Neurophysiological characterization of oropharyngeal dysphagia in older patients

OBJECTIVE

To characterize swallowing biomechanics and neurophysiology in older patients with oropharyngeal dysphagia (OD).

METHODS

Observational study in 12 young healthy volunteers (HV), 9 older HV (OHV) and 12 older patients with OD with no previous diseases causing OD (OOD). Swallowing biomechanics were measured by videofluoroscopy, neurophysiology with pharyngeal sensory (pSEP) and motor evoked-potentials (pMEP) to intrapharyngeal electrical and transcranial magnetic stimulation (TMS), respectively, and salivary neuropeptides with enzyme-linked immunosorbent assay (ELISA).

RESULTS

83.3% of OOD patients had unsafe swallows (Penetration-Aspiration scale = 4.3 ± 2.1; p < 0.0001) with delayed time to laryngeal vestibule closure (362.5 ± 73.3 ms; p < 0.0001) compared to both HV groups. OOD patients had: (a) higher pharyngeal sensory threshold (p = 0.009) and delayed pSEP P1 and N2 latencies (p < 0.05 vs HV) to electrical stimulus; and (b) higher pharyngeal motor thresholds to TMS in both hemispheres (p < 0.05) and delayed pMEPs latencies (right, p < 0.0001 HV vs OHV/OOD; left, p < 0.0001 HV vs OHV/OOD).

CONCLUSIONS

OOD patients have unsafe swallow and delayed swallowing biomechanics, pharyngeal hypoesthesia with disrupted conduction of pharyngeal sensory inputs, and reduced excitability and delayed cortical motor response.

SIGNIFICANCE

These findings suggest new elements in the pathophysiology of aging-associated OD and herald new and more specific neurorehabilitation treatments for these patients.

Functional Constipation in Older Adults: Prevalence, Clinical Symptoms and Subtypes, Association with Frailty, and Impact on Quality of Life

INTRODUCTION

Functional constipation (FC) is very prevalent in older adults, especially in women, but its relationship with frailty is not fully understood. The aims were to assess FC prevalence, clinical symptoms and subtypes, association with frailty, and impact on quality of life (QoL) in older people.

METHODS

This epidemiological study included 384 individuals aged over 70 years recruited from the community, a hospital, and a nursing home and stratified into robust, pre-frail, and frail groups (Fried criteria). The following criteria were evaluated: frailty, FC (Rome III criteria), stool consistency (Bristol Stool Chart), comorbidities (Charlson), dependency (Barthel), QoL (EQ5D), and clinical and sociodemographic data. Defined by symptom aggregation were 2 main clinical subtypes as follows: slow colonic transit time (CTT) and functional defecation disorder (FDD).

RESULTS

Mean age was 79.11 ± 6.43 years. Overall FC prevalence was 26.8%, higher in women (32.4% women vs. 21.8% men; p = 0.019) and highest in frail patients (41.7% frail vs. 33.9% pre-frail vs. 24.2% robust; p < 0.001). Straining and hard stools (Bristol 1-2) were the most prevalent symptoms (89.3 and 75.7%, respectively). Frailty and benzodiazepine intake were independently associated with FC. Patients with FC obtained poorer QoL scores in the EQ5D (perceived health 66.09 ± 17.8 FC patients vs. 56.4 ± 19.03 non-FC patients; p < 0.05). The FDD subtype became significantly more prevalent as frailty increased (6.5, 25.8, and 67.7% for robust, pre-frail, and frail patients, respectively); the slow CTT subtype was significantly more frequent in robust patients (38.5% robust vs. 30.5% pre-frail vs. 23.1% frail), p = 0.002.

DISCUSSION/CONCLUSION

FC prevalence in older adults was high, especially in women, and was associated with frailty and poor QoL. Clinical subtypes as related to frailty phenotypes reflect specific pathophysiological aspects and should lead to more specific diagnoses and improved treatment.

Kegel Exercises, Biofeedback, Electrostimulation, and Peripheral Neuromodulation Improve Clinical Symptoms of Fecal Incontinence and Affect Specific Physiological Targets: An Randomized Controlled Trial

Background/Aims

Fecal incontinence (FI) is a prevalent condition among community-dwelling women, and has a major impact on quality of life (QoL). Research on treatments commonly used in clinical practice—Kegel exercises, biofeedback, electrostimulation, and transcutaneous neuromodulation—give discordant results and some lack methodological rigor, making scientific evidence weak. The aim is to assess the clinical efficacy of these 4 treatments on community-dwelling women with FI and their impact on severity, QoL and anorectal physiology.

Methods

A randomized controlled trial was conducted on 150 females with FI assessed with anorectal manometry and endoanal ultrasonography, and pudendal nerve terminal motor latency, anal/rectal sensory-evoked-potentials, clinical severity, and QoL were determined. Patients were randomly assigned to one of the following groups Kegel (control), biofeedback + Kegel, electrostimulation + Kegel, and neuromodulation + Kegel, treated for 3 months and re-evaluated, then followed up after 6 months.

