Sleep disturbance predicts worse cognitive performance in subsequent years: A longitudinal population-based cohort study.

BACKGROUND: Poor sleep is a potential modifiable risk factor for later life development cognitive impairment. The aim of this study is to examine if subjective measures of sleep duration and sleep disturbance predict future cognitive decline in a population-based cohort of 60, 66, 72 and 78-year-olds with a maximal follow up time of 18 years. METHODS: This study included participants from the Swedish National Study on Ageing and Care - Blekinge, with assessments 2001-2021. A cohort of 60 (n = 478), 66 (n = 623), 72 (n = 662) and 78 (n = 548) year-olds, were assessed at baseline and every 6 years until 78 years of age. Longitudinal associations between sleep disturbance (sleep scale), self-reported sleep duration and cognitive tests (Mini Mental State Examination and the Clock drawing test) were examined together with typical confounders (sex, education level, hypertension, hyperlipidemia, smoking status, physical inactivity and depression). RESULTS: There was an association between sleep disturbance at age 60 and worse cognitive function at ages 60, 66 and 72 years in fully adjusted models. The association was attenuated after bootstrap-analysis for the 72-year-olds. The items of the sleep scale most predictive of later life cognition regarded nightly awakenings, pain and itching and daytime naps. Long sleep was predictive of future worse cognitive function. CONCLUSION: Sleep disturbance was associated with worse future cognitive performance for the 60-year-olds, which suggests poor sleep being a risk factor for later life cognitive decline. Questions regarding long sleep, waking during the night, pain and itching and daytime naps should be further explored in future research and may be targets for intervention.

CoGNIT Automated Tablet Computer Cognitive Testing in Patients With Mild Cognitive Impairment: Feasibility Study.

BACKGROUND: Early diagnosis of cognitive disorders is becoming increasingly important. Limited resources for specialist assessment and an increasing demographical challenge warrants the need for efficient methods of evaluation. In response, CoGNIT, a tablet app for automatic, standardized, and efficient assessment of cognitive function, was developed. Included tests span the cognitive domains regarded as important for assessment in a general memory clinic (memory, language, psychomotor speed, executive function, attention, visuospatial ability, manual dexterity, and symptoms of depression). OBJECTIVE: The aim of this study was to assess the feasibility of automatic cognitive testing with CoGNIT in older patients with symptoms of mild cognitive impairment (MCI). METHODS: Patients older than 55 years with symptoms of MCI (n=36) were recruited at the research clinic at the Blekinge Institute of Technology (BTH), Karlskrona, Sweden. A research nurse administered the Mini-Mental State Exam (MMSE) and the CoGNIT app on a tablet computer. Technical and testing issues were documented. RESULTS: The test battery was completed by all 36 patients. One test, the four-finger-tapping test, was performed incorrectly by 42% of the patients. Issues regarding clarity of instructions were found in 2 tests (block design test and the one finger-tapping test). Minor software bugs were identified. CONCLUSIONS: The overall feasibility of automatic cognitive testing with the CoGNIT app in patients with symptoms of MCI was good. The study highlighted tests that did not function optimally. The four-finger-tapping test will be discarded, and minor improvements to the software will be added before further studies and deployment in the clinic.

The Computerized General Neuropsychological INPH Test revealed improvement in idiopathic normal pressure hydrocephalus after shunt surgery.

