HIV-related neuromuscular diseases: nemaline myopathy, amyotrophic lateral sclerosis and bibrachial amyotrophic diplegia.

The human immunodeficiency virus (HIV) causes diverse disorders of the brain, spinal cord and peripheral nerves. Rarely, polymyositis and myoglobinuria are seen. Two other neuromuscular syndromes in people with HIV antibodies are nemaline myopathy and bibrachial amyotrophic diplegia, a form of motor neuron disease. The associations between these diseases and the possibility that HIV infection could be a risk factor for either amyotrophic lateral sclerosis (ALS) itself or other motor neuron diseases are investigated.

Study of 962 patients indicates progressive muscular atrophy is a form of ALS.

BACKGROUND: Progressive muscular atrophy (PMA) is clinically characterized by signs of lower motor neuron dysfunction and may evolve into amyotrophic lateral sclerosis (ALS). Whether PMA is actually a form of ALS has important consequences clinically and for therapeutic trials. We compared the survival of patients with PMA or ALS to analyze the clinical features that influence survival in PMA. METHODS: We reviewed the medical records of patients with PMA (n = 91) or ALS (n = 871) from our ALS Center and verified survival by telephoning the families or using the National Death Index. RESULTS: In PMA, patients were more likely to be male (p < 0.001), older (p = 0.007), and lived longer (p = 0.01) than in ALS. Cox model analysis suggested that the risk of death increased with age at onset in both patient groups (p < 0.005). Upper motor neuron (UMN) signs developed in 22% of patients with PMA within 61 months after diagnosis. Demographic and other clinical variables did not differ at diagnosis between those who did or did not develop UMN signs. In PMA, the factors present at diagnosis that predicted shorter survival were greater number of body regions affected, lower forced vital capacity, and lower ALS Functional Rating Scale-Revised score. Noninvasive ventilation and gastrostomy were used frequently in PMA. CONCLUSION: Although patients with progressive muscular atrophy (PMA) tended to live longer than those with amyotrophic lateral sclerosis (ALS), shorter survival in PMA is associated with the same risk factors that predict poor survival in ALS. Additionally, PMA is relentlessly progressive, and UMN involvement can occur, as also reported in imaging and postmortem studies. For these reasons, PMA should be considered a form of ALS.

Clinical features that distinguish PLS, upper motor neuron-dominant ALS, and typical ALS.

OBJECTIVE: To determine how clinical features at the first evaluation and in follow-up can be used to suggest a diagnostic outcome for patients with only upper motor neuron (UMN) signs at disease onset. METHODS: We reviewed the records of 34 patients (9 primary lateral sclerosis [PLS], 15 UMN-dominant amyotrophic lateral sclerosis [ALS], and 10 randomly selected control patients with ALS) seen in 1984-2007. Analysis of variance F tests for continuous variables and chi2 tests for categorical variables analyzed differences in baseline data among the diagnostic categories. Linear and generalized mixed effects models assessed the relation between examination data and diagnostic group over time. RESULTS: At first examination, the lowest score of the weakest muscle (p < 0.001), the site of onset (p = 0.041), and time to evaluation (p = 0.05) discriminated between eventual diagnostic group; patients with PLS were stronger, slower in progressing, and more likely to have limb onset than the other groups. Strength < or = 4 on any muscle was associated with the diagnosis of ALS (p = 0.0001), but not PLS. Across all visits, muscle strength (p = 0.003), ALS Functional Rating Scale score (p = 0.009), and vital capacity (p = 0.026) predicted group assignment. UMN-dominant and ALS groups had more weight loss (p = 0.004), even when controlled for dysphagia (p = 0.021) and muscle atrophy (p = 0.009), and patients with ALS were more likely to have hyporeflexia (p = 0.001). CONCLUSIONS: Features at baseline most suggestive of eventual lower motor neuron signs were focal muscle weakness or bulbar onset. Later, weight loss, reduced forced vital capacity, and limb weakness predicted lower motor neuron dysfunction. We suggest that patients with only upper motor neuron signs have periodic evaluations of strength, weight, forced vital capacity, Amyotrophic Lateral Sclerosis Functional Rating Scale score, and EMG, because a change in any can signal the imminent development of lower motor neuron signs.

