Randall, Nicholas R.

Abstract To review key concepts in facial nerve anatomy, physiology, injury mechanisms, and recovery patterns, and to summarize current approaches to classification, evaluation, and management of facial nerve dysfunction following skull base surgery. Narrative review of anatomical, clinical, and evaluative frameworks relevant to facial nerve dysfunction. Academic and clinical contexts involving the assessment and management of facial nerve injury, with emphasis on skull base surgery. Not applicable; this is a literature-based review. Descriptions of facial nerve anatomy and microanatomy; established classification systems for facial nerve injury; mechanisms of injury; patterns of recovery; common clinical presentations of post-surgical facial paralysis; and current grading scales and evaluation protocols. The review synthesizes foundational anatomical principles with contemporary understanding of facial nerve injury and recovery. It outlines the full spectrum of clinical outcomes observed after facial nerve injury, including typical post-surgical paralysis patterns and their natural course. Commonly used facial paralysis grading scales are compared, and standardized evaluation strategies are highlighted to promote consistent assessment across providers. Taken together, the findings provide a comprehensive framework for understanding and evaluating facial nerve dysfunction following skull base surgery. Understanding and treating facial nerve dysfunction requires nuanced knowledge of anatomy, injury mechanisms, recovery trajectories, and standardized evaluation methods. Consolidating these elements offers valuable guidance for skull base surgeons, facial plastic surgeons, and other clinicians caring for patients with facial paralysis, and supports more consistent and informed clinical decision-making.

Background: Facial nerve injury can result in a spectrum of clinical presentations from complete facial paralysis (CFP) to facial synkinesis. Willingness to pay (WTP) and quality-adjusted life years are established metrics used to assess the societal value of treatments. Objective: To quantify the perceived value of surgery for CFP and synkinesis amongst casual observers, as measured by WTP and quality of life indices. Methods: Casual observers were shown standardized videos of faces with complete paralysis, synkinesis, and nonparalyzed controls (eight videos each). Observers were asked to imagine having each condition and to rate their quality of life and WTP for surgical repair. Results: A total of 557 observers were included (mean age 36.5 years, 59% female). Both complete paralysis and synkinesis were associated with reduced quality-adjusted life year indices (0.9 [95% confidence interval [CI] 0.87–0.93]) for synkinesis; 0.86 (95% CI: 0.83–0.89) for complete paralysis, p = 0.0011). The mean WTP was $22,791 for complete flaccid paralysis and $15,718 for synkinesis repair and increased with income. WTP per quality-adjusted-life year gained was $6,844 for complete paralysis and $6,604 for synkinesis ( p > 0.05). Conclusion: Observers perceived surgical repair of CFP and synkinesis as highly valuable and within common cost-effectiveness thresholds.

Background: There is a spectrum of facial paralysis patient presentations from complete flaccid facial paralysis (CFFP) to facial aberrant reinnervation syndrome (FARS). Objective: To objectively compare how laypersons direct attention to faces with different facial paralysis subtypes using eye-tracking technology. Methods: Lay observers freely gazed at standardized videos of 24 individuals’ faces as follows: 8 with CFFP, 8 with FARS, and 8 nonparalyzed Controls performing common facial expressions. Eye-tracking measured observers’ gaze and extracted data as time in milliseconds looking at facial subsites. Mixed effects regression was used for comparative analyses. Results: A total of 85 observers completed the study. For faces at rest, measurable differences in gaze patterns were noted for CFFP faces (more attention spent on nonparalyzed hemiface), whereas FARS and Control faces showed similar symmetric gaze patterns. With dynamic movement (smiling and brow-elevation), gaze patterns for both CFFP and FARS faces became altered and asymmetrical compared with Control faces. Conclusions: Faces with CFFP and FARS are viewed differently by casual observers, which has implications for patient care and future research. While CFFP showed gaze alterations (compared with Control) in both rest and facial expression states, FARS caused gaze alterations only with facial movement.

