1
|
Best AF, Hilbert JE, Wood L, Martens WB, Nikolenko N, Marini-Bettolo C, Lochmüller H, Rosenberg PS, Moxley RT, Greene MH, Gadalla SM. Survival patterns and cancer determinants in families with myotonic dystrophy type 1. Eur J Neurol 2018; 26:58-65. [PMID: 30051542 DOI: 10.1111/ene.13763] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 06/21/2018] [Indexed: 12/22/2022]
Abstract
BACKGROUND AND PURPOSE Research indicates that patients with myotonic dystrophy type 1 (DM1) are at increased risk of cancer and early death. Family data may provide insights given DM1 phenotypic heterogeneity, the broad range of non-muscular manifestations and the usual delays in the diagnosis of DM1. METHOD Family history data were collected from 397 genetically and/or clinically confirmed DM1 patients (respondents) enrolled in the US or UK myotonic dystrophy registries. Standardized mortality ratios were calculated for DM1 first-degree relatives (parents, siblings and offspring) by their reported DM1 status (affected, unaffected or unknown). For cancer-related analyses, mixed effects logistic regression models were used to evaluate factors associated with cancer development in DM1 families, including familial clustering. RESULTS A total of 467 deaths and 337 cancers were reported amongst 1737 first-degree DM1 relatives. Mortality risk amongst relatives reported as DM1-unaffected was comparable to that of the general population [standardized mortality ratio (SMR) 0.82, P = 0.06], whilst significantly higher mortality risks were noted in DM1-affected relatives (SMR = 2.47, P < 0.0001) and in those whose DM1 status was unknown (SMR = 1.60, P < 0.0001). In cancer risk analyses, risk was higher amongst families in which the DM1 respondent had cancer (odds ratio 1.95, P = 0.0001). Unknown DM1 status in the siblings (odds ratio 2.59, P = 0.004) was associated with higher cancer risk. CONCLUSION There is an increased risk of death, and probably cancer, in relatives with DM1 and in those whose DM1 status is unknown. This suggests a need to perform a careful history and physical examination, supplemented by genetic testing, to identify family members at risk for DM1 and who might benefit from disease-specific clinical care and surveillance.
Collapse
Affiliation(s)
- A F Best
- Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| | - J E Hilbert
- Department of Neurology, Neuromuscular Disease Center, University of Rochester Medical Center, Rochester, NY, USA
| | - L Wood
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - W B Martens
- Department of Neurology, Neuromuscular Disease Center, University of Rochester Medical Center, Rochester, NY, USA
| | - N Nikolenko
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - C Marini-Bettolo
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - H Lochmüller
- John Walton Muscular Dystrophy Research Centre, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.,Department of Neuropediatrics and Muscle Disorders, Faculty of Medicine, Medical Center - University of Freiburg, Freiburg, Germany.,Centro Nacional de Análisis Genómico (CNAG-CRG), Center for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - P S Rosenberg
- Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| | - R T Moxley
- Department of Neurology, Neuromuscular Disease Center, University of Rochester Medical Center, Rochester, NY, USA
| | - M H Greene
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| | - S M Gadalla
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA
| |
Collapse
|
2
|
Gadalla SM, Hilbert JE, Martens WB, Givens S, Moxley RT, Greene MH. Pigmentation phenotype, photosensitivity and skin neoplasms in patients with myotonic dystrophy. Eur J Neurol 2017; 24:713-718. [PMID: 28317292 DOI: 10.1111/ene.13276] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 01/04/2017] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND PURPOSE Recent studies have suggested a possible excess risk of skin neoplasms in patients with myotonic dystrophy (DM). Risk factors related to this observation have not been defined. METHOD Information regarding personal history of skin tumors, pigmentation phenotype, and skin reaction to sun exposure were collected from 266 DM patients who were enrolled in the US National Institutes of Health National Registry of Myotonic Dystrophy and Facioscapulohumeral Muscular Dystrophy Patients and Family Members. RESULTS Seventy-seven subjects reported having skin tumors that were either benign (n = 31), malignant (n = 32) or both (n = 14). Female gender [odds ratio (OR) = 2.27, 95% confidence interval (CI) 1.02-5.05, P = 0.04], older age (OR = 1.10, 95% CI 1.05-1.16, P < 0.001) and DM1 subtype (OR = 3.42, 95% CI 1.27-9.26, P = 0.02) were associated with a malignant skin tumor. The associations between malignant skin tumors and known risk factors [light eye color (OR = 1.62, 95% CI 0.78-3.39, P = 0.20), light skin complexion (OR = 1.31, 95% CI 0.63-2.73, P = 0.48) and moderate/extensive face freckles (OR = 1.47, 95% CI 0.50-4.34, P = 0.49)] were modest. Strong, but not statistically significant, associations were noted with sunburn reactions when exposed to sunlight (OR = 4.28, 95% CI 0.91-19.95, P = 0.06, and OR = 2.19, 95% CI 0.67-7.09, P = 0.19, for sunburn with and without blistering, respectively). CONCLUSIONS Although our study was limited by small sample size, the risk factors for malignant skin tumors in DM strongly resemble the general population. It is recommended that DM patients adhere to sun exposure protective behavior.
Collapse
Affiliation(s)
- S M Gadalla
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - J E Hilbert
- Department of Neurology, Neuromuscular Disease Center, University of Rochester Medical Center, Rochester, NY, USA
| | - W B Martens
- Department of Neurology, Neuromuscular Disease Center, University of Rochester Medical Center, Rochester, NY, USA
| | - S Givens
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| | - R T Moxley
- Department of Neurology, Neuromuscular Disease Center, University of Rochester Medical Center, Rochester, NY, USA
| | - M H Greene
- Clinical Genetics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Bethesda, MD, USA
| |
Collapse
|
3
|
|
4
|
Groh WJ, Moss AJ, Logigian EL, Moxley RT. Mexiletine is an effective antimyotonia treatment in myotonic dystrophy type 1. Neurology 2011; 76:409; author reply 409. [DOI: 10.1212/wnl.0b013e3181fe72d7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
5
|
Logigian EL, Martens WB, Moxley RT, McDermott MP, Dilek N, Wiegner AW, Pearson AT, Barbieri CA, Annis CL, Thornton CA, Moxley RT. Mexiletine is an effective antimyotonia treatment in myotonic dystrophy type 1. Neurology 2010; 74:1441-8. [PMID: 20439846 DOI: 10.1212/wnl.0b013e3181dc1a3a] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
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.
Collapse
Affiliation(s)
- E L Logigian
- Department of Neurology, University of Rochester, Rochester, NY, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Moxley RT, Ashwal S, Pandya S, Connolly A, Florence J, Mathews K, Baumbach L, McDonald C, Sussman M, Wade C. Practice parameter: corticosteroid treatment of Duchenne dystrophy: report of the Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society. Neurology 2005; 64:13-20. [PMID: 15642897 DOI: 10.1212/01.wnl.0000148485.00049.b7] [Citation(s) in RCA: 203] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The Quality Standards Subcommittee of the American Academy of Neurology and the Practice Committee of the Child Neurology Society develop practice parameters as strategies for patient management based on analysis of evidence. OBJECTIVE To review available evidence on corticosteroid treatment of boys with Duchenne dystrophy. METHODS Relevant literature was reviewed, abstracted, and classified. Recommendations were based on a four-tiered scheme of evidence classification, and areas for future research are defined. RESULTS Seven class I studies and numerous less rigorous trials all demonstrated that corticosteroid treatment for 6 months with prednisone (0.75 or 1.5 mg/kg/day) increased muscle strength, performance, and pulmonary function and significantly slowed the progression of weakness. Two class I trials examined the effect of lower dosage of prednisone (0.30 and 0.35 mg/kg/day), demonstrated lesser but similar benefits, and showed a lower frequency of side effects (e.g., weight gain). The only significant side effects in all class I trials were weight gain and development of a cushingoid facial appearance. One longer-term trial of daily prednisone (0.3 to 0.7 mg/kg/day), a class III study, showed prolongation of functional ability and slower progression of weakness in patients during 3 years of treatment. One class IV, open trial of alternate-day prednisone (2 mg/kg for 2 months, then two-thirds dose every other day) extended ambulation by approximately 2 years in treated compared with untreated patients. Deflazacort, a corticosteroid similar in structure to prednisone, produced similar improvement in muscle strength and function with a similar side effect profile. CONCLUSIONS Prednisone has been demonstrated to have a beneficial effect on muscle strength and function in boys with Duchenne dystrophy and should be offered (at a dose of 0.75 mg/kg/day) as treatment. If side effects require a decrease in prednisone, tapering to dosages as low as 0.3 mg/kg/day gives less robust but significant improvement. Deflazacort (0.9 mg/kg/day) can also be used for the treatment of Duchenne dystrophy in countries in which it is available. Benefits and side effects of corticosteroid therapy need to be monitored. The offer of treatment with corticosteroids should include a balanced discussion of potential risks.
