Surgical prehabilitation in older and frail individuals: a scoping review

Background:

Older individuals who are scheduled for elective procedures often have co-morbidities at baseline and may be classified as frail. Both older age and frailty are associated with poor fitness and preoperative deconditioning, which can be predictors of postoperative complications. Prehabilitation aims to improve preoperative health in order to reduce complications and expedite postoperative recovery. To date, the effect of prehabilitation on improving outcomes in older and frail individuals is unclear, and the evidence in support of multi-modal treatments is evolving.

Methods:

In this scoping review, searches of PubMed and Cochrane Library between August 2012 and August 2022 were performed to identify studies investigating the efficacy of prehabilitation prior to surgical procedures.

Results:

A total of 36 articles were included in the review. Most of these examined the efficacy of unimodal (n=21) prehabilitation interventions, most commonly exercise therapy. Multimodal prehabilitation programs (n=15) included a variety of intervention components (e.g., exercise training, nutrition, psychological intervention or geriatric consultation). The most commonly studied populations were patients with gastrointestinal cancer (mostly colorectal cancer). Exercise therapy and multimodal interventions are likely to be of greatest impact on postoperative functional decline in patients awaiting total knee or hip arthroplasty, and cancer-related resection surgery (e.g., due to colorectal, gastric or lung cancer) in older and frail patients.

Conclusions:

Presurgical prehabilitation showed the potential to diminish postoperative outcomes in older and frail patients prior to surgery. However, adequately powered, randomized controlled, assessor blinded intervention trials demonstrating overall benefit of prehabilitation are needed.

Aims

This scoping review aims to summarize the current literature on the efficacy of prehabilitation in older and frail individuals who are undergoing surgical procedures in order to support clinical protocols and inform future research.

An accurate fully automated panel of plasma biomarkers for Alzheimer's disease

INTRODUCTION

There is a great need for fully automated plasma assays that can measure amyloid beta (Aβ) pathology and predict future Alzheimer's disease (AD) dementia.

METHODS

Two cohorts (n = 920) were examined: Panel A+ (n = 32 cognitively unimpaired [CU], n = 106 mild cognitive impairment [MCI], and n = 89 AD) and BioFINDER-1 (n = 461 CU, n = 232 MCI). Plasma Aβ42/Aβ40, phosphorylated tau (p-tau)181, two p-tau217 variants, ApoE4 protein, neurofilament light, and GFAP were measured using Elecsys prototype immunoassays.

RESULTS

The best biomarker for discriminating Aβ-positive versus Aβ-negative participants was Aβ42/Aβ40 (are under the curve [AUC] 0.83-0.87). Combining Aβ42/Aβ40, p-tau181, and ApoE4 improved the AUCs significantly (0.90 to 0.93; P< 0.01). Adding additional biomarkers had marginal effects (ΔAUC ≤0.01). In BioFINDER, p-tau181, p-tau217, and ApoE4 predicted AD dementia within 6 years in CU (AUC 0.88) and p-tau181, p-tau217, and Aβ42/Aβ40 in MCI (AUC 0.87).

DISCUSSION

The high accuracies for Aβ pathology and future AD dementia using fully automated instruments are promising for implementing plasma biomarkers in clinical trials and clinical routine.

Neurofilament as a blood marker for diagnosis and monitoring of primary progressive aphasias

Objective:

To assess the utility of serum neurofilament for diagnosis and monitoring of primary progressive aphasia (PPA) variants.

Methods:

We investigated neurofilament light chain (NF-L) levels in blood of 99 patients with PPA (40 with nonfluent variant PPA [nfvPPA], 38 with semantic variant PPA [svPPA], 21 with logopenic variant PPA [lvPPA]) and compared diagnostic performance with that reached by CSF NF-L, phosphorylated neurofilament heavy chain (pNF-H), β-amyloid (Aβ1-42), tau, and phosphorylated tau. The longitudinal change of blood NF-L levels was measured and analyzed for correlation with functional decline and brain atrophy.

Results:

Serum NF-L is increased in PPA compared to controls and discriminates between nfvPPA/svPPA and lvPPA with 81% sensitivity and 67% specificity (cutoff 31 pg/mL). CSF NF-L, pNF-H, tau, phosphorylated tau, and Aβ1-42achieved similar performance, and pNF-H was the only marker for discrimination of nfvPPA from svPPA/lvPPA. In most patients with nfvPPA and svPPA, but not lvPPA, serum NF-L increased within follow-up. The increase correlated with functional decline and progression of atrophy of the left frontal lobe of all patients with PPAs and the right middle frontal gyrus of patients with nfvPPA and svPPA.

Conclusions:

Blood level of NF-L can aid the differential diagnosis of PPA variants, especially in combination with CSF pNF-H. Because serum NF-L correlates with functional decline and atrophy in the disease course, it qualifies as an objective disease status marker. Extended follow-up studies with cases of known neuropathology are imperative.

Classification of evidence:

This study provides Class I evidence that in patients with PPA, blood levels of NF-L can distinguish the logopenic variant from the nonfluent/agrammatic and semantic variants.