1/3. Cerebral glucose metabolism in type I alpha-n-acetylgalactosaminidase deficiency: an infantile neuroaxonal dystrophy.Cerebral glucose metabolism was investigated in a 4.8-year-old boy with alpha-n-acetylgalactosaminidase deficiency using 2-[18F]fluoro-2-deoxy-D-glucose and positron emission tomography (PET). In comparison to normal values for age, the overall cerebral glucose metabolism was reduced and the regional cerebral glucose metabolism was decreased in proportion to the degree of atrophy. In the supratentorial cortical regions, the hypometabolism was asymmetric. However, the level of regional cerebral glucose metabolism in all cortical regions excluded a persistent vegetative state. In the lentiform nucleus and the head of the caudate, comparatively increased regional cerebral glucose metabolism was documented, similar to findings in neurodegenerative disorders with active epilepsy. In contrast, the infratentorial structures (cerebellar hemispheres, brain stem, mesencephalon, and hypothalamus), which are predominantly affected by the atrophic process, showed distinct and symmetric hypometabolism. Thus, the 2-[18F]-fluoro-2-deoxy-D-glucose PET scans provided additional insight into and correlation of the functional and structural disturbances in type I alpha-n-acetylgalactosaminidase deficiency, in addition to documenting the hypometabolism due to brain atrophy.- - - - - - - - - - ranking = 1keywords = nucleus (Clic here for more details about this article) |
2/3. Transganglionic gracile response following limb amputation in man.Gracile neuroaxonal dystrophy (nad) is an distinctive morphological alteration of central projecting axon terminals of dorsal root ganglion neurons. Experimentally, lower limb amputation has been shown to accelerate the formation of gracile nad, suggesting that the transganglionic response to peripheral axotomy may play a role in its development. To determine if a similar response occurs in the human sensory nervous system following peripheral nerve injury, we have performed postmortem histopathological examinations of the dorsal column nuclei of three patients (aged 15, 55, and 77 years old); all of whom had undergone accidental or therapeutic unilateral limb amputation (1 year, 38 years, and 1 year 8 months prior to death, respectively). In a 15-year-old man who underwent therapeutic leg amputation, the gracile nuclei on the transected side revealed reactive gliosis and many small axonal spheroids. The spheroids and fine neurites were immunolabelled with antibodies for growth-associated protein-43, ubiquitin and neuropeptide y (NPY). Neither routine histological nor immunohistochemical methods demonstrated comparable changes in the contralateral gracile nucleus. In a 77-year-old man who underwent leg amputation, the gracile nucleus on the amputated side was gliotic and showed several NPY and ubiquitin-immunoreactive spheroids, which were not seen in the contralateral non-transected side. A 55-year-old man with a history of accidental arm amputation showed well-developed nad in the cuneate nucleus only on the transected side. This study clearly demonstrates the occurrence of transganglionic response to limb amputation in human dorsal column nuclei. The extent of the regenerative and/or degenerative responses may vary depending on the age of the patient and the time interval following the peripheral axotomy.- - - - - - - - - - ranking = 3keywords = nucleus (Clic here for more details about this article) |
3/3. Distal infantile neuroaxonal dystrophy--a new familial variant with perineuronal argyrophilic bodies.We report on two sisters with an infantile onset of dyskinetic movements, tonic spasms, seizures and apneic spells. The condition deteriorated to a hypotonic "burnt out" stage by the age of 3 years in the older sister and to a stable dyskinetic condition by the age of 2.5 years in the younger one. A skin biopsy from the older sister revealed myelinated nerve fibers crowded with neurofilaments. The extensive investigation for neurometabolic disorder, magnetic resonance imaging of the brain, and ophthalmological and neurophysiological examinations were not especially revealing. The older sister died at the age of 3 years. The autopsy revealed no apparent loss of nerve cells in the brain and no sign of storage disease. However, silver-stained coarse granules, immunopositive for neurofilament polypeptide, were found around nerve cell bodies in the cortex and in the basal ganglia. Electron microscopy revealed perineuronal membrane-bound profiles filled with filaments. silver-stained axonal torpedoes were found in the cerebellum, but there were no spheroids. The substantia nigra, the locus ceruleus and the nucleus basalis of Meynert showed extensive perineuronal and perivascular swelling. homovanillic acid was severely reduced, while 5-hydroxyindoleacetic acid and hydroxymethylphenyl glycol were normal in the cerebrospinal fluid of the severely affected, autopsied case. The two cases are considered to represent a new form of infantile neuroaxonal dystrophy, characterized by the degeneration of perineuronal terminals in the cerebral cortex and in the basal ganglia, as well as by axonal degeneration in the cerebellum and peripheral nerves.- - - - - - - - - - ranking = 1keywords = nucleus (Clic here for more details about this article) |