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Biomedical subjects

C Armon

Publications and source records attributed to C Armon.

At least 37 records · Page 2Linked to original sources

Relationship of the Tufts Quantitative Neuromuscular Exam (TQNE) and the Sickness Impact Profile (SIP) in measuring progression of ALS. SSNJV/CNTF ALS Study Group.

The Tufts Quantitative Neuromuscular Exam (TQNE) is a standardized tool for measuring muscle strength and pulmonary function in patients with amyotrophic lateral sclerosis (ALS). We describe the relationship of TQNE scores to functional disability and health-related quality of life as measured by the Sickness Impact Profile (SIP) in 524 ALS patients. There was a significant relationship (p < 0.0001) between TQNE and SIP scores, both in cross section and over time. TQNE scores strongly relate to ALS patients' quality of life and ability to perform activities of daily living.

Activities of Daily Living↗

Reversible parkinsonism and cognitive impairment with chronic valproate use.

Following our initial report of the insidious development of reversible, valproate-induced hearing, motor, and cognitive dysfunction in two patients, we evaluated 36 patients in an epilepsy clinic who had been taking therapeutic levels of valproate for at least 12 months; 29 of these patients were examined according to a prospective protocol. We observed varying degrees of parkinsonism and cognitive impairment, from none to severe. Discontinuation of valproate in 32 affected patients led to subjective and objective improvement on follow-up testing at least 3 months later. Improvement was greatest in patients who were affected most. We conclude that a syndrome of reversible parkinsonism and cognitive impairment may develop insidiously in patients who have been treated with valproate for more than 12 months. The association with valproate may be overlooked due to the insidious onset.

Adult↗

Placebo-controlled trial of gabapentin in patients with amyotrophic lateral sclerosis. WALS Study Group. Western Amyotrophic Lateral Sclerosis Study Group.

We designed a phase II trial to evaluate the efficacy of gabapentin in slowing the rate of decline in muscle strength of patients with amyotrophic lateral sclerosis (ALS) and to assess safety and tolerability. Gabapentin (800 mg) or placebo was administered t.i.d. in a randomized, double-blinded, placebo-controlled, trial for 6 months. We enrolled 152 patients at eight sites in the United States. The primary outcome measure was the slope of the arm megascore, the average maximum voluntary isometric strength from eight arm muscles standardized against a reference ALS population. A secondary outcome measure was forced vital capacity. Slopes of arm megascores for patients on gabapentin were compared with slopes of those taking placebo using a two-way ANOVA. We observed a nonstatistically significant trend (p = 0.057-0.08) toward slower decline of arm strength in patients taking gabapentin compared with those taking placebo (mean difference 24%, median 37%). We observed no treatment effect on forced vital capacity. Gabapentin was well tolerated by patients with ALS. These results suggest that further studies of gabapentin in ALS are warranted.

Acetates↗

Comparing composite scores based on maximal voluntary isometric contraction and on semiquantitative manual motor testing in measuring limb strength in patients with ALS.

Maximal voluntary isometric contraction (MVIC) is a standardized tool for measuring disease progression in patients with ALS. After normalization, summation, and averaging, it generates composite scores (CS) ("megascores"). In a cross-sectional study, these scores were highly correlated with "average strength" composite scores based on semi-quantitative manual motor testing (SQMMT): r = 0.697 (p < 0.0001). Each 10% difference in the raw SQMMT-CS corresponds to a 0.56 difference in the MVIC-CS (95% confidence limits [CL], 0.38, 0.74). Controlling for height (a highly significant covariate, p < 0.0001), each 10% difference in SQMMT-CS corresponds to a 0.39 difference in MVIC-CS (95% CL, 0.24, 0.54).

Adult↗

Mechanical trauma as a risk factor in classic amyotrophic lateral sclerosis: lack of epidemiologic evidence.