Transcranial magnetic stimulation in ALS: utility of central motor conduction tests.

OBJECTIVE: To investigate transcranial magnetic stimulation (TMS) measures as clinical correlates and longitudinal markers of amyotrophic lateral sclerosis (ALS). METHODS: We prospectively studied 60 patients with ALS subtypes (sporadic ALS, familial ALS, progressive muscular atrophy, and primary lateral sclerosis) using single pulse TMS, recording from abductor digiti minimi (ADM) and tibialis anterior (TA) muscles. We evaluated three measures: 1) TMS motor response threshold to the ADM, 2) central motor conduction time (CMCT), and 3) motor evoked potential amplitude (correcting for peripheral changes). Patients were evaluated at baseline, compared with controls, and followed every 3 months for up to six visits. Changes were analyzed using generalized estimation equations to test linear trends with time. RESULTS: TMS threshold, CMCT, and TMS amplitude correlated (p < 0.05) with clinical upper motor neuron (UMN) signs at baseline and were different (p < 0.05) from normal controls in at least one response. Seventy-eight percent of patients with UMN (41/52) and 50% (4/8) of patients without clinical UMN signs had prolonged CMCT. All three measures revealed significant deterioration over time: TMS amplitude showed the greatest change, decreasing 8% per month; threshold increased 1.8% per month; and CMCT increased by 0.9% per month. CONCLUSIONS: Transcranial magnetic stimulation (TMS) findings, particularly TMS amplitude, can objectively discriminate corticospinal tract involvement in amyotrophic lateral sclerosis (ALS) from controls and assess the progression of ALS. While central motor conduction time and response threshold worsen by less than 2% per month, TMS amplitude decrease averages 8% per month, and may be a useful objective marker of disease progression.

Quantitative objective markers for upper and lower motor neuron dysfunction in ALS.

OBJECTIVE: To investigate the value of objective biomarkers for upper (UMN) and lower (LMN) motor neuron involvement in ALS. METHODS: We prospectively studied 64 patients with ALS and its subsets using clinical measures, proton MR spectroscopic imaging ((1)H MRSI), diffusion tensor imaging, transcranial magnetic stimulation, and the motor unit number estimation (MUNE) at baseline and every 3 months for 15 months and compared them with control subjects. RESULTS: (1)H MRSI measures of the primary motor cortex N-acetyl-aspartate (NAA) concentration were markedly reduced in ALS (p = 0.009) and all UMN syndromes combined (ALS, familial ALS [fALS], and primary lateral sclerosis; p = 0.03) vs control values. Central motor conduction time to the tibialis anterior was prolonged in ALS (p < 0.0005) and combined UMN syndromes (p = 0.001). MUNE was lower in ALS (p < 0.0005) and all LMN syndromes combined (ALS, fALS, and progressive muscular atrophy; p = 0.001) vs controls. All objective markers correlated well with the ALS Functional Rating Scale-Revised, finger and foot tapping, and strength testing, suggesting these markers related to disease activity. Regarding changes over time, MUNE changed rapidly, whereas neuroimaging markers changed more slowly and did not significantly differ from baseline. CONCLUSIONS: (1)H MR spectroscopic imaging measures of the primary motor cortex N-acetyl-aspartate (NAA) concentration and ratio of NAA to creatine, central motor conduction time to the tibialis anterior, and motor unit number estimation significantly differed between ALS, its subsets, and control subjects, suggesting they have potential to provide insight into the pathobiology of these disorders.

Randomized controlled phase II trial of glatiramer acetate in ALS.

