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Biomedical subjects

S G Diamond

Publications and source records attributed to S G Diamond.

At least 37 records · Page 2Linked to original sources
PubMed1988

Ocular counterrolling abnormalities in spasmodic torticollis.

Spasmodic torticollis is a focal dystonic movement disorder of unknown origin, long hypothesized to have some vestibular involvement. An examination of otolith function, ocular counterrolling, was performed on eight patients with this disorder. The test consisted of photographing both eyes while the subject underwent rotation in both naso-occipital and earth-horizontal long axes. Measurements of eye torsion were made with a superimposition technique accurate to 0.1 degrees. Results showed all eight patients had abnormal ocular counterrolling. The most notable defect was the lack of sustained eye torsion at the extreme positions, resulting in rolling of the eyes in the direction of head tilt rather than counterrolling, a phenomenon previously observed only in persons with known brain-stem problems. That finding, as well as the majority of the patients showing spontaneous vestibular nystagmus in the dark and directional preponderance with caloric stimulation, implies that one difficulty in spasmodic torticollis lies in central vestibular connections, manifested by disruption of brain-stem pathways.

Adult↗
PubMed1988

Ocular torsion in upright and tilted positions during hypo- and hypergravity of parabolic flight.

Four subjects considered resistant to motion sickness were tested in KC-135 parabolic flight to examine ocular torsion at hypo- and hypergravity. Three of these showed no significant torsion at zero G in either the upright position or when tilted 30 degrees to right or left. At 1.8 G in the tilted positions they showed greater ocular counterrolling than at 1 G. None of these three subjects became motion sick. The fourth subject showed eye torsion toward his left in all positions at zero G. This leftward bias could also be seen at 1.8 G when tilted left ear down, the side that induces rightward counterrolling. There he had less eye torsion than at 1 G. This subject became motion sick. All subjects had normal counterrolling in ground-based testing. These results support the hypothesis that asymmetry of the utricular system may be well compensated in the normal 1 G environment, but unmasked in unaccustomed gravitational situations, suggesting a possible predictive test for space adaptation syndrome.

Adult↗
PubMed1987

Multi-center study of Parkinson mortality with early versus later dopa treatment.

Four geographically diverse centers provided data on mortality in 359 patients with Parkinson's disease, the majority of whom began dopa treatment during the early experimental trials of 1968 to 1970. Patients were classified into three groups based on the duration of symptoms prior to starting dopa treatment: Group 1, 1 to 3 years; Group 2, 4 to 6 years; Group 3, 7 to 9 years. After 15 years of treatment and 3,689 person-years of observation, Group 1 had an observed-to-expected mortality ratio of 1.43; Group 2, 2.44; and Group 3, 2.95 (p less than 0.05). This result confirmed that increased duration of disease was associated with increased mortality risk. To examine the effect of the time of initiation of dopa treatment, duration of disease was held constant at 17 years for all three groups. Observed-to-expected mortality ratios were 1.43 for Group 1; 2.66 for Group 2; 2.63 for Group 3. This statistically significant advantage for Group 1 (p less than 0.0001) led to the conclusion that early treatment with dopa has a beneficial effect on life expectancy. After 17 years of disease, causes of death in Group 1 were less likely (p = 0.027) to be due to Parkinson's disease than was found in the other groups.

Aged↗
PubMed1987

Parkinson's disease: sensory and motor problems in arms and hands.

Fifteen undemented patients with Parkinson's disease (PD) and 15 age-matched controls were given a battery of tests to assess sensorimotor integration in the arms. PD patients made more errors (p less than 0.01) than controls, particularly in tests of proprioception. Age was not related to errors. Compared with controls, two-point discrimination thresholds were significantly higher (p less than 0.02) on the index finger of PD patients, but not on the forearm. Results confirm the sensorimotor deficits found earlier in an orofacial study, and imply that PD involves a generalized dysfunction of sensorimotor integration and proprioception, probably a result of impaired basal ganglia function in processing and integrating sensory input to organize and guide movement.

Aged↗
PubMed1986

Deficits in orofacial sensorimotor function in Parkinson's disease.

Orofacial sensorimotor function was assessed in patients with Parkinson's disease and in age-matched controls. Tests were designed to assess sensory function, motor abilities, and the integration of sensory information for the performance of specific movements. Patients with Parkinson's disease and normal subjects both made more errors with increasing age; however, overall, patients with Parkinson's disease made significantly more errors in our tests than did normal subjects. Interestingly, patients with Parkinson's disease showed greater deficits in tests of sensory function and sensorimotor integration than in tests of motor function. These results suggest that one aspect of Parkinson's disease consists of complex deficits in the utilization of specific sensory inputs to organize and guide movements. The results are further discussed in relation to a proposed sensory gating or filtering schema of basal ganglia motor functioning.

Aged↗
PubMed1986

Long-term follow-up of early dopa treatment in Parkinson's disease.

