When a patient can write but not copy: report of a single case

A dissociation between spared spontaneous and impaired writing on copy is described in a patient with severe limb and constructional apraxia. Visual-perceptual abilities were normal as well as oral language and reading. The findings are discussed in the light of an information processing model of writing.     

Processing of global,but not local,motion direction is deficient in schizophrenia

Visual motion processing is compromised in a substantial proportion of schizophrenic patients, but precise neural mechanisms underlying the motion-processing deficit have not yet been elaborated. The visual motion pathway includes a local and a global processing stage, each of which has distinct neural substrates. Here, we attempt to identify the stage(s) that are implicated in impaired motion processing of schizophrenia-local, global, or both. For schizophrenia patients (n=23) and normal controls (n=26), we measured (1) the thresholds for detecting the motion direction of a random dot pattern, a task that requires global motion processing, and (2) the thresholds for detecting the motion direction of a grating, a task that requires only local motion processing, using psychophysical methods. Schizophrenia patients showed elevated thresholds for detecting the direction of coherent motion, particularly for the high dot-density target. In contrast, schizophrenia patients showed normal thresholds for detecting the direction of motion of a grating. The results indicate that the global, but not the local, processing stage of the visual motion system is compromised in schizophrenia patients, thus implicating motion-sensitive brain areas that possess large receptive fields for spatial and temporal integration, such as Middle Temporal Area/Medial Superior Temporal Area.     

The puzzle of noncompliance in the manic patient

Patients with affective disorders may be seriously compromised by failure to comply with prescribed medication regimens. At the time of his hospitalization, the patient discussed here had a severe bipolar disorder characterized by disruptive and repetitive manic episodes that were generated by medication noncompliance and substance abuse. Through an understanding of the longitudinal and progressive development of this rapidly cycling disorder, the consultant emphasizes the importance of long-term maintenance pharmacotherapy in the context of environmental restructuring to attempt to reverse the malignant nature of the patient's affective disorder.     

Visual perception without awareness in a patient with posterior cortical atrophy: impaired explicit but not implicit processing of global information.

A patient with progressive posterior cortical atrophy (PCA) was examined on several tests of visual cognition. The patient displayed multiple visual cognitive deficits, which included problems identifying degraded stimuli, attending to two or more stimuli simultaneously, recognizing faces, tracing simple visual stimuli, matching simple shapes, and copying objects. The patient was also impaired in identifying visual targets contained at the global level within global-local stimuli (i.e., smaller letters that compose a larger letter). Although the patient denied any conscious awareness of the global form, he nevertheless displayed a normal pattern of global interference when asked to identify local level targets. Thus, the patient processed the global information despite not being consciously aware of such information. These results suggest that global-local processing can take place in the absence of awareness. Possible neurocognitive mechanisms explaining this dissociation are discussed.     

Ascorbic acid is neuroprotective against global ischaemia in striatum but not hippocampus: histological and voltammetric data

Following reports that ascorbic acid (AA) blocks NMDA receptors, we examined its possible neuroprotective properties in vivo (gerbil bilateral carotid artery occlusion model: BCAO) and in vitro (ischaemia-induced dopamine (DA) release in brain slices). Five minutes of BCAO caused substantial cell loss of 90-95% and 40-50% in gerbil CA1 hippocampus and striatum, respectively, measured in haematoxylin and eosin-stained sections, 5 days post-insult. AA (500 mg kg(-1) day(-1) i.p. for 312 days, first dose 1 h before occlusion) significantly (P<0.05) reduced striatal cell loss (from 40 to 13%) while only reducing CA1 cell loss from 95 to 88%. A lower dose (250 mg kg(-1) day(-1) i.p. for 312 days) was ineffective in either region. AA (750 mg kg(-1) day(-1) i.p. for 312 days) caused significant striatal protection (cell loss reduced from 49 to 20%) if treatment was initiated 1 h before occlusion. Initiation of treatment immediately post occlusion did not cause significant protection. Neither treatment regime protected CA1 hippocampus. In separate experiments we examined the effect of AA on DA release, monitored by voltammetry, in an in vitro model of striatal ischaemia. Four DA release variables were measured: T(on)--time from initiation of ischaemia to the onset of DA release, T(pk)--the time from onset of DA release to maximum, deltaDA/deltat--the mean rate of DA release and [DA](max)-- the maximum extracellular DA concentration. Control values in drug-naive slices were: T(on)=193+/-8 s, T(pk) = 24 +/- 4 s, [DA](max) = 69 +/- 6 microM and deltaDA/deltat = 4.2 +/- 0.7 microM s(-1) (means+/-S.E.M., n=15). 212 h pretreatment with AA (0.4 to 10 mM) did not affect T(on) or [DA](max) but increased T(pk) and decreased deltaDA/deltat (P<0.05) with an EC50 of 1.66 mM. NMDA (100 microM) shortened T(on). N-ethylmaleimide (20 microM) had no effect on the response to AA but potentiated the action of NMDA on T(on). AA (2 or 10 mM) had no effect on the response to NMDA. We conclude that AA is neuroprotective against global ischaemia in the striatum and that some of this action may be due to attenuation of ischaemia-induced DA release. This action is mediated neither by blockade of the NMDA receptor nor modulation of its redox status.     