Collapse
Affiliation(s)
- R T Moxley
- Department of Neurology, University of Rochester School of Medicine and Dentistry, NY, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Logigian EL, Blood CL, Dilek N, Martens WB, Moxley RT, Wiegner AW, Thornton CA, Moxley RT. Quantitative analysis of the “warm-up” phenomenon in myotonic dystrophy type 1. Muscle Nerve 2005; 32:35-42. [PMID: 15880468 DOI: 10.1002/mus.20339] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
To quantitate improvement in hand-grip myotonia and muscle strength (i.e., the "warm-up" phenomenon) in myotonic dystrophy type 1 (DM1), six successive, standardized maximum voluntary isometric contractions (MVICs) were recorded on 2 separate days using a computerized isometric hand-grip myometer in 25 genetically confirmed DM1 patients and in 17 normal controls. An automated computer program placed cursors along the declining (relaxation) phase of the MVICs at 90%, 50%, and 5% of peak force (PF) and calculated relaxation times (RTs) between these points. Mean 90% to 5% RT (a measure of myotonia) rapidly declined from 2.5 s in MVIC 1 to 0.8 s in MVIC 6 (warm-up = 1.7 s) in DM1; in controls, it remained 0.4 s for all six MVICs (warm-up = 0). In DM1, 70% of warm-up occurred between MVIC 1 and 2, almost exclusively in the terminal 50% to 5% phase of muscle relaxation. Day 1 warm-up was highly correlated with the severity of myotonia, and with day 2 warm-up. Improvement in myotonia was not accompanied by either transient paresis or improvement in PF. We conclude that, with this testing paradigm: warm-up of myotonia in DM1 can be reliably measured; is proportional to severity of myotonia; occurs rapidly, being most prominent between the first and second grips; mainly results from shortening of the terminal phase of muscle relaxation; and is not accompanied by significant warm-up in force output.
Collapse
Affiliation(s)
- E L Logigian
- Department of Neurology, University of Rochester Medical Center, Box 673, 601 Elmwood Avenue, Rochester, New York 14642, USA.
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Logigian EL, Moxley RT, Blood CL, Barbieri CA, Martens WB, Wiegner AW, Thornton CA, Moxley RT. Leukocyte CTG repeat length correlates with severity of myotonia in myotonic dystrophy type 1. Neurology 2004; 62:1081-9. [PMID: 15079005 DOI: 10.1212/01.wnl.0000118206.49652.a3] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To quantitate hand muscle myotonia and to assess the relationship between CTG repeat length and myotonia in myotonic dystrophy type 1 (DM1). METHODS First dorsal interosseous twitch and tetanic contractions evoked by single and 10-Hz ulnar nerve stimulation were recorded with a force transducer in 15 patients with genetically confirmed DM1 and 15 control subjects. An automated computer program analyzed three single and three tetanic recordings per subject on 2 successive days by placing cursors along the declining (relaxation) phase of the force recordings at 90, 50, and 5% of peak force (PF) and calculating relaxation times (RT) between these points. RESULTS Tetanic and twitch RT was longer and PF lower in patients than subjects. RT (90 to 5%) was above the normal mean + 2.5 SD in 13 tetanic (87%) and 11 (73%) twitch patient recordings. In DM1, prolongation of RT was due mainly to delay in the terminal (50 to 5%), rather than the initial (90 to 50%) phase of relaxation, and was much greater in tetanic than single-twitch recordings. Mean test-retest variability was 19% for tetanic RT and 16% for tetanic PF. In DM1, both tetanic and twitch RT were positively correlated with leukocyte CTG repeat length. CONCLUSIONS In DM1, myotonia of intrinsic hand muscles can be quantitated reliably by automated analysis of tetanic and twitch RT, targeting, in particular, the terminal phase of muscle relaxation after tetanic stimulation. Severity of hand muscle myotonia depends on CTG repeat length consistent with a "triplet repeat dosage" effect on chloride channel mRNA splicing and function.
Collapse
Affiliation(s)
- E L Logigian
- Department of Neurology, University of Rochester, NY, USA.
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Meola G, Sansone V, Perani D, Scarone S, Cappa S, Dragoni C, Cattaneo E, Cotelli M, Gobbo C, Fazio F, Siciliano G, Mancuso M, Vitelli E, Zhang S, Krahe R, Moxley RT. Executive dysfunction and avoidant personality trait in myotonic dystrophy type 1 (DM-1) and in proximal myotonic myopathy (PROMM/DM-2). Neuromuscul Disord 2003; 13:813-21. [PMID: 14678804 DOI: 10.1016/s0960-8966(03)00137-8] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A previous study in proximal myotonic myopathy (PROMM/DM-2) and myotonic dystrophy type 1 (DM-1) using brain positron emission tomography demonstrated a reduced cerebral blood flow in the frontal and temporal regions associated with cognitive impairment. The objective was to investigate further cognitive and behavioural aspects in a new series of patients with DM-1 and PROMM/DM-2. Nineteen patients with genetically determined PROMM/DM-2 and 21 patients with moderately severe DM-1 underwent neuropsychological testing and neuropsychiatric interviews. DM-1 and PROMM/DM-2 patients had significantly lower scores on tests of frontal lobe function compared to controls. Neuropsychiatric interviews demonstrated an avoidant trait personality disorder in both patient groups. Brain single photon emission computed tomography showed frontal and parieto-occipital hypoperfusion. The results suggest that there is a specific cognitive and behavioural profile in PROMM/DM-2 and in DM-1, and that this profile is associated with hypoperfusion in frontal and parieto-occipital regions of the brain.
Collapse
Affiliation(s)
- G Meola
- Department of Neurology, University of Milan, San Donato Hospital, Via Morandi 30, San Donato Milanese, 20097 Milan, Italy.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Abstract
Cardiac involvement in myotonic dystrophy type 1 (DM1) is well known. In contrast, the severity and frequency of cardiac abnormalities in proximal myotonic myopathy (PROMM) are still unclear. To identify similarities and differences in the rate of progression of muscle weakness and cardiac disturbances in these two disorders, 16 patients with PROMM (3q-unlinked PROMM: n=10; uniformative for linkage: n=6) were compared to 33 patients with moderately severe myotonic dystrophy type 1 (DM1). There was no significant difference in disease duration between PROMM and DM1. Patients underwent serial manual muscle strength testing, EKG, 24-h Holter monitoring, 2D-echocardiography. Muscle weakness progressed slowly in both groups. Most DM1 patients developed conduction defects. No significant atrioventricular disturbances on initial and follow-up examinations were found in PROMM patients. One patient developed right bundle branch block. Many families with PROMM appear to have more benign cardiac manifestations and less severe prognosis compared to DM1. Further studies of subgroups of PROMM (linked to the 3q21 locus and without linkage) are necessary to determine whether the cardiac conduction disturbances are more common in a specific genotype of PROMM.