Results

Mean age was 61.09 ± 12.17. Severity of FI and QoL was significantly improved in a similar way after all treatments. The effect on physiology was treatment-specific Kegel and electrostimulation + Kegel, increased resting pressure (P < 0.05). Squeeze pressures strongly augmented with biofeedback + Kegel, electrostimulation + Kegel and neuromodulation + Kegel (P < 0.01). Endurance of squeeze increased in biofeedback + Kegel and electrostimulation + Kegel (P < 0.01). Rectal perception threshold was reduced in the biofeedback + Kegel, electrostimulation + Kegel, and neuromodulation + Kegel (P < 0.05); anal sensory-evoked-potentials latency shortened in patients with electrostimulation + Kegel (P < 0.05).

Conclusions

The treatments for FI assessed have a strong and similar efficacy on severity and QoL but affect specific pathophysiological mechanisms. This therapeutic specificity can help to develop more efficient multimodal algorithm treatments for FI based on pathophysiological phenotypes.

A randomized clinical trial on the acute therapeutic effect of TRPA1 and TRPM8 agonists in patients with oropharyngeal dysphagia

BACKGROUND

Oropharyngeal dysphagia (OD) treatment is moving away from compensatory strategies toward active treatments that improve swallowing function. The aim of this study was to assess the acute therapeutic effect of TRPA1/M8 agonists in improving swallowing function in OD patients.

METHODS

Fifty-eight patients with OD caused by aging, stroke, or neurodegenerative disease were included in a three-arm, quadruple-blind, randomized clinical trial (NCT02193438). Swallowing safety and efficacy and the kinematics of the swallow response were assessed by videofluoroscopy (VFS) during the swallow of 182 ± 2 mPa·s viscosity (nectar) boluses of a xanthan gum thickener supplemented with (a) 756.6 μmol/L cinnamaldehyde and 70 μmol/L zinc (CIN-Zn) (TRPA1 agonists), (b) 1.6 mmol/L citral (CIT) (TRPA1 agonist), or (c) 1.6 mmol/L citral and 1.3 mmol/L isopulegol (CIT-ISO) (TRPA1 and TRPM8 agonists). The effects on pharyngeal event-related potentials (ERP) were assessed by electroencephalography.

KEY RESULTS

TRPA1 stimulation with either CIN-Zn or CIT reduced time to laryngeal vestibule closure (CIN-Zn P = .002, CIT P = .023) and upper esophageal sphincter opening (CIN-Zn P = .007, CIT P = .035). In addition, CIN-Zn reduced the penetration-aspiration scale score (P = .009), increased the prevalence of safe swallows (P = .041), and reduced the latency of the P2 peak of the ERP. CIT-ISO had no positive effect on biomechanics or neurophysiology. No significant adverse events were observed.

CONCLUSIONS AND INFERENCES

TRPA1 stimulation with CIN-Zn or CIT improves the swallow response which, in the case of CIN-Zn, is associated with a significant improvement in cortical activation and safety of swallow. These results provide the basis for the development of new active treatments for OD using TRPA1 agonists.

Defective Conduction of Anorectal Afferents Is a Very Prevalent Pathophysiological Factor Associated to Fecal Incontinence in Women

Background/Aims

Fecal incontinence (FI) is a prevalent condition among women. While biomechanical motor components have been thoroughly researched, anorectal sensory aspects are less known. We studied the pathophysiology of FI in community-dwelling women, specifically, the conduction through efferent/afferent neural pathways.

Methods

A cross-sectional study was conducted on 175 women with FI and 19 healthy volunteers. The functional/structural study included anorectal manometry/endoanal ultrasound. Neurophysiological studies including pudendal nerve terminal motor latency (PNTML) and sensory-evoked-potentials to anal/rectal stimulation (ASEP/RSEP) were conducted on all healthy volunteers and on 2 subgroups of 42 and 38 patients, respectively.

Results

The main conditions associated with FI were childbirth (79.00%) and coloproctological surgery (37.10%). Cleveland score was 11.39 ± 4.09. Anorectal manometry showed external anal sphincter and internal anal sphincter insufficiency in 82.85% and 44.00%, respectively. Sensitivity to rectal distension was impaired in 27.42%. Endoanal ultrasound showed tears in external anal sphincter (60.57%) and internal anal sphincter disruptions (34.80%). Abnormal anorectal sensory conduction was evidenced through ASEP and RSEP in 63.16% and 50.00% of patients, respectively, alongside reduced activation of brain cortex to anorectal stimulation. In contrast, PNTML was delayed in only 33.30%. Stools were loose/very loose in 56.70% of patients.

Conclusions

Pathophysiology of FI in women is mainly associated with mechanical sphincter dysfunctions related to either muscle damage or, to a lesser extent, impaired efferent conduction at pudendal nerves. Impaired conduction through afferent anorectal pathways is also very prevalent in women with FI and may play an important role as a pathophysiological factor and as a potential therapeutic target.