Functional connectivity in the default network during resting state is preserved in a vegetative but not in a brain dead patient

Recent studies on spontaneous fluctuations in the functional MRI blood oxygen level‐dependent (BOLD) signal in awake healthy subjects showed the presence of coherent fluctuations among functionally defined neuroanatomical networks. However, the functional significance of these spontaneous BOLD fluctuations remains poorly understood. By means of 3 T functional MRI, we demonstrate absent cortico‐thalamic BOLD functional connectivity (i.e. between posterior cingulate/precuneal cortex and medial thalamus), but preserved cortico‐cortical connectivity within the default network in a case of vegetative state (VS) studied 2.5 years following cardio‐respiratory arrest, as documented by extensive behavioral and paraclinical assessments. In the VS patient, as in age‐matched controls, anticorrelations could also be observed between posterior cingulate/precuneus and a previously identified task‐positive cortical network. Both correlations and anticorrelations were significantly reduced in VS as compared to controls. A similar approach in a brain dead patient did not show any such long‐distance functional connectivity. We conclude that some slow coherent BOLD fluctuations previously identified in healthy awake human brain can be found in alive but unaware patients, and are thus unlikely to be uniquely due to ongoing modifications of conscious thoughts. Future studies are needed to give a full characterization of default network connectivity in the VS patients population. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.     

Attended but unseen: visual attention is not sufficient for visual awareness

Does any one psychological process give rise to visual awareness? One candidate is selective attention-when we attend to something it seems we always see it. But if attention can selectively enhance our response to an unseen stimulus then attention cannot be a sufficient precondition for awareness. Kentridge, Heywood & Weiskrantz [Kentridge, R. W., Heywood, C. A., & Weiskrantz, L. (1999). Attention without awareness in blindsight. Proceedings of the Royal Society of London, Series B, 266, 1805-1811; Kentridge, R. W., Heywood, C. A., & Weiskrantz, L. (2004). Spatial attention speeds discrimination without awareness in blindsight. Neuropsychologia, 42, 831-835.] demonstrated just such a dissociation in the blindsight subject GY. Here, we test whether the dissociation generalizes to the normal population. We presented observers with pairs of coloured discs, each masked by the subsequent presentation of a coloured annulus. The discs acted as primes, speeding discrimination of the colour of the annulus when they matched in colour and slowing it when they differed. We show that the location of attention modulated the size of this priming effect. However, the primes were rendered invisible by metacontrast-masking and remained unseen despite being attended. Visual attention could therefore facilitate processing of an invisible target and cannot, therefore, be a sufficient precondition for visual awareness.     

The lupus anticoagulant is a risk factor for myocardial infarction (but not atherosclerosis): Hopkins Lupus Cohort

Antiphospholipid antibodies, both anticardiolipin and lupus anticoagulant, are common in SLE. We asked, in a prospective cohort, whether these antibodies are predictive of atherosclerosis and/or coronary artery disease. Methods: Three hundred eighty patients, 92% female, 49% Caucasian, 51% African-American, mean age 46.4±12.3 years are followed quarterly, with assessment of both anticardiolipin and lupus anticoagulant (dRVVT). These patients underwent both helical CT and carotid duplex. Results: Both the lupus anticoagulant and anticardiolipin are predictive of later venous or arterial thrombosis. Twenty years after diagnosis, SLE patients with the lupus anticoagulant (LA) have a 50% chance of a venous thrombotic event. Myocardial infarction occurs significantly more often in those with LA 22% vs. 9%, p=0.04. Neither anticardiolipin nor LA are associated with carotid IMT, carotid plaque, nor coronary calcium by helical CT. In aCL positive patients carotid IMT was 0.57±0.01 vs. 0.58±0.01 in aCL negative patients (p=NS); carotid plaque 0.47±0.13 vs. 0.32±0.10 (p=NS); and coronary calcium 65.4±37.4 vs. 65.4±30.2 (p=NS). In LA positive patients, carotid IMT was 0.59±0.03 vs. 0.59±0.02 in LA negative patients (p=NS); carotid plaque 0.07±0.02 (SE) vs. 0.80±0.02 (SE) (p=0.06); and coronary calcium 28.1±3.7 (SE) vs. 85.7±2.6 (SE) (p=NS). Conclusion: Antiphospholipid antibodies are not associated with subclinical atherosclerosis (carotid IMR, carotid plaque, helical CT coronary calcium), but are associated with actual thrombotic sequelae (myocardial infarction).     

The assessment of need for mental health services

BACKGROUND: The field of psychiatric epidemiology has yielded several large and important studies of the prevalence of psychiatric disorders. These surveys have been enhanced by the inclusion of methodologies that reflect the needs for care of the population in question. Clinical studies of psychiatric disorders and unmet needs have focussed on identifying needs and correlating them with service evaluation and satisfaction measures. The association between prevalence, service use and unmet need requires review in order to establish whether there are trends and consistent findings. METHOD: Peer-reviewed studies involving the assessment of need up to the present were included. These were of two broad groups: population-based studies and clinical studies. Studies based on outcome measures, review articles, and child psychiatry, old age, and intellectual disability samples were excluded. We conducted a search of MEDLINE and PSYCHINFO using the key words, "mental health needs","assessment of need", and "needs assessment". In addition, we hand-searched key journals and sought personal communication with researchers in the field. RESULTS: A total of 14 population studies and 19 clinical studies were retrieved. The percentage of the general population who reported at least one need for care ranged from 9.5% to 13.8%. The numbers of needs in psychiatric patients ranged from 3.3 to 8.6. Correlates of unmet need include: unemployment, single status, low quality of life and high disability scores, and the presence of certain psychiatric diagnoses, such as affective psychosis and personality disorders. Higher rates of met need and service satisfaction are correlated with a longer duration of service contact. CONCLUSION: The assessment of need to date has been established either by service use data to make inferences about unmet need, by asking limited guided questions about needs, or by using established needs assessment instruments. The high prevalence of psychiatric disorders and the weak correlation between disorder and unmet need require a combined approach towards service development.