Background: Facial aberrant reinnervation syndrome (FARS) is a common sequelae of facial nerve injury followed by aberrant reinnervation and recovery. Patients with FARS can present with different patterns of facial synkinesis, facial muscle hypertonicity, and facial spasm/twitching. 1 Synkinesis associated with FARS is described as undesired muscle contraction when a voluntary movement is triggered. One of the most common and bothersome types of facial synkinesis is oral-ocular synkinesis, where patients experience unwanted eyelid closure with movement of the mouth such as smiling or pursing the lips. First-line treatment options for FARS include facial physical therapy and botulinum toxin selective chemodenervation. For patients with persistent or more significant symptoms, there are surgical options, including selective neurectomy and selective myectomy of the involved facial nerve branches and muscles. 2 , 3 Selective myectomy of the orbicularis oculi muscle has been shown to be an effective surgical treatment option for oral-ocular synkinesis. 3 – 4 There is nuance to this procedure, including deciding whether to target the upper eyelid, lower eyelid, or both, as well as which segments and how much of the orbicularis oculi muscle to remove, balancing the goals of improving synkinesis and hypertonicity while avoiding the creation of lagophthalmos. The novel implementation of autologous microfat grafting to the procedure can help improve postoperative eyelid volume and contour and may help prevent the cut edges of the muscle from fusing, thus reducing the likelihood of persistent or recurrent ocular synkinesis. Objective: To describe a selective myectomy of the orbicularis oculi with the novel addition of autologous microfat grafting for the treatment of oral-ocular synkinesis. Methods: This video demonstrates the procedural steps for a selective myectomy of the orbicularis oculi with autologous microfat grafting for a patient with oral-ocular synkinesis due to FARS. In addition, it demonstrates the preparation of harvested abdominal fat that is utilized for the autologous microfat grafting. Results: Selective myectomy of the orbicularis oculi with autologous microfat grafting has been routinely performed safely and effectively by the senior author for treatment of oral-ocular synkinesis. Postoperative aesthetic eyelid shape and functional results have been reassuring with improvements up to 1 year postoperative and a need for additional long-term follow-up. Conclusion: To the authors’ knowledge, a selective myectomy of the orbicularis oculi with autologous microfat grafting has not been demonstrated in video documentation. Autologous microfat grafting may be a helpful addition to selective myectomy of the orbicularis oculi to enhance both eyelid aesthetics and function. Patient Consent Statement: All patients included in the video have consented to the use of videos and photographs of their faces for research and educational purposes. Funding and Conflicts of Interest: The authors have no funding, financial relationships, or conflicts of interest to disclose. Runtime of video: 7 mins 11 secs.

Purpose: Functional septorhinoplasty is an effective treatment for nasal airway obstruction. Little distinction exists between bilaterally and unilaterally obstructed patients in literature. Our study evaluates outcomes in patients with unilateral nasal airway obstruction compared to those with bilateral nasal airway obstruction as measured by nasal obstruction symptom evaluation scores following functional septorhinoplasty. Materials and Methods: A total of 227 patients underwent functional septorhinoplasty for nasal airway obstruction. Patients were grouped into unilateral (n = 64) and bilateral (n = 163) nasal obstruction cohorts based on patient report and physician assessment. Nasal obstruction symptom evaluation (NOSE) scores were obtained pre-operatively and post-operatively at least 3 months following surgery. Results: Patients with unilateral nasal obstruction had slightly less severe symptoms preoperatively than patients with bilateral obstruction. Average preoperative NOSE scores for patients with unilateral obstruction was 64 (SD = 19) and 72 (SD = 18) for patients with bilateral obstruction ( P = .004). Postoperative NOSE scores following septorhinoplasty were significantly reduced for patients with both unilateral and bilateral nasal obstruction (postoperative NOSE scores unilateral: 17, SD = 16 ; bilateral: 23, SD = 21). There was no statistical significance in outcomes between patients with unilateral or bilateral nasal obstruction groups. Conclusions: Symptoms in patients with unilateral obstruction are similar but slightly less severe than patients with bilateral obstruction. Patients with unilateral and bilateral nasal obstruction experienced a similar degree of improvement in symptom following functional septorhinoplasty.