We have examined the relationship between mechanical injuries and the subsequent development of classic amyotrophic lateral sclerosis (ALS) through a critical review of the literature. Only prospective evaluation of a large cohort of trauma victims can provide an unbiased answer to this controversy. However, such an evaluation would be prohibitively expensive, and the results would not be available in our lifetime. The results of retrospective case-control studies are conflicting in part because of biases in the selection of patients and controls, poor definition of the nature and extent of the trauma and its chronological relationship to the onset of ALS, and a non-uniform approach to the collection of antecedent information. More rigorously designed studies show no association of ALS to antecedent trauma. The existing data thus do not suggest that mechanical trauma is a risk factor for ALS. Future case-control studies should conform to a standardized methodology. The critical analysis presented here of the research on the purported connection between mechanical injury and ALS may serve as a model for the evaluation of the role of trauma in other chronic diseases. Application of these methodological principles may bring increased scientific rigor to assessing the frequently litigated question of what constitutes a true trauma sequela.

Adult↗

Antecedent medical diseases in patients with amyotrophic lateral sclerosis. A population-based case-controlled study in Rochester, Minn, 1925 through 1987.

Odds ratios (ORs) were estimated for the prevalence of antecedent endocrine, metabolic, or vascular diseases among 45 patients with amyotrophic lateral sclerosis from the Rochester, Minn, population compared with 90 control subjects matched for sex, year of birth, period of observation, and residence. Hypertension occurred less frequently in male patients with amyotrophic lateral sclerosis (4%) than in control subjects (30%; OR = .10). Because of small population size, no conclusions can be drawn with respect to the following antecedent conditions: thyroid disease (OR = 1.61), coronary artery disease (OR = .58), obesity (OR = .52), diabetes (OR = 1.00), cerebrovascular disease (OR = .21), and peripheral vascular disease (OR = 1.23). The heterogeneity of antecedent thyroid disease makes it highly unlikely that any specific thyroid lesion is causally associated with most cases of amyotrophic lateral sclerosis. Hypertension may be a marker for protective factors against the development of amyotrophic lateral sclerosis in men.

Aged↗

Hyperbaric treatment of cerebral air embolism sustained during an open-heart surgical procedure.

A case of cerebral air embolism sustained during replacement of the mitral valve resulted in postoperative coma and seizures. Hyperbaric treatment, begun 30 hours after the occurrence of the air embolism, resulted in good immediate and long-term recovery. Mild deficits of the left hemisphere were present at follow-up 53 days after the embolus was sustained, and lesser, minimal residua were present at 14-month follow-up. Hyperbaric treatment is the definitive therapy for cerebral air embolism. Although it is most effective when administered early, the outcome may be excellent even with late treatment.

Cardiopulmonary Bypass↗

Psychologic and adaptational difficulties anteceding amyotrophic lateral sclerosis: Rochester, Minnesota, 1925-1987.

Comprehensive medical records of 45 amyotrophic lateral sclerosis (ALS) patients and 90 controls from the same community, matched by age, gender, and period of observation, were reviewed. Three (13%) of 23 men with ALS, 15 (33%) of 46 control men, 10 (45%) of 22 women with ALS, and 19 (43%) of 44 control women had antecedent psychologic or adaptational difficulties. The proportions of long-standing or serious conditions were comparable in all four groups. However, no man in whom ALS developed had a record of mild antecedent difficulties alone, whereas 3 would have been expected (p = 0.024).

Adaptation, Psychological↗

When is an apparent excess of neurologic cases epidemiologically significant?

To conserve clinical and public health resources, it is necessary to screen reports from the community of an excess or cluster of cases of chronic neurologic diseases for potential epidemiologic significance, ie, to identify those clusters that may have occurred owing to the operation of an underlying etiologic cause rather than to chance alone. Traditionally, the probability that such a cluster has occurred by chance within the reporting community is computed, ignoring the fact that many other similar communities have not reported a cluster. We propose a modified approach that takes this larger universe of communities into account, thereby raising the threshold for potential epidemiologic significance. As a result, the lowest value for the ratio of observed-to-expected cases that may be considered of epidemiologic significance should be increased by factors of 2 for small clusters (one to three expected cases), 1.5 for intermediate clusters (seven to 30 expected cases), and 1.3 for large clusters (60 to 90 expected cases). Consequently, case ascertainment and full field investigations can be reserved for only those reports that, if confirmed, would represent a cluster not due to chance alone. We illustrate this with a case from our own experience.

Amyotrophic Lateral Sclerosis↗

Epidemiologic correlates of sporadic amyotrophic lateral sclerosis.

