Clinical Professor, Neurology & Neurological Sciences
Neurophysiology course director, Stanford University (2002 - Present)
Chairman of Lumbosacral Radiculopathy Committee, AAEM (2002 - 2005)
Director of ALS Clinic, Stanford University (2004 - Present)
Honors & Awards
Who's Who in Medical Sciences Education, WWMSE (2004)
Medical Education: Georgetown University School of Medicine (1996) DC
Fellowship: Massachusetts General Neuromuscular Medicine Fellowship (2001) MA
Residency: Stanford University Neurology Residency (2000) CA
Internship: Kaiser Permanente Oakland Internal Medicine Residency (1997) CA
Board Certification: American Board of Psychiatry and Neurology, Neurology (2002)
ScB, Brown University (1990)
MS, Columbia University (1992)
MD, Georgetown University (1996)
Current Research and Scholarly Interests
Clinical research focused on peripheral nerve and muscle disorders. Also involved with prevention of cerebrovascular disesase in the intraoperative setting. Ongoing clincial studies include treatments for Amyotrophic Lateral Sclerosis (ALS), Inflammatory Demyelinating Neuropathy and HIV neuropathic pain.
Caffeine/Propranolol Intervention for Acute Migraine
This is a research study to assess the safety of caffeine/propranolol at different dose levels. We want to find out what effects, good and/or bad, it has on patients and their migraines.
Stanford is currently not accepting patients for this trial. For more information, please contact S. Charles Cho, (650) 723 - 5184.
Independent Studies (5)
- Directed Reading in Neurology and Neurological Science
NENS 299 (Aut, Win, Spr, Sum)
- Early Clinical Experience in Neurology and Neurological Sciences
NENS 280 (Aut, Win, Spr, Sum)
- Graduate Research
NENS 399 (Aut, Win, Spr, Sum)
- Medical Scholars Research
NENS 370 (Aut, Win, Spr, Sum)
- Undergraduate Research
NENS 199 (Aut, Win, Spr, Sum)
- Directed Reading in Neurology and Neurological Science
Graduate and Fellowship Programs
EMG, MEP, and SSEP in the Intraoperative Neurophysiologic Monitoring of Lumbar Surgeries
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000475965903154
Driving Ability Correlated with Severity of Polyneuropathy
LIPPINCOTT WILLIAMS & WILKINS. 2019
View details for Web of Science ID 000475965903017
Novel Intraoperative Neurophysiologic Monitoring (IONM) Techniques during Thoracic Endovascular Aortic Repair (TEVAR) to Rapidly Assess Central Spinal Cord versus Peripheral Limb Ischemia
LIPPINCOTT WILLIAMS & WILKINS. 2016
View details for Web of Science ID 000411328602313
Hippocampal-neocortical functional reorganization contributes to children's cognitive development
2014; Sep; 17 (9): 1263-9
The importance of the hippocampal system for rapid learning and memory is well recognized, but its contributions to a cardinal feature of children's cognitive development-the transition from procedure-based to memory-based problem-solving strategies-are unknown. Here we show that the hippocampal system is pivotal to this strategic transition. Longitudinal functional magnetic resonance imaging (fMRI) in 7-9-year-old children revealed that the transition from use of counting to memory-based retrieval parallels increased hippocampal and decreased prefrontal-parietal engagement during arithmetic problem solving. Longitudinal improvements in retrieval-strategy use were predicted by increased hippocampal-neocortical functional connectivity. Beyond childhood, retrieval-strategy use continued to improve through adolescence into adulthood and was associated with decreased activation but more stable interproblem representations in the hippocampus. Our findings provide insights into the dynamic role of the hippocampus in the maturation of memory-based problem solving and establish a critical link between hippocampal-neocortical reorganization and children's cognitive development.
