Neuropsychiatry, neuropsychology, and behavioral neurology最新文献

Objectives and background: This experiment sought to quantify the extent to which patients with Huntington disease (HD) have difficulties in orienting attention, via a vibrotactile version of a Posner-type cost-benefit paradigm.

Method: Participants were required to push a button in response to a vibration delivered to the index finger of either hand. Prior to each stimulus vibration, a precue (valid, neutral, or invalid) was delivered to the finger. Benefits and costs were calculated from valid and invalid precues.

Results: Although patients with HD were overall slower than the controls, their performance was no different; both patients and controls demonstrated increased benefits from valid compared with invalid and neutral cues. Of interest was the finding that patients, unlike controls, performed significantly slower with the cue presented to the left compared with the right side. The crossed arm configuration proved to be too difficult for the patients with HD, and thus an analysis on these data was not permitted.

Conclusions: Patients may experience difficulties in allocating attentional resources toward their left nonpreferred hand. Overall, findings demonstrate that patients with HD, with minimal caudate damage at early stages of disease onset, may not experience problems in their ability to orient attention.

Objective: To characterize patterns of orienting dysfunction that were typical to patients with lesions in the right hemisphere (RH).

Background: Brain lesions in the right hemisphere are commonly associated with dysfunction of visual orienting (e.g., visual neglect and extinction). In a clinical study of these symptoms, the multicomponent nature of attentional orienting calls upon a multivariate statistical design with careful selection of neurocognitive variables.

Methods: Thirty-eight patients with verified brain lesions and four patients with peripheral motor dysfunction after poliomyelitis were included in the study. Cognitive function was evaluated in all patients. Three reaction-time (RT) measures derived from the cue-target paradigm were selected as features in a data-driven multivariate classification scheme to generate natural subgroups of patients.

Results: Four subgroups were generated, with only RH patients allocated to two of them. All patients within one of the RH subgroups were characterized by a pattern of impairment earlier described as a "disengage failure" by Posner et al. ( 5, 6), signs of visual neglect on Behavioral Inattention Test, and a severely impaired cognitive function. Results for the other RH subgroup were heterogeneous on both experimental and clinical variables. Age and cognitive function were found to strongly influence two of the features, but could not predict the clusters generated from the RT measures.

Conclusions: The present findings show that the cue-target paradigm together with multivariate clustering of selected feature variables can serve as a useful tool to explore and characterize patients with right hemisphere lesions. Although the concept of "disengage failure" was suited to describe the typical RT pattern in patients with neglect, other neurocognitive models and concepts can be applied to the results in the current study.

Objective: To examine the possible association of neuropsychiatric symptoms and pallidal surgery for Parkinson disease (PD).

Background: Parkinson disease may be accompanied by a variety of psychiatric symptoms. It is important to distinguish these from psychiatric syndromes that are associated with the treatment of PD.

Methods: Case description of a patient with PD and a history of right pallidotomy who developed a psychiatric syndrome, including prominent hypersexuality, after surgical implantation of a deep brain stimulator electrode in the left globus pallidus.

Results and conclusions: This case demonstrates that patients receiving antiparkinson medication may be at risk for the development of psychiatric sequelae after pallidal surgery.

Objective: A case is presented of a 37-year-old black woman with a 5-year history of a chronic psychotic illness, diagnosed as schizophrenia, who presented to the emergency room complaining of a severe headache, while appearing confused and experiencing visual and auditory hallucinations. The purpose of this case study is to illustrate the way in which the appellation of schizophrenia can be misapplied in a patient with a complicated medical history and poor follow-up evaluation and treatment.

Background: Patients with active psychosis are frequently unable to provide a coherent or comprehensive medical history. In the absence of obvious indications to the contrary, a diagnosis of a primary psychiatric illness is often assumed, especially if this label has been applied in the past. However, the differential diagnosis of psychosis is extensive.

Methods: This patient was given a complete psychiatric and neurologic evaluation, and aspects of the history that had been lost or ignored were uncovered and reevaluated.

Results: A diagnosis other than schizophrenia was made and another treatment, other than antipsychotic drugs, was initiated. The patient responded rapidly with improved cognitive function and resolution of her psychotic symptoms.

Conclusions: This case serves to illustrate how the absence of a careful clinical assessment and historical case review, in patients who have been previously labeled as schizophrenic, can perpetuate misdiagnoses and inappropriate treatments. It highlights the importance, especially in patients with an incomplete medical history, of ruling out all organic causes of psychosis to avoid inappropriately labeling someone as having a psychiatric illness.

Objective: To investigate the relation between apathy and cognitive deficits in patients with severe traumatic brain injury (TBI).

Background: Apathy defined as reduced goal-directed behavior due to lack of motivation constitutes a major neuropsychiatric symptom following TBI. According to definition, apathy should not be associated with global cognitive reduction, but rather with specific areas of cognitive dysfunction.

Methods: results from the Apathy Evaluation Scale (AES) and a comprehensive neuropsychologic assessment were collected in up to 53 patients with severe TBI. Neuropsychologic tests were organized in the following seven areas of cognitive function: acquisition and memory, attention span, executive function, psychomotor speed, verbal skills, nonverbal skills, and motor speed.

Results: Apathy score was significantly correlated with reduced performance on acquisition and memory, psychomotor speed, and executive functions. A principal component analysis showed that these specific areas of cognitive functions clustered together with the cognitive dimension of apathy, not with behavioral or emotional aspects of apathy.

Conclusions: Apathy is associated with specific cognitive deficits related to frontal lobe dysfunction. The results are in accordance with the definition of apathy and confirm apathy-cognitive function relationships reported in other neurologic populations.

