Detection and staging of early clinical dementia

In order to find neuropsychological indicators for detection and staging of dementia, groups of very mild, mild, and moderate dementia were compared to healthy aged individuals in neuropsychological tests tapping various cognitive and finger-motor functions. Results showed that the groups differed significantly in all cognitive tests, but not in the finger-motor tests. A stepwise disriminant analysis indicated that detection of very mild dementia was best accomplished by three tests assessing episodic memory, semantic memory, and visuospatial functioning. Staging of dementia was best accomplished by means of only one canonical function based on tests tapping episodic memory, semantic memory, visuospatial functions, and psychomotor speed. These results indicate that the pattern of dysfunction is similar for different levels of dementia, suggesting that similar cognitive functions may be involved in detection and staging of dementia.     

Mechanisms of action underlying the efficacy of deep brain stimulation of the subthalamic nucleus in Parkinson's disease: central role of disease severity

Despite consensus on some neurophysiological hallmarks of the Parkinsonian state (such as beta) band increase) a single mechanism is unlikely to explain the efficacy of deep brain stimulation (DBS) of the subthalamic nucleus (STN). Most experimental evidence to date correlates with an extreme degree of nigral neurodegeneration and not with different stages of PD progression. It seems inappropriate to combine substantially different patients – newly diagnosed, early fluctuators or advanced dyskinetic individuals – within the same group. An efficacious STN‐DBS imposes a new activity pattern within brain circuits, favouring alpha‐ and gamma‐like neuronal discharge, and restores the thalamo‐cortical transmission pathway through axonal activation. In addition, stimulation via the dorsal contacts of the macro‐electrode may affect cortical activation antidromically. However, basal ganglia (BG) modulation remains cardinal for ‘OFF’‐’ON’ transition (as revealed by cGMP increase occurring during STN‐DBS in the substantia nigra pars reticulata and internal globus pallidus). New research promises to clarify to what extent STN‐DBS restores striato‐centric bidirectional plasticity, and whether non‐neuronal cellular actions (microglia, neurovascular) play a part. Future studies will assess whether extremely anticipated DBS or lesioning in selected patients are capable of providing neuroprotection to the synuclein‐mediated alterations of synaptic efficiency. This review addresses these open issues through the specific mechanisms prevailing in a given disease stage. In patients undergoing early protocol, alteration in endogenous transmitters and recovery of plasticity are concurrent players. In advanced stages, re‐modulation of endogenous band frequencies, disruption of pathological pattern and/or antidromic cortical activation are, likely, the prominent modes.     

Combat stress casualties in Iraq. Part 2: psychiatric screening prior to aeromedical evacuation

TOPIC: Exposure to combat-related trauma is a leading cause of posttraumatic stress disorder. Deployed military mental health practitioners serve important roles in the assessment, diagnosis, and aeromedical evacuation of psychiatric patients from the combat zone. PURPOSE: To review the role of military mental health professionals working with psychiatric patients at a combat hospital and aeromedical staging facility in Iraq. SOURCE OF INFORMATION: Military operating instructions, existing theoretical and research literature, and personal experiences of the authors while deployed to Iraq. CONCLUSIONS: Psychiatric screening can help reduce risk in potentially unstable mental health patients prior to aeromedical evacuation. Civilian nurse psychotherapists and advanced practice psychiatric nurses will be needed to provide psychiatric follow-up care for the large number of military veterans returning from combat.     

A rule-based automatic sleep staging method

In this paper, a rule-based automatic sleep staging method was proposed. Twelve features including temporal and spectrum analyses of the EEG, EOG, and EMG signals were utilized. Normalization was applied to each feature to eliminating individual differences. A hierarchical decision tree with fourteen rules was constructed for sleep stage classification. Finally, a smoothing process considering the temporal contextual information was applied for the continuity. The overall agreement and kappa coefficient of the proposed method applied to the all night polysomnography (PSG) of seventeen healthy subjects compared with the manual scorings by R&K rules can reach 86.68% and 0.79, respectively. This method can integrate with portable PSG system for sleep evaluation at-home in the near future.     

Morphogenesis of the brain in the harbour porpoise

Morphogenesis of the brain in a cetacean species has been investigated by means of reconstructions from serial sections of successive prenatal stages of the harbour porpoise (Phocoena phocoena). Four specimens ranging from 10 to 46 mm crown-rump length (CRL) were selected and three-dimensional reconstructions of the developing brains were obtained with the plate model method. External and internal characteristics, established as criteria for staging embryonic development of primates and rodents, revealed that a common ontogenetic plan regarding the chronological sequence of morphogenetic events exists in mammalian orders as different as primates and odontocetes. Comparison of the 10-mm and 11.5-mm CRL harbour porpoise brains with those in other mammalian embryos of a similar ontogenetic stage (stages 16 and 17) showed a high degree of correspondence in morphological features. This ontogenetic age group therefore might still be considered as a generalized mammalian one. However, during succeeding morphogenesis of the Phocoena brain, qualitative and quantitative divergences from other mammalian groups became manifest, such as those found in the 24-mm CRL specimen (corresponding to mammalian stages 20, 21). Early foetuses of the harbour porpoise (46 and 65 mm CRL) already exhibited a variety of typical odontocete brain features, such as absence of olfactory bulb, thick cochlear nerve, and strong progression of brainstem structures. Morphogenesis of the harbour porpoise brain is discussed from a comparative perspective, incorporating the literature on the development of mammalian brains. Part of this study has been published in abstract form (Buhl and Oelschl?ger: Acta Anat. (Basel) 120:15-16 (Abstract), '84).     

