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Biomedical subjects

Michel Kliot

Publications and source records attributed to Michel Kliot.

At least 19 recordsLinked to original sources
PubMed2007

The relationship between electrodiagnostic findings and patient symptoms and function in carpal tunnel syndrome.

OBJECTIVE: To examine whether, in patients with carpal tunnel syndrome (CTS), electrodiagnostic study findings were associated with patient symptom severity and functional limitations after controlling for potentially confounding variables including depression, somatization, and pain-related catastrophizing. DESIGN: Cross-sectional design including data from 2 ongoing CTS studies. SETTING: Patients enrolled from hospitals and clinics in Washington State between October 2002 and February 2006. PARTICIPANTS: Adults with CTS (N=215) (based on symptoms and abnormal electrodiagnostic findings) were analyzed. Exclusion criteria were any mass, tumor, severe trauma, or deformity in the hand or wrist, radiculopathy, polyneuropathy, pregnancy, lactation, or severe CTS. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The Carpal Tunnel Syndrome Assessment Questionnaire (CTSAQ) functional status scale assessed the ability to perform 9 common hand-related tasks. The CTSAQ symptom severity scale included 11 items that assess pain, numbness, and weakness. Patients also rated their average hand and wrist pain in the last month. RESULTS: With and without controlling for patient characteristics, including age, sex, body mass index, symptom duration, depression, somatization, and pain-related catastrophizing, there were no statistically significant relationships between the electrodiagnostic findings and patient functional status and symptom severity. CONCLUSIONS: Electrodiagnostic findings and patient CTS-related symptoms and function appear to be independent measures. Clinicians and researchers interested in CTS outcomes need to assess both.

Adult↗
PubMed2006

The clinico-anatomic explanation for tibial intraneural ganglion cysts arising from the superior tibiofibular joint.

OBJECTIVE: To demonstrate that tibial intraneural ganglia in the popliteal fossa are derived from the posterior portion of the superior tibiofibular joint, in a mechanism similar to that of peroneal intraneural ganglia, which have recently been shown to arise from the anterior portion of the same joint. DESIGN: Retrospective clinical study and prospective anatomic study. MATERIALS: The clinical records and MRI findings of three patients with tibial intraneural ganglion cysts were analyzed and compared with those of one patient with a tibial extraneural ganglion cyst and one volunteer. Seven cadaveric limbs were dissected to define the articular anatomy of the posterior aspect of the superior tibiofibular joint. RESULTS: The condition of the three patients with intraneural ganglia recurred because their joint connections were not identified initially. In two patients there was no cyst recurrence when the joint connection was treated at revision surgery; the third patient did not wish to undergo additional surgery. The one patient with an extraneural ganglion had the joint connection identified at initial assessment and had successful surgery addressing the cyst and the joint connection. Retrospective evaluation of the tibial intraneural ganglion cysts revealed stereotypic features, which allowed their accurate diagnosis and distinction from extraneural cases. The intraneural cysts had tubular (rather than globular) appearances. They derived from the postero-inferior portion of the superior tibiofibular joint and followed the expected course of the articular branch on the posterior surface of the popliteus muscle. The cysts then extended intra-epineurially into the parent tibial nerves, where they contained displaced nerve fascicles. The extraneural cyst extrinsically compressed the tibial nerve but did not directly involve it. All cadaveric specimens demonstrated a small single articular branch, which derived from the tibial nerve to the popliteus. The branch coursed obliquely across the posterior surface of the popliteus muscle before innervating the postero-inferior aspect of the superior tibiofibular joint. CONCLUSIONS: The clinical, MRI and anatomic features of tibial intraneural ganglion cysts are the posterior counterpart of the peroneal intraneural ganglion cysts arising from the anterior portion of the superior tibiofibular joint. These predictable features can be exploited and have implications for the pathogenesis of these intraneural cysts and treatment outcomes. These ganglion cysts are joint-related and provide further evidence to support the unifying articular theory. In each case the joint connection needs to be identified preoperatively, and the articular branches and the superior tibiofibular joint should be addressed operatively to prevent cyst recurrence.

Adult↗
PubMed2006

Two-year outcome of unilateral sural nerve interposition graft after radical prostatectomy.

