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presence of a companion on the first visit yielded a sensitivity of 0.96 (95% CI = 0.88–0.99) for detecting dementia and a specificity of 0.57 (95% CI = 0.49–0.65). Positive and negative likelihood ratios were 2.21 (95% CI = 1.84–2.66) and 0.08 (95% CI = 0.03–0.24), respectively. The sensitivity for detecting any cognitive impairment was 0.80 (95% CI = 0.72–0.87), and specificity was 0.66 (95% CI = 0.56–0.75). Positive and negative likelihood ratios for any cognitive impairment were 2.35 (95% CI = 1.78–3.11) and 0.31 (95% CI = 0.21–0.44), respectively.
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4. Grober E, Buschke H. Genuine memory deficits in dementia. Dev Neuropsychol 1987;3:13–36. 5. Ostrosky-Solıs F, Ardila A, Rosselli M. NEUROPSI: A brief neuropsychological test battery in Spanish with norms by age and educational level. J Int Neuropsychol Soc 1999;5:413–433. 6. Morris JC. The Clinical Dementia Rating (CDR): Current version and scoring rules. Neurology 1993;43:2412–2414. 7. American Psychiatric Associations. Diagnostic and Statistical Manual of Mental Disorders, 4th Ed. Washington, DC: American Psychiatric Association Press, 1994. 8. Larner AJ. Screening utility of the “attended alone” sign for subjective memory impairment. Alzheimer Dis Assoc Disord 2012; Oct 25. [Epub ahead of print]. doi: 10.1097/WAD.0b013e3182769b4f
DISCUSSION Attending the clinical encounter alone may be a demonstration of preserved instrumental ADLs. These findings are consistent with those of a previous study8 that suggested that the lack of a companion on the first medical encounter can reliably exclude dementia. In contrast to those findings, the lack of a companion may have limited value in the exclusion of milder forms of cognitive impairment. Some differences between the two studies may explain these discrepancies. First, the previous study was conducted in a British memory clinic, whereas the current study was conducted in a geriatric clinic with patients from diverse socioeconomic backgrounds. Second, in contrast to the previous study, the current study participants were not told to bring an informant to the first medical encounter. Third, in our study the researchers who recorded whether participants were accompanied or alone were not involved with the diagnostic examination, thus avoiding bias. These results cannot be extrapolated to all healthcare settings. It may be that individuals with dementia who live alone and have no caregiver are more likely to attend primary care than to request a specialist appointment for memory evaluation. In conclusion, in older adults referred to a specialty clinic with suspected cognitive impairment, the lack of a companion at the first clinical encounter can be used to exclude dementia but not milder forms of cognitive impairment. Further work is needed to investigate the validity of these findings in nonspecialist settings. Daniel Apolinario, PhD Aline Thomaz Soares, MD Regina Miksian Magaldi, MD Alexandre Leopold Busse, PhD Antonio Carlos Pereira Barretto-Filho, MD Wilson Jacob-Filho, PhD Division of Geriatrics, Department of Internal Medicine University of S~ao Paulo Medical School, S~ ao Paulo, Brazil
REFERENCES 1. Larner AJ. “Who came with you?” A diagnostic observation in patients with memory problems? J Neurol Neurosurg Psychiatry 2005;76:1739. 2. Larner AJ. “Attended alone” sign: Validity and reliability for the exclusion of dementia. Age Ageing 2009;38:476–478. 3. Sheehan DV, Lecrubier Y, Sheehan KH et al. The Mini-International Neuropsychiatric Interview (MINI): The development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. J Clin Psychiatry 1998;59(Suppl 20):22–23.
