Solinsky, Ryan

ABSTRACT Introduction/Aims Patients with cervical spinal cord injury (SCI) prioritize recovery of upper extremity function. Upper extremity reconstruction can restore function in carefully selected individuals. Infralesional cord damage, observed below the neurological level of injury (NLI), may affect postoperative outcomes. We characterized the extent of infralesional lower motor neuron (LMN) injury in patients with traumatic cervical SCI. Methods Each patient underwent electromyography (EMG) of potential donor and recipient muscles based on preoperative clinical evaluation and specific candidacy for nerve and/or tendon transfers. The presence of infralesional pathologic insertional activity (IA), reduced motor unit potential (MUP) recruitment and/or neurogenic MUPs was assessed. The caudal‐most segment with infralesional LMN injury was determined. Inclusion criteria were patients with (1) traumatic cervical SCI; (2) injury ≥ 3 months duration; (3) preoperative planning EMG for nerve and/or tendon transfers. Results Forty‐eight upper extremity EMGs in 25 patients (68% male; mean age 39.5 years at injury) with traumatic cervical SCI were included. The NLI was at C7 or above in each patient, and 64% of SCIs were motor complete. Infralesional EMG abnormalities (median time from injury to EMG 466 days) were found a median of 3.0 (IQR 3.0–4.0) segments below the NLI. Three patients with an NLI as rostral as C1–C2 exhibited LMN injury seven segments below the NLI. Discussion In persons with traumatic cervical SCI, evidence of LMN injury may be observed several segments below the NLI. Defining the true extent of LMN involvement directly informs timing and selection of reconstructive procedures to maximize functional recovery.

Epidural and dorsal root stimulation have emerged as promising therapies to restore function after spinal cord injury. However, how each modality uniquely or jointly engages spinal circuits remains unclear. To address this, we analyzed leg electromyography (EMG) responses to epidural stimulation (ES) and dorsal root ganglia stimulation (DRGS) delivered to the lumbosacral cord in the same individuals.

Abstract Background Individuals with spinal cord injury (SCI) are known to have high rates of cardiovascular disease that have traditionally been attributed to inability to engage in adequate intensity exercise. However, individuals with SCI also commonly experience instability in blood pressure. Blood pressure fluctuations are known to contribute to cardiovascular disease in other conditions, though this relationship in SCI is unknown. Objective To evaluate correlations between a clinical history of symptomatic blood pressure instability and objective evidence of vascular endothelial dysfunction in individuals with SCI. Design Case control. Setting Academic medical center. Participants Twenty‐four individuals with SCI, 14 uninjured controls of matched age, gender, and body mass index. Interventions Not applicable. Main Outcome Measures Symptomatic blood pressure instability was measured by the Autonomic Dysfunction Following SCI (ADFSCI) survey. Vascular endothelial dysfunction was quantified by ultrasound recordings of brachial flow mediated dilation following 5 minutes of forearm arterial occlusion. Results Total ADFSCI scores were significantly higher in individuals with SCI compared to controls (41.0 vs. 9.0, p = .002). Both percentage of brachial flow mediated dilation and consensus recommended allometrically scaled percentage of flow mediated dilation were significantly less in individuals with SCI ( p < .001 for both), demonstrating greater vascular dysfunction. More symptoms of blood pressure instability on the ADFSCI survey were correlated with more objective evidence of vascular dysfunction ( R 2 = 0.24, p = .03) for individuals with SCI. This relationship was not seen in uninjured controls. Conclusions In individuals with SCI, more severe symptoms of blood pressure instability are significantly correlated with more severe vascular endothelial dysfunction, making management of orthostatic hypotension and autonomic dysreflexia both high potential, modifiable risk factors for individuals with SCI to mitigate cardiovascular disease.

Abstract Background After high‐level spinal cord injury (SCI), motor recovery of wrist extensors has significant functional consequences as it can facilitate grasp through tenodesis. A small seminal study from 1993 established widely used prognostic rules for wrist extensor recovery, though these have not been replicated with larger, real‐world samples since inception. Objective To determine the prognostic value of initial C5 sharp‐dull discrimination, C5 motor strength, and C6 motor strength on predicting 1‐year ipsilateral wrist extensor motor recovery for patients with SCI with neurological level of C4 or C5. Design Retrospective cohort replication study. Setting SCI Model Systems. Participants 35,675 total individuals with acute traumatic SCI with 219 cases of initial wrist extensor weakness (0/5–2/5) meeting inclusion criteria. Intervention Not applicable. Main outcome measure Recovery of wrist extensor strength to ≥3/5 at 1 year. Results The positive predictive and negative predictive values were 57% (95% CI, 47.4%–66.1%) and 66% (56.0%–75.1%) if initial C5 sharp‐dull discrimination was present, 61% (52.7%–69.3%) and 82% (71.4%–89.7%) if initial C5 myotome strength was at least antigravity, and 74% (63.7%–82.5%) and 74% (65.5%–81.4%) if initial C6 myotome strength was at least a 1/5 or 2/5. Synthesizing these three rules, an updated branched nomogram for functional wrist extensor recovery prediction was created. Conclusions In isolation, none of the previously established wrist extensor motor recovery predictive rules had as high of a prognostic value when using a larger dataset. As such, singular reliance on these prediction rules to identify who will gain 1‐year antigravity wrist extension should be approached with decreased certainty. The best positive and negative predictors were trace C6 strength and absent C5 strength, respectively. An updated nomogram provides more nuanced prognostic information to guide clinical care following acute SCI.