Collapse
Affiliation(s)
- Giovanni Meola
- Department of Neurology, University of Milan, Istituto Policlinico San Donato, Via Morandi, 30 20097, San Donato Milanese, Milan, Italy.
| | | | | | | | | | | | | |
Collapse
|
11
|
Mankodi A, Urbinati CR, Yuan QP, Moxley RT, Sansone V, Krym M, Henderson D, Schalling M, Swanson MS, Thornton CA. Muscleblind localizes to nuclear foci of aberrant RNA in myotonic dystrophy types 1 and 2. Hum Mol Genet 2001; 10:2165-70. [PMID: 11590133 DOI: 10.1093/hmg/10.19.2165] [Citation(s) in RCA: 313] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The phenotypes in myotonic dystrophy types 1 and 2 (DM1 and DM2) are similar, suggesting a shared pathophysiologic mechanism. DM1 is caused by expansion of a CTG repeat in the DMPK gene. Pathogenic effects of this mutation are likely to be mediated, at least in part, by the expanded CUG repeat in mutant mRNA. The mutant transcripts are retained in the nucleus in multiple discrete foci. We investigated the possibility that DM2 is also caused by expansion of a CTG repeat or related sequence. Analysis of DNA by repeat expansion detection methods, and RNA by ribonuclease protection, did not show an expanded CTG or CUG repeat in DM2. However, hybridization of muscle sections with fluorescence-labeled CAG-repeat oligonucleotides showed nuclear foci in DM2 similar to those seen in DM1. Nuclear foci were present in all patients with symptomatic DM1 (n = 9) or DM2 (n = 9) but not in any disease controls or healthy subjects (n = 23). The foci were not seen with CUG- or GUC-repeat probes. Foci in DM2 were distinguished from DM1 by lower stability of the probe-target duplex, suggesting that a sequence related to the DM1 CUG expansion accumulates in the DM2 nucleus. Muscleblind proteins, which interact with expanded CUG repeats in vitro, localized to the nuclear foci in both DM1 and DM2. These results support the idea that nuclear accumulation of mutant RNA is pathogenic in DM1, suggest that a similar disease process occurs in DM2, and point to a role for muscleblind in the pathogenesis of both disorders.
Collapse
Affiliation(s)
- A Mankodi
- Department of Neurology, School of Medicine and Dentistry, University of Rochester, 601 Elmwood Avenue, Rochester, NY 14642, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Musser WS, Barbano RL, Thornton CA, Moxley RT, Herrmann DN, Logigian EL. Distal myasthenia gravis with a decrement, an increment, and denervation. J Clin Neuromuscul Dis 2001; 3:16-19. [PMID: 19078648 DOI: 10.1097/00131402-200109000-00004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We present two patients with distal myasthenia gravis poorly responsive to immunomodulatory therapy. In addition to a typical decrement on slow repetitive nerve stimulation, both had borderline to low compound muscle action potential (CMAP) amplitudes, a large increment in CMAP amplitude and area after exercise, and active denervation in distal muscles. Both had elevated acetylcholine receptor antibody (AChR Ab) levels, but normal voltage-gated calcium channel antibody levels. We hypothesize that these electrophysiological findings represent a more severe form of myasthenia gravis.
Collapse
Affiliation(s)
- W S Musser
- From the EMG Laboratory and Neuromuscular Disease Center, Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, New York
| | | | | | | | | | | |
Collapse
|
13
|
Fenichel GM, Griggs RC, Kissel J, Kramer TI, Mendell JR, Moxley RT, Pestronk A, Sheng K, Florence J, King WM, Pandya S, Robison VD, Wang H. A randomized efficacy and safety trial of oxandrolone in the treatment of Duchenne dystrophy. Neurology 2001; 56:1075-9. [PMID: 11320181 DOI: 10.1212/wnl.56.8.1075] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND A pilot study suggested that oxandrolone, an anabolic steroid, improved strength in boys with Duchenne dystrophy (DD) and indicated the need for a more definitive study. METHODS A 6-month, randomized, double-blind, placebo-controlled study of oxandrolone in boys with an established diagnosis of DD, using the change from baseline to 6 months in the average muscle strength score (MMT) as the primary efficacy measure. RESULTS The mean change from baseline for the oxandrolone group was +0.035 and that for the placebo group was -0.140. Although the oxandrolone group did not get worse and the placebo patients showed some deterioration in strength, the difference was not significant (p = 0.13). The average of the four quantitative muscle tests (QMT) showed a significant improvement in the oxandrolone-treated boys as compared with placebo. No adverse reactions attributable to oxandrolone were recorded. CONCLUSIONS Although oxandrolone did not produce a significant change in the average manual muscle strength score as compared with placebo, the mean change in QMT was significant. Because oxandrolone is safe, accelerates linear growth, and may have some beneficial effect in slowing the progress of weakness, it may be useful before initiating corticosteroid therapy.
Collapse
Affiliation(s)
- G M Fenichel
- Department of Neurology, Ohio State University College of Medicine, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Forbes GB, Griggs RC, Moxley RT, Thornton CT, Tawil R. K-40 and dual-energy X-ray absorptiometry estimates of lean weight compared. Normals and patients with neuromuscular disease. Ann N Y Acad Sci 2000; 904:111-4. [PMID: 10865720 DOI: 10.1111/j.1749-6632.2000.tb06431.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- G B Forbes
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, New York 14642, USA.
| | | | | | | | | |
Collapse
|
15
|
Abstract
No specific diagnostic test is available to identify patients with proximal myotonic myopathy and to distinguish them from common disorders causing similar complaints. We describe three patients from three separate families who were initially diagnosed as having hypothyroid myopathy. Proximal weakness, stiffness and myotonia have persisted in each patient (2-10 years) despite the restoration of the euthyroid state. A familial pattern of autosomal dominant inheritance for proximal weakness, myotonia, and cataracts was clearly identified in one family and was likely in the other two families. DNA testing showed normal size of CTG repeat in the gene for myotonic dystrophy. The clinical presentation of these three patients strongly suggests that hypothyroidism can unmask PROMM in asymptomatic individuals who carry the genetic abnormality. Other cases of 'hypothyroid myopathy' may represent examples of unmasked PROMM.
Collapse
Affiliation(s)
- V Sansone
- Department of Neurology, University of Milan, San Donato Hospital, Via Morandi, 30, 20097 San Donato Milanese, Milan, Italy.
| | | | | |
Collapse
|
16
|
Meola G, Sansone V, Perani D, Colleluori A, Cappa S, Cotelli M, Fazio F, Thornton CA, Moxley RT. Reduced cerebral blood flow and impaired visual-spatial function in proximal myotonic myopathy. Neurology 1999; 53:1042-50. [PMID: 10496264 DOI: 10.1212/wnl.53.5.1042] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To compare brain involvement in myotonic dystrophy (DM) with that of proximal myotonic myopathy (PROMM). BACKGROUND PROMM is a multisystem disease with many features in common with DM. METHODS Twenty patients with DM (CTGF[500-700), 20 patients with PROMM, and 20 normal control subjects were studied. Neuropsychological testing was performed in 12 patients with PROMM and in 18 patients with DM; brain MRI was performed in 17 of 20 PROMM patients and 15 of 20 DM patients. Ten patients with PROMM and 11 patients with DM were subjected to H2(15)O PET. RESULTS Two-thirds of the patients with PROMM and one-half of those with DM were impaired on visual-spatial recall, whereas one-third of the patients with PROMM and less than half of those with DM showed an impairment in visual-spatial construction. Brain MRI was normal, or showed only nonspecific white matter abnormalities in both PROMM and DM patients. PET studies in PROMM patients showed a bilateral decrease in regional cerebral blood flow (rCBF) of the orbitofrontal and medial frontal cortex, whereas DM patients had more widespread hypoperfusion that extended to the dorsolateral frontal cortex and subcortical regions. CONCLUSIONS Impaired visual-spatial function may be present in proximal myotonic myopathy. This correlates best with a reduction in regional cerebral blood flow observed in H2(15)O PET brain scans rather than with specific structural abnormalities observed on brain MRI.
