Lower motor neuron disease with accumulation of neurofilaments in a cat.
A young cat had signs of tetraparesis that progressed to tetraplegia within a few weeks. Clinically, there was lower motor neuron disease with areflexia and muscle atrophy in all limbs. Degeneration of the motor neurons in the spinal cord was seen on histological examination. Ultrastructurally, the degeneration of nerve cells was characterized by abnormal proliferation of neurofilaments. These findings were compared to other motor neuron diseases and neurofibrillary accumulations in man and animals. (+info)
Neuromyotonia: an unusual presentation of intrathoracic malignancy.
A 48 year old woman is described who presented with increasing muscular rigidity and who was found to have a mediastinal tumour. Electrophysiological studies revealed that the muscular stiffness resulted from very high frequency motor unit activity which outlasted voluntary effort, and which was abolished by nerve block. The abnormal activity may have arisen at the anterior horn cell level. Marked improvement followed the administration of diphenylhydantoin. (+info)
Toxic polyneuropathy of shoe-industry workers. A study of 122 cases.
The toxic polyneuropathy observed in a group of shoe-industry workers in Italy was clinically characterised by a symmetrical prevalently distal motor deficit, with occasional marked weakness of pelvic girdle muscles, and frequently by only subjective sensory symptoms; non-specific disturbances usually preceded neurological signs. Subclinical cases of 'minimal' chronic neuropathy, characterised by alterations of a neurogenic type in the EMG without a reduction of motor nerve conduction velocity, were also observed. Worsening of the clinical picture, with further lowering of nerve conduction velocity, was noted in some cases up to four months after removal from the toxic environment. In the most severe cases clinical recovery took up to three years. The electromyographic and electroneurographic features were consistent with a mixed axonal neuropathy, with clear prevalence of the damage in the distal part of the nerve (dying-back neuropathy). Volatile substances, such as n-hexane and other low boiling point hydrocarbons found in high percentage in solvents and glues, are suggested as the causative agent. (+info)
The 'MW' sacropelvic construct: an enhanced fixation of the lumbosacral junction in neuromuscular pelvic obliquity.
Fixation to the lumbosacral spine to correct pelvic obliquity in neuromuscular scoliosis has always remained a surgical challenge. The strongest fixation of the lumbosacral junction has been achieved with either a Galveston technique with rods or screws or with iliosacral screws. We have devised a new fixation system, in which iliosacral screws are combined with iliac screws. This is made possible by using the AO Universal Spine System with side opening hooks above and below the iliosacral screws and iliac screws below it. The whole sacropelvis is thus encompassed by a maximum width (MW) fixation, which gives an 'M' appearance on the pelvic radiographs and a 'W' appearance in the axial plane. We report on our surgical technique and the early results where such a technique was used. We feel that this new means of fixation (by combining the strongest fixation systems) is extremely solid and should be included in the wide armamentarium of sacropelvic fixation. (+info)
Autonomic dysfunction in patients with nocturnal hypoventilation in extrapulmonary restrictive disease.
In chronic obstructive pulmonary disease, persistent hypoxia may be associated with autonomic dysfunction. The effect of nocturnal oxygen desaturation on autonomic function in patients with chest wall deformities and neuromuscular disease is unknown. This study examined the effect of nocturnal oxygen desaturation upon heart rate variability, a sensitive measure of autonomic function. Twenty-seven patients with chest wall deformity or neuromuscular disease underwent analysis of overnight oximetry, blood gases, and 24 h heart rate variability (HRV), specifically the standard deviation of normal-to-normal (SDNN) RR intervals, and the number of increases in successive NN intervals >50 ms (SNN50). Subjects were grouped according to nocturnal arterial oxygen saturation (Sa,O2): group 1 had episodes of Sa,O2 <90%, group 2 had Sa,O2 >90% throughout the night, and group 3 were 27 healthy age-matched controls who also underwent HRV analysis. The mean+/-SD SDNN for group 1 was 79.3+/-23.7 ms, less than group 2 (149.8+/-58.9 ms, p<0.02) and group 3 (155.1+/-37.1 ms, p<0.001). The geometric mean sNN50 was less in group 1 than group 2 (1,530 versus 5,843, p<0.01), but not significantly different from group 3 (2,712, p=0.053). There was no significant difference between groups 2 and 3. Within group 1, both SDNN and sNN50 were significantly lower in those patients with more severe nocturnal hypoxia. The minimum overnight Sa,O2 was the best predictor of abnormal HRV. In conclusion, patients with nocturnal hypoxia have evidence of autonomic dysfunction, even in cases with only transient episodes of nocturnal oxygen desaturation. The severity of autonomic dysfunction is related to the degree of nocturnal oxygen desaturation. (+info)
Bethlem myopathy and engineered collagen VI triple helical deletions prevent intracellular multimer assembly and protein secretion.