View details for DOI 10.1038/nn.3788
Transplantation of human cord blood mononuclear cells and umbilical cord-derived mesenchymal stem cells in autism
JOURNAL OF TRANSLATIONAL MEDICINE
Autism is a pervasive neurodevelopmental disorder. At present there are no defined mechanisms of pathogenesis and therapy is mostly limited to behavioral interventions. Stem cell transplantation may offer a unique treatment strategy for autism due to immune and neural dysregulation observed in this disease. This non-randomized, open-label, single center phase I/II trial investigated the safety and efficacy of combined transplantation of human cord blood mononuclear cells (CBMNCs) and umbilical cord-derived mesenchymal stem cells (UCMSCs) in treating children with autism.37 subjects diagnosed with autism were enrolled into this study and divided into three groups: CBMNC group (14 subjects, received CBMNC transplantation and rehabilitation therapy), Combination group (9 subjects, received both CBMNC and UCMSC transplantation and rehabilitation therapy), and Control group (14 subjects, received only rehabilitation therapy). Transplantations included four stem cell infusions through intravenous and intrathecal injections once a week. Treatment safety was evaluated with laboratory examinations and clinical assessment of adverse effects. The Childhood Autism Rating Scale (CARS), Clinical Global Impression (CGI) scale and Aberrant Behavior Checklist (ABC) were adopted to assess the therapeutic efficacy at baseline (pre-treatment) and following treatment.There were no significant safety issues related to the treatment and no observed severe adverse effects. Statistically significant differences were shown on CARS, ABC scores and CGI evaluation in the two treatment groups compared to the control at 24 weeks post-treatment (p < 0.05).Transplantation of CBMNCs demonstrated efficacy compared to the control group; however, the combination of CBMNCs and UCMSCs showed larger therapeutic effects than the CBMNC transplantation alone. There were no safety issues noted during infusion and the whole monitoring period.ClinicalTrials.gov: NCT01343511, Title "Safety and Efficacy of Stem Cell Therapy in Patients with Autism".
View details for DOI 10.1186/1479-5876-11-196
View details for Web of Science ID 000323758600001
View details for PubMedCentralID PMC3765833
Effects of noninvasive ventilation on sleep outcomes in amyotrophic lateral sclerosis.
Journal of clinical sleep medicine
2013; 9 (4): 345-351
The objective was to study the effects on noninvasive ventilation on sleep outcomes in patient with ALS, specifically oxygenation and overall sleep quality.Patients with ALS who met criteria for initiation of NIV were studied with a series of 2 home PSG studies, one without NIV and a follow-up study while using NIV. Primary outcome was a change in the maximum overnight oxygen saturation; secondary outcomes included change in mean overnight oxygen saturation, apnea and hypopnea indexes, sleep latency, sleep efficiency, sleep arousals, and sleep architecture.A total of 94 patients with ALS were screened for eligibility; 15 were enrolled; and 12 completed study procedures. Maximum overnight oxygen saturation improved by 7.0% (p = 0.01) and by 6.7% during REM sleep (p = 0.02) with NIV. Time spent below 90% oxygen saturation was also significant-ly better with NIV (30% vs 19%, p < 0.01), and there was trend for improvement in mean overnight saturation (1.5%, p = 0.06). Apnea index (3.7 to 0.7), hypopnea index (6.2 to 5.7), and apnea hypopnea index (9.8 to 6.3) did not significantly improve after introducing NIV. NIV had no effect on sleep efficiency (mean change 10%), arousal index (7 to 12), or sleep stage distribution (Friedman chi-squared = 0.40).NIV improved oxygenation but showed no significant effects on sleep efficiency, sleep arousals, restful sleep, or sleep architecture. The net impact of these changes for patients deserves further study in a larger group of ALS patients.
View details for DOI 10.5664/jcsm.2586
View details for PubMedID 23585750
View details for PubMedCentralID PMC3601313
Detection of inferolateral trunk syndrome by neuromonitoring during catheter angiography with provocative testing.
Journal of neurointerventional surgery
2013; 5 (2)
It is not uncommon that endovascular balloon test occlusion (BTO) is performed to assess collateral blood flow and risk of injury of permanent occlusion of the internal carotid artery (ICA). This case is the first reported of detection and reversal of the inferolateral trunk (ILT) syndrome in an awake patient during provocative BTO; prompt recognition of the syndrome effectively prevented permanent neurologic deficits.The case of a 42-year-old woman is reported who had a left sphenoid wing meningioma with extension into the cavernous sinus and who underwent awake catheter angiography with provocative BTO of the ICA. Serial examinations by intraoperative monitoring neurologists and neurointerventionalists detected acute progressive left retro-orbital pressure followed by sudden inability to adduct the left eye, or a left medial rectus palsy, indicative of the ILT syndrome which led to immediate balloon deflation and resolution of the deficits. The hypothesis was that hypoperfusion of the ILT, an arterial branch of the ICA which provides blood supply to several cranial nerves (CN) III, CN V1 and CN V2, caused her acute symptoms.Although cerebral ischemia is a well known complication of endovascular procedures, CN ischemia is a rare potential risk. Knowledge of cerebrovascular anatomy and serial examinations prevented neurologic deficits; this case underscores the added utility of examinations by intraoperative monitoring neurologists and interdisciplinary collaboration.
