Neuropsychiatry, neuropsychology, and behavioral neurology最新文献

Objective: We hypothesized that tendency toward psychopathology is associated with lower frontotemporal volumes.

Background: Although there is considerable evidence for structural abnormalities in patients with major psychiatric disorders and increased recognition that neural substrates may underlie individual differences in personality, there have been no studies in healthy people attempting to relate personality to volumetric measures of brain structure.

Method: We used magnetic resonance imaging with an advanced method for automated segmentation of cranial compartments to gray matter, white matter, and cerebrospinal fluid. We examined the relation between frontal and temporal lobe volumes and Minnesota Multiphasic Personality Inventory measures of tendency toward psychopathology in 59 healthy individuals.

Results: As hypothesized, higher scores on the clinical scales were associated with lower average frontal lobe volume. When the sample was divided according to sex, however, these correlations were significant in men (n = 29) but not in women (n = 30). The highest correlation was observed between lower frontal white matter volume in men and high schizophrenia scale score (r[27] = -0.59, p <0.001).

Conclusions: The findings suggest that personality dimensions in healthy people can be linked to neural substrates, which can potentially serve as endophenotypic markers of disposition to psychopathology. The sexually dimorphic effects are consistent with gender-related differences in the clinical manifestations of psychiatric disorders and may suggest sex hormone modulation of the psychopathologic processes.

Objective: The aim of this study was to assess the potential impact of effort in comparative studies assessing neurocognitive dysfunction in patients with and without a neurologic diagnosis.

Background: It was hypothesized that a subgroup within a group of patients with prominent neurocognitive complaints but without a neurologic diagnosis would have impaired performance on a task originally designed to detect malingering.

Method: We compared the neuropsychological performance of a group of 40 patients with a definite diagnosis of multiple sclerosis (MS) with that of 67 patients with chronic fatigue syndrome (CFS). The Amsterdam Short-Term Memory Test, a forced-choice memory task, served as measure to detect submaximal effort. In addition, we administered a regular neuropsychological task generally considered to be sensitive for cognitive deterioration.

Results: Compared with the MS group (13%), a larger proportion of the matched CFS group (30%) obtained scores indicative of reduced effort. In contrast, the proportions of patients scoring below the cutoff value on a conventional neuropsychological test did not differ significantly (17% of MS patients and 16% of CFS patients).

Conclusions: The results obtained raise the question of to what extent abnormal test findings in the absence of documented neurologic impairment should be interpreted as a sign of cerebral impairment. The suggestion has been made to screen more often for biased results in comparative research studies so as to enhance valid interpretation of neuropsychological findings.

Objective: Our aim was to investigate the influence of optokinetically induced rotatory self-motion sensation (circular vection [CV]) on asymmetries in real and representational space in normal subjects.

Background: Vestibular and optokinetic stimulation (particularly when accompanied by rightward CV) can reduce left-sided hemineglect in patients.

Method: Twenty healthy right-handed men were administered a line bisection (LB) task and a stimulus-response compatibility task monitoring mental representation of space (the RULER task). The RULER task required speeded unimanual decisions ("smaller than 6?" vs. "larger than 6?") to foveally presented numbers between 1 and 11. Both tasks were performed in a baseline condition (no stimulation) and with full-field optokinetic stimulation to induce CV to either side.

Results: The bisection marks of both hands were shifted significantly to the left during leftward CV, introducing a pseudoneglect for the left and right hands. Rightward CV did not influence LB. In the RULER task, we found a stimulus-response compatibility, namely, faster right-hand responses to large numbers (i.e., 7-11) and faster left-hand responses to small numbers (i.e., 1-5). Although optokinetic stimulation did not significantly affect subjects' representation of space, the overall pattern of observed deviations was strikingly similar to that obtained in LB.

Conclusions: Optokinetic stimulation affects healthy subjects' exploration and, to a lesser extent, their representation of space. In contrast to previous studies in neglect patients and healthy subjects, we found that leftward CV rather than rightward CV induced a leftward deviation of the subjective midpoint. This discrepancy is most likely a consequence of the exclusively peripheral visual field stimulation in our experiment. We suggest that the leftward deviation during rightward CV described in former studies may be due to the cuing effect of the leftward moving dots in the central visual field. In the absence of these central cues, the direction of CV seems to be the main determining factor for observed hemispatial effects.

Objective: A 70-year-old right-handed man presented with a subthalamic infarction followed by persistent hypersexuality and hemiballism. A lacunar infarction 1 cm in diameter was observed on magnetic resonance imaging. We hypothesized that metabolic abnormalities would be detected in cortical areas related to his neurobehavioral symptoms.

Background: Statistical validation of the regional metabolic changes that may relate to neuropsychiatric symptoms has been elusive. Relating metabolic changes to neuropsychiatric symptoms is especially important in unique neurobehavioral cases.

Method: Quantitative fluorodeoxyglucose positron emission tomography was obtained for a single-subject comparison with scans from 60 healthy subjects.

Results: Substantial glucose hypometabolism (p <0.001, uncorrected; [df = 56]) was identified in the subthalamic nucleus at the site of the lacunar infarction. Hypermetabolism (p <0.01) was identified within the basal forebrain and temporal lobes, anterior cingulate and medial prefrontal cortices (areas previously associated with hypersexuality), and striatum (p <0.001) ipsilateral to the stroke (areas known to relate to hemiballism).

