Stephen McKenna

Pancreatic tumor motion on a single planning 4D-CT does not correlate with intrafraction tumor motion during treatment

Purpose:To quantify pancreas tumor motion on both a planning 4D-CT and during a single fraction treatment using the CyberKnife linear accelerator and Synchrony respiratory tracking software, and to investigate whether a single 4D-CT study is reliable for determining radiation treatment margins for patients with locally advanced pancreas cancer. Methods and Materials:Twenty patients underwent fiducial placement, biphasic pancreatic protocol CT scan and 4D-CT scan in the treatment position while free-breathing. Patients were then treated with a single 25 Gy fraction of stereotactic body radiotherapy. Predicted pancreas motion in the superior-inferior (SI), left-right (LR), and anterior-posterior (AP) directions was calculated from the maximum inspiration and maximum expiration 4D-CT scan. For CyberKnife treatments, mean respiratory cycle motion and maximum respiratory cycle motion was determined in the SI, LR, and AP directions. Results:The range of centroid movement based on 4D-CT in the SI, LR, and AP directions were 0.9 to 28.8 mm, 0.1 to 13.7 mm, and 0.2 to 7.6 mm, respectively. During CyberKnife treatment, in the SI direction, the mean motion of the centroid ranged from 0.5 to 12.7 mm. In the LR direction, the mean motion range was 0.4 to 9.4 mm. In the AP direction, the mean motion range was 0.6 to 5.5 mm. The maximum range of movement (mean) during CyberKnife treatment in the SI, LR, and AP directions were 4.5 to 48.8 mm (mean 20.8 mm), 1.5 to 41.3 mm (mean 11.3 mm), and 1.6 to 68.1 mm (mean 13.4 mm), respectively. Neither the maximum or mean motion correlated with the 4D-CT movement. Conclusions:There is substantial respiratory associated motion of pancreatic tumors. The 4D-CT planning scans cannot accurately predict the movement of pancreatic tumors during actual treatment on CyberKnife.

Functional electrical stimulation in spinal cord injury respiratory care.

The management of chronic respiratory insufficiency and/or long-term inability to breathe independently has traditionally been via positive-pressure ventilation through a mechanical ventilator. Although life-sustaining, it is associated with limitations of function, lack of independence, decreased quality of life, sleep disturbance, and increased risk for infections. In addition, its mechanical and electronic complexity requires full understanding of the possible malfunctions by patients and caregivers. Ventilator-associated pneumonia, tracheal injury, and equipment malfunction account for common complications of prolonged ventilation, and respiratory infections are the most common cause of death in spinal cord-injured patients. The development of functional electric stimulation (FES) as an alternative to mechanical ventilation has been motivated by a goal to improve the quality of life of affected individuals. In this article, we will review the physiology, types, characteristics, risks and benefits, surgical techniques, and complications of the 2 commercially available FES strategies - phrenic nerve pacing (PNP) and diaphragm motor point pacing (DMPP).

Combined SCI and TBI: recovery of forelimb function after unilateral cervical spinal cord injury (SCI) is retarded by contralateral traumatic brain injury (TBI), and ipsilateral TBI balances the effects of SCI on paw placement.

A significant proportion (estimates range from 16 to 74%) of patients with spinal cord injury (SCI) have concomitant traumatic brain injury (TBI), and the combination often produces difficulties in planning and implementing rehabilitation strategies and drug therapies. For example, many of the drugs used to treat SCI may interfere with cognitive rehabilitation, and conversely drugs that are used to control seizures in TBI patients may undermine locomotor recovery after SCI. The current paper presents an experimental animal model for combined SCI and TBI to help drive mechanistic studies of dual diagnosis. Rats received a unilateral SCI (75 kdyn) at C5 vertebral level, a unilateral TBI (2.0 mm depth, 4.0 m/s velocity impact on the forelimb sensori-motor cortex), or both SCI+TBI. TBI was placed either contralateral or ipsilateral to the SCI. Behavioral recovery was examined using paw placement in a cylinder, grooming, open field locomotion, and the IBB cereal eating test. Over 6weeks, in the paw placement test, SCI+contralateral TBI produced a profound deficit that failed to recover, but SCI+ipsilateral TBI increased the relative use of the paw on the SCI side. In the grooming test, SCI+contralateral TBI produced worse recovery than either lesion alone even though contralateral TBI alone produced no observable deficit. In the IBB forelimb test, SCI+contralateral TBI revealed a severe deficit that recovered in 3 weeks. For open field locomotion, SCI alone or in combination with TBI resulted in an initial deficit that recovered in 2 weeks. Thus, TBI and SCI affected forelimb function differently depending upon the test, reflecting different neural substrates underlying, for example, exploratory paw placement and stereotyped grooming. Concurrent SCI and TBI had significantly different effects on outcomes and recovery, depending upon laterality of the two lesions. Recovery of function after cervical SCI was retarded by the addition of a moderate TBI in the contralateral hemisphere in all tests, but forepaw placements were relatively increased by an ipsilateral TBI relative to SCI alone, perhaps due to the dual competing injuries influencing the use of both forelimbs. These findings emphasize the complexity of recovery from combined CNS injuries, and the possible role of plasticity and laterality in rehabilitation, and provide a start towards a useful preclinical model for evaluating effective therapies for combine SCI and TBI.