View details for DOI 10.1136/neurintsurg-2011-010236
View details for PubMedID 22345146
Waveform Analysis of Transcranial Motor Evoked Potentials (TcMEPs) To Predict Impending Motor Deficits in Spinal Surgeries
LIPPINCOTT WILLIAMS & WILKINS. 2013
View details for Web of Science ID 000332068601298
Human umbilical cord blood-derived mononuclear cell transplantation: case series of 30 subjects with Hereditary Ataxia
JOURNAL OF TRANSLATIONAL MEDICINE
The differential diagnosis for hereditary ataxia encompasses a variety of diseases characterized by both autosomal dominant and recessive inheritance. There are no curative treatments available for these neurodegenerative conditions. This open label treatment study used human umbilical cord blood-derived mononuclear cells (CBMC) combined with rehabilitation training as potential disease modulators.30 patients suffering from hereditary ataxia were treated with CBMCs administered systemically by intravenous infusion and intrathecally by either cervical or lumbar puncture. Primary endpoint measures were the Berg Balance Scale (BBS), serum markers of immunoglobulin and T-cell subsets, measured at baseline and pre-determined times post-treatment.A reduction of pathological symptoms and signs was shown following treatment. The BBS scores, IgG, IgA, total T cells and CD3+CD4 T cells all improved significantly compared to pre-treatment values (P < 0.01~0.001). There were no adverse events.The combination of CBMC infusion and rehabilitation training may be a safe and effective treatment for ataxia, which dramatically improves patients' functional symptoms. These data support expanded double blind, placebo-controlled studies for these treatment modalities.
View details for DOI 10.1186/1479-5876-9-65
View details for Web of Science ID 000291593800001
View details for PubMedID 21575250
View details for PubMedCentralID PMC3112442
Chemotherapy-related polyneuropathy may deteriorate quality of life in patients with B-cell lymphoma
QUALITY OF LIFE RESEARCH
2010; 19 (8): 1097-1103
This prospective study was performed to evaluate the effect of chemotherapy-related neurotoxicity on quality of life (QOL) of patients with lymphoma.Thirty-two patients with diffuse large B-cell or follicular lymphoma without prior evidence of neuropathy were enrolled. Patients underwent the evaluations based on neuropathy symptom and disability score, nerve conduction studies, and SF-36 questionnaire for QOL assessment. They received six cycles of chemotherapy every three weeks, and all evaluations were repeated during and after the completion of 6th cycle.Sensory neuropathy-associated symptoms were observed in 27 patients (84.4%), and polyneuropathy was confirmed by nerve conduction study in 14 patients (43.8%). These patients with polyneuropathy showed worse QOL in domains mainly associated with physical health status including "physical function" compared to patients without polyneuropathy. There was a significant association of neuropathy symptom and disability scores with "bodily pain" and "vitality" of QOL domains. The serial evaluations of patients with neuropathy showed a worsening of QOL and neuropathy symptom scores during chemotherapy, then improvement of these values after chemotherapy. Thus, the final nerve conduction study confirmed the decrease in polyneuropathy compared to the 2nd evaluation (P = 0.032).Chemotherapy-related polyneuropathy may deteriorate QOL of patients with lymphoma, mainly physical health-associated QOL.
View details for DOI 10.1007/s11136-010-9670-0
View details for Web of Science ID 000281902800002
View details for PubMedID 20443066
ELECTROPHYSIOLOGIC CORRELATIONS WITH CLINICAL OUTCOMES IN CIDP
MUSCLE & NERVE
2010; 42 (4): 492–97
Data are lacking on correlations between changes in nerve conduction (NC) studies and treatment response in chronic inflammatory demyelinating polyneuropathy (CIDP). This report examined data from a randomized, double-blind trial of immune globulin intravenous, 10% caprylate/chromatography purified (IGIV-C [Gamunex]; n = 59) versus placebo (n = 58) every 3 weeks for up to 24 weeks in CIDP. Motor NC results and clinical measures were assessed at baseline and endpoint/week 24. Improvement from baseline in adjusted inflammatory neuropathy cause and treatment score correlated with improvement in proximally evoked compound muscle action potential (CMAP) amplitudes (r = -0.53; P < 0.001) of all nerves tested and with improvement in CMAP amplitude of the most severely affected motor nerve (r = -0.36; P < 0.001). Correlations were observed between improvement in averaged CMAP amplitudes and dominant-hand grip strength (r = 0.44; P < 0.001) and Medical Research Council sum score (r = 0.38; P < 0.001). Overall, the change in electrophysiologic measures of NC in CIDP correlated with clinical response to treatment.
