Incorporating MMSE and HDS-R into Rehabilitation Planning for Cognitive Function
[Positioning of this magazine] This article is positioned as Step 4: Integration with Cognitive Function and ADL Assessment. Cognitive decline is an independent predictor of balance and ADL recovery. This article explains how to incorporate MMSE and HDS-R scores into rehabilitation plans and multidisciplinary reports.
Magazine: Evidence-Based Functional Assessment and Clinical Judgment
Let's start with the conclusion.
Cognitive decline directly affects ADL recovery and balance in post-orthopedic surgery patients. Rather than ending with 'it's difficult because of dementia,' incorporating MMSE and HDS-R scores into the rehabilitation plan is the first step toward setting realistic discharge goals.
I measured the MMSE in the assessment room. It was 26 points. I recorded that number in the chart and moved on to the next patient. —Could you be using it this way? Cognitive function tests are not for 'determining the presence or absence of dementia,' but rather 'information for predicting how post-operative rehabilitation will progress and for changing intervention strategies.' Only by understanding the meaning of the scores can they function in a clinical setting.
Basics of MMSE and HDS-R
MMSE (Mini-Mental State Examination)
The MMSE is a cognitive function screening test published by Folstein MF et al. in 1975 (Folstein et al., 1975, J Psychiatr Res). It is scored out of 30 points, and the test items cover the following domains.
Orientation (time/place): 10 points
Memory (immediate/delayed recall): 6 points
Attention and calculation: 5 points
Language (naming, repetition, three-step command): 8 points
Visuospatial construction (figure copying): 1 point
The standard cutoff is 23 points or less for 'suspected cognitive decline,' with a reported sensitivity of 87% and specificity of 82% (23/24 cutoff). However, it is important to note that scores tend to be lower in elderly individuals and those with lower educational backgrounds because the test is influenced by age and education.
HDS-R (Revised Hasegawa's Dementia Scale)
The HDS-R is a Japanese cognitive function screening test published by Shinji Kato et al. in 1991 (Kato Shinji et al., 1991, Japanese Journal of Geriatric Psychiatry). It is scored out of 30 points, and the cutoff is 20 points or less for 'suspected dementia.'
The test consists of 9 questions: age, orientation, memory (3-word immediate and delayed recall), calculation, digit span backward, and object memory (5 items). Unlike the MMSE, which requires English, it can be administered entirely in Japanese, making it easier to use with elderly patients in acute care. The test takes about 5 to 10 minutes.
How to use MMSE and HDS-R
The HDS-R is easier to use for routine assessment in acute care wards. It is practical because it can be administered in a short time to patients experiencing post-operative pain or fatigue.
Impact on post-operative rehabilitation
Impact on ADL recovery
Multiple studies have shown that cognitive decline has a significant impact on functional outcomes after hip fracture surgery.
The MMSE score at admission significantly correlates with the FIM motor score at discharge. Patients with lower cognitive function tend to have lower FIM motor efficiency (FIM gain ÷ length of stay), and it has been reported that while the high MMSE score group shows good postoperative recovery, the low score group remains at a low level of functional recovery (Gruber-Baldini et al., 2003, J Am Geriatr Soc; PMID 12919233).
This fact implies two things. First, setting discharge goals for patients with cognitive decline at the 'same level as those without cognitive impairment' may result in overly ambitious goals. Second, even with cognitive decline, improvements can be achieved if appropriate rehabilitation is provided—meaning that giving up on evaluation by saying 'it's impossible' has no basis.
Relationship with Postoperative Delirium
In acute orthopedic postoperative patients, postoperative delirium is an issue that cannot be overlooked. Preoperative cognitive decline is one of the strongest predictors of postoperative delirium, and prospective cohort studies have shown that when postoperative delirium is superimposed on cognitive decline, it becomes an independent risk factor for functional decline in ADLs and IADLs (Bickel et al., 2014, PLoS ONE; PMID 25402484).
As a PT, you must check for the presence of delirium every day and make decisions to proceed with mobilization in stages only after the condition has improved.
Balance and Fall Risk
Cognitive decline is an independent predictor of fall risk. A systematic review and meta-analysis targeting community-dwelling elderly individuals reported that dementia increases the risk of falls with an odds ratio of approximately 2.0 (95% CI: 1.41–2.86) compared to those without it.
Why does balance collapse with cognitive decline? There are multiple mechanisms. First is the decline in dual-tasking. When dual tasks such as 'talking while walking' or 'checking surroundings while walking' become difficult, attention allocation during walking breaks down, and checking one's footing is delayed. In orthopedic postoperative cases, the addition of attention to pain further increases the risk of falls. Second is the decline in risk perception. The ability to make appropriate judgments such as 'this step is dangerous' or 'I should stop here and rest' is impaired. Cases where patients take unsafe actions after surgery due to overconfidence, such as 'it doesn't hurt' or 'I can walk now,' are an extension of this. Third is the decline in motor learning. The acquisition of new movement patterns, such as 'remembering how to use assistive devices' or 'walking while adhering to weight-bearing restrictions,' is delayed. The lower the MMSE score, the more repetition and time are required for learning new movements.