Mutations in the genes that code for collagen VI subunits, COL6A1, COL6A2, and COL6A3, are the cause of the autosomal dominant disorder, Bethlem myopathy. Although three different collagen VI structural mutations have previously been reported, the effect of these mutations on collagen VI assembly, structure, and function is currently unknown. We have characterized a new Bethlem myopathy mutation that results in skipping of COL6A1 exon 14 during pre-mRNA splicing and the deletion of 18 amino acids from the triple helical domain of the alpha1(VI) chain. Sequencing of genomic DNA identified a G to A transition in the +1 position of the splice donor site of intron 14 in one allele. The mutant alpha1(VI) chains associated intracellularly with alpha2(VI) and alpha3(VI) to form disulfide-bonded monomers, but further assembly into dimers and tetramers was prevented, and molecules containing the mutant chain were not secreted. This triple helical deletion thus resulted in production of half the normal amount of collagen VI. To further explore the biosynthetic consequences of collagen VI triple helical deletions, an alpha3(VI) cDNA expression construct containing a 202-amino acid deletion within the triple helix was produced and stably expressed in SaOS-2 cells. The transfected mutant alpha3(VI) chains associated with endogenous alpha1(VI) and alpha2(VI) to form collagen VI monomers, but dimers and tetramers did not form and the mutant-containing molecules were not secreted. Thus, deletions within the triple helical region of both the alpha1(VI) and alpha3(VI) chains can prevent intracellular dimer and tetramer assembly and secretion. These results provide the first evidence of the biosynthetic consequences of structural collagen VI mutations and suggest that functional protein haploinsufficiency may be a common pathogenic mechanism in Bethlem myopathy. (+info)
Expression of selectin families and their ligand sialyl Lewis X in the muscles of inflammatory myopathies: an immunohistochemical study.
OBJECT: Adhesion molecules are suggested to play important roles in the pathogenesis of inflammatory diseases. We examined the expression of adhesion molecules in the muscles of human inflammatory myopathies. METHODS: We immunohistochemically studied the expression and distribution of two molecules in the selectin family (E- and P-selectin) and their common ligand sialyl Lewis X in 18 inflammatory myopathies, 13 disease controls, and 16 normal controls. RESULTS: In inflammatory myopathies, E- and P-selectin were upregulated on the surface of blood vessels, especially on the endothelial cells of the venules. Sialyl Lewis X was upregulated in the blood vessels, infiltrating leukocytes, and the surface of some atrophic myofibers. Some control muscles also showed weakly positive staining with these molecules, however, expression of these molecules was most striking in the muscles of inflammatory myopathies. CONCLUSION: The results suggested that these molecules are upregulated in inflammatory myopathies and might play a role in the pathogenesis of inflammatory myopathies. (+info)
Progressive myelopathy caused by dural arteriovenous fistula at the craniocervical junction--case report.
A 68-year-old male presented an unusual dural arteriovenous fistula (AVF) located at the craniocervical junction. Magnetic resonance imaging revealed dilated perimedullary veins around the spinal cord at C-1 and C-2 levels, as well as high intensity signals in the spinal cord on T2-weighted images. Vertebral angiography identified an AVF at the point where the right vertebral artery penetrates the dura. The fistula was a single and direct communication between the vertebral artery and the spinal vein. Surgical interruption of the fistula at its venous side resulted in prompt improvement of both motor and sensory signs and symptoms. (+info)