View details for DOI 10.1002/mus.21733
View details for Web of Science ID 000282487900006
View details for PubMedID 20665514
Utility of the cutaneous silent period in the evaluation of carpal tunnel syndrome
2010; 121 (9): 1584-1588
This study investigates the utility of the cutaneous silent period (CuSP) in evaluating patients with carpal tunnel syndrome (CTS).The authors measured the CuSP from the abductor pollicis brevis muscle in 135 hands of patients with idiopathic CTS and 30 hands of age- and gender-matched controls. The patient group was further divided into subgroups according to the Canterbury scale. The differences in parameters between the patient subgroups and control group were analysed. A predetermined analysis looked at the possible correlation between the CuSP and symptom severity as measured by the Boston-Questionnaire.The mean CuSP latencies in the patient group (72.4+/-16.1 ms) was significantly longer than the control group (64.6+/-13.4 ms; P=0.014), although there was no difference in the duration of the CuSP between groups. The duration and latency of the CuSP correlated to a higher severity on the Canterbury scale (r=0.273, P<0.001 and r=-0.164, P=0.036, respectively). However, the CuSP parameters did not correlate with the Boston-Questionnaire scores.Although patients with CTS had significantly prolonged CuSP latency, the CuSP did not correlate with the clinical symptoms scale.The CuSP is a useful ancillary test to evaluate Adelta fibre function; however, it is not a reliable tool to quantify clinical severity.
View details for DOI 10.1016/j.clinph.2010.03.012
View details for Web of Science ID 000280555400023
View details for PubMedID 20378398
UTILITY OF ELECTRODIAGNOSTIC TESTING IN EVALUATING PATIENTS WITH LUMBOSACRAL RADICULOPATHY: AN EVIDENCE-BASED REVIEW
MUSCLE & NERVE
2010; 42 (2): 276-282
This is an evidence-based review of electrodiagnostic (EDX) testing of patients with suspected lumbosacral radiculopathy to determine its utility in diagnosis and prognosis. Literature searches were performed to identify articles applying EDX techniques to patients with suspected lumbosacral radiculopathy. From the 355 articles initially discovered, 119 articles describing nerve conduction studies, electromyography (EMG), or evoked potentials in adequate detail were reviewed further. Fifty-three studies met inclusion criteria and were graded using predetermined criteria for classification of evidence for diagnostic studies. Two class II, 7 class III, and 34 class IV studies described the diagnostic use of EDX. One class II and three class III articles described H-reflexes with acceptable statistical significance for use in the diagnosis and confirmation of suspected S1 lumbosacral radiculopathy. Two class II and two class III studies demonstrated a range of sensitivities for use of muscle paraspinal mapping. Two class II studies demonstrated the utility of peripheral myotomal limb electromyography in radiculopathies.
View details for DOI 10.1002/mus.21759
View details for PubMedID 20658602
Utility of the cutaneous silent period in patients with diabetes mellitus
JOURNAL OF THE NEUROLOGICAL SCIENCES
2010; 293 (1-2): 1-5
We performed this study to evaluate whether or not the cutaneous silent period (CSP) is a useful metric to identify small-fiber neuropathy in diabetic patients. The CSP was measured from the abductor pollicis brevis muscle in 30 healthy controls and 110 diabetic patients, who in turn were divided into 3 subgroups (patients with large-fiber neuropathy, patients with small-fiber neuropathy, and asymptomatic patients). The measured CSP and clinical characteristics were compared among the groups. The power of the CSP in discriminating patients from controls and any correlation with other clinical variables were analyzed. Each patient subgroup had a significantly delayed CSP latency compared to the controls. The latency of patients with large-fiber neuropathy was also significantly prolonged compared to the other subgroups of patients. The CSP latency was the only variable to discriminate patients. The latency showed a significant correlation with the late responses in nerve conduction studies. Thus, the CSP latency may be a useful tool in evaluating small neural fiber function in diabetic patients.
