Background: Hereditary motor and sensory neuropathy type Ia (HMSN Ia) is known as a primarily demyelinating peripheral nerve disease. Evidence is accumulating that axonal involvement determines the course of the disea...Background: Hereditary motor and sensory neuropathy type Ia (HMSN Ia) is known as a primarily demyelinating peripheral nerve disease. Evidence is accumulating that axonal involvement determines the course of the disease process. Methods: Fifty- one patients were investigated. Physical disability and impairments were scored. Nerve conduction velocities (NCVs) were used as indirect measures for myelination status and compound muscle/sensory nerve action potential (CMAP/SNAP) amplitudes served as indirect measures for axonal function. Results: Median age was 39 years (range 6- 69). Muscle weakness and sensory dysfunction was more severe in the legs than in the arms and distally more than proximally. However, more than 40 % of the patients had proximal muscle weakness in the legs. Three point grip was used as representative of combined distal arm muscle groups. CMAP amplitude was the most important independent variable in a multiple linear regression model (forward selection) to explain the relation between three point grip strength and four different features, i. e., CMAP amplitude of the abductor pollicis brevis, median nerve MNCV, gender, and duration of signs and symptoms. The severity of axonal dysfunction was nerve length- dependent and was related to the myelination status. The mild physical disability due to both muscle weakness and sensory dysfunction was also related to axonal dysfunction. Conclusions: In HMSN Ia, clinical disease severity at the impairment and disability levels is related to the severity of axonal dysfunction. Our data support the hypothesis that the myelination status is one of the factors that determine the extent of axonal dysfunction later in life. Proximal weakness of the legs is encountered in a considerable proportion of our patients.展开更多
To test whether infants with bronchopulmonary dysplasia (BPD) express the same functional impairments at term as healthy, preterm infants, and whether clinical severity of BPD is qualitatively or quantitatively relate...To test whether infants with bronchopulmonary dysplasia (BPD) express the same functional impairments at term as healthy, preterm infants, and whether clinical severity of BPD is qualitatively or quantitatively related. Prospective measurements on a consecutive sample of 50 infants with BPD and 19 healthy preterm controls in a university hospital. BPD infants were classified as “severe, ”“moderate, ”or “mild, ”according to their need for oxygen. A multiple-breath nitrogen wash-out method was used to assess functional residual capacity (FRC)-and gas mixing efficiency. Mechanical variables were estimated by the occlusion test. Infants with severe BPD had lower FRC, less efficient gas mixing, and higher specific conductance than those with mild and moderate BPD, and the preterm controls. Mild and moderate BPD did not differ in any property from each other but differed from controls in the same variables. The elastic properties of the respiratory system appeared unaffected by BPD. The ventilatory impairments in BPD were of the same nature as in healthy preterm infants when compared with term infants, but their magnitude was related to the clinical severity of the BPD. Gas mixing efficiency together with FRC appears to be useful to assess lung development in BPD.展开更多
文摘Background: Hereditary motor and sensory neuropathy type Ia (HMSN Ia) is known as a primarily demyelinating peripheral nerve disease. Evidence is accumulating that axonal involvement determines the course of the disease process. Methods: Fifty- one patients were investigated. Physical disability and impairments were scored. Nerve conduction velocities (NCVs) were used as indirect measures for myelination status and compound muscle/sensory nerve action potential (CMAP/SNAP) amplitudes served as indirect measures for axonal function. Results: Median age was 39 years (range 6- 69). Muscle weakness and sensory dysfunction was more severe in the legs than in the arms and distally more than proximally. However, more than 40 % of the patients had proximal muscle weakness in the legs. Three point grip was used as representative of combined distal arm muscle groups. CMAP amplitude was the most important independent variable in a multiple linear regression model (forward selection) to explain the relation between three point grip strength and four different features, i. e., CMAP amplitude of the abductor pollicis brevis, median nerve MNCV, gender, and duration of signs and symptoms. The severity of axonal dysfunction was nerve length- dependent and was related to the myelination status. The mild physical disability due to both muscle weakness and sensory dysfunction was also related to axonal dysfunction. Conclusions: In HMSN Ia, clinical disease severity at the impairment and disability levels is related to the severity of axonal dysfunction. Our data support the hypothesis that the myelination status is one of the factors that determine the extent of axonal dysfunction later in life. Proximal weakness of the legs is encountered in a considerable proportion of our patients.
文摘To test whether infants with bronchopulmonary dysplasia (BPD) express the same functional impairments at term as healthy, preterm infants, and whether clinical severity of BPD is qualitatively or quantitatively related. Prospective measurements on a consecutive sample of 50 infants with BPD and 19 healthy preterm controls in a university hospital. BPD infants were classified as “severe, ”“moderate, ”or “mild, ”according to their need for oxygen. A multiple-breath nitrogen wash-out method was used to assess functional residual capacity (FRC)-and gas mixing efficiency. Mechanical variables were estimated by the occlusion test. Infants with severe BPD had lower FRC, less efficient gas mixing, and higher specific conductance than those with mild and moderate BPD, and the preterm controls. Mild and moderate BPD did not differ in any property from each other but differed from controls in the same variables. The elastic properties of the respiratory system appeared unaffected by BPD. The ventilatory impairments in BPD were of the same nature as in healthy preterm infants when compared with term infants, but their magnitude was related to the clinical severity of the BPD. Gas mixing efficiency together with FRC appears to be useful to assess lung development in BPD.
