1/42. diffusion-weighted imaging in wallerian degeneration.We report two patients displaying hyperintensities on diffusion-weighted imaging (DWI) in the area of wallerian degeneration (WD) at 12 days after stroke. High signal intensities were more conspicuous on DWI than on T2-weighted images. Both patients showed decreased diffusion anisotropy resulting in elevated apparent diffusion coefficient in the area of WD. These patients illustrate that DWI may be useful in the detection of the early stage of WD.- - - - - - - - - - ranking = 1keywords = degeneration (Clic here for more details about this article) |
2/42. A histopathological analysis of the human cervical spinal cord in patients with acute traumatic central cord syndrome.STUDY DESIGN: We have applied conventional histochemical and morphometric techniques to study the changes within the human spinal 'hand' motor neuron pool after spinal cord injury in patients who presented with acute traumatic central cord syndrome (ATCCS). OBJECTIVE: To determine whether a reduction of large alpha motor neurons at the C7, C8 and T1 spinal cord levels underlies the mechanism which causes hand dysfunction seen in patients with (ATCCS). BACKGROUND: The etiology of upper extremity weakness in ATCCS is debated and injury and/or degeneration of motor neurons within the central gray matter of the cervical enlargement has been advanced as one potential etiology of hand weakness. methods: The spinal cords of five individuals with documented clinical evidence of ATCCS and three age-matched controls were obtained. The ATCCS spinal cords were divided into acute/sub-acute (two cases) and chronic (three cases) groups depending on the time to death after their injury; the chronic group was further subdivided according to the epicenter of injury. We counted the motor neurons using light microscopy in 10 randomly selected axial sections at the C7, C8 and T1 spinal cord levels for each group. We also analyzed the lateral and ventral corticospinal tracts (CST) in all groups for evidence of wallerian degeneration and compared them to controls. RESULTS: A primary injury to the lateral CST was present in each case of ATCCS with evidence of wallerian degeneration distal to the epicenter of injury. There was minimal wallerian degeneration within the ventral corticospinal tracts. In the chronic low cervical injury group, there was a decrease in motor neurons supplying hand musculature relative to the other injury groups where the motor neurons sampled at the time of death were not reduced in number when compared to the control group. CONCLUSIONS: We hypothesize that hand dysfunction in ATCCS can be observed after spinal cord injury without any apparent loss in the number of motor neurons supplying the hand musculature as seen in our acute/sub-acute (n=2) and our chronic high injury (n=1) groups. The motor neuron loss seen in the chronic low level injury was felt to be secondary to the loss of C7, C8, and T1 neurons adjacent to the injury epicenter.- - - - - - - - - - ranking = 0.8keywords = degeneration (Clic here for more details about this article) |
3/42. Acute axonal neuropathy in maple syrup urine disease.A 25-year-old woman with maple syrup urine disease (MSUD) developed generalized weakness over 1 week. She had severe leg and moderate arm weakness, areflexia, and distal sensory loss. plasma branched-chain amino acid concentrations were elevated, reflecting an acute exacerbation of the disease. Electrodiagnostic studies indicated an acute axonal polyneuropathy and sural nerve biopsy revealed acute wallerian degeneration without inflammation. Peripheral neuropathy, although not identified previously as a clinical feature of MSUD, may become more common as chronic dietary restrictions and improved management of the disease allow survival into adulthood.- - - - - - - - - - ranking = 0.2keywords = degeneration (Clic here for more details about this article) |
4/42. "Pseudo-conduction block" in a patient with vasculitic neuropathy.A 63-year-old man presented with progressive asymmetric weakness and numbness in his hands of 2 weeks duration. Nerve conduction studies showed low amplitude motor evoked potentials of both median nerves. The right ulnar, left tibial and peroneal nerves had normal potentials on distal stimulation with markedly decreased amplitudes proximally, suggestive of "conduction block". Three weeks later, amplitudes were decreased throughout. The patient was diagnosed with vasculitis. The acute ischemic injury presumably resulted in axonal damage between the distal and proximal stimulation sites, with subsequent wallerian degeneration.- - - - - - - - - - ranking = 0.2keywords = degeneration (Clic here for more details about this article) |
5/42. Fixation-off sensitivity in an adult with symptomatic occipital epilepsy.An adult patient had EEG occipital spike fixation-off sensitivity and spontaneous occipital seizures due to perinatal asphyxia with bioccipital hemorrhage. EEG abnormalities consisted of repetitive posterior spikes that occurred when the eyes were closed and other conditions of fixation-off. magnetic resonance imaging (MRI) documented severe posterior lesions with wallerian degeneration of the optic radiation. Electron capture detector single-photon emission computed tomography (ECD-SPECT) during the state of fixation-off showed regional hyperperfusion in the right posterior regions. We suggest that partial denervation of the primary visual cortex in this patient resulted in an increased cortical excitability and that the inhibitory effect of central vision and fixation leads to a suppression of spontaneous epileptic activity. This unusual symptomatic case may serve as a model for the pathophysiology in the more often reported cases of idiopathic benign epilepsy syndrome of childhood.- - - - - - - - - - ranking = 0.2keywords = degeneration (Clic here for more details about this article) |
