The Verbal Clock Test: preliminary validation of a brief, vision- and motor-free measure of executive function in a clinical sample.

Assessment of executive functions is frequently time-consuming, and although some brief measures exist they are subject to problems associated with limited education, culture of origin, impairments of motor or visual systems, and tolerability. Preliminary validation of a newly developed measure, the Verbal Clock Test (VCT), was conducted in a clinical sample of 294 patients who underwent neuropsychological evaluation. The evidence supports the interpretation of VCT scores as demonstrating construct validity, criterion-related validity, and sound internal consistency. Performance does not vary substantially with gender or mood, and variability associated with age, education, and ethnicity is modest. Confounding effects of motor and visual impairments are eliminated. Initial data suggest the VCT represents a reasonable method of assessing abstract reasoning and concept formation when clinical circumstances limit the use of currently available measures.

Diagnostic accuracy of a new instrument for detecting cognitive dysfunction.

BACKGROUND: Effective screening of cognitive disorders is limited by psychometric and practical properties of available instruments. The Brief Cognitive Screen (BCS) was developed to improve sensitivity and overall diagnostic accuracy of case detection for cognitive dysfunction in a quick and convenient format. METHODS: This validation study compared psychometric properties of the BCS with the Mini mental state examination (MMSE) in 308 patients with suspected or known disorders of cognition. Diagnostic accuracy of the MMSE was determined using the traditional 23/24 clinical cutoff and area under the curve (AUC) from receiver operating characteristics (ROC) analyses. Diagnostic accuracy of BCS summary scores and components was determined by ROC analyses. Comprehensive neuropsychological evaluation served as the criterion standard for determining cognitive dysfunction. RESULTS: The MMSE sensitivity (34.8%) was inadequate at the 23/24 cutoff. Under ROC analyses, diagnostic accuracy of a BCS summary score was superior (AUC = 0.950) to the MMSE total score (AUC = 0.862) for the total sample. Excluding all patients with a history of cognitive deficit, classification accuracy of the BCS remained high (AUC = 0.936). CONCLUSIONS: Findings suggest that BCS is an effective, convenient alternative screening instrument for use in clinical populations with suspected cognitive dysfunction.

Putative mechanisms of cognitive dysfunction in chemotherapy-naïve diffuse large B-cell lymphoma: a case report and review of the literature.

Cognitive impairment is now recognized as a frequent consequence of treatments for cancers localized outside the central nervous system (CNS). In contrast, little attention has been given to the potentially deleterious cognitive effects from non-CNS cancers themselves. The present case study proposes that cognitive deficits occur in a subset of treatment-naive patients with diffuse large B-cell lymphoma in whom no gross evidence of lymphoma-related CNS involvement is apparent. Evidence is presented from a case study and elaborate putative mechanisms centering on deleterious effects of B-cell-mediated inflammatory cytokine secretion on neurons. Moreover, this case study speculates that genetic variability involving apolipoprotein E or other factors may mediate cognitive variability among these patients.

Diagnostic accuracy of a new instrument for detecting cognitive dysfunction in an emergent psychiatric population: the Brief Cognitive Screen.

OBJECTIVES: In certain clinical contexts, the sensitivity of the Mini-Mental State Examination (MMSE) is limited. The authors developed a new cognitive screening instrument, the Brief Cognitive Screen (BCS), with the aim of improving diagnostic accuracy for cognitive dysfunction in the psychiatric emergency department (ED) in a quick and convenient format. METHODS: The BCS, consisting of the Oral Trail Making Test (OTMT), animal fluency, the Clock Drawing Test (CDT), and the MMSE, was administered to 32 patients presenting with emergent psychiatric conditions. Comprehensive neuropsychological evaluation served as the criterion standard for determining cognitive dysfunction. Diagnostic accuracy of the MMSE was determined using the traditional clinical cutoff and receiver operating characteristic (ROC) curve analyses. Diagnostic accuracy of individual BCS components and BCS Summary Scores was determined by ROC analyses. RESULTS: At the traditional clinical cutoff, MMSE sensitivity (46.4%) and total diagnostic accuracy (53.1%) were inadequate. Under ROC analyses, the diagnostic accuracy of the full BCS Summary Score (area under the curve [AUC]=0.857) was comparable to the MMSE (AUC=0.828). However, a reduced BCS Summary Score consisting of OTMT Part B (OTMT-B), animal fluency, and the CDT yielded classification accuracy (AUC=0.946) that was superior to the MMSE. CONCLUSIONS: Preliminary findings suggest the BCS is an effective, convenient alternative cognitive screening instrument for use in emergent psychiatric populations.