Cell proliferation in intracranial tumours: selective silver staining of nucleolar organizer regions (AgNORs). Application to surgical and experimental neuro-oncology

A novel tool in diagnostic and experimental pathology, the AgNOR-technique, which consists of visualization of ribosomal gene activity by selective silver staining, was applied to 144 cytological specimens of human tumours of the nervous system. The number of silver-stained nucleolar organizer regions (AgNORs) was correlated with the biological behaviour of the tumours investigated; low AgNOR number were observed in benign neoplasms such as meningiomas and schwannomas and higher AgNOR numbers in glioblastomas and metastases. The mean AgNOR number per cell was 3.15 in astrocytomas, 4.5 in anaplastic astrocytomas and 5.86 in glioblastoma multiforme. Benign and malignant lesions showed different distribution patterns of AgNORs, with few but centrally located AgNORs in benign, and multiple but scattered AgNORs in malignant tumours. AgNOR number per cell and AgNOR area revealed an inverse relationship (correlation coefficient -0.15, linear regression). In addition to the human tumours, two N-nitroso-N-ethyl-urea (NEU) induced tumors in BD-IX rats a mixed glioma (G-XIII) and a malignant schwannoma (N-XII), were investigated. Twelve G-XIII gliomas revealed homogenous AgNOR-counts (standard error of the mean less than 10%), with absolute values between the values obtained for human glioblastomas and metastases. Seven N-XIII subcutaneously transplanted schwannomas revealed higher AgNOR values than human schwannomas, but lower than experimental gliomas. It is concluded that the AgNOR method, as a technique for visualization of ribosomal gene activity, is valuable for assessing proliferative activity and malignancy in both diagnostic and experimental neuropathology.     

Staging of multiple sclerosis (MS) lesions: pathology of the time frame of MS

Several processes take place during an attack of demyelination in multiple sclerosis (MS). The timing of these various processes, and thus of the attack in its entirety, is important if therapeutic stratagies are to be planned. Attempts have been made to introduce and investigate variables relevant to timing the disease processes, leading to staging systems for MS. Here, the terminology and the various parameters used are reviewed, including inflammatory cells, glial cells, axonal loss and myelin staining; then the different systems are compared, including the system put forward by Bö and Trapp, our own modification of that, the Brück and Lassmann system and the recent consensus reached at a Vienna meeting. It is concluded that an ideal staging system does not yet exist, and that, more than anything else, the material dictates the choice for a staging system. The terminology of the Vienna consensus could be used as a reference to facilitate international comparison.     

Applying clinical staging to young people who present for mental health care

Aim: The study aims to apply clinical staging to young people who present for mental health care; to describe the demographic features, patterns of psychological symptoms, disability correlates and clinical stages of those young people; and to report longitudinal estimates of progression from less to more severe stages. Methods: The study uses cross‐sectional and longitudinal assessments of young people managed in specialized youth clinics. On the basis of clinical records, subjects were assigned to a specific clinical ‘stage’ (i.e. ‘help‐seeking’, ‘attenuated syndrome’, ‘discrete disorder’ or ‘persistent or recurrent illness’). Results: Young people (n = 209, mean age = 19.9 years (range = 12–30 years), 48% female) were selected from a broader cohort of n = 1483 subjects. Ten percent were assigned to the earliest ‘help‐seeking’ stage, 54% to the ‘attenuated syndrome’ stage, 25% to the ‘discrete disorder’ stage and 11% to the later ‘persistent or recurrent illness’ stage. The interrater reliability of independent ratings at baseline was acceptable (κ = 0.71). Subjects assigned to the ‘attenuated syndrome’ stage reported symptom and disability scores that were similar to those assigned to later stages. Longitudinally (median = 48 weeks), transition to later clinical stages were 11% of the ‘help‐seeking’, 19% of the ‘attenuated syndrome’ and 33% of the ‘discrete disorder’ groups. Conclusion: Among young people presenting for mental health care, most are clinically staged as having ‘attenuated syndromes’. Despite access to specialized treatment, a significant number progress to more severe or persistent disorders.     

Duration of neurofibrillary changes in the hippocampal pyramidal neurons

The total number of neurons with and without neurofibrillary changes in sectors CA1 to CA4, subiculum, and dentate gyrus of 16 subjects with Alzheimer disease (AD) was estimated. The duration of neurofibrillary changes was calculated on the basis of regressions between the duration of AD and neuronal numbers. In the CA1 and subiculum, it takes 3.4 and 5.4 years, respectively, for an intact neuron affected by neurofibrillary pathology to become a ghost tangle.