to examine associations among motor fatigue, strength, and ambulatory impairment in MS patients.

BACKGROUND

Motor fatigue, defined as the loss of the maximal capacity to generate force during exercise, and weakness are common in patients with MS.

METHOD

Twenty ambulatory MS patients and 20 age- and sex-matched healthy control subjects participated in the study. Test-retest reliability was assessed in two identical testing sessions, separated by 3 to 5 days. Maximal voluntary isometric strength was determined by fixed myometry of seven muscle groups on each side. Motor fatigue was assessed using three exercise protocols: sustained maximal contractions (static fatigue), repetitive maximal contractions, and walking as far as 500 m. Four analysis models for static fatigue were examined for their test-retest reliability and their ability to discriminate between normal fatigue and pathologic fatigue from MS.

RESULTS

Test-retest reliability in MS patients was excellent for isometric strength and very good for static fatigue. Test-retest reliability was lower for exercise protocols that involved repetitive contractions or ambulation. Compared with healthy control subjects, MS patients were weak in lower extremity muscles, but upper extremity strength was relatively preserved. Fatigue was greater in MS patients, even in muscles that were not clearly weak. There were no significant associations between strength and fatigue in any of the muscles tested. A fatigue analysis model based on the area under the force-versus-time curve gave the best combination of reliability and sensitivity to detect differences between MS patients and healthy control subjects.

CONCLUSIONS

Strength and motor fatigue can be measured reliably in patients with MS. MS patients experience more fatigue than healthy control subjects during sustained contractions, repetitive contractions, and ambulation. Motor fatigue appears to be distinct from weakness because the degree of fatigue was not associated with the degree of weakness in individual muscles. Quantitative assessment of strength and fatigue may be useful to monitor changes in motor function over time in MS patients.

Higher-moment approaches to approximate interval estimation for a certain intraclass correlation coefficient

We consider the problem of constructing a confidence interval for the intraclass correlation coefficient in an interrater reliability study when the raters are assumed to be randomly selected from a population of raters. A Monte Carlo simulation study is conducted to investigate the true coverage probabilities of the commonly used intervals proposed by Fleiss and Shrout, which rely on Satterthwaite's two-moment approximation. These intervals are shown to be substantially anticonservative in certain cases. We propose intervals based on higher-moment approximations obtained using the Pearson system of distributions. The modified intervals are more conservative and generally more satisfactory than those obtained by the two-moment approximation. The competing methods are illustrated using data from a study of the natural history of facioscapulohumeral muscular dystrophy.

Lipid intolerance in neonates receiving dexamethasone for bronchopulmonary dysplasia

BACKGROUND

We hypothesized that dexamethasone induces hypertriglyceridemia (triglyceride levels >2.82 mmol/L [250 mg/dL]) and increases free fatty acid (FFA) levels and that steroid-induced hypertriglyceridemia is associated with hyperinsulinemia and elevated FFA levels.

OBJECTIVE

To study the effect of dexamethasone sodium phosphate on lipid metabolism in neonates receiving intravenous lipids.

DESIGN

A prospective cohort study with patients serving as their own controls.

SETTING

Neonatal Intensive Care Unit, Children's Hospital at Strong, Rochester, NY.

METHODS

All neonates younger than 29 weeks' gestational age at birth receiving 3 g/kg per day of intravenous lipids who were to start dexamethasone therapy for bronchopulmonary dysplasia were eligible. Exclusion criteria included neonates with active infection, prior hypertriglyceridemia, bleeding manifestations, recent surgery, thyroid medication, and human recombinant insulin intravenous infusion therapy. Ten neonates were studied. Blood was drawn for triglyceride, FFA, and insulin assays before initiating and at 1, 2, 3, and 5 days after starting dexamethasone therapy. On day 3, dexamethasone dosage was decreased as per protocol. Intravenous lipid intake was kept constant. Statistical analysis was done using a paired t test.

RESULTS

Six of 10 neonates reached a state of hypertriglyceridemia (95% confidence interval, 26.2%-87.8%). The mean average increase in triglycerides, insulin, and FFA levels in neonates receiving 3 g/kg per day of intravenous lipids after initiation of dexamethasone therapy was 0.75 mmol/L (66.6 mg/dL) (P=.007), 127 pmol/L (P = .006), and 47.5 micromol/L (P = .65), respectively. Six neonates who developed hypertriglyceridemia had significantly elevated mean peak FFA levels (918.3 micromol/L) prior to developing hypertriglyceridemia compared with 4 neonates (mean peak FFA levels, 380.2 micromol/L) who had triglyceride levels lower than 2.82 mmol/L (250 mg/dL) (P = .002).

CONCLUSION

We conclude that dexamethasone induces hypertriglyceridemia in the presence of hyperinsulinemia and increased FFA levels.

Randomized trial of the platelet-activating factor antagonist lexipafant in HIV-associated cognitive impairment. Neurological AIDS Research Consortium

OBJECTIVE

To assess the safety and tolerability of lexipafant in HIV-associated cognitive impairment.

BACKGROUND

Cognitive impairment is the most common neurologic complication of advanced HIV-1 infection. There is evidence that a variety of inflammatory mediators, including platelet-activating factor (PAF), may contribute to neuronal injury. We hypothesized that lexipafant, a PAF antagonist, might improve cognitive dysfunction in HIV-infected people.

METHODS

We conducted a randomized, double-blind, placebo-controlled clinical trial to assess the safety and tolerability of lexipafant 500 mg/day. The primary outcome measure for tolerability was the ability to complete the study on the originally assigned dosage of medication. Thirty patients with cognitive impairment were enrolled.

RESULTS

Lexipafant was safe and well tolerated. Ninety-three percent in the placebo group and 88% in the lexipafant group completed the study at the originally assigned dosage. Trends toward improvement were seen in neuropsychological performance, especially verbal memory, in the lexipafant treatment group.

CONCLUSIONS

This study shows that lexipafant, the first PAF antagonist used in HIV-associated cognitive impairment, is a safe and well tolerated compound. The observed trends toward improvement in neuropsychological test scores warrant the pursuit of a larger and longer efficacy trial to assess the impact of lexipafant on cognitive performance.