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Biomedical subjects

Kathleen Y Haaland

Publications and source records attributed to Kathleen Y Haaland.

9 recordsLinked to original sources
PubMed2006

West Nile virus neuroinvasive disease.

Since 1999, there have been nearly 20,000 cases of confirmed symptomatic West Nile virus (WNV) infection in the United States, and it is likely that more than 1 million people have been infected by the virus. WNV is now the most common cause of epidemic viral encephalitis in the United States, and it will likely remain an important cause of neurological disease for the foreseeable future. Clinical syndromes produced by WNV infection include asymptomatic infection, West Nile Fever, and West Nile neuroinvasive disease (WNND). WNND includes syndromes of meningitis, encephalitis, and acute flaccid paralysis/poliomyelitis. The clinical, laboratory, and diagnostic features of these syndromes are reviewed here. Many patients with WNND have normal neuroimaging studies, but abnormalities may be present in areas including the basal ganglia, thalamus, cerebellum, and brainstem. Cerebrospinal fluid invariably shows a pleocytosis, with a predominance of neutrophils in up to half the patients. Diagnosis of WNND depends predominantly on demonstration of WNV-specific IgM antibodies in cerebrospinal fluid. Recent studies suggest that some WNV-infected patients have persistent WNV IgM serum and/or cerebrospinal fluid antibody responses, and this may require revision of current serodiagnostic criteria. Although there is no proven therapy for WNND, several vaccines and antiviral therapy with antibodies, antisense oligonucleotides, and interferon preparations are currently undergoing human clinical trials. Recovery from neurological sequelae of WNV infection including cognitive deficits and weakness may be prolonged and incomplete.

Animals↗
PubMed2006

Left hemisphere dominance for movement.

Clinical neuropsychology's dependence upon a core scientific background in clinical neuropsychology, and clinical psychology, neurology, and neuroanatomy, as well as biopsychology, cognitive neuroscience, and cognitive science is the basis of its designation as an APA-approved clinical specialty. This dependence highlights the importance of these scientific underpinnings and the scientist-practitioner model of training, detailed in the Houston Guidelines. This presentation is meant to demonstrate that cognitive neuroscience research should influence our conception of brain behavior relationships, which, in turn, should influence our clinical work. In addition, I want to illustrate how the utilization of converging methods, which is an increasingly popular approach to research, can ensure more valid conclusions about the neuroanatomical substrates for complex skills. Limb apraxia will be used as an example of a deficit that has functional implications and whose cognitive mechanisms and neuroanatomical correlates are better understood as a result of research that combines neuroanatomical imaging of brain damaged patients, functional imaging, and cognitive paradigms. This work demonstrates that left frontoparietal circuits control limb praxis and motor sequencing, suggesting that these complex motor skills should be examined in patients with such damage.

Apraxias↗
PubMed2006

Mental status after West Nile virus infection.

Mental status after acute West Nile virus infection has not been examined objectively. We compared Telephone Interview for Cognitive Status scores of 116 patients with West Nile fever or West Nile neuroinvasive disease. Mental status was poorer and cognitive complaints more frequent with West Nile neuroinvasive disease (p = 0.005).

Acute Disease↗
PubMed2005

Functional implications of ipsilesional motor deficits after unilateral stroke.

OBJECTIVE: To investigate the functional impact of ipsilesional motor deficits after unilateral stroke and the best predictors of those deficits. DESIGN: Observational cohort. SETTING: Primary care Veterans Affairs and private medical center. PARTICIPANTS: Volunteer right-handed sample; stroke patients with left (LHD) or right hemisphere damage (RHD) a mean of 3.9 to 5.2 years poststroke and able-bodied participants who were tested using their left (LAB) or right hand. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: The Jebsen-Taylor Hand Function Test (JHFT). RESULTS: Ipsilesional JHFT performance was impaired to the same extent in the LHD and RHD groups. LHD patients with apraxia had poorer scores on the JHFT than LHD patients without apraxia and the LAB group. Regression analyses showed that severity of apraxia was the best predictor of JHFT performance for the LHD group and that right (ipsilesional) motor performance (grip strength, finger tapping) was the best predictor of JHFT performance for the RHD group. CONCLUSIONS: Ipsilesional deficits are present on simulated activities of daily living after LHD or RHD, suggesting that rehabilitation after stroke should include the ipsilesional arm and that ipsilesional limb apraxia is a better predictor of ipsilesional functional motor skills after LHD than aphasia or simple motor skills (grip strength, finger tapping). These findings suggest that limb apraxia should be assessed more routinely after stroke of the left hemisphere.

Activities of Daily Living↗
PubMed2004

Hemispheric asymmetries for kinematic and positional aspects of reaching.

