Olivia Hogue

Subsequent Pulse Generator Replacement Surgery Does Not Increase the Infection Rate in Patients With Deep Brain Stimulator Systems: A Review of 1537 Unique Implants at a Single Center

Deep brain stimulation (DBS) is a well‐recognized treatment for patients with movement disorders and other neurological diseases. The implantable pulse generator (IPG) is a fundamental component of the DBS system. Although IPG implantation and replacement surgeries are comparatively minor procedures relative to the brain lead insertion, patients often require multiple IPG replacements during their lifetime with each operation carrying a small but possibly cumulative risk of complications. To better educate our patients and improve surgical outcomes, we reviewed our series of patients at our institution.

Rate of Complications Following Spinal Cord Stimulation Paddle Electrode Removal: SPINAL CORD STIMULATION PADDLE REMOVAL

Spinal cord stimulation (SCS) is a safe, reversible surgical treatment for complex regional pain syndrome and failed back surgery syndrome refractory to conventional medical management. Paddle electrodes are routinely used for the permanent implant because of the reduced risk of migration, lower energy requirements, and expanded coverage options. The risks associated with paddle lead removal are not well defined in the literature.

Predicting early cognitive decline in newly-diagnosed Parkinson's patients: A practical model

OBJECTIVE To create a multivariable model to predict early cognitive decline among de novo patients with Parkinsons disease, using brief, inexpensive assessments that are easily incorporated into clinical flow. METHODS Data for 351 drug-naïve patients diagnosed with idiopathic Parkinsons disease were obtained from the Parkinsons Progression Markers Initiative. Baseline demographic, disease history, motor, and non-motor features were considered as candidate predictors. Best subsets selection was used to determine the multivariable baseline symptom profile that most accurately predicted individual cognitive decline within three years. RESULTS Eleven per cent of the sample experienced cognitive decline. The final logistic regression model predicting decline included five baseline variables: verbal memory retention, right-sided bradykinesia, years of education, subjective report of cognitive impairment, and REM behavior disorder. Model discrimination was good (optimism-adjusted concordance index = .749). The associated nomogram provides a tool to determine individual patient risk of meaningful cognitive change in the early stages of the disease. CONCLUSIONS Through the consideration of easily-implemented or routinely-gathered assessments, we have identified a multidimensional baseline profile and created a convenient, inexpensive tool to predict cognitive decline in the earliest stages of Parkinsons disease. The use of this tool would generate prediction at the individual level, allowing clinicians to tailor medical management for each patient and identify at-risk patients for clinical trials aimed at disease modifying therapies.

Long-term Outcomes Using Intrathecal Drug Delivery Systems in Complex Regional Pain Syndrome

OBJECTIVE Providing durable long-term pain control for patients with complex regional pain syndrome (CRPS) is challenging. A multidisciplinary approach focused on physical therapy is frequently prescribed, with opioids and invasive procedures reserved for those challenged by functional progression. In this study, we examined the long-term efficacy of intrathecal drug delivery systems (IDDS) in patients with CRPS at our institution. METHODS Patients with CRPS implanted with an IDDS between 2000 and 2013 who had four or more years of continuous follow-up were included in the analysis. The outcome variables of interest were pain intensity and oral opioid intake. The primary predictor of interest was dose of intrathecal opioids, with ziconotide, bupivacaine, and clonidine characterized as binary secondary predictors. RESULTS Of the 1,653 IDDS identified, 62 were implanted primarily for CRPS-related pain. Of these, 26 had four or more years of complete follow-up data. Pain scores did not significantly decrease over time, and we observed no correlation between pain intensity and use of any intrathecal medication. Although oral opioid intake decreased over time, intrathecal opioid dose did not affect oral opioid consumption. Ziconotide was associated with a hastening of the decrease in oral opioid intake, whereas the presence of bupivacaine paradoxically increased oral opioid intake. CONCLUSIONS Our study demonstrates that intrathecal opioid dose was not associated with long-term decreases in oral opioid intake. Additionally, ziconotide was associated with a decrease in oral opioid intake over the four-year follow-up, and bupivacaine was associated with an increase in oral opioid intake. Our study examines the long-term effectiveness of intrathecal medications in managing pain in patients with complex regional pain syndrome. We present a detailed follow-up over four years for 26 patients, tracking oral opiate intake, pain scores, and intrathecal pump settings. Our findings suggest that intrathecal opiates may not be effective in reducing oral opiate intake, ziconotide may hasten a decrease in intake, and bupivacaine may lead to an increase in intake.

Quality of Life Improvement Following Deep Brain Parkinson's Disease: Development of a Prognostic Model

BACKGROUND There is a growing attention to determine the factors that predict quality of life (QoL) improvement after deep brain stimulation (DBS) for Parkinsons disease. Prior literature has largely focused on examining predictors one at a time, sometimes controlling for covariates. OBJECTIVE To develop a model that could be used as a nomogram to predict improvement in QoL following DBS surgery in patients with Parkinsons disease. METHODS All patients with complete pre- and postoperative movement disorder and neuropsychological testing who underwent DBS at a single institution between 2007-2012 were analyzed. The Parkinsons Disease Questionnaire-39 (PDQ-39) was used to measure QoL. Potential predictive factors, including patient demographics, clinical presentation characteristics, radiographic imaging, and motor and psychological testing were analyzed for impact on QoL. RESULTS Sixty-seven patients were identified, 36 (53.73%) of whom had meaningfully improved QoL following surgery. Five baseline variables showed significant relationships with the outcome: years since symptom onset, percent change in on/off motor evaluation, levodopa equivalent daily dose, bilateral vs unilateral DBS implantation, and PDQ-39 score. The final model includes PDQ-39, percent change in UPRS-III, and years since symptom onset and is able to predict improvement in QoL with 81% accuracy. CONCLUSION Our model accurately predicted whether QoL would improve in patients undergoing subthalamic nucleus DBS 81% of the time. Our data may serve as the foundation to further refine a clinically relevant prognostic tool that would assist the decision-making process for clinicians and DBS multidisciplinary teams assessing patient candidacy for surgery.