The authors conducted a randomized controlled trial to test the safety and immunology of glatiramer acetate in ALS. Twenty treated patients were randomly assigned to daily or biweekly injections. Ten control patients were selected from another trial and followed up concurrently. Injection reactions were the only common adverse event (p = 0.01). Treated patients showed enhanced lymphocyte proliferation (p = 0.02). The safety profile and immune effects support conducting larger trials of dose selection and efficacy.

The natural history of primary lateral sclerosis.

OBJECTIVE: To define the syndrome of primary lateral sclerosis (PLS) and disorders that contain features of both ALS and PLS, to determine the time beyond which PLS is less likely to become ALS clinically, and to determine the outcome of people with PLS and those who develop lower motor neuron (LMN) signs. METHODS: The authors reviewed the records of all 39 patients initially diagnosed with PLS in 1984 to 2004. Diagnostic subgroups were defined based on clinical features. The authors used Kaplan-Meier methods to estimate the time to diagnosis, linear regression analyses to assess function, and a Cox proportional hazard model to assess survival in subgroups. RESULTS: Of the 39 patients, 29 had only upper motor neuron (UMN) signs on initial evaluation. Thirteen of the 29 were later classified as having UMN-dominant ALS (UMN-D) because they acquired evidence of denervation by EMG (3.17 years) or examination (3.67 years). Sixteen of the 29 patients, classified as clinically pure PLS, retained only UMN signs and a normal EMG (mean follow-up 8.7 years). Ten patients who met criteria for ALS at the initial visit were used as controls. The UMN-dominant ALS group had lower functional scores (p = 0.033) than the PLS group, and similar scores to those with ALS. Survival was longer in both the PLS group (p = 0.027) and the UMN-D group (p = 0.067) than the ALS group. CONCLUSIONS: Clinically pure PLS can be defined by isolated UMN signs 4 years after symptom onset, and is a syndrome of slow progression with high levels of function. Prior to the fourth year, the diagnosis of PLS cannot be made with certainty because many patients develop LMN signs. UMN-dominant ALS, defined by predominantly UMN disease with minor LMN signs, has disability similar to ALS, but slower progression.

Challenges and opportunities in clinical trials for spinal muscular atrophy.

Spinal muscular atrophy (SMA) is the most common fatal neuromuscular disease of infancy. SMA type I is the most severe and mortality is usually due to respiratory failure. In type II the disability is of later onset and less severe, and prognosis has improved primarily due to supportive care. Type III is the mildest form with onset usually of weakness in adolescence or young adulthood. SMA is an autosomal recessive disorder with deletions or mutations of the gene at the 5 q11 locus. There is no specific prevention or treatment, but current progress toward potential therapies has been substantial and several candidates including histone deacetylase (HDAC) inhibitors are under consideration for further evaluation. The authors sought to address the challenges and opportunities for testing new therapies for SMA.

Prevalence of depressive disorders and change over time in late-stage ALS.

OBJECTIVE: To determine the prevalence of depressive disorders and symptoms in patients with late-stage ALS, to identify possible risk and protective factors associated with depression, and to determine whether depression increases as death approaches. METHODS: Semistructured interviews were conducted monthly with hospice-eligible patients with ALS and caregivers until the study endpoints of death or tracheostomy. Standardized measures were administered to assess depressive disorders and symptoms, hopelessness, spiritual beliefs, attitudes toward hastened death, quality of life, and related constructs. RESULTS: Sixty-three percent of eligible patients were enrolled. Of the 80 participants, 17 were seen only once; the number of monthly assessments for the others ranged from 2 to 18. For the 53 patients who died, median interval between last assessment and death was 30 days. At study baseline, 81% had no depressive disorder, 10% had minor depression, and 9% had symptoms consistent with major depression. Diagnoses of depression were made on 16% of 369 monthly assessments. Fifty-seven percent of patients never had a depression diagnosis at any visit, and 8% were depressed at all visits. There was no trend toward increasing depression as death approached. Presumed protective factors including spiritual beliefs, spouse as care partner, financial situation, depression in caregiver, and hospice participation did not distinguish between those who were depressed and those who were not. CONCLUSIONS: Results of multiple measures of depression and distress converged to indicate that major depression in people with late-stage ALS is rare, although transient depressive symptoms may occur, and depression does not generally increase as death approaches.