Kinematic analyses of reaching have suggested that the left hemisphere is dominant for controlling the open loop component of the movement, which is more dependent on motor programmes; and the right hemisphere is dominant for controlling the closed loop component, which is more dependent on sensory feedback. This open and closed loop hypothesis of hemispheric asymmetry would also predict that advance planning should be dependent on the left hemisphere, and on-line response modification, which defines closed loop processes, should be dependent on the right hemisphere. Using kinematic analyses of reaching in patients with left or right hemisphere damage (LHD or RHD), we examined the ability: (i) to plan reaching movements in advance by examining changes in reaction time (RT) when response amplitude and visual feedback were cued prior to the response; and (ii) to modify the response during implementation when target location changed at the RT. Performance was compared between the stroke groups, using the ipsilesional arm, and age-matched control groups using their right (RNC) or left (LNC) arm. Aiming movements to a target that moved once or twice, with the second step occurring at the RT, were performed with or without visual feedback of hand position. There were no deficits in advance planning in either stroke group, as evidenced by comparable group changes in RT with changes in amplitude and visual feedback. Response modification deficits were seen for the LHD group in secondary velocity only. In addition, LHD produced slower initial peak velocity with prolongation of the deceleration phase and faster secondary peak velocities, and the RHD group produced deficits in final error only. These differences are more consistent with the dynamic dominance hypothesis, which links left hemisphere specialization to movement trajectory control and right hemisphere specialization to position control, rather than to global deficits in open and closed loop processing.

Aged↗
PubMed2004

Age-associated memory impairment of Logical Memory and Visual Reproduction.

The standardization sample from the WMS-III (weighted N = 1250) (The Psychological Corporation, 1997; Tulsky & Ledbetter, 2000), which varied in age from 16 to 89, was used to determine whether storage of verbal and spatial information was affected by normal aging. A previous study with the same sample using an analysis of variance approach showed that the age-associated deterioration for Logical Memory (LM) and Visual Reproduction (VR) delayed recall and recognition were comparable and largely explained by poor immediate recall. This led to the conclusion that age-associated memory impairment was due primarily to encoding deficits. However, that study did not control for the age-associated deterioration in immediate recall in order to ensure that the small age-associated effects for delayed recall and recognition were not confounded by the fact that the elderly had less to remember on the delayed recall and recognition trials. The current study used covariance analysis to statistically adjust the dependent measures, LM and VR delayed recall and recognition, based on immediate recall scores. These analyses showed that the age-associated changes in these measures were statistically significant, but the effect sizes were very small. Partial eta(2) for the main effect of age for LM was 0.06 with weak effect sizes for the interaction of recall type and age (0.02). The partial eta(2) for the main effect of age for VR was 0.09, and the interaction of recall type and age (0.04). This pattern of findings shows that after adjustment for immediate recall, LM and VR recall and recognition demonstrated comparable, slight declines with age suggesting that normal aging produced minimal changes in the ability to store new information when age-associated changes in initial encoding and retrieval were statistically controlled.

Adolescent↗
PubMed2004

Motor sequence complexity and performing hand produce differential patterns of hemispheric lateralization.

Studies in brain damaged patients conclude that the left hemisphere is dominant for controlling heterogeneous sequences performed by either hand, presumably due to the cognitive resources involved in planning complex sequential movements. To determine if this lateralized effect is due to asymmetries in primary sensorimotor or association cortex, whole-brain functional magnetic resonance imaging was used to measure differences in volume of activation while healthy right-handed subjects performed repetitive (simple) or heterogeneous (complex) finger sequences using the right or left hand. Advanced planning, as evidenced by reaction time to the first key press, was greater for the complex than simple sequences and for the left than right hand. In addition to the expected greater contralateral activation in the sensorimotor cortex (SMC), greater left hemisphere activation was observed for left, relative to right, hand movements in the ipsilateral left superior parietal area and for complex, relative to simple, sequences in the left premotor and parietal cortex, left thalamus, and bilateral cerebellum. No such volumetric asymmetries were observed in the SMC. Whereas the overall MR signal intensity was greater in the left than right SMC, the extent of this asymmetry did not vary with hand or complexity level. In contrast, signal intensity in the parietal and premotor cortex was greater in the left than right hemisphere and for the complex than simple sequences. Signal intensity in the caudal anterior cerebellum was greater bilaterally for the complex than simple sequences. These findings suggest that activity in the SMC is associated with execution requirements shared by the simple and complex sequences independent of their differential cognitive requirements. In contrast, consistent with data in brain damaged patients, the left dorsal premotor and parietal areas are engaged when advanced planning is required to perform complex motor sequences that require selection of different effectors and abstract organization of the sequence, regardless of the performing hand.

Adult↗
PubMed2003

What does the WMS-III tell us about memory changes with normal aging?

The standardization sample from the WMS-III (N = 1250), which varied in age from 16 to 89, was used to determine whether encoding, retrieval, or storage of verbal and spatial information was most affected by normal aging. Immediate and delayed recall and recognition of Logical Memory and Visual Reproduction were examined. Immediate verbal and spatial recall significantly deteriorated with increasing age, and the age-associated deterioration in delayed recall and recognition was largely explained by poorer immediate memory. These findings, in concert with the smaller aging effects for percent retention after a delay, suggest that the aging effect is due to deterioration in encoding more than retrieval or storage of new information. While Visual Reproduction deteriorated more rapidly with age than Logical Memory, the pattern of performance decrements as a function of age were comparable across both tests. Decreases in performance were first seen in the fifth decade with gradual deterioration until the eighth decade when there was another precipitous drop. These results suggest that functions that are more dependent on the frontal lobes are more vulnerable to aging than those that are more dependent on the temporal lobes.

Adolescent↗