OBJECTIVES: To study 41 men treated for prostate cancer with unilateral nerve-sparing radical prostatectomy and contralateral sural nerve grafting from January 2000 to September 2003. METHODS: Patients were considered for sural nerve grafting if they were considered at high risk of extracapsular extension before or during surgery, were younger than 70 years of age with good preoperative erectile function, were sexually active, and had no significant risk factors for erectile dysfunction. Potency was assessed by patient-reported questionnaires, including the International Index of Erectile Function erectile domain and Rigiscan testing. RESULTS: The mean follow-up was 27.4 +/- 14.5 months. At 24 months, 24 (63.2%) of 38 men had erections sufficient for intercourse, with or without phosphodiesterase type 5 inhibitor use. Four men had partial erections that were occasionally satisfactory (10.5%), and 10 men reported no sexual activity, no spontaneous erections, or partial erections unsatisfactory for intercourse (26.3%). In contrast, in a group of 49 men who underwent unilateral nerve-sparing prostatectomy without nerve grafting during the same period at our institution, 13 (26.5%) had rigid erections adequate for intercourse with or without phosphodiesterase type 5 inhibitor use at 24 months of follow-up. CONCLUSIONS: At 24 months of follow-up, men who had undergone unilateral nerve-sparing prostatectomy with contralateral sural nerve interposition graft repair of a cut cavernosal nerve had a greater rate of return of erectile function than men undergoing unilateral nerve-sparing prostatectomy alone.

Follow-Up Studies↗
PubMed2006

Sterile recurrent spinal epidural abscess in a patient with Crohn's disease: a case report.

BACKGROUND: The frequency of SEA is increasing. There are several well-established predisposing factors. CASE DESCRIPTION: Our case presents certain unusual features that include an association with CD, persistent sterile cultures, and multiple recurrences of lesions at adjacent levels. CONCLUSIONS: A review of the literature showed only 13 case reports of SEA in patients with CD with an additional patient mentioned in one series. Recurrence of SEA at the same location was reported only twice. The diagnostic workup and treatment modalities pertinent to this case are discussed.

Adult↗
PubMed2006

Suprascapular intraneural ganglia and glenohumeral joint connections.

OBJECT: Unlike the more commonly noted paralabral cysts (extraneural ganglia), which are well known to result in suprascapular nerve compression, only four cases of suprascapular intraneural ganglia have been reported. Because of their rarity, the pathogenesis of suprascapular intraneural ganglia has been poorly understood and a pathoanatomical explanation has not been provided. In view of the growing literature demonstrating strong associations between paralabral cysts and labral (capsular) pathology, joint connections, and joint communications, the authors retrospectively reviewed the magnetic resonance (MR) imaging studies and postoperative results in the two featured patients to test a hypothesis that suprascapular intraneural ganglia would have analogous findings. METHODS: Two patients who presented with suprascapular neuropathy were found to have intraneural ganglia. Connections to the glenohumeral joint could be established in both patients through posterior labrocapsular complex tears. In neither patient was the joint connection identified preoperatively or intraoperatively, and cyst decompression was performed by itself without attention to the labral tear. The suprascapular intraneural ganglia extended from the glenohumeral joint as far proximally as the level of the nerves' origin from the upper trunk in the supraclavicular fossa. Although both patients experienced symptomatic improvement after surgery, neurological recovery was incomplete. In both cases, postoperative MR images revealed cyst persistence. In addition, previously unrecognized superior labral anteroposterior (SLAP) Type II lesions (tears of the superior labrum extending anteroposterior and involving the biceps anchor at the labrum without actual extension into the tendon) were visualized. In one patient with a persistent cyst, an MR arthrogram was obtained and demonstrated a communication between the joint and the cyst. CONCLUSIONS: The findings in these two patients support the synovial theory for intraneural ganglia. Based on their experience with intraneural ganglia at other sites, the authors believe that suprascapular intraneural ganglia arise from the glenohumeral joint, egress through a superior (posterior) labral tear, and dissect within the epineurium along an articular branch into the main nerve, following the path of least resistance. Furthermore, these two cases of intraneural ganglia with SLAP lesions are directly analogous to the many cases of paralabral cysts associated with these types of labral tears. By better understanding the origin of this unusual type of ganglia and drawing analogies to the more common extraneural cysts, surgical strategies can be formulated to address the underlying pathoanatomy, improve operative outcomes, and prevent recurrences.

Adult↗
PubMed2005

Randomized clinical trial of surgery versus conservative therapy for carpal tunnel syndrome [ISRCTN84286481].