The impact of project closure on HIV incidence and mortality in a cohort of couples in Lusaka, Zambia.

Abstract The objective of this study was to assess the impact of temporary closure of an HIV research clinic on the health of study participants. Primary data were collected quarterly from couples enrolled in research studies at an established HIV study site. There were 632 participating couples enrolled when the project closed, 475 of whom returned when it re-opened six months later. HIV sero-incidence, mortality rates and risk-taking behaviours were compared before and during the closure. Perceived impact of the closure was measured in returning participants. Demographic data collected at the last pre-closure study visit were used to look at the differences between returning and non-returning study participants. Serologic data from those who returned were compared pre- and post-closure to examine changes in HIV incidence. Mortality rates were estimated from reported deaths, and were compared pre- and during project closure. Perceptions of the impact of the closure among returning participants were examined through an interviewer administered questionnaire. It was found that couples who returned were not demographically different from couples who did not return. Most participants reported no problems with finding alternate sources of condoms and the incidence of HIV did not change significantly during the closure. Eighty-four percent respondents reported that the closure had a negative impact on them, 87% of whom rated loss of medical care as the main impact. The mortality rate among HIV-positive participants doubled from 6.7/100 person years to 12.4/100 person years during the closure (p=0.01). Results indicate that couples voluntary counselling and testing (CVCT) established durable risk-reduction behaviours that persisted during project closure. ThIn ae loss of healthcare was perceived as the most negative impact on participants, reflected in increased mortality rates. Research projects should make transition plans and budget for mechanisms to reduce the negative impact on participants of project closures.

Venous Thromboembolism is Associated with Lack of Vitamin D Supplementation in Patients with Spinal Cord Injury and Low Vitamin D Levels

The role of vitamin D in the pathogenesis of venous thromboembolism (VTE) and prevalence of low vitamin D (LVitD) in spinal cord injury (SCI) has motivated vitamin D testing and supplementation. This is an exploratory study of data collected at a time before the routine clinical practice of vitamin D supplementation, allowing for evaluation of the natural history of vitamin D levels in patients with SCI.

Poster 22: Lack of Vitamin D Replacement in Low Vitamin D Individuals with Spinal Cord Injury is Associated with an Increased Risk of Venous Thrombotic Events During Acute Inpatient and Rehabilitation Hospitalization

Disclosures: Reza Ehsanian: I Have No Relevant Financial Relationships To Disclose Objective: To determine if lack of vitamin D replacement in persons with acute spinal cord injury (SCI) and low vitamin D levels is associated with an increased risk of venous thrombotic events (VTE). Design: Retrospective cohort study. Setting: Academic Medical Center. Participants: Two hundred eighty two persons admitted consecutively to acute inpatient rehabilitation at Santa Clara Valley Medical Center (SCVMC) with a diagnosis of SCI from December 2009 to January 2013. Interventions: Not applicable. Main Outcome Measures: We investigated the incidence of low vitamin D in our patient population and determined significant associations with regard to demographic variables, injury characteristics, low vitamin D and replacement status. Specific to our hypothesis, we looked at whether low vitamin D levels and status of vitamin D replacement correlated with VTE incidence. Results: The risk of VTE is clinically relevant but not statistically significant among SCI patients who have low vitamin D levels (43/228 1⁄4 18.8%) vs. normal vitamin D levels (6/54 1⁄4 11.1%) (Fisher’s exact test, p 1⁄4 .23). Individuals with low vitamin D who did not have vitamin D replaced had a VTE rate of 24 % (42/178) vs. 2% (1/50) amongst those with low vitamin D who did not receive replacement (p 1⁄4 .0002); Odds ratio 15.13; 95% CI 2.03-113. In contrast, there was no statistically significant difference of VTE rates (p1⁄4 1.0) in persons with normal vitamin D levels who were not taking vitamin D supplementation vs. those who were taking vitamin D supplementation (10.8% (5/46) vs. 12.5% (1/8). Conclusions: This study is the first to demonstrate an association between lack of vitamin D replacement and VTE occurrence in person with acute SCI and low vitamin D. Level of Evidence: Level III