Background: Facial aberrant reinnervation syndrome is characterized by aberrant facial muscle reinnervation after facial nerve injury producing facial synkinesis, hypertonicity, and muscle spasm. Objective: To systematically review the surgical treatments for facial aberrant reinnervation syndrome and assess their effectiveness as measured by patient-reported outcomes, physician-graded outcomes, or computer-automated grading systems. Methods: We conducted a systematic review using PubMed, Embase, and Cochrane CENTRAL in accordance with PRISMA guidelines. Texts reporting outcomes of any surgical treatment for facial aberrant reinnervation syndrome from 2003 to 2023 were included. Results: After screening, 25 studies with 731 patients were included. Surgical procedures included selective neurectomy (SN), selective myectomy (SM), cross-facial nerve graft, masseter nerve transfer, and gracilis muscle transfer. All surgical techniques and combinations showed significant improvement in at least one clinical outcome measure from baseline ( p < 0.05), although one study found no significant improvement. Thirty different outcome measures were used, the most common being the FaCE and eFACE scales (seven studies each). Conclusions: All surgical procedures in this review yield improved clinical outcome measures for facial aberrant reinnervation syndrome, with SN and SM being the dominant surgical treatments. Standardized outcome assessment and more nuanced patient evaluation are necessary to determine the most effective surgical treatments.

Introduction The exercise pressor reflex (EPR) is suggested to be linked to activated group III/IV afferents. However, the predominating mechanical and/or metabolic stimuli by which the EPR is mediated remains unclear. It is suggested that high pedal frequency increases the recruitment of type II muscle fibers, which may result in augmented production of metabolic byproducts as a function of increased anaerobic processes. Therefore, this study tested the hypothesis that compared to low frequency, high pedal frequency will be associated with increased blood pressure during postexercise suprasystolic regional circulatory occlusion (SupraRCO). Further, although subsystolic RCO (SubRCO) during exercise is suggested to provoke venous distension associated with mechanically‐mediated activation of group III/IV afferents, we hypothesized the rise in blood pressure during postexercise SubRCO will be blunted vs postexercise SupraRCO irrespective of pedal frequency. Methods Healthy adults (N=13, 6 male, 7 female), age 36±19 yrs participated in 2 days of testing, each consisting of 3 sessions of recumbent cycle ergometry at pedal frequencies of 100 (HIGH) or 35 (LOW) rpm (randomized) at 20 W for 8 min. At cessation of exercise, bilateral upper thigh pressure tourniquets were inflated to SupraRCO (200 mm Hg), SubRCO (90 mm Hg), or no inflation (NR) for 2 min (randomized). Blood pressure via manual sphygmomanometry was measured at rest, end‐exercise, and 2 min postexercise. Mean arterial pressure (MAP) was calculated as (SBP + 2 * DBP)/3. Results For both rest and end‐exercise, MAP did not differ across repeated transients for either HIGH or LOW (both P>0.05). However, mean MAP across repeated transients was greater in HIGH vs LOW at end‐exercise (P<0.05). At 2 min postexercise in HIGH, compared to NR (89±8 mm Hg), MAP was higher in SupraRCO (105±18 mm Hg; P=0.02), but not in SubRCO (98±9 mm Hg; P=0.38); whereas MAP did not differ between SupraRCO and SubRCO (P=0.70). Similarly, at 2 min postexercise in LOW, MAP was increased in SupraRCO vs NR (96±10 vs 85±7 mm Hg, respectively; P=0.02); whereas there were no differences between SubRCO (88±7 mm Hg) with either NR (P=0.91) or SupraRCO (P=0.23). Lastly, compared to LOW, MAP was greater in HIGH at 2 min postexercise for both SupraRCO (P<0.01) and SubRCO (P<0.01), but not in NR (P=0.59). Conclusions In intact exercising humans it remains challenging to elucidate exact contributions of group III/IV afferents to the EPR. However, these data are consistent with the role of group III/IV afferents in contributing to the EPR in humans. New to this field, our observations suggest that at low fixed workloads, increased pedal frequency augments the postexercise pressor response to both SupraRCO and SubRCO in healthy adults. These data contribute to an improved understanding of specific stimuli associated with the EPR linked to group III/IV afferents in humans. Support or Funding Information NHLBI R25 HL115473; NHLBI RO1 HL126638; AHA 16POST30260021