Objective: To determine whether longitudinal changes in personality as measured by the Minnesota Multiphasic Personality Inventory (MMPI) can be detected among clinically presymptomatic individuals carrying the expanded Huntington disease (HD) allele.

Background: Emotional symptoms are considered one of the cardinal features of HD. However, the literature is replete with conflicting reports of psychiatric symptoms in presymptomatic HD gene carriers.

Methods: A longitudinal, case-control, double-blind study comparing presymptomatic gene carriers and nongene carriers at risk for HD evaluated with an abbreviated MMPI and a quantified neurologic rating scale examined an average of 3.7 years apart.

Results: Presymptomatic gene carriers (PSGC) had a greater increase in abnormality over time for the MMPI scales, cynical hostility (repeated-measures ANOVA, = 0.04) and irritability (repeated measures ANOVA, = 0.005), when compared with the nongene carriers (NGC). Among both the PSGCs and NGCs, no significant correlation was found between the number of CAG repeats and the change in MMPI score between visits.

Conclusions: This study provides significant evidence for increasing irritability and cynical hostility in presymptomatic gene carriers before the onset of overt clinical symptoms.

Objective: To learn which neuropsychologic tasks are affected in Spanish patients with sporadic late-onset Alzheimer Disease and to determine which are more relevant to make a diagnosis with minimum cost but without losing accuracy.

Background: The sample used in this study comprised of 88 subjects: 42 subjects diagnosed with SLOAD and 46 subjects who, with no family history of dementia at the time of examination, showed no type of neurologic or psychiatric disorder; neither did they have any record of alcoholism or drug addiction.

Methods: The evaluation of each subject in the clinical group consisted of a full neurologic examination, a neuropsychologic evaluation with a battery of tests designed for this study, and an assessment of mood with the Beck Depression Inventory. The battery of neuropsychologic tests used in diagnosing AD was subjected to discriminant analysis by the stepwise method, using diagnosis (1 = AD, 2 = control) as a dependent variable. The objective of the stepwise method of this technique is to select from the set of independent variables those that best discriminate between the two groups of the dependent variable, thus, satisfying the criterion of parsimony with which greater classifying specificity is obtained with a minimum number of variables.

Results: The analysis selected the following tests as optimum and sufficient: Babcock Story Recall (Delay), Categories Completed (Wisconsin), and Remote Memory.

Conclusions: The results of discriminant analysis made it possible to obtain a highly significant discriminant function. This analysis reduced the initial battery to three tests, yielding a sensitivity of 96.6% in the correct diagnostic classification of the subjects.

Objective: To elucidate the neural mechanisms of depression.

Background: Despite extensive study, the neurophysiology of the brain's state(s) corresponding to depression remains uncertain.

Methods: HMPAO single photon emission computed tomographic (SPECT) scans were obtained from eight adults diagnosed with major depression resistant to medication (average age 51 years; 4 men) before and immediately after 10 days of 20 Hz repetitive transcranial magnetic stimulation (rTMS) (2000 stimuli/daily 30' treatment). To maximize the likelihood that SPECT scans reflected the state of depression, rather than uncontrolled responses of patients to poorly constrained environments, HMPAO was administered while subjects performed a simple task involving continuous monitoring of the direction of a large arrow on a computer screen and continuously tapping with the left or right index finger according to the direction of the arrow. Mean baseline Beck Depression Inventory (BDI) score was 27.4 (SD = 8.3) and mean posttreatment BDI score was 17.5 (SD = 8.5).

Results: Treatment responders (defined by reduction in BDI score of > or = 30%) had significantly less pretreatment blood flow in the left amygdala compared with nonresponders. Responders demonstrated two patterns of change in regional blood flow with treatment: a reduction in orbitofrontal blood flow and/or a reduction in anterior cingulate blood flow. Nonresponders did not demonstrate any regional changes in blood flow with treatment.

Conclusions: These results suggest that there may be either more than one state of depression, or that depression may be associated with more than one pattern of psychologic activity, which in turn defines the depressive experience for individual patients.

Objective: To standardize a new rating scale for the assessment of apathy in Alzheimer disease (AD) and report on its reliability, structure, and relation to other clinical features of AD.

Background: apathy is a common prominent behavioral syndrome accompanying AD and is associated with excess disability and increased caregiver burden. Current instruments for the assessment of apathy in AD do not explicitly and systematically attempt to differentiate limited activity and engagement due to lack of interest from inability or longstanding, premorbid personality traits. The present assessment, the Dementia Apathy Interview and Rating (DAIR), was developed taking these discriminations into account in question construction and interview format.

Methods: One hundred participants (50% women) in the University Memory and Aging Center Research Registry with Probable or Possible AD (by NINCDS-ADRDA criteria) were assessed through caregiver interview or direct patient assessment for apathy, depression, and severity of cognitive and functional deficits. Item distribution characteristics, factor analysis, and evaluation of reliability were used to develop the final item set for the DAIR, and correlations with other measures were examined.

Results: A 16-item unidimensional apathy scale with excellent internal consistency (alpha = 0.89) and temporal reliability ( = 0.85 over 2 months) was developed. Individual differences in apathy on the DAIR were unrelated to dysphoria. Apathy was significantly associated with functional and cognitive impairment, while depression was not.

Conclusions: The DAIR is a reliable informant-based assessment of apathy in persons with AD. Although apathy is assessed with respect to behaviors within the repertoire of patients, this behavioral syndrome remains associated with more severe deficits in cognitive and adaptive functioning. Associations between depression and dementia severity reported in some studies may reflect the confounding of apathy and depression in some assessment instruments.