1/6. Morphometric study of nucleus ambiguus in multiple system atrophy presenting with vocal cord abductor paralysis.AIM: To identify lesions responsible for vocal cord abductor paralysis (VCAP) in multiple system atrophy (MSA), we performed a morphometric study of the nucleus ambiguus which innervates the intrinsic laryngeal muscles. methods: Two autopsied cases of MSA presenting with VCAP and one control were examined. Both cases of MSA showed selective neurogenic atrophy of the posterior cricoarytenoid muscles among the intrinsic laryngeal muscles, while no abnormalities were seen in the control. From a block of the medulla oblongata, sections 10 microm thickness were cut serially without spacing and stained with cresyl violet. The ambiguus neurons were counted in all the sections to make a histogram. RESULTS: In the control case, ambiguus neurons showed densely populated areas and sparsely populated areas alternately with significant difference in the mean neuronal density between two areas. In MSA, ambiguus neurons were significantly decreased in number at all levels. It indicates that the neurogenic atrophy of the posterior cricoarytenoid muscle is derived from the neuronal loss of the nucleus ambiguus. CONCLUSION: Though it has still been controversial whether or not the ambiguus neurons are decreased in number in MSA with VCAP, we speculated possible reasons for the disagreement on the involvement of the nucleus ambiguus as follows: different mechanism of VCAP are playing role, and histometric data have been disturbed by factors such as split-cell counting error and marked variation in the distribution of the ambiguus neurons.- - - - - - - - - - ranking = 1keywords = nucleus (Clic here for more details about this article) |
2/6. Familial amyotrophic lateral sclerosis with bulbar onset and a novel Asp101Tyr Cu/Zn superoxide dismutase gene mutation.We describe a patient with familial amyotrophic lateral sclerosis (FALS) in whom we identified a novel missense mutation in exon 4 (Asp101Tyr) of the Cu/Zn superoxide dismutase (SOD1) gene. The disease started with a bulbar symptom (rapidly progressive hoarseness) and at autopsy showed degenerative changes restricted to the upper and lower motor neuron systems (more strictly, with lower motor predominance, showing the most severe degeneration in the nucleus ambiguus). Occasional intracytoplasmic Lewy-body-like hyaline inclusions that were immunoreactive for ubiquitin and SOD1, but immunonegative for neurofilament protein, were found in the lower motor neurons. This is the first report of hoarseness as the initial manifestation of FALS. This SOD1 gene mutation may be associated with a particular clinicopathological phenotype.- - - - - - - - - - ranking = 0.14285714285714keywords = nucleus (Clic here for more details about this article) |
3/6. Distal spinal and bulbar muscular atrophy caused by dynactin mutation.Impaired axonal transport has been postulated to play a role in the pathophysiology of multiple neurodegenerative disorders. In this report, we describe the results of clinical and neuropathological studies in a family with an inherited form of motor neuron disease caused by mutation in the p150Glued subunit of dynactin, a microtubule motor protein essential for retrograde axonal transport. Affected family members had a distinct clinical phenotype characterized by early bilateral vocal fold paralysis affecting the adductor and abductor laryngeal muscles. They later experienced weakness and atrophy in the face, hands, and distal legs. The extremity involvement was greater in the hands than in the legs, and it had a particular predilection for the thenar muscles. No clinical or electrophysiological sensory abnormality existed; however, skin biopsy results showed morphological abnormalities of epidermal nerve fibers. An autopsy study of one patient showed motor neuron degeneration and axonal loss in the ventral horn of the spinal cord and hypoglossal nucleus of the medulla. immunohistochemistry showed abnormal inclusions of dynactin and dynein in motor neurons. This mutation of dynactin, a ubiquitously expressed protein, causes a unique pattern of motor neuron degeneration that is associated with the accumulation of dynein and dynactin in neuronal inclusions.- - - - - - - - - - ranking = 0.14285714285714keywords = nucleus (Clic here for more details about this article) |
4/6. sarcoidosis as a cause of left recurrent laryngeal nerve palsy.vocal cord paralysis is an unusual complication of sarcoidosis. sarcoidosis may affect vocal cord function by either direct involvement of the cord or by involvement of the neural pathways, including the nucleus ambiguous, the 10th cranial nerves, and the superior and recurrent laryngeal nerves. There have been only two previous case reports of sarcoidosis with mediastinal adenopathy causing compression of the left recurrent laryngeal nerve and vocal cord paralysis. We present a third such case.- - - - - - - - - - ranking = 0.14285714285714keywords = nucleus (Clic here for more details about this article) |
5/6. Bulbar changes with laryngeal paralysis.There are two hypotheses that attempt to explain how a lesion in the lower part of the chest may cause paralysis of both laryngeal nerves with intermediate position of the afflicted cord. The first proposes retrograde degeneration of the vagus nerve up to its nucleus ambiguus, the second, ascending metastasis along the vagus nerve until the superior laryngeal nerve becomes paralyzed. In one case of inoperable lung cancer, the brain-stem was sectioned into a gapless series. The number of cells of the nucleus ambiguus on each side was equal, thus excluding an irreversible retrograde degeneration. However, central chromatolysis was found more than twice as often on the side of laryngeal paralysis. Intermediate vocal cord position was again associated with paralysis of both laryngeal nerves of that side.- - - - - - - - - - ranking = 0.28571428571429keywords = nucleus (Clic here for more details about this article) |
6/6. Dural metastasis at medulla oblongata: a rare cause of vocal fold paralysis.Malignancy is a major cause of vocal fold paralysis. Nevertheless, metastatic disease at the brainstem leading to high vagal paralysis is rarely encountered. We illustrate an unusual case of unilateral vocal fold paralysis caused by dural metastasis directly compressing on the nucleus ambiguus. The median position of the paralysed vocal fold is inconsistent with the Wagner and Grossman theory predicting the location of the lesion.- - - - - - - - - - ranking = 0.14285714285714keywords = nucleus (Clic here for more details about this article) |