Background Neurophysiological coupling between ventilation and locomotor muscle group III/IV muscle afferent fibers during exercise is an important relationship that favorably influences ventilation in young healthy adults. In contrast, we have shown that group III/IV locomotor muscle afferents provoke aberrant ventilation in aging heart failure patients, which is suggested to be a primary effect of heart failure. However, there remains a limited understanding of the effect of aging in the absence of cardiovascular disease on the group III/IV muscle afferent pathway. Subsystolic circulatory occlusion to elicit venous distension has been suggested to stimulate locomotor muscle afferent neurologic feedback. The purpose of this study was to compare ventilatory responses in young vs aging healthy adults during submaximal constant‐load exercise with intermittent bilateral subsystolic occlusion of locomotor muscles. Methods Healthy adults completed 2 visits (10 young [YNG] vs 9 OLD; age 22±1 vs 66±3 yrs, BSA 1.8±0.1 vs 1.9±0.1 m 2 ; % predicted peak VO 2 99±7 vs 115±7 %; peak workload 188±16 vs 144±9 W, respectively; age and workload P <0.05). Visit 1: peak exercise ergometry test. Visit 2: constant‐load cycle ergometry at 30% peak workload (YNG=56±5 vs OLD=43±3 W, P <0.05) with the first 3 min without cuffing (0 mm Hg) and intermittent subsystolic bilateral thigh cuff inflations to 20, 40, 60, 80, or 100 mm Hg for 2 min (randomized), with 2 min deflation between occlusions thereafter. Minute ventilation (V E ), respiratory rate (RR), tidal volume (V T ), oxygen uptake (VO 2 ) indexed to weight, carbon dioxide output (VCO 2 ), respiratory exchange ratio (RER), V E /VCO 2 , and end tidal partial pressure CO 2 (P ET CO 2 ) were measured continuously via breath by breath system. Results At rest, V E , RR, V T , or RER did not differ in YNG vs OLD ( P >0.05); whereas VO 2 (6.3±0.3 vs 3.9±0.2 mL/kg/min) and VCO 2 (0.3±0.0 vs 0.2± 0.0 L/min) were higher in YNG vs OLD (respectively, P <0.05). During all exercise occlusions, V E was higher in YNG vs OLD, with the largest difference at 100 mm Hg (36.7±1.7 vs 30.2±1.6 L/min, respectively, P <0.05). However, the % change from rest to 0 mm Hg or each cuff occlusion resulted in no differences in YNG vs OLD for V E ( P >0.05). In contrast, in YNG vs OLD, the largest % change from 0 mm Hg to the cuff occlusion resulting in between group differences included V E (3.3±3.0 vs 17.3±3.6 at 80 mm Hg, P <0.05), VCO 2 (2.3±2.3 vs 20.8±3.4 at 100 mm Hg, P <0.05) and V E /VCO 2 (7.0±2.6 vs 0.5±1.8 at 100 mm Hg, P <0.05). In addition, there was a trend for significant differences between YNG and OLD for V T (−1.2±4.4 vs 5.9±4.1 % at 80 mm Hg, P =0.15), VO 2 (−2.1±1.5 vs 3.3±1.8 %, at 100 mm Hg, P =0.09) and P ET CO 2 (−6.4±1.9 vs −2.3±1.4 % at 100 mm Hg, P =0.11). Conclusions These data suggest that aging is associated with altered ventilatory responses to venous occlusion of locomotor muscles during constant load submaximal exercise. These changes may be a result of an increased contribution of locomotor muscle afferents on ventilatory control with aging. Support or Funding Information none