Predicting Clinical Outcomes Following Surgical Correction of Adult Spinal Deformity

BACKGROUND Deformity reconstruction surgery has been shown to improve quality of life (QOL) in cases of adult spinal deformity (ASD) but is associated with significant morbidity. OBJECTIVE To create a preoperative predictive nomogram to help risk-stratify patients and determine which would likely benefit from corrective surgery for ASD as measured by patient-reported health-related quality of life (HRQoL). METHODS All patients aged 25-yr and older with radiographic evidence of ASD and QOL data that underwent thoracolumbar fusion between 2008 and 2014 were identified. Demographic and clinical parameters were obtained. The EuroQol 5 dimensions questionnaire (EQ-5D) was used to measure HRQoL preoperatively and at 12-mo postoperative follow-up. Logistic regression of preoperative variables was used to create the prognostic nomogram. RESULTS Our sample included data from 191 patients. Fifty-one percent of patients experienced clinically relevant postoperative improvement in HRQoL. Seven variables were included in the final model: preoperative EQ-5D score, sex, preoperative diagnosis (degenerative, idiopathic, or iatrogenic), previous spinal surgical history, obesity, and a sex-by-obesity interaction term. Preoperative EQ-5D score independently predicted the outcome. Sex interacted with obesity: obese men were at disproportionately higher odds of improving than nonobese men, but obesity did not affect odds of the outcome among women. Model discrimination was good, with an optimism-adjusted c-statistic of 0.739. CONCLUSION The predictive nomogram that we developed using these data can improve preoperative risk counseling and patient selection for deformity correction surgery.

Histopathologic subtype of hippocampal sclerosis and episodic memory performance before and after temporal lobectomy for epilepsy

The International League Against Epilepsy (ILAE) proposed a classification system for hippocampal sclerosis (HS) based on location and extent of hippocampal neuron loss. The literature debates the usefulness of this classification system when studying memory in people with temporal lobe epilepsy (TLE) and determining memory outcome after temporal lobe resection (TLR). This study further explores the relationship between HS ILAE subtypes and episodic memory performance in patients with TLE and examines memory outcomes after TLR.

Validation of computerized episodic memory measures in a diverse clinical sample referred for neuropsychological assessment

Abstract Objective: To examine the convergent and discriminant validity of two brief computerized episodic memory measures in a large, diverse clinical sample of adults undergoing neuropsychological assessment. Method: Computerized measures of word and face memory were administered to 233 adults (age 30 and over) who also completed comprehensive neuropsychological testing. Results: Moderate correlations were observed between the computerized memory tests and a wide range of traditional neuropsychological measures of episodic memory (e.g. word-list learning, story recall, face recognition, design recall). Select measures of visuomotor processing speed and language were also related to performance on the computerized tasks. In contrast, the computerized memory tests showed weak correlations with tests in other cognitive domains (i.e. visuospatial skills, attention/working memory, executive function, motor dexterity, academic skills) and self-report screening measures of mood and anxiety. Similar to traditional measures of episodic memory, the computerized memory measures were sensitive to effects of age and gender. Conclusions: Computerized measures of word and face memory showed good convergent and discriminant validity in this diverse clinical sample supporting the construct validity of these measures. This indicates that it may be feasible to measure memory function in clinical settings using brief, well-designed computerized memory measures.

Lateral cerebellar nucleus stimulation promotes motor recovery and suppresses neuroinflammation in a fluid percussion injury rodent model

BACKGROUND Many traumatic brain injury (TBI) survivors live with persistent disability from chronic motor deficits despite contemporary rehabilitation services, underscoring the need for novel treatment. OBJECTIVE/HYPOTHESIS We have previously shown that deep brain stimulation (DBS) of the lateral cerebellar nucleus (LCN) can enhance post-stroke motor recovery and increase the expression of markers of long-term potentiation in perilesional cerebral cortex. We hypothesize that a similar beneficial effect will be for motor deficits induced by unilateral fluid percussion injury (FPI) in rodents through long-term potentiation- and anti-inflammatory based mechanisms. METHODS Male Long Evans rats with a DBS macroelectrode in the LCN underwent FPI over contralateral primary motor cortex. After 4 weeks of spontaneous recovery, DBS treatment was applied for 4 weeks, with the pasta matrix, cylinder, and horizontal ladder tests used to evaluate motor performance. All animals were euthanized and tissue harvested for further analysis by histology, immunohistochemistry, RNA microarray assay and Western Blot. RESULTS LCN DBS-treated animals experienced a significantly greater rate of motor recovery than untreated surgical controls, with treated animals showing enhanced expression of RNA and protein for excitability related genes, suppressed expression of pro-inflammatory genes, suppressed microglial and astrocytic activation, but proliferation of c-fos positive cells. Finally, our data suggest a possible role for anti-apoptotic effects with LCN DBS. CONCLUSION LCN DBS enhanced the motor recovery following TBI, possibly by elevating the neuronal excitability at the perilesional area and mediating anti-apoptotic and anti-inflammatory effects.