Collapse
Affiliation(s)
- G Meola
- Department of Neurology, H. San Raffaele, University of Milan, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Duong DJ, Spigel GT, Moxley RT, Gaspari AA. American experience with low-dose thalidomide therapy for severe cutaneous lupus erythematosus. Arch Dermatol 1999; 135:1079-87. [PMID: 10490113 DOI: 10.1001/archderm.135.9.1079] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND There is a renewed interest in thalidomide therapy after its surprising effectiveness in treating erythema nodosum leprosum was first published. Thalidomide has subsequently been reported to be effective in treating a number of dermatoses, including cutaneous lupus erythematosus. We examined the efficacy and adverse effects of low-dose, long-term thalidomide monotherapy in 7 patients with various forms of cutaneous lupus erythematosus that were unresponsive to traditional systemic treatments. OBSERVATIONS Six of the 7 patients treated with thalidomide after discontinuation of other oral agents had complete or marked resolution of their previously treatment-resistant cutaneous lesions, with an average response time of 2.2+/-0.8 months. Our cohort of 7 patients with cutaneous lupus erythematosus was treated with thalidomide therapy for an average of 2.4+/-3.1 years (range, 1 month to 9 years). The most common adverse effects were sedation, constipation, and weight gain. Two patients reported experiencing intermittent shaking episodes, an adverse effect not previously reported in the literature. Four patients reported symptoms of paresthesia, but none was found to be caused by thalidomide-induced peripheral neuropathy. CONCLUSIONS A low starting dose of thalidomide as a monotherapy with continued sun avoidance is a safe and effective treatment for the various cutaneous manifestations of lupus erythematosus after traditional therapeutic options have failed to control disease. Our experience with low-dose, long-term thalidomide therapy suggests that peripheral neuropathy is not as common as suggested by other studies (up to 50% of patients treated with thalidomide in some series).
Collapse
|
18
|
|
19
|
Moxley RT. 54th ENMC International Workshop: PROMM (proximal myotonic myopathies) and other proximal myotonic syndromes. 10-12th October 1997, Naarden, The Netherlands. Neuromuscul Disord 1998; 8:508-18. [PMID: 9829282 DOI: 10.1016/s0960-8966(98)00068-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
20
|
Menken M, Goldblatt D, Moxley RT, Hachinski V. Managed care and the survival of neurology referral centers. A commitment to centers of excellence. Arch Neurol 1997; 54:1349-50. [PMID: 9362980 DOI: 10.1001/archneur.1997.00550230026010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Since the collapse of federal health system reform legislation in 1994, there has been a growing concern with the quality of care provided within managed care systems. Just as physicians practicing under a traditional fee-for-service payment base have financial incentives to do as much as possible for each patient (doing well by doing good), physicians working for managed care plans are sometimes given perverse incentives to do as little as possible. A major quality-related concern among patients and payers (often referred to jointly and ambiguously as consumers of care) is the much larger role assigned to primary care physicians in managed care plans than is usually the case with traditional indemnity insurance.
Collapse
Affiliation(s)
- M Menken
- Department of Medicine, Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | | | | | | |
Collapse
|
21
|
Thornton CA, Wymer JP, Simmons Z, McClain C, Moxley RT. Expansion of the myotonic dystrophy CTG repeat reduces expression of the flanking DMAHP gene. Nat Genet 1997; 16:407-9. [PMID: 9241283 DOI: 10.1038/ng0897-407] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Myotonic dystrophy, or dystrophia myotonica (DM), is a highly variable multisystem disease in which the classic adult-onset form displays progressive muscle wasting, cataracts, heart block, gonadal atrophy, insulin resistance and neuropsychiatric impairment. Its genetic basis is an expansion of CTG trinucleotide repeats in the DMPK protein kinase gene. Among the triplet repeat expansion disorders, DM is distinguished by the extended length of the repeat tract (5-13 kb in postmortem tissue) and its location in the 3' untranslated region of the gene that contains it. The pathophysiological mechanism for multisystem degeneration in DM is not understood. In contrast to the profound muscle wasting that characterizes advanced DM, only minor histopathological abnormalities have occurred in DMPK knockout mice or in mice that overexpress a human DMPK transgene, making it unlikely that changes in DMPK activity provide a unitary explanation for the disease. A DNAse hypersensitive site that maps 0.7 kb downstream (centromeric) from the CTG repeats is eliminated on DM chromosomes. This finding indicates that the repeat expansion may alter the adjacent chromatin structure and raises the possibility that it may also affect the expression of flanking genes. An interesting candidate flanking gene is DMAHP, a recently discovered homeodomain-encoding gene. We show here that DMAHP expression in myoblasts, muscle and myocardium is reduced by the DM mutation is cis, and the magnitude of this effect depends on the extent of CTG repeat expansion. These observations support the hypothesis that DMAHP participates in the pathophysiology of DM.
Collapse
Affiliation(s)
- C A Thornton
- Department of Neurology, School of Medicine and Dentistry, University of Rochester, NY 14642, USA
| | | | | | | | | |
Collapse
|
22
|
|
23
|
Abstract
The recent discoveries that mutations in the genes for the skeletal muscle sodium and chloride channels are responsible, respectively, for paramyotonia/hyperkalemic periodic paralysis and for myotonia congenita of Thomsen have made the classification, diagnosis, and treatment of these disorders much easier. The discovery that myotonic dystrophy results from an unstable [CTG]n trinucleotide expansion has permitted the accurate diagnosis of both symptomatic and asymptomatic individuals, and has led to major advances in preventive treatment, including prenatal and genetic counseling. Diseases that resemble the inherited myotonic disorders are now easier to identify, and as a result of genetic testing a new clinical disorder that is similar to but distinct from myotonic dystrophy has emerged. This new disorder, proximal myotonic myopathy, does not appear to be linked to the genes for the sodium or chloride channels, and has cataracts, myotonia, weakness, and no abnormal expansion of the [CTG]n repeat in the gene for myotonic dystrophy. This review discusses the diagnosis and treatment of these myotonic disorders.
Collapse
Affiliation(s)
- R T Moxley
- Department of Neurology, University of Rochester School of Medicine and Dentistry, NY 14642, USA
| |
Collapse
|
24
|
DiDonato CJ, Ingraham SE, Mendell JR, Prior TW, Lenard S, Moxley RT, Florence J, Burghes AH. Deletion and conversion in spinal muscular atrophy patients: is there a relationship to severity? Ann Neurol 1997; 41:230-7. [PMID: 9029072 DOI: 10.1002/ana.410410214] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The spinal muscular atrophy-determining gene, survival motor neuron (SMN), is present in two copies, telSMN and cenSMN, which can be distinguished by base-pair changes in exons 7 and 8. The telSMN gene is often absent in spinal muscular atrophy patients, which could be due to deletion or sequence conversion (telSMN conversion to cenSMN giving rise to two cenSMN genes). To test for conversion events in spinal muscular atrophy, we amplified a 1-kb fragment that spanned exons 7 and 8 of SMN from 5 patients who retained telSMN exon 8 but lacked exon 7. In all patients, sequence analysis demonstrated that cenSMN exon 7 was adjacent to telSMN exon 8, indicating conversion. All 5 patients with this mutation had type II or III spinal muscular atrophy, strongly supporting an association with chronic spinal muscular atrophy. We also identified 3 families in which 2 siblings had no detectable telSMN but presented with markedly different phenotypes. We suggest that sequence conversion is a common event in spinal muscular atrophy and is associated with the milder form of the disease. The severity, however, can be modified in either a positive or negative direction by other factors that influence splicing or expression of the sequence converted SMN gene.