Conclusions: Single-subject statistical parametric mapping may improve our understanding of unique neurobehavioral cases.

Objective: In this case study, the significance of perfusion abnormalities in catatonia is examined.

Background: Recurrent catatonic symptoms are frequently observed in psychiatric disorders, but the predictors of relapse of the catatonic symptoms remain unknown. Perfusion abnormalities have been reported during catatonic states; however, little is known about brain functioning of catatonic patients during remission.

Method: A catatonic patient was evaluated by clinical interview, behavioral examination, and functional neuroimaging (single photon emission computed tomography) to determine diagnosis and brain perfusion.

Results: The patient exhibited persistent hypoperfusion of the basal ganglia even after achieving symptomatic remission.

Conclusions: These findings predict a secondary cause and may predict a chronic course.

Objective: The goal of this investigation was to describe the neuropsychological and magnetic resonance imaging (MRI) findings in a patient with an extramedullary plasmacytoma that extensively infiltrated the cerebral dura, especially over the frontal region.

Background: Extramedullary plasmacytomas are rare tumors that have been reported to involve the dura matter in only a small number of cases. In most of the reported occurrences, the dura plasmacytomas were successfully treated with a combination of surgery and irradiation, without prominent cognitive sequelae.

Method: MRI of the brain and neuropsychological tests were conducted approximately 13 months after the patient underwent radiotherapy. In addition, measures of frontal lobe personality characteristics were obtained before and after radiotherapy.

Results: MRI findings revealed extensive enhancement around the anterior frontal lobes and prominent involvement of the anterior longitudinal fissure. Results from neuropsychological testing indicated mild to moderately impaired performance on tests of working memory, complex attention, and cognitive flexibility. Further, the patient reported experiencing personality changes consistent with frontal lobe dysfunction as part of the initial symptoms of the disease, which remained unchanged after treatment.

Conclusions: Our findings are the first to describe cognitive sequelae of dural plasmacytomas. In addition, results from this case study reveal that plasmacytomas of the frontal dura produce personality changes similar to those observed in patients with significant frontal lobe injury. Finally, plasmacytomas that significantly infiltrate the frontal lobes may be insensitive to radiotherapy and result in residual cognitive and personality abnormalities.

Objective: This study evaluated the possible pathologic relation between Kleine-Levin syndrome (KLS) and mood disorders.

Background: A 28-year-old man with a remote history of KLS had the sudden onset of a manic episode with psychotic features after the end of hypersomnolence.

Method: The patient received an extensive laboratory examination, including single photon emission computed tomography and magnetic resonance imaging.

Results: Single photon emission computed tomography showed decreased tracer perfusion in the basal ganglion, hypothalamus, and right frontotemporal region. Magnetic resonance imaging revealed a cystic lesion in the pineal region.

Conclusions: Hypothalamic dysfunction has been described in KLS and mood disorders, but pineal gland dysfunction has been mentioned only rarely. The clinical and neuroimaging findings suggest the need for further study of KLS.

Objective: This study aimed to examine cognitive functioning in postpolio syndrome (PPS) after controlling for the effects of depression and illness behavior.

Background: Few studies have investigated the possible cognitive sequelae of PPS, despite widespread documented subjective complaints of "mental fatigue."

Method: A total of 23 PPS sufferers, 20 polio survivors without PPS, and 22 matched controls were compared using the Beck Depression Inventory-II; the Illness Behaviour Questionnaire; a chronic fatigue syndrome symptom checklist; and several measures of memory, attention, and concentration, including the Brown-Petersen Task, Stroop Test, Austin Maze, California Verbal Learning Test, Trail Making Test, Controlled Oral Word Association Test, and Symbol-Digit Modalities Test.

Results: In those participants with a medically confirmed diagnosis of PPS, there was a significantly higher level of depressive and hypochondriacal symptomatology as compared with the other two groups. Nevertheless, no significant differences existed between the three groups on neuropsychological measures.

Conclusions: These results indicate that the attention and memory difficulties reported by PPS sufferers may be linked to the physical or psychological manifestations of the illness rather than to objective decrements in cognitive performance.

Objective: The objective of this study was to examine the central nervous system changes that may occur after acceleration/deceleration injuries in motor vehicle accidents.

Background: Occupants of motor vehicles involved in a collision often develop a disabling syndrome consisting of head, neck, and back pain; impaired short-term memory and concentration; fatigue and a loss of stamina; poor balance; and a change in personality. Injury victims experience a loss of motivation, emotional lability, and a decrease in libido. The major features of this injury syndrome are subjective, and there usually are few objective findings on physical examination. The pathogenesis of this syndrome is poorly understood, but it is hypothesized that the collision impact produces an inertial strain injury to the anterior regions of the brain which depresses the functions of the frontotemporal lobes, at the same time, sensitizing somatosensory neural afferent systems. Damage to the orbital surfaces of the frontotemporal lobes, in particular, impairs the gating mechanisms that normally limit sensory input to the brain and further promotes central sensitization. The psychiatric disorders that emerge in the wake of these injuries are likely grounded in these pathologic events.

Method: The current literature on the biomechanics of head injury and the associated brain imaging findings in minor head injury are reviewed. A summary of some of the biochemical sequelae of strain injury to the brain is also provided, with an emphasis on the changes in energy metabolism and excitatory amino acid release.

Conclusions: Early intervention to arrest the injury-induced metabolic cascade, and treatment with agents that activate cerebral metabolism may mitigate the symptoms of this injury syndrome.