View details for DOI 10.1016/j.jns.2010.03.032
View details for Web of Science ID 000278652500001
View details for PubMedID 20417526
Intraoperative Neurophysiologic Monitoring in the Endovascular and Surgical Treatment of Pediatric Arteriovenous Malformations
LIPPINCOTT WILLIAMS & WILKINS. 2010: A501
View details for Web of Science ID 000275274002422
DRIVING WITH POLYNEUROPATHY
MUSCLE & NERVE
2010; 41 (3): 324-328
Polyneuropathy may result in pain, numbness, and weakness, which may in turn affect driving ability. Medications used to treat neuropathic pain may alter cognition, which may further affect driving. Although such impairments have engendered questions about the driving safety in this group of patients, the rate of motor vehicle accidents (MVAs) in patients with neuropathy has not been studied rigorously. We surveyed patients with neuropathy from three medical centers for reported accident rate, and we analyzed variables related to increased risk for accidents compared to National Highway Traffic Safety Administration data. Surveys from 260 subjects demonstrated that 40.6% were involved in traffic accidents (0.11 accidents/year). Their accident rate was 10.8 MVAs per million vehicle miles traveled (MVA/MVMT), compared to 3.71 MVA/MVMT in 55-59-year-old drivers and 3.72 in 60-64-year-olds (National Highway Traffic Safety Administration data). In all, 72.4% cited their neuropathy and 55.2% cited their medications as playing a role in their accidents, and 51.6% changed their driving habits after developing neuropathy. Independently, elevated levels of pain, motor weakness, and ambulation difficulty met statistical significance for increased MVA frequency. We conclude that accident frequency and discomfort with driving are higher in neuropathy patients compared to age-matched national statistics. However, most patients seem to change habits according to their ability to drive; as such, driving issues should be addressed with caution and on a case-by-case basis.
View details for DOI 10.1002/mus.21511
View details for PubMedID 19882633
Surgical strategies for managing foraminal nerve sheath tumors: the emerging role of CyberKnife ablation
EUROPEAN SPINE JOURNAL
2010; 19 (2): 242-256
Sixteen Stanford University Medical Center (SUMC) patients with foraminal nerve sheath tumors had charts reviewed. CyberKnife radiosurgery was innovative in management. Parameters were evaluated for 16 foraminal nerve sheath tumors undergoing surgery, some with CyberKnife. Three neurofibromas had associated neurofibromatosis type 1 (NF1). Eleven patients had one resection; others had CyberKnife after one (two) and two (three) operations. The malignant peripheral nerve sheath tumor (MPNST) had prior field-radiation and adds another case. Approaches included laminotomy and laminectomies with partial (three) or total (two) facetectomies/fusions. Two cases each had supraclavicular, lateral extracavitary, retroperitoneal and Wiltze and costotransversectomy/thoracotomy procedures. Two underwent a laminectomy/partial facetectomy, then CyberKnife. Pre-CyberKnife, one of two others had a laminectomy/partial facetectomy, then total facetectomy/fusion and the other, two supraclavicular approaches. The MPNST had a hemi-laminotomy then laminectomy/total facetectomy/fusion, followed by CyberKnife. Roots were preserved, except in two. Of 11 single-operation-peripheral nerve sheath tumors, the asymptomatic case remained stable, nine (92%) improved and one (9%) worsened. Examinations remained intact in three (27%) and improved in seven (64%). Two having a single operation then CyberKnife had improvement after both. Of two undergoing two operations, one had symptom resolution post-operatively, worsened 4 years post-CyberKnife then has remained unchanged after re-operation. The other such patient improved post-operatively, had no change after re-operation and improved post-CyberKnife. The MPNST had presentation improvement after the first operation, worsened and after the second surgery \and CyberKnife, the patient expired from tumor spread. In conclusion, surgery is beneficial for pain relief and function preservation in foraminal nerve sheath tumors. Open surgery with CyberKnife is an innovation in these tumors' management.
