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Biomedical subjects

R C Griggs

Publications and source records attributed to R C Griggs.

At least 37 records · Page 2Linked to original sources
PubMed1999

Improving adherence to dementia guidelines through education and opinion leaders. A randomized, controlled trial.

BACKGROUND: Educational methods that encourage physicians to adopt practice guidelines are needed. OBJECTIVE: To evaluate an educational strategy to increase neurologists' adherence to specialty society-endorsed practice recommendations. DESIGN: Randomized, controlled trial. SETTING: Six urban regions in New York State. PARTICIPANTS: 417 neurologists. INTERVENTION: The educational strategy promoted six recommendations for evaluation and management of dementia. It included a mailed American Academy of Neurology continuing medical education course, practice-based tools, an interactive evidence-based American Academy of Neurology-sponsored seminar led by local opinion leaders, and follow-up mailings. MEASUREMENTS: Neurologists' adherence to guidelines was measured by using detailed clinical scenarios mailed to a baseline group 3 months before the intervention and to intervention and control groups 6 months after the intervention. In one region, patients' medical records were reviewed to determine concordance between neurologists' scenario responses and their actual care. RESULTS: Compared with neurologists in the baseline and control groups, neurologists in the intervention group were more adherent to three of the six recommendations: neuroimaging for patients with dementia only when certain criteria are present (odds ratio, 4.1 [95% CI, 1.9 to 8.9]), referral of all patients with dementia and their families to the Alzheimer's Association (odds ratio, 2.8 [CI, 1.7 to 4.8]), and encouragement of all patients and their families to enroll in the Alzheimer's Association Safe Return Program (odds ratio, 10.8 [CI, 3.5 to 33.2]). For the other three recommendations, adherence did not differ between the intervention and the nonintervention groups. Agreement between scenario responses and actual care ranged from 27% to 99% for the six recommendations and was 95% or more for three of the recommendations. CONCLUSION: A multifaceted educational program can improve physician adoption of practice guidelines.

Dementia↗
PubMed1999

The dropped head plus syndrome: quantitation of response to corticosteroids.

Severe neck extensor weakness causes the dropped head syndrome and is a disabling symptom of many specific disorders. When a diagnosis cannot be established, it has been considered a manifestation of a restricted noninflammatory myopathy. A 44-year-old man presenting with dropped head and subsequent severe limb weakness did not respond to a first trial of corticosteroids but responded well to a subsequent prolonged trial of azathioprine followed by prednisone. The decision to persist with the second trial of treatment was prompted by documented sequential increases in lean body and muscle mass, and an improvement in the quantitative myometry score which preceded clinically obvious improvement. While mechanical damage to overstretched cervical paraspinal muscles is thought to preclude a response to treatment, cases of unexplained dropped head syndrome may merit consideration of prolonged immunosuppressant treatment.

Adrenal Cortex Hormones↗
PubMed1998

Spontaneous abdominal hematoma in dermatomyositis.

Dermatomyositis is associated with a number of systemic manifestations and diseases. We present 2 patients with dermatomyositis, aged 11 and 50 years, who developed acute abdominal pain, both a result of spontaneous hemorrhage. Hemorrhage was detectable by physical examination in one and on computed tomography scan of the abdomen in the other. Both patients made a full recovery with supportive treatment. While the cause of the hemorrhage was uncertain, in 1 patient massive calcinosis of the abdominal wall was present, and trauma may have been the precipitant. Spontaneous abdominal hematoma is a cause of acute abdominal pain in patients with dermatomyositis, and surgery may be avoided if the diagnosis is recognized.

Abdominal Muscles↗
PubMed1998

Facioscapulohumeral dystrophy: a distinct regional myopathy with a novel molecular pathogenesis. FSH Consortium.

Facioscapulohumeral muscular dystrophy (FSHD) is one of the most common inherited diseases of muscle. Until recently, FSHD had received little attention because of its relatively benign course and the perception that it represented a syndrome rather than a distinct myopathy. Research interest into this disease was reignited with the demonstration of linkage of FSHD to chromosome 4q35 in 1990. Clinical and molecular genetic research in FSHD has since helped define it as a distinct clinical entity, outlined its natural history, and defined the primary molecular defect associated with the condition. FSHD is now known to be associated with large deletions of variable size on chromosome 4q35. These deletions, however, do not appear to disrupt a transcribed gene but are thought to interfere with the expression of a gene or genes located proximal to the deletions. These observations complicate the search for the FSHD gene but also imply the presence of a potentially novel molecular pathogenesis.

Animals↗
PubMed1998

Mode switching kinetics produced by a naturally occurring mutation in the cytoplasmic loop of the human acetylcholine receptor epsilon subunit.