Collapse
Affiliation(s)
- C J DiDonato
- Department of Molecular Genetics, College of Biological Sciences, Ohio State University, Columbus, USA
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Moxley RT. The myotonias: their diagnosis and treatment. Compr Ther 1996; 22:8-21. [PMID: 8654027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
MESH Headings
- Adolescent
- Adult
- Aged
- Child
- Child, Preschool
- Chloride Channels/genetics
- Chromosomes, Human, Pair 19
- DNA Mutational Analysis
- Diagnosis, Differential
- Female
- Genes, Dominant/genetics
- Genes, Recessive/genetics
- Humans
- Hyperkalemia/classification
- Hyperkalemia/diagnosis
- Hyperkalemia/genetics
- Infant
- Infant, Newborn
- Male
- Middle Aged
- Myotonia/classification
- Myotonia/diagnosis
- Myotonia/genetics
- Myotonia Congenita/classification
- Myotonia Congenita/diagnosis
- Myotonia Congenita/genetics
- Myotonic Dystrophy/classification
- Myotonic Dystrophy/diagnosis
- Myotonic Dystrophy/genetics
- Paralyses, Familial Periodic/classification
- Paralyses, Familial Periodic/diagnosis
- Paralyses, Familial Periodic/genetics
- Protein Kinases/genetics
- Sodium Channels/genetics
- Trinucleotide Repeats/genetics
Collapse
Affiliation(s)
- R T Moxley
- University of Rochester School of Medicine and Dentistry, Department of Neurology, New York 14642, USA
| |
Collapse
|
26
|
Thornton C, Griggs RC, Moxley RT. PROMM syndrome (Ricker's disease). Ann Neurol 1995; 38:273. [PMID: 7654079 DOI: 10.1002/ana.410380224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
27
|
|
28
|
Ricker K, Koch MC, Lehmann-Horn F, Pongratz D, Speich N, Reiners K, Schneider C, Moxley RT. Proximal myotonic myopathy. Clinical features of a multisystem disorder similar to myotonic dystrophy. Arch Neurol 1995; 52:25-31. [PMID: 7826272 DOI: 10.1001/archneur.1995.00540250029009] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Previous investigations in three families have shown that proximal myotonic myopathy (PROMM) is not linked to the gene loci for myotonic dystrophy (DM) or to the loci of the genes of the muscle sodium and chloride channels associated with other myotonic disorders. It is important to extend our clinical knowledge of this interesting new disorder by studying other families. PATIENTS Thirty-five patients in 14 new families; 27 patients were examined. METHODS Clinical examination, electromyography, muscle biopsy, DNA analysis. RESULTS The following findings were noted: proximal without distal weakness of the legs (n = 21); myotonia on electromyograms (n = 23); intermittent clinical myotonia (n = 17); cataracts (n = 24) and a number of the cataracts were identical to the type in DM (n = 11); and peculiar muscle pain (n = 14). A few patients had cardiac arrhythmias, and others had elevations in the concentrations of serum gamma-glutamyltransferase. None of the patients had significant muscle atrophy. Muscle biopsy specimens showed mild myopathic changes. All patients had normal trinucleotide (cytosine, thymine, and guanine) repeat size of the DM gene in leukocyte DNA. Muscle DNA probes from three patients showed findings identical to those of their leukocyte DNA probes. CONCLUSIONS Proximal myotonic myopathy is a new genetic disorder similar to, but distinct from, DM. Patients suspected of having DM but with negative DNA studies may have PROMM. The gene defect for PROMM awaits discovery. Because of the similarities between PROMM and DM, this discovery will not only shed light on the pathomechanism of PROMM, but it may also increase our understanding of DM.
Collapse
Affiliation(s)
- K Ricker
- Department of Neurology, University of Würzburg, Germany
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Abstract
Prednisone improves strength in Duchenne dystrophy and changes the natural history of the disease. We studied the in vivo effects of prednisone (0.75 mg.kg-1.day-1) on muscle and whole body protein metabolism in six patients with Duchenne dystrophy and three patients with Becker dystrophy. Patients were admitted to the Clinical Research Center for study and consumed a constant flesh-free diet. Strength was measured by manual and quantitative muscle testing. Fractional muscle protein breakdown was estimated by the ratio of 3-methylhistidine to creatinine excretion determined in three consecutive 24-h urine collections. Whole body protein kinetics were studied in the postabsorptive state using a primed continuous infusion of L-[1-13C]leucine. Fractional muscle protein synthesis was determined from tracer incorporation into noncollagen muscle protein obtained by needle biopsy. After 6-8 wk of prednisone treatment, average muscle strength increased by 15% (P < 0.04), and 24-h creatinine excretion (an index of muscle mass) increased by 21% (P = 0.002). 3-Methylhistidine excretion decreased by 10%, but the change was not statistically significant. The ratio of 3-methylhistidine to creatinine excretion decreased by 26% (P < 0.04). Fractional muscle protein synthesis and whole body protein synthesis and breakdown did not change significantly. We conclude that the beneficial effect of prednisone on strength in Duchenne dystrophy appears to be associated with an increase in muscle mass, which may be mediated by inhibition of muscle proteolysis rather than stimulation of muscle protein synthesis.
Collapse
Affiliation(s)
- Z Rifai
- Department of Neurology, University of Rochester, New York 14642
| | | | | | | | | |
Collapse
|
30
|
Abstract
OBJECTIVES To define a new type of dominant myotonic muscle disorder and to identify the gene lesion. DESIGN Case series, clinical examination and electromyography, measurements of grip force and relaxation time, and DNA analysis to probe for mutation in the gene for the skeletal muscle sodium channel. SETTING Outpatient clinic and home. PATIENTS Three families studied; all together, 17 affected and nine unaffected individuals. RESULTS The findings in these three families confirm the existence of myotonia fluctuans as we described it previously in another family. Myotonia (prolongation of relaxation time) developed 20 to 40 minutes after exercise. Potassium caused generalized myotonia. Cooling had no major effect on muscle function. Three families had a common mutation in exon 22 and one family had a mutation in exon 14 of the gene for the sodium channel alpha subunit. CONCLUSIONS Myotonia fluctuans is a disorder of the muscle sodium channel. There are at present two other distinct clinical muscle disorders associated with mutations in the sodium channel: hyperkalemic periodic paralysis and paramyotonia congenita. The findings in the present report indicate that myotonia fluctuans belongs to a third type of sodium channel disorder. Further work is needed to understand the complex genotype-phenotype correlations in sodium channel disorders.
Collapse
Affiliation(s)
- K Ricker
- Department of Neurology, University of Würzburg, Germany
| | | | | | | |
Collapse
|
31
|
Moxley RT. Evaluation of neuromuscular function in inflammatory myopathy. Rheum Dis Clin North Am 1994; 20:827-43. [PMID: 7855324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The assessment of neuromuscular function during the course of treatment in patients with inflammatory myopathy requires a combination of tests tailored to the clinical status of the patient. The use of timed functional tests, pulmonary function, functional grading, and manual muscle strength testing (coordinated with a physical therapist) provides the clinician and patient with reliable, easily performed measurements that are flexible enough for virtually all outpatient settings. Some patients may require assessment with only timed functional tests, such as the time to run 30 feet, climb four steps, and arise from supine to standing; other patients may need an assessment that uses function tests, functional grade scoring, and manual muscle strength testing. The 24-hour urinary excretion of creatinine is a simple method to measure changes in muscle mass, and determinations at 3- to 6-month intervals may provide a useful means to document the effects of treatment. Occasionally, more elaborate methods, such as MR imaging of muscle may be necessary to identify persistent inflammation in certain muscles or aid in the selection of a specific area of muscle to biopsy. The use of myometry, especially fixed myometry with QMT, is most suitable for clinical research. In the future, hand-held myometric equipment and, perhaps, even QMT, may become more adaptable to office practice, and their use will be more feasible for the routine care of patients with inflammatory myopathy.
Collapse
Affiliation(s)
- R T Moxley
- University of Rochester Medical Center, New York
| |
Collapse
|
32
|
Abstract
The recent development of recombinant human growth hormone (GH) and insulin-like growth factor 1 (IGF-1) has provided the opportunity to study the effects of these growth factors in humans. The majority of studies have been performed in healthy young and older adults. Both GH and IGF-1 have shown very positive effects on muscle protein anabolism. Relatively few side effects have developed. Initial studies have shown a beneficial effect of GH in reversing the catabolic actions of oral prednisone, and GH treatment has led to an increase in muscle mass and protein synthesis in pilot studies of myotonic dystrophy. Combination therapy in normal subjects using both GH and IGF-1 has shown encouraging results. There is a greater enhancement of protein anabolism during combined treatment than there is with either agent alone, and concomitant therapy with GH diminished the side effects of IGF-1. It is now feasible to consider therapeutic trials in patients. Future studies of GH and IGF-1 treatment in patients with primary muscle disease and in patients receiving long-term corticosteroid therapy are needed.