Acute and subacute effects of oropharyngeal sensory stimulation with TRPV1 agonists in older patients with oropharyngeal dysphagia: a biomechanical and neurophysiological randomized pilot study

BACKGROUND

Older people with oropharyngeal dysphagia (OD) present a decline in pharyngeal sensory function. The aim of this proof-of-concept study was to assess the biomechanical and neurophysiological effects of acute and subacute oropharyngeal sensory stimulation with transient receptor potential vanilloid 1 (TRPV1) agonists (capsaicinoids) in older patients with OD.

METHODS

We studied the effect of a single dose versus multiple doses (2 weeks) of oral capsaicin treatment (10^-5 M) or placebo in 28 older patients with OD (81.2 ± 4.6 years) using videofluoroscopy (penetration-aspiration scale [PAS], timing of swallow response) and electroencephalography (EEG) (latency and amplitude of pharyngeal event-related potential [ERP]).

RESULTS

Acute stimulation by capsaicinoids 10^-5 M did not improve swallow function and did not produce significant changes in pharyngeal ERP. In contrast, after 10 days of treatment, patients presented a clinically relevant and statistically significant reduction in the laryngeal vestibule closure (LVC) time (22.5%, p = 0.042), and in the PAS (24.2%, p = 0.038), compared with the placebo group. EEG results showed a reduction in the latency of the N1 peak (28.6%, p = 0.007) and an increase of the amplitude of the P1-N2 (59.4%, p = 0.038) and the N2-P2 (43.6%, p = 0.050) peaks. We observed a strong and significant correlation between the reduction in the latency of the N1 peak and change in LVC time after subacute treatment (r = 0.750, p = 0.003).

CONCLUSIONS

After 2 weeks of treatment, oropharyngeal sensory stimulation with capsaicinoids induced cortical changes that were correlated with improvements in swallowing biomechanics in older patients with OD. These results further show that sensory stimulation by TRPV1 agonists can become a useful pharmacological treatment for older patients with OD.

Spatiotemporal characteristics of the pharyngeal event-related potential in healthy subjects and older patients with oropharyngeal dysfunction

BACKGROUND

Oropharyngeal dysphagia (OD) is a highly prevalent symptom in older people. Appropriate oropharyngeal sensory feedback is essential for safe and efficient swallowing. However, pharyngeal sensitivity decreases with advancing age and could play a fundamental role in the physiopathology of swallowing dysfunction associated with aging. We aimed to characterize pharyngeal sensitivity and cortical response to a pharyngeal electrical stimulus in healthy volunteers (HV) and older patients with and without OD.

METHODS

Eight young HV, eight older HV without OD, and 14 older patients with OD were studied by electroencephalography through 32 scalp electrodes. Pharyngeal event-related potentials (ERP) were assessed following electrical stimulation of the pharynx. Sensory and tolerance thresholds to the electrical stimulus and latency, amplitude, and scalp current density of each ERP component were analyzed and compared. An ERP source localization study was also performed using the sLORETA software.

KEY RESULTS

Older participants (with and without OD) presented an increased sensory threshold to pharyngeal electrical stimulation (10.2 ± 1.7 mA and 11.5 ± 1.9 mA respectively), compared with young HV (6.0 ± 1.2 mA). The cortical activation of older HV in response to pharyngeal electrical stimulus was reduced compared with young HV (N2 amplitude: 0.22 ± 0.79 vs -3.10 ± 0.59, P<.05). Older patients with OD also presented disturbances to the pharyngo-cortical connection together with disrupted pattern of cortical activation.

CONCLUSIONS AND INFERENCES

Older people present a decline in pharyngeal sensory function, more severe in older patients with OD. This sensory impairment might be a critical pathophysiological element and a potential target for treatment of swallowing dysfunction in older patients.

Quality of Life Differences in Female and Male Patients with Fecal Incontinence

Background/Aims

To explore and compare quality of life (QoL) differences in female and male patients with fecal incontinence.

Methods

Ninety-one patients with fecal incontinence (60 women, mean (SD) age 64.13 (9.72) years; 31 men, mean (SD) age 63.61 (13.33) years) were assessed for pathophysiology (anorectal manometry and ultrasound), clinical severity (Wexner and Vaizey scales), QoL (Fecal Incontinence Quality of Life Score [FIQL]) and health status (EQ-5D).

Results

External and internal anal sphincter impairment rates were 96.5% and 70.2%, respectively, in women, compared to 30% and 43.3% respectively in men (P < 0.05). Clinical severity was similar in both sexes, with mean (SD) Wexner scores of 10.95 (4.35) for women and 9.81 (4.30) for men, and mean (SD) Vaizey scores of 13.27 (4.66) for women and 11.90 (5.22) for men. Scores for women were significantly lower for all FIQL depression and coping subscales (P < 0.001) and the EQ-5D depression subscale (P < 0.01). EQ-5D index was 0.687 (0.20) for women and 0.835 (0.15) for men (P < 0.001). QoL was negatively affected by female gender (−1.336), anxiety/depression (−1.324) and clinical severity (−0.302), whereas age had a positive impact (0.055 per year) (P < 0.01).

Conclusions

The pathophysiology of fecal incontinence differed between the sexes. For similar severity scores, impact on QoL was higher in women. Gender had the highest impact on QoL compared to other factors. QoL measurements should be part of assessment and treatment protocols.