A group of 19 patients with Parkinson's disease, who began dopa therapy 1 to 3 years after onset of symptoms, were followed for 12 years. They were evaluated every 3 to 4 months on the UCLA disability scale and the Hoehn and Yahr functional classification scale. This present group was compared to two other historical groups reported on earlier [8], one that began treatment with dopa 4 to 6 years after onset of symptoms and the other that began dopa treatment 7 to 9 years after onset of symptoms. Results on both scales showed that the mean disability scores of the three groups did not differ significantly when duration of disease was matched, even though duration of dopa therapy among the groups varied from 1 to 12 years. The highly significant differences between the groups prior to dopa treatment continued throughout the study. These longitudinal data support the conclusion that the worsening over time is the result of progression of Parkinson's disease and not a result of the duration of dopa treatment. Early treatment improves the beginning years of the disease and has no adverse effect on later years. Twelve years after beginning dopa therapy, 32% of the present group had died at a mean age of 76.0, in contrast to 50% (mean age, 74.7) and 57% (mean age, 71.5) in the groups who began dopa increasingly later in the course of their disease. Incidence of dementia increased with disease duration regardless of treatment duration.(ABSTRACT TRUNCATED AT 250 WORDS)

Dementia↗
PubMed1985

Double-blind trial of pergolide for Parkinson's disease.

Pergolide mesylate, a dopamine agonist, was studied as adjunctive therapy in a 6-month double-blind trial in 20 patients with Parkinson's disease who were achieving less than optimal response from Sinemet. As pergolide or placebo was administered in increasing dosage, Sinemet was reduced if side effects developed. Both the pergolide and placebo groups improved significantly (p less than 0.05). The pergolide group improved 30% at the end of 24 weeks, and the placebo group 23%. There was no significant difference between drug and placebo groups, possibly due to a fortuitous support group and the side effects that may have burdened the pergolide group. Nevertheless, pergolide had a definite antiparkinsonian effect.

Aged↗
PubMed1983

Ocular counterrolling as an indicator of vestibular otolith function.

Sixteen normal subjects, 8 patients with unilateral vestibular nerve section, and 11 patients with acoustic neuromas underwent dynamic ocular counterrolling (OCR) testing. Both eyes were photographed at every 10 degrees as the subject was tilted about the naso-occipital axis at a constant velocity of 3 degrees/sec. Normal subjects differed from patients in four characteristics: (1) The binocular OCR patterns of normal subjects were consistent from one trial to the next. (2) The two eyes were mostly conjugate in movement. (3) The patterns were smooth. (4) OCR was approximately symmetric to right and left tilts. In the patients, patterns were abnormal when tilted to the side opposite the lesion. In quantified measures of the four characteristics, differences between the normal group and the group of patients with unilateral vestibular nerve sections were significant in consistency and total scores. In the patients with acoustic neuromas, OCR abnormalities corresponded to the size and location of the tumors and the extent to which they impinged on the utricular nerve and brainstem.

Adult↗
PubMed1983

Evaluating the evaluations: or how to weigh the scales of parkinsonian disability.

We used four disability scales to evaluate eight patients with Parkinson's disease who were treated with pergolide mesylate for 1 year. Disability was rated on all four scales by the same neurologist at each of 11 visits. Prior ratings were not available to the examiner, who did not know that the scales themselves were an object of study. Disability scores, converted to percentage improvement relative to baseline, varied considerably between scales; for instance, at 5 months, one showed 13% improvement and another 58%. At 9 months, one showed worsening of 6% and another showed improvement of 34%. The four disability scales clearly measure different aspects of parkinsonism, and comparing results of different studies may not be valid if the disability scales are not the same.

Drug Evaluation↗
PubMed1981

Evidence to support early levodopa therapy in Parkinson disease.

To see whether duration of disease or of levodopa treatment was responsible for gradual worsening of parkinsonian patients, 58 persons treated with levodopa were classified into three groups based on predopa disease duration. Data over 6 years of treatment showed that disease duration was the determining factor. Patients matched for disease duration had similar disability scores regardless of duration of therapy. Matched for therapy duration, patients with longer disease duration had consistently higher disability scores. Side effects showed no differences between groups and did not increase over time. In sum, delaying therapy fails to improve disability in the early years of disease and does not confer any benefit in later years.

Athetosis↗
PubMed1978

A double-blind comparison of levodopa, Madopa, and Sinemet in Parkinson disease.

A sixteen-week study examined the effect of Madopa and Sinemet on patients with Parkinson disease disease suffering nausea or vomiting as side-effects of levodopa therapy and compared the efficacy of the three preparations in controlling the symptoms of Parkinson disease. Following a control period on levodopa, 20 patients underwent four consecutive four-week regimens as follows: (1) double-blind, in which a randomized half received levodopa and half received Madopa; (2) single-blind, in which all received Madopa; (3) double-blind, in which a re-randomized half received Madopa and half Sinemet; and (4) single-blind, in which all received Sinemet. Levodopa administration via Sinemet and Madopa was held to a fixed 20% of prior levodopa dosage. Almost all patients showed great reduction in nausea and vomiting with both Madopa and Sinemet. Seventy percent of the patients showed improvement in disability compared to their levodopa baseline levels. Group means showed no difference between the improvement seen on Madopa and that seen on Sinemet. However, examination of individual responses showed that the majority of patients fared distinctly better on either Sinemet or Madopa.

Adult↗