COGNITIVE IMPAIRMENT IS ASSOCIATED WITH HIGH COATED-PLATELET LEVELS IN INDIVIDUALS WITH CAROTID ATHEROSCLEROSIS To the Editor: Coated-platelets are a subpopulation of procoagulant platelets observed upon dual agonist stimulation with thrombin and collagen.1 Individuals with nonlacunar ischemic stroke have higher coated-platelet levels than individuals without stroke or with lacunar stroke.2 Higher coated-platelet levels in symptomatic individuals with 50% or more carotid stenosis are associated with early stroke recurrence.3 Carotid disease is a risk factor for cognitive impairment, thought to be due to cerebral emboli or hypoperfusion with or without silent brain infarctions.4 A pilot study was undertaken to test the hypothesis that high coated-platelet levels are associated with cognitive impairment in individuals with carotid atherosclerosis. Consecutive outpatients referred for carotid Doppler evaluation were screened for cognitive impairment using the Montreal Cognitive Assessment (MoCA) test5 and for depression using the Beck Depression Inventory-II (BDI-II).6 Exclusion criteria included stroke or transient ischemic attack (TIA) within the previous 6 months, known dementia, use of anticoagulants, prolonged coagulation tests (prothrombin time, partial thromboplastin time, international normalized ratio), severe depression (BDI-II score ≥33),6 or intake of sedating substances within 2 hours before screening. Electronic medical records were reviewed for evidence of stroke and TIA within the previous 6 months or prior diagnosis of memory loss. After informed consent, 5 mL of blood was drawn, and coated-platelet levels were determined as described previously.2,3 Levels are reported as percentage of cells converted to coated-platelets.2 Repeated measurements of coated-platelet levels were also available for a subset of participants (n = 14). Descriptive statistics were determined and independent-sample t tests, and chi-square tests were performed. Covariates were determined using correlations between potential covariates and coated-platelet levels, as well as group differences in relevant variables, and included as needed. The stability of coated-platelet levels at 6-month
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JAGS
Table 1. Demographic Characteristics, Coated-Platelet Levels, Pertinent Comorbidities, and Medications for All Participants and According to Montreal Cognitive Assessment Group Factor
Demographic characteristic Age, mean SD Male, n (%) Caucasian, n (%) Stenosis severity, n (%)
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presence of a companion on the first visit yielded a sensitivity of 0.96 (95% CI = 0.88–0.99) for detecting dementia and a specificity of 0.57 (95% CI = 0.49–0.65). Positive and negative likelihood ratios were 2.21 (95% CI = 1.84–2.66) and 0.08 (95% CI = 0.03–0.24), respectively. The sensitivity for detecting any cognitive impairment was 0.80 (95% CI = 0.72–0.87), and specificity was 0.66 (95% CI = 0.56–0.75). Positive and negative likelihood ratios for any cognitive impairment were 2.35 (95% CI = 1.78–3.11) and 0.31 (95% CI = 0.21–0.44), respectively.
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4. Grober E, Buschke H. Genuine memory deficits in dementia. Dev Neuropsychol 1987;3:13–36. 5. Ostrosky-Solıs F, Ardila A, Rosselli M. NEUROPSI: A brief neuropsychological test battery in Spanish with norms by age and educational level. J Int Neuropsychol Soc 1999;5:413–433. 6. Morris JC. The Clinical Dementia Rating (CDR): Current version and scoring rules. Neurology 1993;43:2412–2414. 7. American Psychiatric Associations. Diagnostic and Statistical Manual of Mental Disorders, 4th Ed. Washington, DC: American Psychiatric Association Press, 1994. 8. Larner AJ. Screening utility of the “attended alone” sign for subjective memory impairment. Alzheimer Dis Assoc Disord 2012; Oct 25. [Epub ahead of print]. doi: 10.1097/WAD.0b013e3182769b4f