We describe the genetic and kinetic defects in a congenital myasthenic syndrome caused by heteroallelic mutations of the acetylcholine receptor (AChR) epsilon subunit gene. The mutations are an in-frame duplication of six residues in the long cytoplasmic loop (epsilon1254ins18) and a cysteine-loop null mutation (epsilonC128S). The epsilon1254 ins18 mutation causes mode switching in the kinetics of receptor activation in which three modes activate slowly and inactivate rapidly. The epsilon1245ins18-AChR at the endplate shows abnormally brief activation episodes during steady state agonist application and appears electrically silent during the synaptic response to acetylcholine. The phenotypic consequences are endplate AChR deficiency, simplification of the postsynaptic region, and compensatory expression of fetal AChR that restores electrical activity at the endplate and rescues the phenotype.

Acetylcholine↗
PubMed1998

Overview of distal myopathies: from the clinical to the molecular.

Five distinct predominantly distal myopathies have been identified with discrete clinical and genetic patterns as follows: (1) Welander myopathy (late adult onset, type 1), with autosomal dominant inheritance and unknown molecular localization; (2) Markesbery-Griggs/Udd myopathies (late adult onset, type 2), with autosomal dominant inheritance and linkage to chromosome 2q; (3) Nonaka myopathy (early adult onset, type 1), with autosomal recessive inheritance and molecular localization to 9p1-q1. Nonaka myopathy is identical to quadriceps-sparing familial inclusion body myopathy; (4) Miyoshi myopathy (early adult onset, type 2), with autosomal recessive inheritance and localization to 2p; (5) Laing myopathy (early onset, type 3), with autosomal dominant inheritance and linkage to chromosome 14. The gene and abnormal gene product have not yet been defined for any of the distal myopathies. However, it is already clear that disorders allelic to the distal myopathies can begin with proximal weakness. Given such major phenotypic variation, it is possible that some of the diseases we regard as distal myopathies may become obsolete. Instead, these conditions may become known by their genetic mutation or abnormal gene product, much like Duchenne and Becker dystrophy.

Age of Onset↗
PubMed1998

Pilot trial of albuterol in facioscapulohumeral muscular dystrophy. FSH-DY Group.

BACKGROUND/OBJECTIVE: Facioscapulohumeral muscular dystrophy (FSHD) is currently untreatable, and there have been few therapeutic trials of any agent in the disease. Animal studies have demonstrated that beta2-adrenergic agonists induce muscle hypertrophy and prevent atrophy after a variety of physical and biochemical insults, and two human studies have shown that these agents increase certain measures of strength in healthy volunteers. We conducted an open-label pilot trial of a beta2-agonist (albuterol) in patients with FSHD. METHODS: Fifteen FSHD patients were given sustained-release albuterol (16.0 mg/day) for 3 months. The primary outcome measure was lean body mass, which was assessed through dual energy X-ray absorptiometry (DEXA). Strength was evaluated through maximal voluntary isometric contraction testing (MVICT) and manual muscle testing. RESULTS: Albuterol significantly increased DEXA lean body mass (the skeletal muscle compartment) by 1.29 +/- 1.18 kg (mean +/- SD, p = 0.001). Strength assessed through composite MVICT scores also increased by an average of 0.33 +/- 0.60 (p = 0.05), representing an overall 12% improvement in strength. CONCLUSIONS: These encouraging results suggest that beta2-agonists may have a role in treating FSHD and possibly other neuromuscular diseases. The effects of albuterol in FSHD are currently being evaluated in a larger, randomized, double-blind, placebo-controlled trial lasting 1 year.

Absorptiometry, Photon↗
PubMed1997

Chronic inflammatory demyelinating polyneuropathy in non-Hodgkin's lymphoma.

A 42-year-old man was diagnosed with large cell non-Hodgkin's lymphoma 3 years after autologous bone marrow transplantation for Hodgkin's disease. The day before beginning systemic chemotherapy, the patient began to have symptoms of a sensorimotor neuropathy characterized by proximal and distal weakness, lower-extremity areflexia, elevated cerebrospinal fluid protein level, and evidence of demyelination on nerve conduction studies. Symptoms progressed despite two courses of intrathecal methotrexate, for possible lymphomatous meningitis, as well as systemic chemotherapy. The diagnosis of chronic inflammatory demyelinating polyneuropathy was made. Daily plasma exchange was performed for a total of 10 treatments with immediate improvement and eventual complete recovery in strength, sensation, and gait. A review of the literature confirms that inflammatory demyelinating polyneuropathy is a highly unusual but important cause of peripheral nervous system dysfunction. The potential for complete response to plasma exchange should be recognized in patients with symptoms, signs, and nerve conduction studies suggestive of chronic inflammatory demyelinating polyneuropathy.

Adult↗
PubMed1997

Andersen's syndrome: a distinct periodic paralysis.

