Trident sign in osmotic demyelination syndrome

Loss of Ephaptic Contacts in the Murine Thalamus during Osmotic Demyelination Syndrome

BACKGROUND AND AIM

A murine model mimicking osmotic demyelination syndrome (ODS) revealed with histology in the relay posterolateral (VPL) and ventral posteromedial (VPM) thalamic nuclei adjoined nerve cell bodies in chronic hyponatremia, amongst the damaged 12 h and 48 h after reinstatement of osmolality. This report aims to verify and complement with ultrastructure other neurophysiology, immunohistochemistry, and molecular biochemistry data to assess the connexin-36 protein, as part of those hinted close contacts.This ODS investigation included four groups of mice: Sham (NN; n = 13), hyponatremic (HN; n = 11), those sacrificed 12 h after a fast restoration of normal natremia (ODS12h; n = 6) and mice sacrificed 48 h afterward, or ODS48 h (n = 9). Out of these, thalamic zones samples included NN (n = 2), HN (n = 2), ODS12h (n = 3) and ODS48h (n = 3).

RESULTS

Ultrastructure illustrated junctions between nerve cell bodies that were immunolabeled with connexin36 (Cx36) with light microscopy and Western blots. These cell's junctions were reminiscent of low resistance junctions characterized in other regions of the CNS with electrophysiology. Contiguous neurons showed neurolemma contacts in intact and damaged tissues according to their location in the ODS zones, at 12 h and 48 h post correction along with other demyelinating alterations. Neurons and ephaptic contact measurements indicated the highest alterations, including nerve cell necrosis in the ODS epicenter and damages decreased toward the outskirts of the demyelinated zone.

CONCLUSION

Ephapses contained C × 36between intact or ODS injured neurons in the thalamus appeared to be resilient beyond the core degraded tissue injuries. These could maintain intercellular ionic and metabolite exchanges between these lesser injured regions and, thus, would partake to some brain plasticity repairs.

Osmotic Demyelination Syndrome: Clinical, Neuroimaging Characteristics, and Outcomes in a Series of 18 Cases

Objective

To investigate the etiology, clinical as well as neuroimaging characteristics, and outcomes after proper treatment in a series of 18 patients with osmotic demyelination syndrome.

Methods

Medical records, including video records, of 18 patients with osmotic demyelination syndrome were retrospectively examined. Demographic and clinical information, imaging results, plans of management, and outcomes during the follow-up period were collected and analyzed.

Results

Eighteen patients, including 10 males and 8 females, were included in the present study. The mean age at diagnosis of CNS insult was 47.4 ± 13.3 years (ranged from 30 to 78 years). Etiologies included rapidly corrected hyponatremia (50%), alcoholism (27.8%), and others. Neurological manifestations included encephalopathy (61.1%), dysphonia (50%), extrapyramidal symptoms (38.9%), and seizures (22.2%). Neuroimaging results showed that 6 patients (33.3%) had central pontine myelinolysis, 5 (27.8%) had extrapontine myelinolysis, and 7 (38.9%) had both. After treatment, 12 patients showed improvement and the other 6 did not. Among these patients, those who showed symptoms of encephalopathy had a favorable outcome. The majority of those who presented with mental retardation, seizures, and no other symptoms recovered better than their counterparts who had other symptoms. Nine out of 11 patients with pseudobulbar paralysis and/or extrapyramidal symptoms showed improvement, but the other 2 did not show improvement. Five patients who did not improve after treatment during admission were followed up for 1-3 months with rehabilitation training recommended, and it was found that 3 showed significant improvement after training, and the other 2 did not respond to this training.

Conclusions

Osmotic demyelination syndrome is a complex disease entity due to a variety of etiologies, manifesting with symptoms involving diverse systems of the brain. Early identification and removal/correction of conditions leading to osmotic demyelination syndrome are the key to prevent and/or manage this disease.

Rehabilitation of anterior pituitary dysfunction combined with extrapontine myelinolysis: A case report

BACKGROUND

Extramedullary myelinolysis is a rare demyelinating disease, often caused by rapid increases in serum sodium concentration in patients with hyponatremia. Clinical manifestations are neuropsychiatric symptoms, limb weakness, and dysarthria. Because of its poor prognosis and high disability rate, it poses a huge burden on the global economy, societies, and families. This article reports rehabilitation in a patient with pituitary dysfunction combined with extramedullary myelinolysis.

CASE SUMMARY

A 27-year-old Chinese man developed anorexia, vomiting, and limb weakness and was diagnosed with pituitary insufficiency. He had low serum sodium, slow movement, muscle weakness, and muscle tone abnormalities after sodium supplementation, involuntary limb shaking, ataxia, and dysarthria. According to the symptoms and signs and imaging reports, he was diagnosed with extramedullary myelinolysis. After treatment with hormone therapy and neurotrophic drugs, motor and speech function did not improve, so he was treated in the rehabilitation department for 4 wk. The patient's physical status was improved substantially during his stay at the rehabilitation department.

CONCLUSION

Patients with extramedullary myelinolysis who actively participate in rehabilitation intervention can significantly improve their activities of daily living.