[Medial Temporal Lobe Amnesia]

The medial temporal lobe was identified as an important neural structure in human memory by the advent of patient H.M., who suffered from severe amnesia caused by bilateral medial temporal lobectomy. Dozens of neuropsychological study of H.M. led to the classification of human memory into declarative and non-declarative memory, as well as short-term and long-term memory. The medial temporal lobe subserves declarative memory and long-term memory. It also plays an important role especially in the process of memory consolidation. The psychological and neurological mechanisms of the consolidation process can be investigated through the study of retrograde amnesia and epileptic amnesia.

Kidney enlargement and multiple liver cyst formation implicate mutations in PKD1/2 in adult sporadic polycystic kidney disease

Distinguishing autosomal-dominant polycystic kidney disease (ADPKD) from other inherited renal cystic diseases in patients with adult polycystic kidney disease and no family history is critical for correct treatment and appropriate genetic counseling. However, for patients with no family history, there are no definitive imaging findings that provide an unequivocal ADPKD diagnosis. We analyzed 53 adult polycystic kidney disease patients with no family history. Comprehensive genetic testing was performed using capture-based next-generation sequencing for 69 genes currently known to cause hereditary renal cystic diseases including ADPKD. Through our analysis, 32 patients had PKD1 or PKD2 mutations. Additionally, 3 patients with disease-causing mutations in NPHP4, PKHD1, and OFD1 were diagnosed with an inherited renal cystic disease other than ADPKD. In patients with PKD1 or PKD2 mutations, the prevalence of polycystic liver disease, defined as more than 20 liver cysts, was significantly higher (71.9% vs 33.3%, P = .006), total kidney volume was significantly increased (median, 1580.7 mL vs 791.0 mL, P = .027) and mean arterial pressure was significantly higher (median, 98 mm Hg vs 91 mm Hg, P = .012). The genetic screening approach and clinical features described here are potentially beneficial for optimal management of adult sporadic polycystic kidney disease patients.

“Mobile Nurse” Platform for Ubiquitous Medicine

Objectives : We introduce “Mobile Nurse" (MN) - an emerging platform for the practice of ubiquitous medicine.

Methods : By implementing in a dynamic setting of daily life the patient care traditionally provided by the clinical nurses on duty, MN aims at integral data collection and shortening the response time to the patient. MN is also capable of intelligent interaction with the patient and is able to learn from the patient's behavior and disease sign evaluation for improved personalized treatment.

Results : In this paper, we outline the most essential concepts around the hardware, software and methodological designs of MN. We provide an example of the implementation, and elaborate on the possible future impact on medical practice and biomedical science research.

Conclusions : The main innovation of MN, setting it apart from current tele-medicine systems, is the ability to integrate the patient's signs and symptoms on site, providing medical professionals with powerfultools to elucidate disease mechanisms, to make proper diagnoses and to prescribe treatment.

Subcallosal and Heubner artery infarcts following surgical repair of an anterior communicating artery aneurysm: a causal relationship with postoperative amnesia and long-term outcome

Since the 1950s, amnesia or memory impairment has been repeatedly reported in patients following surgical repair of anterior communicating artery (ACoA) aneurysms. Postoperative infarctions following surgical repair of ACoA aneurysms are classified as involvement of the subcallosal artery (the largest unpaired perforator of the ACoA), the recurrent artery of Heubner (RAH), or a combination of both. Postoperative amnesia can seriously affect the patient's quality of life, thus prompting physicians to discuss the symptomatology of the three infarction patterns. We made the following speculations regarding the causal relationship between the infarction pattern and postoperative amnesia. First, postoperative amnesia is most likely caused by an infarction in the territory of the subcallosal artery, particularly in the column of the fornix, a constituent of the Papez neuronal circuit. Second, infarction in the RAH territory alone is unlikely to cause significant amnesia. Third, infarcted foci in the RAH territory, when associated with a subcallosal artery infarction, can cause considerable frontal dysfunction due to impaired frontostriatal circuits in patients with postoperative amnesia, with resultant worsening of the long-term outcome or quality of life.

A change in brain white matter after shunt surgery in idiopathic normal pressure hydrocephalus: a tract-based spatial statistics study

Background

The aim of this study was to elucidate changes in cerebral white matter after shunt surgery in idiopathic normal pressure hydrocephalus (INPH) using diffusion tensor imaging (DTI).

Methods

Twenty-eight consecutive INPH patients whose symptoms were followed for 1 year after shunt placement and 10 healthy control (HC) subjects were enrolled. Twenty of the initial 28 INPH patients were shunt-responsive (SR) and the other 8 patients were non-responsive (SNR). The cerebral white matter integrity was detected by assessing fractional anisotropy (FA) and mean diffusivity (MD). The mean hemispheric DTI indices and the ventricular sizes were calculated, and a map of these DTI indices was created for each subject. The DTI maps were analysed to compare preshunt INPH with HC and preshunt INPH with 1 year after shunt placement in each INPH group, using tract-based spatial statistics. We restricted analyses to the left hemisphere because of shunt valve artefacts.

