Theoretical considerations on the pathophysiology of normal pressure hydrocephalus (NPH) and NPH-related dementia

Normal pressure hydrocephalus (NPH) is considered to be an example of reversible dementia although clinical improvement after shunting varies from subject to subject, and recent studies have pointed to a possible link with other dementia. The authors consider that the craniospinal compartment is a partially closed sphere with control device systems represented by the spinal axis and the sagittal sinus-arachnoid villi complex which interact with each other in the clinical patient setting. We hypothesise that changing spinal compliance by altering the flow process and CSF dynamics lead to hydrocephalus. Therefore four NPH types have been distinguished according to the alterations in spinal compliance, decrease in CSF absorption at the sagittal sinus or both occurrences. The authors consider that NPH and NPH-related diseases (NPH-RD) are initiated by the same common final pathway and demonstrate that NPH could represent an initial stage of NPH-RD. Progression of clinical signs can be explained as damage to the cerebral tissue by both intermittent increased intracranial pressure and pulse pressure waves leading to periventricular ischaemia. In addition, they believe that both volume equilibrium and spinal compliance are restored in patients who improve after CSF shunt, whereas in patients whose condition does not improve, only volume equilibrium is restored and not spinal compliance, which was the underlying cause of hydrocephalus in such cases. They therefore wonder whether cervical decompression should not be indicated in patients who show no improvement. Although attractive, this analysis warrants confirmation from clinical, radiological, and hydrodynamic studies.     

Chronic graft versus host disease of oral mucosa: review of available therapies

The use of hematopoetic stem cell transplantation (HSCT) has greatly expanded in the recent years for many neoplastic and hematological disorders. Chronic graft versus host disease (cGVHD) is a major complication of allogeneic HSCT and a major cause of morbidity and mortality. Oral mucosal involvement is frequent in cGVHD and contributes significantly to the overall burden of the condition. Oral medicine professionals should be familiar with various treatment options for oral cGVHD. This review discusses treatment modalities available for the management of oral mucosal manifestations of cGVHD. Available evidence for efficacy and safety of various systemic and topical agents, including corticosteroids, calcineurin antagonists, mycophenolate mofetil, and extracorporeal photopheresis, is reviewed.     

Thrombophilic polymorphisms – factor V Leiden G1691A,prothrombin G20210A and MTHFR C677T – in Tunisian patients with cerebral venous thrombosis

Cerebral venous thrombosis (CVT) has been associated with thrombophilic defects. We performed a study to evaluate the role of three single nucleotide polymorphisms (SNP), factor V Leiden G1691A (FVL), prothrombin gene mutation G20210A (FII-G20210A) and methylenotetrahydrofolate reductase variant C677T (MTHFR-C677T), as risk factors for CVT in Tunisian patients. A single center case-control study (26 patients with CVT and 197 controls) was performed. Genomic DNA was tested for the three SNP. The principle finding was the association between FVL and CVT (p < 0.001, Odds ratio = 6.1, 95% confidence interval = 2.3–16.5). However, neither the FII-G20210 (p = 0.536) nor the homozygous MTHFR-C677T genotype (p = 0.325) variant contributed to the risk of CVT in these Tunisian patients.     

Differential activity-dependent regulation of the lateral mobilities of AMPA and NMDA receptors

The basis for differences in activity-dependent trafficking of AMPA receptors (AMPARs) and NMDA receptors (NMDARs) remains unclear. Using single-molecule tracking, we found different lateral mobilities for AMPARs and NMDARs: changes in neuronal activity modified AMPAR but not NMDAR mobility, whereas protein kinase C activation modified both. Differences in mobility were mainly detected for extrasynaptic AMPARs, suggesting that receptor diffusion between synaptic and extrasynaptic domains is involved in plasticity processes.