AbstractBackgroundIndividuals with spinal cord injury (SCI) commonly have autonomic dysreflexia (AD) with increased sympathetic activity. After SCI, individuals have decreased baroreflex sensitivity and increased vascular responsiveness.ObjectiveTo evaluate the relationship between baroreflex and blood vessel sensitivity with AD symptoms.DesignCase control.SettingTertiary academic center.Patients14 individuals with SCI, 17 matched uninjured controls.InterventionsAll participants quantified AD symptoms using the Autonomic Dysfunction Following SCI (ADFSCI)‐AD survey. Participants received three intravenous phenylephrine boluses, reproducibly increasing systolic blood pressure (SBP) 15–40 mmHg. Continuous heart rate (R‐R interval, ECG), beat‐to‐beat blood pressures (Finapres), and popliteal artery flow velocity were recorded. Vascular responsiveness (α1 adrenoreceptor sensitivity) and heart rate responsiveness to increased SBP (baroreflex sensitivity) were calculated.Main Outcome MeasuresBaroreflex sensitivity after increased SBP; Vascular responsiveness through quantified mean arterial pressure (MAP) 2‐minute area under the curve and change in vascular resistance.ResultsSCI and control cohorts were well matched with mean age 31.9 and 29.6 years (p = .41); 21.4% and 17.6% female, respectively. Baseline MAP (p = .83) and R‐R interval (p = .39) were similar. ADFSCI‐AD scores were higher following SCI (27.9 ± 22.9 vs. 4.2 ± 2.9 in controls, p = .002). To quantify SBP response, MAP area under the curve was normalized to dose/body weight. Individuals with SCI had significantly larger responses (0.26 ± 0.19 mmHg*s/kg*μg) than controls (0.06 ± 0.06 mmHg*s/kg*μg, p = .002). Similarly, leg vascular resistance increased after SCI (24% vs. 6% to a normalized dose, p = .007). Baroreflex sensitivity was significantly lower after SCI (15.0 ± 8.3 vs. 23.7 ± 9.3 ms/mmHg, p = .01). ADFSCI‐AD subscore had no meaningful correlation with vascular responsiveness (R2 = 0.008) or baroreflex sensitivity (R2 = 0.092) after SCI.ConclusionsAlthough this confirms smaller previous studies suggesting increased α1 adrenoreceptor sensitivity and lower baroreflex sensitivity in individuals with SCI, contrary to our hypothesis these differences lacked correlation to increased symptoms of AD. Further research into physiologic mechanisms is needed to explain why some individuals with SCI develop symptoms.

Spinal cord stimulation for motor recovery after spinal cord injury is a popular research intervention, though off-target effects are a concern. Using continual blood pressure and heart rate recordings during passive spinal cord stimulation parameter testing, we identified frequent episodes of autonomic dysreflexia that were rarely associated with symptoms. This presents a previously unrecognized risk of spinal cord stimulation and appropriate vigilance in targeted monitoring is urged to maintain participant safety.

Abstract Study Design: Secondary outcome measures analysis of a randomized, controlled study. Objectives: To assess the effects of hybrid-functional electrical stimulation (FES) rowing, arms only (AO) rowing and waitlist (WL) controls on pain, pain interference, and depression in individuals with spinal cord injury (SCI). Setting: Outpatient rehabilitation networks Methods: 44 participants were randomly assigned to FES (n = 19), AO (n= 12) or WL (n=13). The FES group completed 6 months of rowing scheduled 3 times per week. Individuals in the AO and WL groups were allowed to cross over to FES rowing after 6 months and were included in subsequent analyses of the effects of FES rowing. Rowing distance and intensity was logged, and maximal oxygen consumption (VO2max) measures were obtained before and after the intervention. Changes in the Patient-Reported Outcomes Measurement Information System (PROMIS-56) derived pain interference, pain, and depression scores were analyzed. Results: FES-rowing led to modest improvements in depression, AO led to modest improvements in pain intensity, and WL did not improve pain nor depression. After incorporating individuals who crossed over to FES rowing, we observed modest but significant improvement in depression scores but not in pain. Among the participants who benefited from the FES intervention, the reduction in depression was correlated to the average weekly rowing distance (r2=0.79 p=0.0001). Conclusions: 6 months of FES rowing spent in a supportive environment can help persons with spinal cord injuries alleviate moderate depression in a dose-dependent manner.

Abstract Study design: Cross-sectional study Objectives: Determine how well common clinical assessments of level and completeness of injury are correlated with symptoms of autonomic blood pressure instability and secondary medical complications after spinal cord injury (SCI). Setting: Academic medical center, United States Methods: Eighty-two individuals with (n=48) and without (n=34) SCI had symptoms of autonomic blood pressure instability quantified with the Autonomic Dysfunction Following SCI (ADFSCI) survey. Health histories quantified the secondary medical complications through number of urinary tract infections and hospitalizations in the past year, time to complete bowel program, and lifetime pressure injuries. Regression models were completed to identify strengths of associated correlations. Results: ADFSCI scores were significantly higher in individuals with SCI than controls. Neurological level of injury and ASIA impairment scale were both minimally correlated to symptoms of autonomic blood pressure instability, accounting for only 11.5% of variability in regression models. Secondary medical complications had similar, minimal correlations to level and motor/sensory completeness of SCI (R2=0.07 and R2=0.03 respectively). Contrasting this, symptoms of blood pressure instability on ADFSCI far outperformed the common clinical motor/sensory bedside exam, with moderately strong correlations to the ranked number of secondary medical complications after SCI (R2=0.31). Conclusion: Neurological level of injury and motor/sensory completeness provided limited insights into which individuals with SCI would have blood pressure instability or secondary medical complications. Interestingly, symptoms of blood pressure instability outperform the clinical motor/sensory bedside exam, with higher correlations to autonomically-mediated secondary medical complications after SCI.