OBJECTIVE: The Computerized General Neuropsychological INPH Test (CoGNIT) provides the clinician and the researcher with standardized and accessible cognitive assessments in patients with idiopathic normal pressure hydrocephalus (INPH). CoGNIT includes tests of memory, executive functions, attention, manual dexterity, and psychomotor speed. Investigations of the validity and reliability of CoGNIT have been published previously. The aim of this study was to evaluate CoGNIT's sensitivity to cognitive change after shunt surgery in patients with INPH. METHODS: Forty-one patients with INPH (median Mini-Mental State Examination score 26) were given CoGNIT preoperatively and at a postoperative follow-up 4 months after shunt surgery. Scores were compared to those of 44 healthy elderly control volunteers. CoGNIT was administered by either a nurse or an occupational therapist. RESULTS: Improvement after shunt surgery was seen in all cognitive domains: memory (10-word list test, p < 0.01); executive functions (Stroop incongruent color and word test, p < 0.01); attention (2-choice reaction test, p < 0.01); psychomotor speed (Stroop congruent color and word test, p < 0.01); and manual dexterity (4-finger tapping, p < 0.01). No improvement was seen in the Mini-Mental State Examination score. Preoperative INPH test scores were significantly impaired compared to healthy control subjects (p < 0.001 for all tests). CONCLUSIONS: In this study the feasibility for CoGNIT to detect a preoperative impairment and postoperative improvement in INPH was demonstrated. CoGNIT has the potential to become a valuable tool in clinical and research work.Clinical trial registration no.: NCT01618500 (clinicaltrials.gov).

A computerized neuropsychological test battery designed for idiopathic normal pressure hydrocephalus.

BACKGROUND: A tool for standardized and repeated neuropsychological assessments in patients with idiopathic normal pressure hydrocephalus (INPH) is needed. The objective of this study was to develop a computerized neuropsychological test battery designed for INPH and to evaluate its reliability, validity and patient's ability to complete the tests. METHODS: Based on a structured review of the literature on neuropsychological testing in INPH, the eight tests most sensitive to the INPH cognitive profile were implemented in a computerized format. The Geriatric Depression Scale (GDS) was also included. Tests were presented on a touch-screen monitor, with animated instructions and speaker sound. The battery was evaluated with the following cohorts: A. Test-retest reliability, 44 healthy elderly; B. Validity against standard pen and pencil testing, 28 patients with various cognitive impairments; C. Ability to complete test battery, defined as completion of at least seven of the eight tests, 40 investigated for INPH. RESULTS: A. All except the figure copy test showed good test-retest reliability, r = 0.67-0.90; B. A high correlation was seen between conventional and computerized tests (r = 0.66-0.85) except for delayed recognition and figure copy task; C. Seventy-eight percent completed the computerized battery; Patients diagnosed with INPH (n = 26) performed worse on all tests, including depression score, compared to healthy controls. CONCLUSIONS: A new computerized neuropsychological test battery designed for patients with communicating hydrocephalus and INPH was introduced. Its reliability, validity for general cognitive impairment and completion rate for INPH was promising. After exclusion of the figure copy task, the battery is ready for clinical evaluation and as a next step we suggest validation for INPH and a comparison before and after shunt surgery. TRIAL REGISTRATION: ClinicalTrials.org NCT01265251.

Transcranial Doppler pulsatility index: not an accurate method to assess intracranial pressure.

BACKGROUND: Transcranial Doppler sonography (TCD) assessment of intracranial blood flow velocity has been suggested to accurately determine intracranial pressure (ICP). OBJECTIVE: We attempted to validate this method in patients with communicating cerebrospinal fluid systems using predetermined pressure levels. METHODS: Ten patients underwent a lumbar infusion test, applying 4 to 5 preset ICP levels. On each level, the pulsatility index (PI) in the middle cerebral artery was determined by measuring the blood flow velocity using TCD. ICP was simultaneously measured with an intraparenchymal sensor. ICP and PI were compared using correlation analysis. For further understanding of the ICP-PI relationship, a mathematical model of the intracranial dynamics was simulated using a computer. RESULTS: The ICP-PI regression equation was based on data from 8 patients. For 2 patients, no audible Doppler signal was obtained. The equation was ICP = 23*PI + 14 (R = 0.22, P < .01, N = 35). The 95% confidence interval for a mean ICP of 20 mm Hg was -3.8 to 43.8 mm Hg. Individually, the regression coefficients varied from 42 to 90 and the offsets from -32 to +3. The mathematical simulations suggest that variations in vessel compliance, autoregulation, and arterial pressure have a serious effect on the ICP-PI relationship. CONCLUSIONS: The in vivo results show that PI is not a reliable predictor of ICP. Mathematical simulations indicate that this is caused by variations in physiological parameters.