View details for DOI 10.1007/s00586-009-1160-0
View details for Web of Science ID 000274545200006
View details for PubMedID 19798517
View details for PubMedCentralID PMC2899818
ELECTROPHYSIOLOGY IN CHRONIC INFLAMMATORY DEMYELINATING POLYNEUROPATHY WITH IGIV
MUSCLE & NERVE
2009; 39 (4): 448–55
Patients with chronic inflammatory demyelinating polyneuropathy (CIDP) received immune globulin intravenous, 10% caprylate/chromatography purified (IGIV-C, Gamunex; n=59) or placebo (n=58) every 3 weeks for up to 24 weeks (first period) in a randomized, double-blind, parallel-group, response-conditional, crossover study. Motor and sensory nerves were assessed at baseline and endpoint/week 24. A nonsignificant trend toward improvement in the proximal amplitude of the most severely affected motor nerve was observed with IGIV-C (0.69+/-1.86 mV) versus placebo (0.47+/-2.29 mV), and a greater improvement of 1.08+/-2.15 mV with IGIV-C versus 0.46+/-2.03 mV with placebo (P=0.089) was observed with exclusion of data from Erb's point stimulation. Greater improvements from baseline favoring IGIV-C were observed for 127/142 electrophysiologic parameters. The averaged motor amplitudes from all motor nerves significantly improved with IGIV-C versus placebo [treatment difference, 0.62 mV; 95% confidence interval (CI), 0.05, 1.20; P=0.035], and conduction block decreased significantly (treatment difference, -5.54%; 95% CI, -10.43, -0.64; P=0.027), particularly in the lower limbs. Overall, the data suggest that IGIV-C improves electrophysiologic parameters in CIDP.
View details for DOI 10.1002/mus.21236
View details for Web of Science ID 000264784800005
View details for PubMedID 19260050
Safety and Short-Term Effects of Umbilical Cord Mesenchymal Stem Cell Therapy in Amyotrophic Lateral Sclerosis: Review of Chinese Data
LIPPINCOTT WILLIAMS & WILKINS. 2009: A363
View details for Web of Science ID 000264527902175
Chemotherapy-Related Polyneuropathy Effect on Quality of Life in Patients with Lymphoma
LIPPINCOTT WILLIAMS & WILKINS. 2009: A219
View details for Web of Science ID 000264527901259
Bilateral isolated phrenic neuropathy causing painless bilateral diaphragmatic paralysis
2005; 65 (9): 1499-1501
The authors report four patients with a syndrome of painless bilateral isolated phrenic neuropathy. Electrophysiologic testing demonstrated active denervation restricted to the diaphragm. Long-term recovery was poor. The authors conclude that bilateral isolated phrenic neuropathy is a cause of painless diaphragmatic paralysis distinguishable from immune brachial plexus neuropathy and other neuromuscular disorders with similar clinical presentation.
View details for Web of Science ID 000233114100037
View details for PubMedID 16275847
Clinical utility of electrodiagnostic consultation in suspected polyneuropathy
MUSCLE & NERVE
2004; 30 (5): 659-662
Although paresthesias of the distal lower limbs are characteristic features of polyneuropathy, they may also herald the presence of a focal neuropathy, polyradiculopathy, or myelopathy. Electromyography and nerve conduction studies (EMG/NCS) are widely used in the evaluation of such symptoms, but their utility has not been subjected to vigorous scrutiny. We investigated the clinical impact of the electrodiagnostic consultation in assessing suspected polyneuropathy. When compared with the clinical impression, the result of the electrodiagnostic consultation was confirmatory in only 39% of all patients, and changed the diagnosis or uncovered an additional diagnosis in 43%. An alternative diagnosis was likely when either weakness was present (75%) or the Achilles stretch reflex was preserved (48%). These data support the use of EMG/NCS in the diagnostic evaluation of patients presenting with distal paresthesias, especially in those with preserved Achilles reflexes or motor deficits.
View details for DOI 10.1002/mus.20119
View details for PubMedID 15389656
Computerized QT dispersion measurement and cardiovascular mortality in male veterans
AMERICAN JOURNAL OF CARDIOLOGY
2004; 93 (4): 483-486
We examined the prognostic value of computerized measurements of QT dispersion in 37,579 male veterans. The results of our study showed that QT dispersion is a poor independent predictor of cardiovascular mortality.
View details for DOI 10.1016/j.amjcard.2003.10.051
View details for PubMedID 14969631
Prognostic value of exercise tests in male veterans with chronic coronary artery disease.
