Biomedical subjects

Brian K Lebowitz

Publications and source records attributed to Brian K Lebowitz.

5 recordsLinked to original sources

PubMed2006

Neurocognitive sequelae of a giant arachnoid cyst: case study.

We conducted a comprehensive neuropsychological evaluation of a normally functioning man with a giant arachnoid cyst encompassing much of the space normally occupied by the left hemisphere. Although of solidly average intellectual ability, the patient demonstrated neurocognitive deficits only revealed upon neuropsychological assessment. Despite the remarkable left hemisphere lesion, the pattern of cognitive dysfunction suggested right hemisphere pathology. We review the arachnoid cyst literature and discuss the possibility of a crowding phenomenon by which language function relocates to the more viable hemisphere. This case illustrates striking preservation of higher cognition in the presence of substantial structural abnormality.

Adult↗

PubMed2006

Executive control and learning pattern on the CVLT.

We evaluated a 23 year-old man after recovery from encephalitis. In contrast to the expected pattern of increasingly better acquisition across the 5 learning trials of the California Verbal Learning Test (CVLT-2), he produced a "J-shaped" curve (Trials 1-5: 8,6,6,9,11). Because he also demonstrated excessive levels of proactive interference as well as poor divided attention, we hypothesized that his atypical learning pattern was due to a build-up of proactive interference secondary to executive dyscontrol. Using a large sample of 4462 healthy adult men, we identified four groups exhibiting various learning patterns. We found that a learning pattern similar to this patient (i.e., a drop after trial 1 followed by recovery) was rare (1.1% of the sample). Individuals with this learning pattern demonstrated increased perseverative responses, as well as greater difficulty maintaining cognitive set on the Wisconsin Card Sorting Test, decreased attentional control on the Paced Auditory Serial Addition Test, and greater levels of proactive interference on the CVLT. Taken together, the results of the study suggest that an early drop, followed by a recovery in learning trial performance, is associated with executive dyscontrol.

Adult↗

PubMed2006

Stability of estimated IQ across mood state in patients with bipolar disorder.

OBJECTIVES: The goal of this study was to assess the impact of mania symptoms on the stability of the American version of the National Adult Reading Test (ANART), a measure that provides a putative estimate of premorbid intellectual functioning. METHODS: The ANART was administered to a sample of 10 inpatients with bipolar disorder who were experiencing an acute episode of mania. During a subsequent follow-up visit during which these individuals exhibited at most minimal mood symptoms, the ANART was re-administered. RESULTS: ANART estimated intelligence quotient (IQ) scores during mania and affective stability were assessed in the 10 patients using a paired sample t-test. Within-subject performance across the two mood states did not significantly differ [t(9) = -1.24, p = 0.25]. Additionally, the greatest individual difference across mood states was only 3.68 points, and the average estimated IQ difference across mood states was 1.66. CONCLUSIONS: While the results are preliminary and based on a small sample, the highly consistent scores achieved across mood states in this study suggest that the ANART is a reliable indicator of premorbid IQ.

Acute Disease↗

PubMed2005

Factors moderating neuropsychological outcomes following mild traumatic brain injury: a meta-analysis.

There continues to be debate about the long-term neuropsychological impact of mild traumatic brain injury (MTBI). A meta-analysis of the relevant literature was conducted to determine the impact of MTBI across nine cognitive domains. The analysis was based on 39 studies involving 1463 cases of MTBI and 1191 control cases. The overall effect of MTBI on neuropsychological functioning was moderate (d = .54). However, findings were moderated by cognitive domain, time since injury, patient characteristics, and sampling methods. Acute effects (less than 3 months postinjury) of MTBI were greatest for delayed memory and fluency (d = 1.03 and .89, respectively). In unselected or prospective samples, the overall analysis revealed no residual neuropsychological impairment by 3 months postinjury (d = .04). In contrast, clinic-based samples and samples including participants in litigation were associated with greater cognitive sequelae of MTBI (d = .74 and .78, respectively at 3 months or greater). Indeed, litigation was associated with stable or worsening of cognitive functioning over time. The implications and limitations of these findings are discussed.

Brain Injuries↗

PubMed2003

Verbal memory in mania: effects of clinical state and task requirements.

OBJECTIVES: Manic patients exhibit impaired verbal learning and memory, particularly following longstanding illness. However, it is unclear whether recognition and recall performance are differentially influenced by a manic mood state. METHODS: To examine this issue, we administered the California Verbal Learning Test and symptom-rating scales to inpatients with pure or mixed mania, euthymic outpatients, and healthy comparison subjects. RESULTS: An overall performance difference was identified between groups. Manic and euthymic patients performed more poorly than healthy subjects on recall. However, manic patients performed more poorly than euthymic patients and healthy subjects on recognition. CONCLUSIONS: These results suggest that verbal retrieval deficits are stable vulnerability indicators in bipolar disorder, whereas verbal encoding deficits are manic episode indicators. The known subcortical dysfunction in this disorder may produce stable retrieval deficits while acute mood symptoms attenuate encoding during affective episodes only.

Adult↗