The use and interpretation of the Friedman test in the analysis of ordinal-scale data in repeated measures designs.

The purpose of this paper is to review the use and interpretation of the Friedman two-way analysis of variance by ranks test for ordinal-level data in repeated measurement designs. Physical therapists frequently make three or more repeated measurements of the same individual to compare different treatments, or to assess the effect of a single treatment over time. When the measurements are ordinal-scaled, such as some ratings of functional status and muscle strength, statistical significance may be determined by the Friedman test. We illustrate the use of the Friedman test and a post hoc multiple comparison test with data from 27 subjects whose performance on a lifting task was rated on three occasions by use of an ordinal scale. We discuss the interpretation of ordinal-level data and recommend that therapists understand the limitations a measurement scale imposes on the inferences that can be made from these tests.

The effects of long-term non-fatiguing resistance exercise in subjects with post-polio syndrome.

Measures of torque were used to evaluate changes in muscle strength and endurance in 17 patients with post-polio syndrome who did prescribed resistance exercise for up to 2 years. Exercise compliance averaged 75%, with 16 subjects increasing the weight lifted in training. Maximum torque was significantly increased in the exercised muscle compared to the control muscle; no difference was seen in muscle endurance. Individuals with post-polio syndrome can increase muscle strength by doing non-fatiguing resistance exercise, but they should undergo quantitative testing of muscle strength a minimum of every 3 months to guard against overwork weakness.

Giant axonal neuropathy: studies with sulfhydryl donor compounds.

Giant axonal neuropathy (GAN) is a disorder characterized pathologically by distal neurofilament-filled bulbous swellings in axons, and widespread collection of intermediate filaments, including masses of vimentin filaments in cultured skin fibroblasts. A morphologically similar neurofibrillary disorder is produced by acrylamide and the toxic hexacarbons, agents which bind to thiol groups. We report, in GAN fibroblasts, inhibition of vimentin filament aggregation by dithiothreitol and penicillamine, sulfhydryl donor compounds which stabilize thiols. In addition, we describe clinical improvement in a GAN patient treated with penicillamine, despite earlier progressive disease. These findings support the hypothesis of disordered thiol metabolism in GAN, and open up avenues for further research.

Endurance exercise training in Friedreich ataxia.

The purpose of this case study was to determine whether a patient with Friedreich ataxia (FA) would experience a clinically significant physiologic adaptation to aerobic endurance training. A 38-year-old man with FA underwent graded exercise testing with collection of expired gases on a bicycle ergometer before and after training, to determine maximum work capacity and oxygen consumption. Training consisted of 27 electrocardiographically monitored exercise sessions on the ergometer, each for 20 to 25 minutes at a workload adjusted to achieve an exercising heart rate equal to 70% to 85% of his pretest maximum, preceded and followed by a stretching routine. Large increases in cardiorespiratory and work measures demonstrated clinically important physiologic adaptations to aerobic conditioning in this patient. Peak VO2 increased 27% and peak ventilation increased 21%. Total exercise time increased five minutes, reflecting a 50-watt increase in maximum workload. In addition, the patient experienced a 4.75-kg weight loss. A medically supervised endurance training program can increase aerobic work capacity and promote weight loss in patients with FA who can pedal a bicycle at training level intensities.

Quantitative measures of neurological function in chronic neuromuscular diseases and ataxia.

Interexaminer and intraexaminer reliability were determined for 30 quantitative measures of neurological function, including sensory threshold, tendon reflexes, maximum isometric strength, and timed tests and coded ratings of functional ability, in patients with Charcot-Marie-Tooth disease (n = 30), idiopathic polyneuropathy (n = 16) and spinocerebellar degeneration (n = 30). Five of 6 sensory and reflex measures had interexaminer reliability greater than 0.80 when the neurologists' examinations were 1 h apart; 2 of 7 achieved this level when the examinations were separated by 1 month. Interexaminer reliability between physical therapists was greater than 0.80 for 19 of 20 measures of strength and functional ability. Intraexaminer reliability coefficients greater than 0.80 were found for 13 of 24 sensory and reflex measures, 28 of 30 isometric strength measures, 24 of 30 timed tests and 5 of 6 coded ratings of functional ability. Electro-oculography, oral diadochokinetic syllable rates, hand and foot accelerometry, and tracings of sine and square waves were examined as quantitative indices of ataxia for patients with spinocerebellar degeneration. Of 11 measures of ataxia, only the oral diadochokinetic syllable rate test had acceptable reliability.

Double-blind controlled trials of Cronassial in chronic neuromuscular diseases and ataxia.

We report three 12-month, double-blind, three-phase studies comparing the effect of placebo and 40 mg and 100 mg IM daily of purified bovine brain gangliosides (Cronassial) in chronic neuromuscular diseases. Thirty patients with Charcot-Marie-Tooth disease, 16 with idiopathic polyneuropathy, and 30 with spinocerebellar degeneration had neuromuscular function measured monthly by quantitative testing of motor and sensory function, coordination, and electrophysiologic factors. Analysis of these studies, and of longer term (up to 2 years) open studies of 100 mg daily of Cronassial in 67 patients failed to show therapeutic efficacy of Cronassial. Statistical power calculations indicated that five of the 37 measures had greater than a 70% chance of detecting a 20% difference in the rate of progression of the active-drug and placebo groups. A number of measures significantly improved during prolonged placebo treatment, suggesting that the placebo effect has a strong influence on "objective" measures of neuromuscular function.

Serial evaluation of neuromuscular function in management of chronic inflammatory demyelinating polyneuropathy. A case report.

In this case report, we describe the serial evaluation of neuromuscular function of a woman with chronic inflammatory demyelinating polyneuropathy and document the return of limb strength and hand function after plasmapheresis and immunosuppressive therapy. The assessment of muscle strength and functional abilities by physical therapists can provide timely, objective, and quantitative information that is important to the medical management of patients with neurologic disease.