Wish to die in end-stage ALS.

BACKGROUND: In retrospective studies, estimates of hastened dying among seriously ill patients range from <2% in one national survey to as much as 20% in end-stage disease cohorts. OBJECTIVE: To examine, in prospective studies, dying patients in the months before death, in order to understand the wish to die. METHODS: Patients with advanced ALS with a high likelihood of death or need for tracheostomy within 6 months were identified. Patients were assessed monthly with an extensive psychosocial interview, including a diagnostic interview for depression. Family caregivers were interviewed on the same schedule and also after patient deaths. RESULTS: Eighty patients with ALS were enrolled, 63% of eligible patients; 53 died over follow-up. Ten (18.9%) of the 53 expressed the wish to die, and 3 (5.7%) hastened dying. Patients expressing the wish to die did not differ in sociodemographic features, ALS severity, or perceived burden of family caregivers. They were more likely to meet criteria for depression, but differences were smaller when suicidality was excluded from the depression interview. Patients who expressed the wish to die reported less optimism, less comfort in religion, and greater hopelessness. Compared with patients unable to act on the wish to die, patients who hastened dying reported reduction in suffering and increased perception of control over the disease in the final weeks of life. CONCLUSION: These findings suggest caution in concluding that the desire to hasten dying in end-stage disease is simply a feature of depression.

The ALSFRSr predicts survival time in an ALS clinic population.

OBJECTIVE: To determine whether the Amyotrophic Lateral Sclerosis Functional Rating Scale-revised (ALSFRSr), a predictor of survival time in ALS clinical trials, predicts survival time in an ALS clinic population. METHODS: The authors prospectively evaluated 267 consecutive patients with ALS at first visit to an ALS clinic using the ALSFRSr and pulmonary function testing. The association of ALSFRSr score at baseline with death or tracheostomy in ALS was examined using Cox proportional hazards models, adjusting for age at baseline, sex, and symptom duration. RESULTS: Of 267 patients with ALS, 103 (39%) reached the endpoint, defined as either death (79 patients) or tracheostomy (24 patients), during a mean follow-up of 1.0 +/- 0.7 years. Among the 103 patients who reached the endpoint during follow-up, 77 (75%) had a baseline ALSFRSr score of less than 38 (the median baseline score of all patients), compared to 53 of 164 (32%) who remained alive without tracheostomy. Patients with a total ALSFRSr score below the median had a 4.4-fold increased risk of death or tracheostomy compared to those who scored above the median (HR: 4.38, 95% CI: 2.79 to 6.86, p < 0.001). Both the total ALSFRSr score at baseline (HR: 0.94, 95% CI: 0.91 to 0.98, p < 0.001) and forced vital capacity at baseline (HR: 0.99, 95% CI: 0.98 to 1.00, p = 0.02) were associated with death or tracheostomy when included in the same Cox model. CONCLUSIONS: In an ALS clinic population, the total Amyotrophic Lateral Sclerosis Functional Rating Scale-revised score at baseline is a strong predictor of death or tracheostomy independently of forced vital capacity and after adjustment for age at baseline, sex, and symptom duration.

Objective tests for upper motor neuron involvement in amyotrophic lateral sclerosis (ALS).