Results

The ventricles became significantly smaller after shunt placement both in the SR and SNR groups. In addition, there was a significant interaction between clinical improvement after shunt and decrease in ventricular size. Although the hemispheric DTI indices were not significantly changed after shunt placement, there was a significant interaction between clinical improvement and increase in hemispheric MD. Compared with the HC group, FA in the corpus callosum and in the subcortical white matter of the convexity and the occipital cortex was significantly lower in SR at baseline, whereas MD in the periventricular and peri-Sylvian white matter was significantly higher in the SR group. Compared with the pre-operative images, the post-operative FA was only decreased in the corona radiata and only in the SR group. There were no significant regions in which DTI indices were altered after shunt placement in the SNR group.

Conclusions

Brain white matter regions in which FA was decreased after shunt placement were in the corona radiata between the lateral ventricles and the Sylvian fissures. This finding was observed only in shunt-responsive INPH patients and might reflect the plasticity of the brain for mechanical pressure changes from the cerebrospinal fluid system.

Electronic supplementary material

The online version of this article (doi:10.1186/s12987-016-0048-8) contains supplementary material, which is available to authorized users.

Hypofibrinolytic Activity after Total Joint Replacement

Tissue-type plasminogen activator (t-PA), tissue-type plasminogen activator inhibitor (t-PAI), and other factors (platelets, fibrinogen, fibrinogen degrada tion products, antithrombin-III, plasminogen, and α2-plasmin inhibitor [α2-PI]) related to the fibrinolytic system were studied in 21 patients undergoing total joint replacement.

Seventeen of the 21 patients revealed an impaired fibrinolytic activity from the first to seventh postoperative day and a subsequent return to the preopera tive level by the fourteenth postoperative day. There were accompanying increases in the level of α2-PI and in the t-PAI/t-PA ratio, and there was decrease in plas minogen level. Such hypofibrinolytic states may be related to a higher incidence of postoperative thrombosis in total joint replacement patients.

Tension-Type Headache and Physical Activity: An Actigraphic Study

There have been some studies on the relationship between tension-type headache (TTH) and physical activity. However, most previous studies were not prospective and assessed physical activity by questionnaire. Therefore, this study was aimed to investigate the relationship between TTH intensity and physical activity prospectively utilizing computerized ecological momentary assessment and actigraphy Thirty-one TTH patients wore watch-type computers equipped with actigraphy inside for 1 week to record momentary headache intensity and physical activity. Multilevel modelling was used to investigate the effect of headache intensity on the simultaneous and subsequent activity level. There were significant negative associations between headache intensity and the simultaneous and subsequent activity level, and activity level was significantly reduced at headache exacerbations. These results provide objective and quantitative evidence suggesting that TTH negatively affects physical activity.

A giant polymer lattice in a polymer-stabilized blue phase liquid crystal

Ultrasmall-angle synchrotron X-ray scattering measurements showed that a three-dimensional polymer lattice of a few 100 nm order with body-centered cubic O(8-) symmetry was formed in a polymer-stabilized blue phase liquid crystal. We obtained clear experimental evidence that the polymer chains condensed selectively in the disclinations within the blue phase during photo-polymerization of monomers in the blue phase.

Amyloid deposits and response to shunt surgery in idiopathic normal-pressure hydrocephalus

OBJECTIVES

In previous studies, patients with idiopathic normal-pressure hydrocephalus (iNPH) occasionally showed Alzheimer's pathology in frontal lobe cortical biopsy during cerebrospinal fluid shunt surgery or intracranial pressure monitoring. In clinical practice, the differential diagnosis of iNPH from Alzheimer's disease (AD) can be problematic, particularly because some iNPH cases exhibit AD comorbidity. In this study, we evaluated amyloid deposition in the brains of patients with iNPH before shunt surgery, and investigated the association between brain amyloid deposits and clinical improvement following the surgery.

MATERIALS & METHODS

Amyloid imaging was performed in patients with iNPH or AD and also in healthy control subjects by using positron emission tomography (PET) and a radiolabeled pharmaceutical compound, (11)C-BF227. Using the cerebellar hemispheres as reference regions, the standard uptake value ratio (SUVR) of the neocortex was estimated and used as an index for amyloid deposition. In patients with iNPH, clinical symptoms were assessed before shunt surgery and 3 months after surgery.

RESULTS

Five of the 10 patients with iNPH had neocortical SUVRs that were as high as those of AD subjects, whereas the SUVRs of the 5 patients were as low as those of healthy controls. A significant inverse correlation between neocortical SUVRs and cognitive improvements after shunt surgery was observed in iNPH.

CONCLUSIONS

The amount of amyloid deposits ranges widely in the brains of patients with iNPH and is associated with the degree of cognitive improvement after shunt surgery.