Introduction Healthy aging in adults is associated with attenuated cardiac output (Q) for a given exercise workload compared to younger healthy adults. This is important because skeletal muscle perfusion pressure during exercise is dependent on coordinated adjustments between cardiac and vascular hemodynamics. Cardiac power (CP) quantifies the flow and peripheral pressure generating capacity of the heart, and may be the strongest measure of cardiac function during exercise. Group III/IV muscle afferents are suggested to favorably influence Q and arterial pressure during exercise in young healthy adults. However, the influence of group III/IV afferents on cardiac hemodynamic and arterial pressure coupling during exercise remains unclear across the aging spectrum. Venous distension via subsystolic circulatory occlusion of locomotor muscles is suggested to increase group III/IV afferent outflow. The aim of this study was to assess the influence of subsystolic circulatory occlusion of locomotor muscles on CP in young vs aging healthy adults. Methods Healthy adults completed 2 visits (10 young [YNG] vs 9 OLD; age 22±1 vs 66±3 yrs, BSA 1.8±0.1 vs 1.9±0.1 m 2 ; % predicted peak VO 2 99±7 vs 115±7 %; peak workload 188±16 vs 144±9 W, respectively; age and workload P <0.05). Visit 1: peak exercise test. Visit 2: constant load cycle ergometry at 30% peak workload (YNG=56±5 vs OLD=43±3 W, P <0.05) with the first 3 min without cuffing (0 mm Hg), but thereafter included intermittent subsystolic bilateral thigh cuff inflations to 20, 40, 60, 80, or 100 mm Hg for 2 min (randomized), with 2 min deflation between inflations. Non‐invasive Q and mean arterial (MAP) pressure were measured using continuous hemodynamic photoplethysmography. We calculated CP=Q*MAP. Q and CP were indexed to BSA. Results At rest, MAP did not differ in YNG vs OLD, but Q and CP were higher in YNG vs OLD (P<0.05), which persisted throughout each exercise cuff occlusion. In YNG, the greatest increase in CP from 0 mm Hg occurred at 100 mm Hg (754±48 vs 899±48 L/min/m 2 · mm Hg, P <0.05) due to increased MAP (19±4%, P <0.05) but not Q (1±2%, P >0.05). In OLD, Q, MAP, and CP did not differ between 0 mm Hg and any occlusion ( P >0.05). The % increase in Q from rest to 0, 20, 60, 80, and 100 mm Hg was higher in YNG vs OLD ( P <0.05). The % increase in MAP from rest to any occlusion did not differ in YNG vs OLD ( P >0.05). The % increase in CP from rest to occlusions of 60 (130±9 vs 98±11%), 80 (142±9 vs 108±20%), and 100 (158±11 vs 114±14%) were higher in YNG vs OLD (all P <0.05). Within YNG, the % increase in CP from rest to 100 mm Hg was higher than the % increase from rest to 0, 20, 40, or 60 mm Hg ( P <0.05), driven by increased MAP ( P <0.05). Within OLD, these differences for % increase in CP did not occur despite MAP that was similar to YNG ( P >0.05). Conclusions These data suggest that CP is attenuated in OLD vs YNG healthy adults during subsystolic circulatory occlusion of locomotor muscles during submaximal constant load exercise. The reduced CP generation in older adults is related to a blunted increase in Q mediated by attenuated influence of group III/IV muscle afferents on cardiac function during exercise.