6/42. Histological findings after hemicerebellectomy in man: anterograde, retrograde and transneuronal degeneration.Histological changes are described in the brain of a patient in whom a hemicerebellectomy had been performed 14 years before death. There is cell and fibre loss, partial or total, in nuclei known to have direct connections with the cerebellum. In some nuclei the sequel to cell loss is marked fibrillary gliosis. In other nuclei the cells have disappeared without trace. The degeneration of these tracts with a direct connection with the cerebellum has also led to degeneration of other tracts in synaptic relationship with them. This transneuronal degeneration has occurred in the corticopontine tracts and in the central tegmental tract, in the former definitely, and in the latter probably, retrogradely. It is probable that transneuronal degeneration has also occurred in other tracts. The extent of the degeneration and, in particular, the occurrence of overt transneuronal degeneration, suggest that the examination of material after a very long term of survival might be of value in experimental work concerned with mapping neuroanatomical networks.- - - - - - - - - - ranking = 2keywords = degeneration (Clic here for more details about this article) |
7/42. Chronic inflammatory polyradiculoneuropathy.The diagnostic criteria, natural history, nerve conduction characteristics, pathology, laboratory features, and efficacy of corticosteroid treatment have been evaluated personally in 53 patients with chronic inflammatory polyradiculoneuropathy (CIP) who were followed up for an average of about 7.5 years. These were patients whose monophasic neurologic deficit had not crested by 6 months, patients with recurrences, and patients with a steady or stepwise progression. The typical features of CIP include absence of an associated disease, frequent history of preceding infection or receipt of foreign protein, and tendency to involve cranial, truncal, and proximal as well as distal limb structures and to have diffusely slow conduction velocity of peripheral nerves. The most marked slowing is often very proximal. The pathologic features include serous edema, mononuclear cell infiltrates (especially in perivascular areas, but without evidence of vasculitis), macrophage-induced segmental demyelination, and hypertrophic neuritis. If our patients are representative, complete recovery occurs only infrequently; about 60% of patients are able to be ambulatory and work, 25% become confined to a wheelchair or become bedridden, and approximately 10% die from their disease. Although the bulk of the pathologic changes affect spinal roots and proximal nerves, the brain and spinal cord may be involved also. Degeneration into linear rows of myelin ovoids is the predominant type of myelinated fiber degeneration of the sural nerve at the ankle.- - - - - - - - - - ranking = 0.2keywords = degeneration (Clic here for more details about this article) |
8/42. wallerian degeneration of the inferior cerebellar peduncle depicted by diffusion weighted imaging.wallerian degeneration of the inferior cerebellar peduncle has never been demonstrated on imaging studies. We describe a case in which it was depicted by thin slice diffusion weighted imaging. Location to the inferior cerebellar peduncle was confirmed by a fibre tracking method.- - - - - - - - - - ranking = 1keywords = degeneration (Clic here for more details about this article) |
9/42. wallerian degeneration in human nerves: serial electrophysiological studies.After nerve transection, the distal stump undergoes wallerian degeneration (WD). Little information is available concerning sequential changes in nerve conduction measurements during WD in humans. Five patients with nerve injuries were studied temporally. Motor-evoked amplitudes were reduced by 50% at 3 to 5 days after injury; the response was absent by day 9. Sensory-evoked amplitudes were reduced by 50% at 7 days after injury; the response was absent by day 11. Sensory and motor nerves with shorter distal stumps showed earlier loss of amplitude than did those with longer distal stumps. denervation potentials were seen 10 to 14 days after injury. Our results suggest that WD occurs earlier if the distal stump is shorter, and that motor-evoked responses are affected earlier than sensory-evoked responses. The time-lag between the loss of the motor-evoked response and the appearance of denervation potentials, the latter coinciding with reduction of sensory evoked responses, suggests that failure of neuromuscular transmission precedes axonal loss during WD.- - - - - - - - - - ranking = 1keywords = degeneration (Clic here for more details about this article) |
10/42. Bilateral wallerian degeneration of the medial cerebellar peduncles after ponto-mesencephalic infarction.Three patients with acute large paramedian ponto-mesencephalic infarctions developed a bilateral retrograde degeneration of the medial cerebellar peduncles within 4 months after the insult. In an initial magnetic resonance imaging (MRI) within the first 2 weeks, the medial cerebellar peduncles showed normal intensities, but a control MRI after 4 months showed bright hyperintensities in the T2-TSE weighted images, and moderately increased signal intensities in echo planar imaging-diffusion weighted imaging were seen, possibly representing bilateral wallerian degeneration of the cerebellar-pontine fibers.- - - - - - - - - - ranking = 1.2keywords = degeneration (Clic here for more details about this article) |
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