OBJECTIVE: To develop objective markers for upper motor neuron (UMN) involvement in ALS, the value of single-voxel MR spectroscopy (MRS) and transcranial magnetic stimulation (TMS) was studied. METHODS: Test results of 164 ALS patients who had MRS only (n = 91), TMS only (n = 13), or both (n = 60) were analyzed; also, 11 autopsy examinations were evaluated. RESULTS: Abnormal test results consistent with UMN involvement were found in 134 patients with clinical UMN signs: 86% on MRS, 77% on TMS, and 70% on MRS and TMS together. Among 30 patients with solely LMN signs (progressive muscular atrophy), UMN results were found in 63% on MRS, 63% on TMS, and 46% on both tests together. There was a significant association of the degree of abnormal N-acetyl aspartate/creatine ratios with UMN signs (p = 0.01). The sensitivity to detect UMN involvement was 0.86 for MRS (specificity 0.37) and 0.77 for TMS (specificity 0.38). At autopsy, all 11 patients had pathologic UMN abnormalities, including 4 with normal MRS and 1 with normal TMS in life. CONCLUSIONS: MRS is highly sensitive, somewhat more than TMS, and shows good correlation with clinical UMN signs. Combining MRS and TMS results in the same patient with further refinement may help in the early diagnosis of ALS.

Premorbid weight, body mass, and varsity athletics in ALS.

Several famous athletes have been affected by ALS, and some epidemiologic studies have indicated that vigorous physical activity (heavy labor or athletics) is a risk factor for the disease. In a case-control study of 279 patients with motor neuron diseases and 152 with other neurologic diseases, the authors found that subjects with motor neuron diseases were more likely than controls to report they had always been slim or they had been varsity athletes. For slimness, the odds ratio (OR) was 2.21; 95% CI, 1.40 to 3.47. For varsity athletics, the OR was 1.70; CI, 1.04 to 2.76.

Incidence and predictors of PEG placement in ALS/MND.

In the Project on Death in America ALS cohort, 121 patients were followed to examine the timing of key milestones in the course of the disease, such as tracheostomy and PEG placement. During the 2- to 4-year follow-up period, 26.5% of patients received PEG, yielding a cumulative incidence of 48%. PEG placement occurred, on average, 16 months after patients received confirmation of the diagnosis at our Center. Patients who received PEG were more likely to have tracheostomies than patients not using PEG (p<0.01). In multivariate proportional hazard models that included both sociodemographic and disease indicators, the strongest predictor of PEG use was a patient's baseline preference for PEG: 57.1% of patients "absolutely in favor" went on to have PEG, compared to only 9.3% of those "absolutely against" (p<0.01). PEG users were more likely to have initiated health care proxies. These findings suggest that patients who use PEG may be consistently proactive in the face of the disease.

Inclusion body myositis mimicking motor neuron disease.

OBJECTIVE: To describe the clinical and electrophysiologic features of patients with inclusion body myositis that was misinterpreted as motor neuron disease. PATIENTS AND METHODS: We retrospectively retrieved the medical records of 70 patients with a pathologic diagnosis of inclusion body myositis. From this group, we selected those who had been first diagnosed as having motor neuron disease or amyotrophic lateral sclerosis. We reviewed the clinical, electrophysiologic, laboratory, and morphologic studies. RESULTS: Nine (13%) of 70 patients with inclusion body myositis had been diagnosed as having motor neuron disease. Six of the 9 patients had asymmetric weakness; in 4 the distal arm muscles were affected. Eight patients had finger flexor weakness. Tendon reflexes were preserved in weak limbs in 6, hyperactive in 2, and absent in 1. Four patients had dysphagia. Fasciculation was seen in 2 patients. None had definite upper motor neuron signs or muscle cramps. Routine electromyographic studies showed fibrillation potentials and positive sharp waves in all 9. Fasciculation potentials were seen in 7 and long-duration polyphasic motor unit potentials were seen in 8. There was no evidence of a myogenic disorder in these 9 patients. Muscle biopsy was done because of slow progression or prominent weakness of the finger flexors and was diagnostic of inclusion body myositis. A quantitative electromyogram was myopathic in 4 of the 5 patients studied. CONCLUSIONS: Inclusion body myositis may mimic motor neuron disease. Muscle biopsy and quantitative electromyographic analysis are indicated in patients with atypical motor neuron disease, especially those with slow progression or early and disproportionate weakness of the finger flexors.