Collapse
Affiliation(s)
- R T Moxley
- University of Rochester School of Medicine, Department of Neurology, NY 14642
| |
Collapse
|
33
|
Ricker K, Koch MC, Lehmann-Horn F, Pongratz D, Otto M, Heine R, Moxley RT. Proximal myotonic myopathy: a new dominant disorder with myotonia, muscle weakness, and cataracts. Neurology 1994; 44:1448-52. [PMID: 8058147 DOI: 10.1212/wnl.44.8.1448] [Citation(s) in RCA: 144] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We describe three families with a dominantly inherited disorder. Affected individuals have myotonia, proximal muscle weakness, and cataracts. There was no abnormal CTG repeat expansion of the myotonic dystrophy (DM) gene in DNA from blood and muscle. The structure of the three families permitted linkage analysis, and there is no linkage to the gene loci for DM or to the loci for the muscle chloride channel disorders or muscle sodium channel disorders. The collection of symptoms in these three families seems to represent a new disorder.
Collapse
Affiliation(s)
- K Ricker
- Department of Neurology, University of Würzburg, Germany
| | | | | | | | | | | | | |
Collapse
|
34
|
Prior TW, Papp AC, Snyder PJ, Sedra MS, Western LM, Bartolo C, Moxley RT, Mendell JR. Heteroduplex analysis of the dystrophin gene: application to point mutation and carrier detection. Am J Med Genet 1994; 50:68-73. [PMID: 8160755 DOI: 10.1002/ajmg.1320500115] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Approximately one-third of the Duchenne muscular dystrophy patients have undefined mutations in the dystrophin gene. For carrier and prenatal studies in families without detectable mutations, the indirect restriction fragment length polymorphism linkage approach is used. Using a multiplex amplification and heteroduplex analysis of dystrophin exons, we identified nonsense mutations in two DMD patients. Although the nonsense mutations are predicted to severely truncate the dystrophin protein, both patients presented with mild clinical courses of the disease. As a result of identifying the mutation in the affected boys, direct carrier studies by heteroduplex analysis were extended to other relatives. We conclude that the technique is not only ideal for mutation detection but is also useful for diagnostic testing.
Collapse
Affiliation(s)
- T W Prior
- Department of Pathology, Ohio State University, Columbus 43210
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Abstract
We report 3 patients from 2 families with myotonic dystrophy who do not show an abnormal expansion of CTG trinucleotide repeats within the myotonic dystrophy gene. Characteristic features of myotonic dystrophy in these patients were frontal balding, cataracts, cardiac conduction abnormalities, and testicular atrophy with myotonia and muscle weakness. Results of muscle histopathology were consistent with myotonic dystrophy. Genetic analysis of leukocyte and muscle DNA showed a normal number of CTG repeats. The demonstration of normal CTG repeat number for the myotonic dystrophy gene does not exclude the diagnosis of myotonic dystrophy.
Collapse
Affiliation(s)
- C A Thornton
- Neuromuscular Disease Center, University of Rochester School of Medicine and Dentistry, NY 14620
| | | | | |
Collapse
|
36
|
Abstract
The genetic basis of myotonic dystrophy is an unstable expansion of CTG repeats located in a gene on chromosome 19 that encodes a putative serine/threonine protein kinase. We studied the somatic mosaicism of the (CTG)n expansion in myotonic dystrophy patients. (CTG)n expansions were 2- to 13-fold greater in DNA isolated from skeletal muscle than in DNA from leukocytes in 10 of 11 patients with myotonic dystrophy. Different muscles of the same individual showed similar (CTG)n expansions. In postmortem tissues from an adult patient, (CTG)n expansions in brain, skeletal muscle, cardiac muscle, testes, and liver were all greater than in leukocytes. Normal myotonic dystrophy gene alleles from 7 healthy subjects had the same number of CTG repeats in leukocytes and muscle. The myotonic dystrophy mutation displays pronounced heterogeneity in somatic cells. The (CTG)n expansion observed in peripheral blood leukocytes is not necessarily representative of the repeat expansion in affected tissues, such as skeletal muscle and myocardium. In some patients with myotonic dystrophy, the predictive value of genetic analysis based on leukocyte DNA may be limited.
Collapse
Affiliation(s)
- C A Thornton
- Department of Neurology, University of Rochester Medical Center, NY 14642
| | | | | |
Collapse
|
37
|
Abstract
Myotonic dystrophy is associated with progressive muscular atrophy. To define the mechanism of muscle wasting in this disease, we studied myofibrillar proteolysis in vivo in 8 men moderately affected with myotonic dystrophy, and compared the results with those of 10 normal men. Myofibrillar proteolysis was estimated by measuring the 3-methylhistidine arteriovenous difference (A-V) and efflux (Q) across the forearm in the postabsorptive state. Plasma 3-methylhistidine concentrations were determined by high-performance liquid chromatography with postcolumn o-phthalaldehyde derivatization and fluorescence detection. Plasma flow to the forearm muscles (F) was estimated to represent 85% of total forearm plasma flow as determined by the indicator-dilution technique. Forearm 3-methylhistidine efflux was calculated as: Q = F(A-V). Mean muscle mass (24-hour creatinine excretion), lean body mass, and forearm volume were decreased in the patients with myotonic dystrophy, confirming the presence of muscle atrophy. Mean forearm 3-methylhistidine arteriovenous difference and efflux were not significantly different in the two groups. We conclude that myofibrillar protein degradation is not increased in myotonic dystrophy, even when measured in a muscle compartment selectively affected by wasting. Muscle atrophy in myotonic dystrophy is probably the result of defective anabolism rather than accelerated catabolism.
Collapse
Affiliation(s)
- Z Rifai
- Department of Neurology, University of Rochester, NY 14642
| | | | | | | |
Collapse
|
38
|
Abstract
Carbonic anhydrase inhibitors can cause nephrolithiasis. We studied 20 patients receiving long-term carbonic anhydrase inhibitor treatment for periodic paralysis and myotonia. Three patients on acetazolamide (15%) developed renal calculi. Extracorporeal lithotripsy successfully removed a renal calculus in one patient and surgery removed a staghorn calculus in another, permitting continued treatment. Renal function remained normal in all patients. Nephrolithiasis is a complication of acetazolamide but does not preclude its use.
Collapse
Affiliation(s)
- R Tawil
- Neuromuscular Disease Center, University of Rochester School of Medicine and Dentistry, NY 14642
| | | | | |
Collapse
|
39
|
Livingston JN, Unger JW, Moxley RT, Moss A. Phosphotyrosine-containing proteins in the CNS of obese Zucker rats are decreased in the absence of changes in the insulin receptor. Neuroendocrinology 1993; 57:481-8. [PMID: 7686643 DOI: 10.1159/000126395] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The location and quantity of the insulin receptor and its associated tyrosine kinase activity have been examined in the forebrains of lean (Fa/?) and obese (fa/fa) Zucker rats using immunocytochemistry (ICC) and biochemical procedures. These studies were performed in conjunction with ICC and Western blot analysis of phosphotyrosine-containing proteins (PY-proteins). The results from ICC show a similar distribution and content for the insulin receptor among forebrain regions of lean and fatty Zucker rats. Biochemical analysis of the receptor was conducted on the hippocampus. Insulin binding studies using lectin-purified receptor extracts demonstrated similar receptor number and comparable hormone binding affinity for lean and obese animals. Autophosphorylation studies with the receptor extracts from the two groups did not find any differences in the tyrosine kinase activity of insulin receptors. In contrast to the normal findings with the insulin receptor, an abnormality in the obese animals was evident in the content of PY-proteins detected by ICC in the hippocampus, piriform cortex and olfactory bulb. Neurons in these brain regions showed a reduction in staining by an antibody against PY-proteins. Furthermore, Western blots of hippocampal extracts from obese rats demonstrated a reduction in phosphotyrosine content of two proteins of Mr 180 and 130 kD. These findings point to a previously unrecognized alteration in the CNS of the obese, insulin-resistant Zucker rat.