Journal of cardiopulmonary rehabilitation
2002; 22 (6): 399-407
The authors evaluate the prognostic value of treadmill testing in a large consecutive series of patients with chronic coronary artery disease. Exercise testing is widely performed, but analyses of the prognostic value of test results have largely concentrated on patients referred for the diagnosis of coronary artery disease, patients after an acute coronary event or procedure, or patients with congestive heart failure.All patients referred for evaluation at two university-affiliated Veterans Affairs Medical Centers who underwent exercise treadmill tests for clinical indications between 1987 and 2000 were determined to be dead or alive using the Social Security Death Index after a mean 5.8-year follow-up. Patients without established heart disease and those with congestive heart failure were excluded, leaving the target population of those with a history myocardial infarction or coronary intervention. Clinical and exercise test variables were collected prospectively according to standard definitions; testing and data management were performed in a standardized fashion using a computer-assisted protocol. All-cause mortality was used as the endpoint for follow-up. Standard survival analysis was performed including Kaplan Meier curves and the Cox Hazard Model.Of the 1,473 patients with coronary artery disease who had exercise testing, 273 (19%) patients had a revascularization procedure (Revascularization group); 813 (55%) had a history of myocardial infarction, diagnostic Q waves (MI group), or both; and 387 (26%) had a history of myocardial infarction or Q wave and revascularization (Combined group). Mean age of the patients was 61.8 +/- 9 years. A total of 401 deaths occurred during a mean follow-up of 5.8 years with an annual mortality rate of 4.5%. Only two variables, age and maximal exercise capacity, were independently and statistically associated with time to death in all three groups and were the strongest predictors of all cause mortality.A simple score based on METs, age, and history of myocardial infarction or diagnostic Q waves can stratify prognosis in patients with chronic coronary artery disease. The score enabled the identification of a group at low risk (32% of the cohort) with an annual mortality rate of 2%, a group at intermediate risk (42% of the cohort) with an annual mortality rate of about 4%, and a group at high risk (26% of the cohort) with an average annual mortality rate of approximately 7%.
View details for PubMedID 12464826
AMERICAN JOURNAL OF MEDICINE
2002; 113 (7): 580-586
Peripheral edema often poses a dilemma for the clinician because it is a nonspecific finding common to a host of diseases ranging from the benign to the potentially life threatening. A rational and systematic approach to the patient with edema allows for prompt and cost-effective diagnosis and treatment. This article reviews the pathophysiologic basis of edema formation as a foundation for understanding the mechanisms of edema formation in specific disease states, as well as the implications for treatment. Specific etiologies are reviewed to compare the diseases that manifest this common physical sign. Finally, we review the clinical approach to diagnosis and treatment strategies.
View details for Web of Science ID 000179453900008
View details for PubMedID 12459405
Echocardiographic and magnetic resonance methods for diagnosing hibernating myocardium
NUCLEAR MEDICINE COMMUNICATIONS
2002; 23 (4): 331-339
Hibernating myocardium refers to regions of impaired left ventricular function at rest due to coronary artery disease that is reversible with revascularization. The accurate identification and assessment of myocardial viability is a critical aspect of the management of the patient with coronary artery disease and left ventricular dysfunction. Several non-invasive methods exist to assist the clinician in distinguishing those patients with significant regions of hibernating myocardium from those who have non-viable scar. This is important not only to identify those patients who would most benefit from percutaneous intervention or surgery, but also to spare the latter group from the morbidity and mortality associated with a revascularization procedure that would provide little benefit. While nuclear medicine imaging is the most widely used means for evaluating myocardial viability, alternative modalities have emerged and have gained increasing acceptance in recent years. This article will review the echocardiographic and magnetic resonance imaging (MRI) methods that are currently available or under investigation to assess myocardial viability. These techniques include rest and stress echocardiography, myocardial contrast echocardiography, stress MRI, contrast-enhanced MRI and magnetic resonance spectroscopy (MRS).
View details for PubMedID 11930186
Clinical utility of EMG/NCS in patients presenting with distal lower limb paresthesias
LIPPINCOTT WILLIAMS & WILKINS. 2001: A318–A319
View details for Web of Science ID 000168270600840
Multinodular polymyositis in a patient with human immunodeficiency and hepatitis C virus coinfection
MUSCLE & NERVE
2001; 24 (3): 433-437
We report a patient who developed multiple inflammatory muscle masses and generalized polymyositis in the setting of combined human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infection. Magnetic resonance imaging (MRI) of muscles showed patchy edema which was particularly intense within the nodular masses. Polymerase chain reaction (PCR) showed no evidence of either virus within muscle. This report reviews earlier literature on muscle nodules associated with myositis and discusses the differential diagnosis of muscle masses in HIV infection.
View details for Web of Science ID 000167117100020
View details for PubMedID 11353433