Poster 12: Post-Traumatic Amnesia Duration, Glasgow Coma Scale, and Intracranial Pressure Correlation: Evidence for Acute Management of Traumatic Brain Injury

Disclosures: Nhung Quach, MD: I Have No Relevant Financial Relationships To Disclose Objective: Elucidate outcomes of individuals with extremely severe post-traumatic amnesia (EsPTA) after Traumatic Brain Injury (TBI) and determine correlating measures. Design: Retrospective cohort study. Setting: Academic Medical Center. Participants: Individuals (N 1⁄4 565) with moderate-severe TBI from the Northern California TBI Model System of Care admitted between 1988 and 2011; followed through 2016. Interventions: Not applicable. Main Outcome Measures: PTA duration, Intracranial Pressure (ICP), Glasgow Coma Scale (GCS), Disability Rating Scale, Functional Independence Measures, and productivity. Results: EsPTA (greater than 28 days) group had higher disability levels, lower functional independence status, and reduced productivity vs. nonEsPTA (less than or equal to 28 days) group. Individuals with GCS less than or equal 8werenearly four timesmore likely to developEsPTA (P<.0001), and were almost at three times higher risk to have intracranial hypertension (ICH) compared with GCS 9-15 group (P < .01). The risk of developing EsPTA increased more than four times for individuals with ICH (ICP greater thanorequal to20mmHg)versus ICPless than20mmHg(P<.0001). Conclusions: GCS correlates with ICH, a factor that may be treated to shorten PTA duration and improve clinical outcomes in persons with moderate to severe TBI. Level of Evidence: Level III

Poster 428: Successful Pregnancy and Delivery in a C1 ASIA A Spinal Cord Injured Woman: The Role of Coordinated Care Between PM&R and Obstetrics Services: A Case Report

literature, this is the first reported case in the U.S. rehabilitation literature of a spinal cord injury secondary to small cell carcinoma. Conclusions: Although spinal cord injury secondary to neoplasia is well known, epidural and paraspinal small cell carcinoma is an unreported cause of spinal cord injury. Tumor growth of this rapidity is also unreported. Although the type of tumor is rare and highly aggressive, rehabilitation played an important role in maintaining the patient’s independence, function, and quality of life.

Re: A Descriptive Study of Vitamin D Levels in Persons With Acute Spinal Cord Injury

5 e: A Descriptive Study of itamin D Levels in Persons With cute Spinal Cord Injury We read with interest the article titled “A Descriptive tudy on Vitamin D Levels in Individuals With Spinal Cord njury in an Acute Inpatient Rehabilitation Setting” by Nemuaitis et al in the March 2010 issue of PM&R [1]. The study ighlights the frequency (93%) of vitamin D inadequacy in he acute spinal cord injury (SCI) population, including evere ( 10 ng/mL of VitD-25(OH)) deficiency in 21% of the opulation. During the past several months, we also have een checking the vitamin D levels of all persons with acute CI who are admitted to our rehabilitation center, and e found very similar rates of inadequacy and severe defiiency as those established by Nemunaitis et al. However, here seemed to be little discussion in the article on the otential impact of vitamin D replacement in such patients eyond the possible delay in progression to osteopenia or steoporosis. Data exist to support other clinical effects of low vitamin D hat may be critical when considering acute SCI rehabilitaion. For instance, a strong correlation has been shown etween hypovitaminosis D and musculoskeletal pain in a on-SCI population [2]. In addition, vitamin D replacement ay play a role in optimizing muscle strength in patients who re participating in acute SCI rehabilitation. Mice that lack itamin D receptor in muscle have been found to have maller and more immature muscle fibers, despite optimizaion of systemic calcium [3]. Improved muscle function has een demonstrated after vitamin D supplementation in older dults [4]. Here, it is noteworthy that the median age at time f SCI continues to increase, and there has been a trend oward a greater frequency of injuries in persons older than 0 years of age. Furthermore, vitamin D deficiency has been ssociated with depressed mood in adults even after adjustng for race, age, gender, and season [5]. Given the impact of ain, muscle function, and mood on the success of a rehabiltation program, it seems important to consider these among ther potential benefits of vitamin D replacement. The medical community appears to be coming to consenus on the appropriate treatment of vitamin D deficiency.