Gelastic epilepsy and dysprosodia in a case of late-onset right frontal seizures.

Gelastic epilepsy (GE) is an uncommon type of seizure disorder characterized by stereotyped, unprovoked, inappropriate ictal laughter. GE is most frequently associated with hypothalamic hamartoma, with onset almost invariably occurring during childhood. GE also occurs occasionally with temporal and frontal cortical seizure foci. We describe an unusual case of senescent-onset GE with a right frontal seizure focus. In addition to laughter, dysprosodia was a clinical feature. Clinical and electroencephalographic evidence of seizure activity ceased on levetiracetam, and the patient showed concurrent improvement in cognitive function. We review the evidence for the cerebral representation of laughter and prosody, and discuss issues bearing on the differential diagnosis and management of GE.

Prominent neuroleptic sensitivity in a case of early-onset Alzheimer disease due to presenilin-1 G206A mutation.

OBJECTIVE: We describe atypical motor and cognitive features in a case of familial Alzheimer disease (FAD) due to presenilin-1 (PS-1) mutation. BACKGROUND: Extrapyramidal signs (EPS) typically are a late-presenting feature of sporadic Alzheimer disease (AD), but relatively little data are available regarding EPS in FAD. METHOD: A 59-year-old, right-handed man of Caribbean-Hispanic descent underwent brain imaging studies, laboratory tests for AD, and serial neurologic and neuropsychologic evaluations. RESULTS: The patient presented with recent-onset delusional ideation associated with cognitive decline. Prominent EPS developed soon after initiation of an atypical neuroleptic agent. Neuropsychologic evaluation revealed global cognitive deficits; he was found to be a carrier of a PS-1 point mutation at position G206A. EPS resolved completely after discontinuing the neuroleptic agent and coincided with improved motor speed, set initiation, and verbal fluency. CONCLUSIONS: Severe neuroleptic sensitivity and associated deficits of cognitive speed occurred in response to a dopaminergic antagonist agent; both responded readily to withdrawal of the offending agent. Patients with PS-1 AD may be at substantially increased risk of neuroleptic-induced EPS. That feature underscores the heterogeneity of the FAD clinical phenotype.

Cognitive dysfunction associated with elemental mercury ingestion and inhalation: a case study.

A 63-year-old man with a history of alcohol dependence ingested elemental mercury as a suicide gesture. Serial abdominal X-rays showed gradual but incomplete clearance of mercury from the colon. Routine chest X-ray showed evidence of punctate radiopaque materials in the lower lobe of the right lung. Blood and urine mercury levels both exceeded thresholds considered to be associated with cognitive dysfunction. Elicited cognitive deficits were most prominent in processing speed, flexibility, and response inhibition. Semantic fluency, visuospatial processing, and recall memory for visual and low-context verbal material were also affected. The deficits may have been attributable primarily to alcohol abuse. Elemental mercury is not readily absorbed from the gastrointestinal tract; however, mercury vapor, which was inhaled inadvertently, readily crosses the blood-brain barrier and is neurotoxic. We argue, therefore, that mercury toxicity is more likely than not to have been a factor contributing to the patient's cognitive dysfunction.