Collapse
Affiliation(s)
- J N Livingston
- Institute for Metabolic Diseases, Miles Research Center, West Haven, Conn
| | | | | | | |
Collapse
|
40
|
Griggs RC, Moxley RT, Mendell JR, Fenichel GM, Brooke MH, Pestronk A, Miller JP, Cwik VA, Pandya S, Robison J. Duchenne dystrophy: randomized, controlled trial of prednisone (18 months) and azathioprine (12 months). Neurology 1993; 43:520-7. [PMID: 8450994 DOI: 10.1212/wnl.43.3_part_1.520] [Citation(s) in RCA: 146] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Prednisone has been shown to improve strength in Duchenne dystrophy. Azathioprine often benefits corticosteroid-responsive diseases and can reduce the dose of prednisone needed. The present study reports a randomized, controlled trial of prednisone and azathioprine designed to assess the longer-term effects of prednisone and to determine whether azathioprine alone, or in combination with prednisone, improves strength. Ninety-nine boys (aged five to 15 years) with Duchenne dystrophy were randomized to one of three groups: (I) placebo; (II) prednisone 0.3 mg/kg/d; or (III) prednisone 0.75 mg/kg/d. After 6 months, azathioprine 2 to 2.5 mg/kg/d was added in groups I and II and placebo added in group III. The study showed that the beneficial effect of prednisone (0.75 mg/kg/d) is maintained for at least 18 months and is associated with a 36% increase in muscle mass. There was weight gain, growth retardation, and other side effects. Azathioprine did not have a beneficial effect. This study suggests that prednisone's beneficial effect is not due to immunosuppression.
Collapse
Affiliation(s)
- R C Griggs
- Department of Neurology, University of Rochester, NY
| | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Kissel JT, Lynn DJ, Rammohan KW, Klein JP, Griggs RC, Moxley RT, Cwik VA, Brooke MH, Mendell JR. Mononuclear cell analysis of muscle biopsies in prednisone- and azathioprine-treated Duchenne muscular dystrophy. Neurology 1993; 43:532-6. [PMID: 8450996 DOI: 10.1212/wnl.43.3_part_1.532] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Prednisone improves strength and function in patients with Duchenne dystrophy. Although the mechanism of this effect is uncertain, prior studies suggested that the benefit might result from immunosuppressive effects on T lymphocytes invading muscle. A recent randomized, double-blind, controlled trial of prednisone and azathioprine demonstrated that azathioprine had no effect in Duchenne dystrophy, raising questions about the role of immunosuppression in mediating clinical improvement. The goal of this current study was to compare the effects of prednisone and azathioprine on mononuclear infiltrates from biopsies performed at the end of the controlled clinical trial (reported separately in the article by Griggs et al on page 520). We studied 14 patients from the prednisone group (0.75 mg/kg/d), 10 from the combination therapy group (prednisone 0.3 mg/kg/d and azathioprine 2.5 mg/kg/d), and 13 from the azathioprine group (2.5 mg/kg/d), and used monoclonal antibodies for cell typing. There were no significant differences between the groups for total T cells, T-cell subsets, B cells, natural killer cells, total mononuclear cells, necrotic muscle fibers, or fibers focally invaded by mononuclear cells. These data indicate that azathioprine decreases mononuclear subsets infiltrating muscle to a similar degree as does prednisone, although azathioprine-treated patients do not show a clinical improvement. This implies that immunosuppressive actions on cellular infiltrates in muscle are probably not the primary mechanism of prednisone-induced clinical improvement.
Collapse
Affiliation(s)
- J T Kissel
- Department of Neurology, Ohio State University, Columbus
| | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Abstract
We report the cases of eight children with histologic findings in the muscle of congenital fiber-type disproportion myopathy. Five had severe muscle weakness at birth; three of them died at 6 months, 18 months, and 6.5 years of age, respectively, and the other two are ventilator dependent and need total care at 2.5 and 4 years of age. The five children with severe weakness at birth had profound respiratory muscle weakness and needed assisted ventilation since early infancy. They also had severe facial and bulbar muscle weakness that required tube feeding, and four had gastrostomy. Ptosis and marked external ophthalmoparesis were also noted. Our study shows that the presence of the above constellation of signs at birth or in early infancy is a predictor of a high rate of mortality in infancy and poor developmental outcome in the survivors.
Collapse
Affiliation(s)
- C F Torres
- Department of Neurology, University of Rochester, Medical School. NY
| | | |
Collapse
|
43
|
Fenichel GM, Florence JM, Pestronk A, Mendell JR, Moxley RT, Griggs RC, Brooke MH, Miller JP, Robison J, King W. Long-term benefit from prednisone therapy in Duchenne muscular dystrophy. Neurology 1991; 41:1874-7. [PMID: 1745340 DOI: 10.1212/wnl.41.12.1874] [Citation(s) in RCA: 199] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Two successive, 6-month, randomized, double-blind, controlled trials of prednisone showed that 0.75 mg/kg/d was the optimal dose to improve strength in boys with Duchenne muscular dystrophy (DMD). We attempted to maintain 93 boys on that dose for an additional 2 years. During the 3 years of observation, the decline in average muscle strength scores of all boys taking prednisone was 0.072 units/yr, as compared with an expected decline of 0.341 units/yr from natural history controls. The occurrence of side effects in some boys prevented maintenance of the full dose, which may have lessened the response. At the time of last visit, dosages ranged from 0.15 mg/kg to 0.75 mg/kg. In addition to maintaining their strength, several of the boys actually improved their performance in lifting kilogram weights and in some timed function tests. Treatment of DMD with prednisone significantly slows the progression of weakness and loss of function for at least 3 years.
Collapse
Affiliation(s)
- G M Fenichel
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212
| | | | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Fenichel GM, Mendell JR, Moxley RT, Griggs RC, Brooke MH, Miller JP, Pestronk A, Robison J, King W, Signore L. A comparison of daily and alternate-day prednisone therapy in the treatment of Duchenne muscular dystrophy. Arch Neurol 1991; 48:575-9. [PMID: 2039377 DOI: 10.1001/archneur.1991.00530180027012] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We previously reported the results of a randomized, double-blind 6-month trial of prednisone therapy in which 102 boys aged 5 to 15 years with Duchenne muscular dystrophy received daily doses of 1.5 and 0.75 mg/kg per day and were compared with those receiving placebo. The strength and function in both prednisone-treated groups improved equally and were significantly better than in the placebo group. To compare alternate-day and daily dosing of prednisone with respect to benefits and adverse side effects, the placebo group was started on alternate-day prednisone therapy, and the treatment group regimens were changed to equivalent doses of alternate-day prednisone without breaking the double-blind nature. At the end of 6 months, the group that was changed from daily to alternate-day therapy had declined in strength back to levels observed 12 months previously, at the start of daily therapy. The group in which alternate-day therapy was started showed a significant improvement in strength at 3 months, similar in magnitude to the response of boys treated with daily therapy. However, their strength declined significantly in the subsequent 3 months compared with boys who received daily therapy. The frequency of side effects was not significantly different for alternate-day therapy compared with daily therapy. We conclude that alternate-day prednisone therapy effectively increases strength but does not sustain the improvement to the same extent as daily therapy or mitigate side effects.