DISCUSSION Attending the clinical encounter alone may be a demonstration of preserved instrumental ADLs. These findings are consistent with those of a previous study8 that suggested that the lack of a companion on the first medical encounter can reliably exclude dementia. In contrast to those findings, the lack of a companion may have limited value in the exclusion of milder forms of cognitive impairment. Some differences between the two studies may explain these discrepancies. First, the previous study was conducted in a British memory clinic, whereas the current study was conducted in a geriatric clinic with patients from diverse socioeconomic backgrounds. Second, in contrast to the previous study, the current study participants were not told to bring an informant to the first medical encounter. Third, in our study the researchers who recorded whether participants were accompanied or alone were not involved with the diagnostic examination, thus avoiding bias. These results cannot be extrapolated to all healthcare settings. It may be that individuals with dementia who live alone and have no caregiver are more likely to attend primary care than to request a specialist appointment for memory evaluation. In conclusion, in older adults referred to a specialty clinic with suspected cognitive impairment, the lack of a companion at the first clinical encounter can be used to exclude dementia but not milder forms of cognitive impairment. Further work is needed to investigate the validity of these findings in nonspecialist settings. Daniel Apolinario, PhD Aline Thomaz Soares, MD Regina Miksian Magaldi, MD Alexandre Leopold Busse, PhD Antonio Carlos Pereira Barretto-Filho, MD Wilson Jacob-Filho, PhD Division of Geriatrics, Department of Internal Medicine University of S~ao Paulo Medical School, S~ ao Paulo, Brazil
REFERENCES 1. Larner AJ. “Who came with you?” A diagnostic observation in patients with memory problems? J Neurol Neurosurg Psychiatry 2005;76:1739. 2. Larner AJ. “Attended alone” sign: Validity and reliability for the exclusion of dementia. Age Ageing 2009;38:476–478. 3. Sheehan DV, Lecrubier Y, Sheehan KH et al. The Mini-International Neuropsychiatric Interview (MINI): The development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. J Clin Psychiatry 1998;59(Suppl 20):22–23.
COGNITIVE IMPAIRMENT IS ASSOCIATED WITH HIGH COATED-PLATELET LEVELS IN INDIVIDUALS WITH CAROTID ATHEROSCLEROSIS To the Editor: Coated-platelets are a subpopulation of procoagulant platelets observed upon dual agonist stimulation with thrombin and collagen.1 Individuals with nonlacunar ischemic stroke have higher coated-platelet levels than individuals without stroke or with lacunar stroke.2 Higher coated-platelet levels in symptomatic individuals with 50% or more carotid stenosis are associated with early stroke recurrence.3 Carotid disease is a risk factor for cognitive impairment, thought to be due to cerebral emboli or hypoperfusion with or without silent brain infarctions.4 A pilot study was undertaken to test the hypothesis that high coated-platelet levels are associated with cognitive impairment in individuals with carotid atherosclerosis. Consecutive outpatients referred for carotid Doppler evaluation were screened for cognitive impairment using the Montreal Cognitive Assessment (MoCA) test5 and for depression using the Beck Depression Inventory-II (BDI-II).6 Exclusion criteria included stroke or transient ischemic attack (TIA) within the previous 6 months, known dementia, use of anticoagulants, prolonged coagulation tests (prothrombin time, partial thromboplastin time, international normalized ratio), severe depression (BDI-II score ≥33),6 or intake of sedating substances within 2 hours before screening. Electronic medical records were reviewed for evidence of stroke and TIA within the previous 6 months or prior diagnosis of memory loss. After informed consent, 5 mL of blood was drawn, and coated-platelet levels were determined as described previously.2,3 Levels are reported as percentage of cells converted to coated-platelets.2 Repeated measurements of coated-platelet levels were also available for a subset of participants (n = 14). Descriptive statistics were determined and independent-sample t tests, and chi-square tests were performed. Covariates were determined using correlations between potential covariates and coated-platelet levels, as well as group differences in relevant variables, and included as needed. The stability of coated-platelet levels at 6-month
1394
LETTERS TO THE EDITOR
JULY 2014–VOL. 62, NO. 7
JAGS
Table 1. Demographic Characteristics, Coated-Platelet Levels, Pertinent Comorbidities, and Medications for All Participants and According to Montreal Cognitive Assessment Group Factor
Demographic characteristic Age, mean SD Male, n (%) Caucasian, n (%) Stenosis severity, n (%)