A previous study of 4 patients defined Andersen's syndrome (AS) as a triad of potassium-sensitive periodic paralysis, ventricular dysrhythmias, and dysmorphic features. AS appears to be distinct in terms of its genetic defect from the alpha-subunit of skeletal muscle sodium channel and the cardiac potassium channel responsible for most long QT syndromes (LQT1). We studied 11 additional patients with AS from 5 kindreds. Spontaneous attacks of paralysis were associated with hypokalemia, normokalemia, or hyperkalemia. All 11 patients had similar dysmorphic features. The QT interval was prolonged in all patients although only 4 were symptomatic. Genetic linkage studies excluded linkage to the alpha-subunit of the skeletal muscle sodium channel and to four distinct LQT loci. In addition, none of the common dihydropyridine receptor mutations responsible for hypokalemic periodic paralysis were present. We conclude that (1) AS is a genetically unique channelopathy affecting both cardiac and skeletal membrane excitability, (2) attacks of paralysis may be either hypokalemic or hyperkalemic, (3) a prolonged QT interval is an integral feature of this syndrome, and (4) a prolonged QT interval may be the only sign in an individual from an otherwise typical AS kindred. This may be confused with more common, potentially lethal LQT syndromes.

Adolescent↗
PubMed1997

Genotype-phenotype correlations of DHP receptor alpha 1-subunit gene mutations causing hypokalemic periodic paralysis.

Hypokalemic periodic paralysis (hypoKPP) is an autosomal dominant or sporadic disorder characterized by periodic, reversible attacks of muscle weakness. Mutations in the skeletal muscle dihydropyridine receptor alpha 1-subunit that functions as a calcium channel (CACNL1A3) cause hypoKPP. We studied a group of 45 hypoKPP probands and demonstrated mutations in 30 of them. When compared with patients in whom CACNL1A3 mutations were not identified, those with mutations had an earlier age of onset and more often had a family history of hypoKPP. To date, three mutations have been identified. The R1239G mutation has only been found in one family. Of the 30 probands with recognized mutations, R528H accounted for 43% and R1239H was seen in 53%. Age of onset and potassium levels during attacks were lower in patients with the R1239H mutation than those with R528H. Cardiac dysrhythmias co-segregated with hypoKPP in one small kindred with the R528H mutation. No mutations were identified in exons of the gene encoding the S4 segments of domains one and three or the cytoplasmic loop between domains two and three. In addition to the 45 hypoKPP probands, an additional 11 probands with clinical variants of hypoKPP (three thyrotoxic hypoKPP and eight Andersen syndrome patients) were examined for CACNL1A3 mutations and none were found.

Adolescent↗
PubMed1997

Early and late losses of motor units after poliomyelitis.

Motor unit number estimation was employed to assess muscle innervation in 76 patients with prior poliomyelitis. Of the 68 patients who were < 70 years of age, new musculoskeletal symptoms had appeared in all but four; the mean latent interval was 38.0 +/- 10.1 years. As expected, there was a high incidence of muscles exhibiting denervation in previously affected limbs (87%). However, the incidence in supposedly unaffected limbs was also high (65%). Significant differences in the degree of denervation were found between muscles of the same hands and feet. Judged on the basis of their potential amplitudes, the surviving motor units in partially denervated muscles tended to be enlarged. The enlargement was proportional to the extent of the denervation and was comparable to that found in amyotrophic lateral sclerosis. In some muscles, possibly those innervated by failing motor neurons, motor-unit enlargement was not present. Needle examination confirmed the high incidences of denervation in affected and allegedly unaffected limbs. Of the 188 muscles with EMG features of chronic denervation, only nine exhibited fibrillations or positive sharp waves (4.8%). Ninety-five muscles of 18 patients were studied a second time after an interval of 2 years. Overall, there was a 13.4% reduction in motor-unit number and a 18.4% diminution in M-wave amplitude (P < 0.001). The rate of motor-unit loss was twice that occurring in healthy subjects aged > 60 years. Analysis of individual patients indicated that some were deteriorating more rapidly than others. These studies confirm that denervation progresses in patients with prior poliomyelitis in both clinically affected and unaffected muscles, and indicate that this progression is more rapid than that occurring in normal ageing.

Adult↗
PubMed1997

A pilot trial of prednisone in facioscapulohumeral muscular dystrophy. FSH-DY Group.

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant, 4q35-linked, slowly progressive muscular dystrophy with no known effective treatment. Since prednisone improves strength in Duchenne dystrophy, we performed a pilot, open-label trial of prednisone in eight subjects fulfilling strict diagnostic criteria for FSHD. Prednisone (1.5 mg/kg/day; maximum 80 mg/day) was administered for 12 weeks. Manual muscle testing, maximum voluntary isometric contraction testing, and muscle mass estimations by dual energy x-ray absorptiometry and urinary creatinine excretion were performed at baseline and at 12 weeks. There were no significant changes in strength or muscle mass. We conclude that prednisone given for 12 weeks does not produce major improvement in strength or increase muscle mass in FSHD. The study did not have sufficient power or length of follow-up to address the possibility that prednisone might arrest or slow disease progression.

Adolescent↗