We evaluated 74 selected patients with amyotrophic lateral sclerosis (ALS) and 201 matched controls for risk factors for ALS by a case-control design and a sequential questionnaire/interview technique to quantitate biographic data. We analyzed occupational and recreational data only for 47 male patients and 47 corresponding patient controls; data for women were insufficient. We used nonparametric analyses to evaluate five primary comparisons of ALS patients with controls: (1) more hard physical labor, p not significant (NS); (2) greater frequency of neurodegenerative disease in family members, p NS; (3) greater exposure to lead, p less than 0.05; (4) more years lived in a rural community, p NS; and (5) more trauma or major surgery, p NS. Men with ALS had worked more frequently at blue-collar jobs (although not a statistically significant difference, p = 0.10) and at welding or soldering (p less than 0.01). These results suggest that there may be an association between ALS in men and exposure to lead vapor. The limited nature of the association favors a multifactorial etiologic mechanism of ALS.

Adult↗

Clinical neurophysiologic studies in stiff-man syndrome: use of simultaneous video-electroencephalographic-surface electromyographic recording.

Three patients with a clinical diagnosis of stiff-man syndrome were studied with simultaneous video-electroencephalographic-surface electromyographic recordings in addition to routine electromyography in order to obtain objective data to confirm their diagnosis, to improve our understanding of the diagnosis of stiff-man syndrome, and to define reproducible clinical and neurophysiologic criteria for the stiff-man syndrome. These patients had the following features of this syndrome: (1) continuous muscle activity that varied with awake and sleep states, posture, passive and active movements, and medications; (2) superimposed intermittent generalized contractions while awake, which continued into drowsiness and interfered with onset of sleep; and (3) abnormal cocontractions of antagonistic muscles. The characteristic findings in the stiff-man syndrome can be recorded by using video-electroencephalographic-surface electromyographic techniques, a useful application of equipment already available in most electroencephalography laboratories. Neurophysiologic techniques can help in elucidating the clinical findings in the stiff-man syndrome. Further systematic study in patients before and during treatment is needed to identify common diagnostic criteria for this syndrome.

Adult↗

How frequently does classic amyotrophic lateral sclerosis develop in survivors of poliomyelitis?

There is a paucity of reports of classic amyotrophic lateral sclerosis (ALS) developing in survivors of paralytic poliomyelitis. We describe a patient with classic ALS and an antecedent paralytic disease thought to have been poliomyelitis from which she recovered completely. If the paucity of ALS preceded by true poliomyelitis is not merely a matter of underreporting, antecedent paralytic poliomyelitis may have a protective role against the development of ALS. This has implications relevant to pathogenesis and to projected secular trends of ALS incidence since the introduction of poliomyelitis vaccines. There is a need to establish the incidence of cases of classic ALS in patients with antecedent poliomyelitis.

Aged↗

Sensorineural hearing loss: a reversible effect of valproic acid.

We report 2 patients over the age of 70 who, while on valproate (VPA) for complex partial seizures, developed sensorineural hearing loss. Following discontinuation of VPA for nonaudiologic reasons, the patients reported improved hearing which was confirmed by audiometry. These findings represent VPA-induced sensorineural hearing loss, possibly in preexisting presbycusis.

Aged↗

Electrophysiological signs of arteriovenous malformations of the spinal cord.

A characteristic pattern of electrophysiological changes was found in 24 patients with confirmed spinal cord arteriovenous malformations (AVMs). The AVMs were limited to the thoracic cord in seven, involved the conus and the cauda equina in 10, and involved all levels in six. Of the patients, 88% had at least one definite electrophysiological abnormality: nerve conduction studies showed abnormal results in 43% (10 of 23), needle electromyography in 77% (17 of 22), and tibial somatosensory evoked potentials in 88% (7 of 8). The pattern of involvement was of scattered, multiple, bilateral thoracolumbosacral radiculopathies, consistent with axonal or neuronal destruction, associated with paraspinal fibrillations or abnormal activation of motor unit potentials. Electrophysiological abnormalities were seen in most patients with lower motor neuron clinical deficit. These abnormalities depended on the caudal extension of the AVM, on an arterial supply at T-10 or below, and on the duration of symptoms. In addition to the expected abnormalities in the distribution of the AVM location, four patients had electrical changes at a distance, which may have been due to venous stasis.

Action Potentials↗