POCD - Dementia & Alzheimer's

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Updated - January 4, 2026

What are the differences between POCD (Peastoperative Cognitive Dysfunction), dementia and Alzheimer's and what is the current medical study situation? This will be examined and explained in detail below.

In a further article (still in progress), the possibilities of using essential oils and their effect on the above-mentioned clinical pictures are shown. All statements are supported by independent scientific studies.

POCD

POCD often occurs after surgery as a result of anesthesia. People of all ages are affected, but mainly patients over 60 years of age. Three months later, around 10 % still suffer from POCD.

Depending on their overall state of health, age, previous illnesses and extent of the operation, level of education, but also depending on the narcotics used, it usually represents a temporary Impairment of cognitive functions (e.g. memory, concentration, learning ability).

The risk of POCD occurring can be estimated using various tests before and after the operation. The decisive factor is always the availability of comparative data collected BEFORE the operation (preoperative).

Statistically occupied, that

• 36.6 % of 18-39 year olds
• 30.4 % of 40-59 year olds and
• 41.4 % of patients over 60 years of age.

suffered from POCD on discharge.

Further Article of the German Medical Journal 2014.

Test methods

A brief summary in advance:

• MoCA is the best validated test for POCD screening with high sensitivity
• 6CIT can be used as Ultra-fast screening can be used, but requires training
• CFQ is not suitable as an objective measure for POCD, rather for subjective cognitive complaints and psychological distress

Comparison of all three test methods

Test	Duration	Points	Remark	Strengths	Limitations
MoCA	10 min	0-30	Best validated	High sensitivity (90% for MCI), detects POCD under general & regional anesthesia	Requires training, longer implementation
6CIT	2 min	0-28*	Fast screening	Very fast, correlates well with MoCA (r=-0.86)	Low reliability in real-world settings without training
CFQ	5-10 min	0-100	Subjective complaints	Captures everyday function, self-report	Does NOT correlate with objective tests, rather measures psychological distress

*Caution - Higher scores indicate poorer cognition!

Montreal Cognitive Assessment (MoCA)

Test description and implementation

The MoCA is a 10-minute cognitive screening tool with maximum 30 points.
The test evaluates:

• Short-term memory
• Visuospatial skills (visuospatial skills)
• Executive functions
• Attention and working memory (attention, working memory)
• Language (language)
• Orientation

Internal consistencyCronbach's alpha of 0.83 in the original version.

With a cut-off score of 26 points:

• MMSESensitivity 18% for the detection of MCI
• MoCASensitivity 90% for the detection of MCI
• For mild Alzheimer's dementiaMMSE 78% Sensitivity vs. MoCA 100%
• SpecificityMMSE 100%, MoCA 87%

Link: https://pubmed.ncbi.nlm.nih.gov/15817019/

• Preoperative vs. 24h postoperative with general anesthesia:
  • MMSE: 27.17±1.93 → 26.23±2.77 (p=0.003)
  • MoCA: 24.32±3.19 → 22.87±3.88 (p=0.000)
• Preoperative vs. 24h postoperative for spinal anesthesia:
  • MMSE: No significant difference
  • MoCA: 24.35±2.84 → 23.13±4.08 (p=0.019)
• POCD incidence: MoCA 32.9% vs. MMSE 15.2% (p=0.018)

DangerMoCA detected cognitive decline in both anesthesia groups, MMSE only in the general anesthesia group.

Further studies:

• Comparison of MoCA vs. MMSE in elderly patients after minor elective surgery
• Comparison of Postoperative Cognitive Decline Using the Mini-Mental State Examination and Montreal Cognitive Assessment After Minor Elective Surgery in Elderly
• MCI as a risk factor for POCD in spinal surgery
• POCD definition using MoCA
• Postoperative cognitive dysfunction in older surgical patients associated with increased healthcare utilization: a prospective study from an upper-middle-income country
• Telephone-MoCA (T-MoCA) in the preoperative setting
• Risk factors for POCD of various degrees of severity
• MoCA cut-off values in clinical practice
  
  for normal cognition:
  ≥26 points95% Sensitivity
• for exclusion of mild dementia:
  ≥21 points98% negative predictive value (NPV)
• for exclusion MCI:
  ≥26 points94% NPV