Clinical Mini-Case
I was in charge of a 79-year-old male patient after THA. He had a history of 'forgetfulness' before surgery, and when I performed the HDS-R at admission, he scored 18 points (cutoff: 20 points or less). On the third day after surgery, when starting mobilization, he made comments like 'Did I have surgery?' and 'Why am I here?'. I reported the suspicion of delirium to the doctor and nurses, and cut the standing training that day to about 5 minutes. From then on, I recorded his condition while performing simple orientation checks (what day is it, where are we) during my morning visits. After the delirium subsided a week after surgery, I resumed full-scale walking training. I made sure to repeat instructions like 'You can put weight on your right leg' and 'Bring the crutches forward before moving your legs' using the exact same words every time. His walking speed at discharge was 0.55 m/s, which did not reach the initially expected 0.7 m/s. However, because I had predicted that it might 'take longer than usual' based on the initial information of an HDS-R score of 18 and had shared this with his family, the doctor, and the nurses, we were able to coordinate his discharge as a 'course according to plan'.
Using MMSE and HDS-R in Reports
Examples of reporting to multidisciplinary teams
Reporting to nurses: 'Mr. A has an HDS-R score of 18, indicating cognitive decline. Since unassisted walking at night may be unsafe, please provide verbal cues or assistance when he goes to the bathroom at night. Please let me know if signs of delirium such as sudden confusion, day-night reversal, or restlessness appear.'
Reporting to doctors (pre-discharge conference): 'Mr. B's preoperative HDS-R score was 16. Postoperative delirium appeared between the 2nd and 5th days after surgery, during which time we limited the amount of training. Currently, the delirium has subsided, and weight-bearing walking is possible. Due to the impact of cognitive function, I believe family supervision will continue to be necessary for safe walking at home.'
Application to Goal Setting
HDS-R 21 points or higher (normal range): Standard rehabilitation program. Learning new movements also proceeds relatively smoothly.
HDS-R 16–20 points (mild decline range): Keep instructions concise, use the same words every time, and provide guidance to the family in parallel.
HDS-R 10–15 points (moderate decline range): Set ADL goals to 'possible with supervision.' Securing a safe discharge destination is prioritized.
HDS-R 9 points or lower (severe decline range): Independent walking is often difficult. Important goals often become 'ensuring safety for wheelchair transfers.'
However, these are just guidelines. Even with cognitive decline, procedural memory (movements learned by the body) may be relatively preserved. Through repeated movement practice, movements may become established even without declarative memory. It is necessary to maintain an attitude of observing actual movement ability and making adjustments rather than deciding uniformly based on scores.
Summary
The MMSE and HDS-R are not tests for "diagnosing" dementia, but rather information tools for "personalizing" postoperative rehabilitation strategies. It is not a simple matter of lowering goals if the score is low; rather, it is required to understand the degree of cognitive impairment to structure instructions, goal setting, information sharing among multidisciplinary teams, and preparation for delirium. Part of the answer to the questions of "why are orthopedic surgery patients prone to falls?" and "why is it difficult for them to follow instructions?" lies within their cognitive function scores. Evaluate, interpret, and incorporate into the plan. That is what it means to "use" the MMSE and HDS-R.
References
Folstein MF, Folstein SE, McHugh PR. "Mini-mental state": A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res. 1975;12(3):189-198.
https://pubmed.ncbi.nlm.nih.gov/1202204/ (Abstract only)
Kato S, Shimogaki H, Onodera A, et al. Development of the Revised Hasegawa's Dementia Scale (HDS-R). Japanese Journal of Geriatric Psychiatry. 1991;2(11):1339-1347. https://www.jstage.jst.go.jp/article/jjcgp/4/0/4_47/_article/-char/ja/ (Abstract only)
Gruber-Baldini AL, Zimmerman S, Morrison RS, et al. Cognitive impairment in hip fracture patients: timing of detection and longitudinal follow-up. J Am Geriatr Soc. 2003;51(9):1227-1236. https://pubmed.ncbi.nlm.nih.gov/12919233/ (Abstract only)
Bickel H, Gradinger R, Kochs E, et al. Interrelationship of postoperative delirium and cognitive impairment and their impact on the functional status in older patients undergoing orthopaedic surgery: a prospective cohort study. PLoS ONE. 2014;9(11):e110339.
https://pubmed.ncbi.nlm.nih.gov/25402484/ (Full text available)
Deandrea S, Lucenteforte E, Bravi F, et al. Risk factors for falls in community-dwelling older people: a systematic review and meta-analysis. Epidemiology. 2010;21(5):658-668.
https://pubmed.ncbi.nlm.nih.gov/20585256/ (Abstract only)
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