Collapse
Affiliation(s)
- G M Fenichel
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37212
| | | | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Griggs RC, Moxley RT, Mendell JR, Fenichel GM, Brooke MH, Pestronk A, Miller JP. Prednisone in Duchenne dystrophy. A randomized, controlled trial defining the time course and dose response. Clinical Investigation of Duchenne Dystrophy Group. Arch Neurol 1991; 48:383-8. [PMID: 2012511 DOI: 10.1001/archneur.1991.00530160047012] [Citation(s) in RCA: 217] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A randomized, controlled trial of daily prednisone was conducted in 99 boys (aged 5 to 15 years) with Duchenne dystrophy to define the time course of improvement and the dose response to treatment. Prednisone at 0.3 mg/kg (n = 33), prednisone at 0.75 mg/kg (n = 34), and placebo (n = 32) were administered for 6 months. Patients were examined using manual muscle and myometry testing, timed functional testing, pulmonary function testing, and laboratory measurements at 10 days, 1 month, 2 months, 3 months, and 6 months of treatment. Boys treated with prednisone had stronger average muscle strength scores, than did boys treated with placebo as early as 10 days after starting therapy. At the 3-month visit, the boys in the group given 0.75 mg/kg of prednisone were significantly stronger than those in the group given 0.3 mg/kg of prednisone, indicating a dose response. At 6 months, significant side effects occurred in the group treated with 0.75 mg/kg of prednisone, including weight gain, cushingoid appearance, and excessive hari growth. Only weight gain was observed in the group taking prednisone at a dose of 0.3 mg/kg. Importantly, no side effects were evident at 10 days or 1 month of treatment, despite improvement in muscle strength and function. We conclude that prednisone produces a rapid increase in muscle strength in patients with Duchenne dystrophy and that this improvement is maximal at a prednisone dosage of 0.75 mg/kg or less.
Collapse
Affiliation(s)
- R C Griggs
- Department of Neurology, University of Rochester, NY 14642
| | | | | | | | | | | | | |
Collapse
|
46
|
Griggs RC, Moxley RT, Mendell JR, Fenichel GM, Brooke MH, Miller PJ, Mandel S, Florence J, Schierbecker J, Kaiser KK. Randomized, double-blind trial of mazindol in Duchenne dystrophy. Muscle Nerve 1990; 13:1169-73. [PMID: 2266990 DOI: 10.1002/mus.880131212] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
There is evidence that growth hormone may be related to the progression of weakness in Duchenne dystrophy. We conducted a 12-month controlled trial of mazindol, a putative growth hormone secretion inhibitor, in 83 boys with Duchenne dystrophy. Muscle strength, contractures, functional ability and pulmonary function were tested at baseline, and 6 and 12 months after treatment with mazindol (3 mg/d) or placebo. The study was designed to have a power of greater than 0.90 to detect a slowing to 25% of the expected rate of progression of weakness at P less than 0.05. Mazindol did not benefit strength at any point in the study. Side effects attributable to mazindol included decreased appetite (36%), dry mouth (10%), behavioral change (22%), and gastrointestinal symptoms (18%); mazindol dosage was reduced in 43% of patients. The effect of mazindol on GH secretion was estimated indirectly by comparing the postabsorptive IGF-I levels obtained following 3, 6, 9, and 12 months in the mazindol treated to those in the placebo groups. Although mazindol-treated patients gained less weight and height than placebo-treated patients, no significant effect on IGF-I levels was observed. Mazindol doses not slow the progression of weakness in Duchenne dystrophy.
Collapse
Affiliation(s)
- R C Griggs
- Department of Neurology, University of Rochester, New York
| | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Moxley RT, Arner P, Moss A, Skottner A, Fox M, James D, Livingston JN. Acute effects of insulin-like growth factor I and insulin on glucose metabolism in vivo. Am J Physiol 1990; 259:E561-7. [PMID: 2221058 DOI: 10.1152/ajpendo.1990.259.4.e561] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have compared the actions of insulin-like growth factor (IGF-I) and insulin on glucose metabolism in vivo, using the glucose clamp technique in rats. Both hormones caused dose-dependent inhibition of hepatic glucose production, stimulation of whole body glucose disposal, and an increase in the glucose metabolic rate of specific muscles. Infusion of IGF-I also decreased the plasma concentration of insulin. An an infusion rate of 0.57 nmol.kg-1.min-1, IGF-I led to stimulation of whole body glucose uptake that was similar to the glucose uptake produced by infusion of 0.01 nmol.kg-1.min-1 insulin. The glucose metabolic rate, as measured by 2-deoxy-D-glucose uptake, was comparable in quadriceps femoris, soleus, and diaphragm muscles during the infusion of 0.57 nmol.kg-1.min-1 IGF-I and 0.01 nmol.kg-1.min-1 insulin. However, at these rates of infusion, IGF-I caused only a 38 +/- 6% inhibition of hepatic glucose output compared with 66 +/- 12% inhibition by insulin (P less than 0.05). Thus, under these conditions, muscle is more responsive than liver to IGF-I, which agrees with the complement of IGF-I receptors in the two tissues.
Collapse
Affiliation(s)
- R T Moxley
- Department of Neurology, University of Rochester, School of Medicine and Dentistry, New York 14642
| | | | | | | | | | | | | |
Collapse
|
48
|
Abstract
A family was studied in which four generations (16 of 41 members) suffered from painful recurrent muscle cramping. A clear pattern of autosomal dominant inheritance was noted. The cramping first developed during adolescence or early adulthood. Electromyographic analysis indicated a neurogenic origin. The cramps seemed to be due to dysfunction of the motor neurons. The mechanisms underlying this alteration are unclear and require further investigation.
Collapse
Affiliation(s)
- K Ricker
- Department of Neurology, University of Würzburg, West Germany
| | | |
Collapse
|
49
|
Abstract
The clinical and electrodiagnostic findings before and during 6 years of therapy are reported in a 59-year-old man with severe hypothyroidism. He had severe sensory neuropathy, carpal and tarsal tunnel syndromes, mild motor neuropathy and moderately severe myopathy. The sensory signs and symptoms disappeared in the 3rd and 4th years of treatment, respectively. Muscle cramps and pain subsided within 2 years, but mild proximal muscle weakness and atrophy persisted. The sensory distal latencies remained slightly prolonged and the electromyographic changes improved. This case shows that thyroid hormone replacement eliminates the neuropathic manifestations of severe hypothyroidism. In contrast, the myopathic features, such as weakness and muscle wasting, may persist despite maintenance of the euthyroid state.
Collapse
Affiliation(s)
- C F Torres
- Department of Neurology, University of Rochester, NY 14642
| | | |
Collapse
|
50
|
Moss AM, Unger JW, Moxley RT, Livingston JN. Location of phosphotyrosine-containing proteins by immunocytochemistry in the rat forebrain corresponds to the distribution of the insulin receptor. Proc Natl Acad Sci U S A 1990; 87:4453-7. [PMID: 1693770 PMCID: PMC54133 DOI: 10.1073/pnas.87.12.4453] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Cellular regulation by certain growth factor receptors and protooncogene products involves tyrosine kinase activity with the resultant tyrosine phosphorylation of protein substrates. In the present report we describe the distribution of phosphotyrosine-containing material detected by immunocytochemistry (ICC) in the rat forebrain. Specificity of the affinity-purified antibody against phosphotyrosine used in the ICC technique was demonstrated by the ability of phosphotyrosine and p-nitrophenyl phosphate but not phosphoserine, phosphothreonine, or L-tyrosine to inhibit the immunostaining reaction. With ICC, relatively high amounts of phosphotyrosine-positive material were observed in neurons in specific structures that included the supraoptic, paraventricular, and arcuate nuclei; the median eminence; medial habenula; subfornical organ; and piriform cortex. Moderate to high amounts were present in the cerebral cortical layers II-IV and in the pyramidal cell layer of the hippocampus. Small to moderate amounts were detected in a few other locations. Glial elements showed minimal staining. Other areas of the rat forebrain failed to react with this antibody. Importantly, the distribution of the areas positive for phosphotyrosine agreed to a remarkable extent with the distribution of the brain insulin receptor, which itself has tyrosine kinase activity. These findings suggest a relationship between the insulin receptor and the increased phosphotyrosine content of these neurons and support the concept that the brain insulin receptor is active in vivo.
Collapse
Affiliation(s)
- A M Moss
- Department of Medicine, University of Rochester School of Medicine, NY 14642
| | | | | | | |
Collapse
|