Diagnostic accuracy of the Montreal Cognitive Assessment (MoCA) for cognitive screening in old age psychiatry: Determining cutoff scores in clinical practice. Avoiding spectrum bias caused by healthy controls

Six Cognitive Item Test (6CIT)

Test description and implementation

The 6CIT (see also. Kingshill Version 2000) is with an average execution time of only 2.05 minutes with a maximum pi score of 28, which describes the worst cognition, while lower values mean better cognition. The test evaluates:

• Memory
• Attention
• Language
• Executive functions
• Motor speed

Median scores according to diagnostic groups:

• SCD (Subjective Cognitive Decline) - 2 points
• MCI (Mild Cognitive Impairment) - 5 points
• dementia - 17 points

Further studies:

• Comparison of the Six Item Cognitive Impairment Test (6CIT) to Commonly-Used Short Cognitive Screening Instruments in a Memory Clinic Population
• Suitability of the 6CIT as a screening test for dementia in primary care patients
• Rapid In-Person Cognitive Screening in the Preoperative Setting: Test Considerations and Recommendations from the Society for Perioperative Assessment and Quality Improvement (SPAQI)

Cognitive Failure Questionnaire (CFQ)

Test description and original development

The CFQ is a self-reported questionnaire with 25 questions to evaluate errors in perception, memory and motor function.

Characteristics:

• Answer scale0 („Never“) to 4 („Very often“)
• Total score range0-100 (higher values indicate greater cognitive impairment)
• StabilityRelatively stable over long periods (trait instead of state measurement)
• Correlation with external criteriaSignificant correlation with ratings by spouses
• Correlation with psychiatric symptomsYes (MHQ - Mental Health Questionnaire)

Four subdomains are included in the result:

• Memory with 0-32 points
• Distractibility with 0-36 points
• Blunders (error) with 0-28 points
• Names with 0-8 points

POCD-typical scope:

• Memory
• Attention
• Language
• Executive functions
• Motor speed

Further studies:

• The Cognitive Failures Questionnaire (CFQ) and its correlates
• Endoscopic Sinus Surgery Improves Cognitive Dysfunction in Patients with Chronic Rhinosinusitis
• Postoperative Cognitive Dysfunction after Coronary Artery Bypass Grafting
• Twelve-month follow-up effects of cognitive training after heart valve surgery on cognitive functions and health-related quality of life: a randomized clinical trial
• Revisiting the Factor Structure and Construct Validity of the Cognitive Failures Questionnaire
• The cognitive failures questionnaire in psychiatry

Influence of narcotics on postoperative POCD

The intravenously applied Propofol according to this study a lower incidence of delirium and POCD compared to inhalation anesthesia with sevoflurane. The study is only available as a paid version in the Full text before.

The incidence of POCD was higher with sevoflurane (57.1%) compared to propofol (32.3%), and the incidence of delirium was also higher with sevoflurane at 34.2% compared to propofol at only 8.8%.

Dementia & Alzheimer's

While dementia is a syndrome and describes symptoms, the Alzheimer the disease, is a specific cause of these symptoms.

Dementia is subdivided into (Frequency):

• Alzheimer's disease - (77%)
• Lewy body dementia (LBD) - (26%)
• Vascular dementia (VaD) - (18%)
• Hippocampal sclerosis (HS) - (13%)
• Frontotemporal dementia (FTD) - (5%)
• Mixed dementia
  Concurrent Alzheimer's disease in LBD patients - (66%)
  Concurrent Alzheimer's disease in VaD patients - (77%)
  Concurrent Alzheimer's disease in HS patients - (66%)

According to current knowledge (01.2026), all forms of dementia are considered incurable. Only the progression can be slowed down. In addition to the known drugs another 138 researched.

In terms of prevention, higher education, physical activity, good coping skills and a strong social network have been shown to have a positive effect on reducing dementia risk factors.

Further studies:

… to be continued …