BACKGROUND: Conservative treatment remains the standard of care for treating mild to moderate carpal tunnel syndrome despite a small number of well-controlled studies and limited objective evidence to support current treatment options. There is an increasing interest in the usefulness of wrist magnetic resonance imaging could play in predicting who will benefit for various treatments. METHOD AND DESIGN: Two hundred patients with mild to moderate symptoms will be recruited over 3 1/2 years from neurological surgery, primary care, electrodiagnostic clinics. We will exclude patients with clinical or electrodiagnostic evidence of denervation or thenar muscle atrophy. We will randomly assign patients to either a well-defined conservative care protocol or surgery. The conservative care treatment will include visits with a hand therapist, exercises, a self-care booklet, work modification/ activity restriction, B6 therapy, ultrasound and possible steroid injections. The surgical care would be left up to the surgeon (endoscopic vs. open) with usual and customary follow-up. All patients will receive a wrist MRI at baseline. Patients will be contacted at 3, 6, 9 and 12 months after randomization to complete the Carpal Tunnel Syndrome Assessment Questionnaire (CTSAQ). In addition, we will compare disability (activity and work days lost) and general well being as measured by the SF-36 version II. We will control for demographics and use psychological measures (SCL-90 somatization and depression scales) as well as EDS and MRI predictors of outcomes. DISCUSSION: We have designed a randomized controlled trial which will assess the effectiveness of surgery for patients with mild to moderate carpal tunnel syndrome. An important secondary goal is to study the ability of MRI to predict patient outcomes.

Carpal Tunnel Syndrome↗
PubMed2005

Compliance with electrodiagnostic guidelines for patients undergoing carpal tunnel release.

OBJECTIVE: To describe how clinical practice in those who underwent carpal tunnel release (CTR) matched the American Association of Electrodiagnostic Medicine (AAEM) 1993 practice parameters for electrodiagnostic evaluation of carpal tunnel syndrome (CTS). DESIGN: Cohort study using 1998-1999 Medicare billing data. SETTING: Washington State. PARTICIPANTS: State Medicare beneficiaries who underwent CTR in 1999 (N=1567) Interventions Not applicable. MAIN OUTCOME MEASURES: Compliance with the AAEM practice parameters. RESULTS: Of the 1567 [corrected] receiving surgery, 324 [corrected] (20.7%) did not have any electrodiagnostic testing before surgery. One hundred seventy-one (10.9%) had testing performed that did not lead to the diagnosis of CTS. One thousand seventy-two (68.4%) patients were diagnosed with CTS through electrodiagnostic testing; 155 (9.9%) had less than 2 sensory nerves studied, 114 (7.3%) had less than 2 motor nerves studied, and 65 (4.2%) of the studies met neither the standard (sensory nerve testing) nor guideline (motor nerve testing). In a multivariate analysis, neurologists were more likely than physiatrists not to meet the AAEM standards (adjusted relative risk [adj RR]=1.61; 95% confidence interval [CI], 1.13-2.31) and patients living in rural areas were more likely to have no or inadequate testing (adj RR=1.6; 95% CI, 1.3-1.9). CONCLUSIONS: Over one third of Medicare patients undergoing CTR in Washington State in 1999 may have had an inappropriate electrodiagnostic workup before the surgery. Policymakers should consider mandating an appropriate electrodiagnostic test before approving CTR.

Aged↗
PubMed2005

Cannabinol delays symptom onset in SOD1 (G93A) transgenic mice without affecting survival.

Therapeutic options for amyotrophic lateral sclerosis (ALS), the most common adult-onset motor neuron disorder, remain limited. Emerging evidence from clinical studies and transgenic mouse models of ALS suggests that cannabinoids, the bioactive ingredients of marijuana (Cannabis sativa) might have some therapeutic benefit in this disease. However, Delta(9)-tetrahydrocannabinol (Delta(9)-THC), the predominant cannabinoid in marijuana, induces mind-altering effects and is partially addictive, compromising its clinical usefulness. We therefore tested whether cannabinol (CBN), a non-psychotropic cannabinoid, influences disease progression and survival in the SOD1 (G93A) mouse model of ALS. CBN was delivered via subcutaneously implanted osmotic mini-pumps (5 mg/kg/day) over a period of up to 12 weeks. We found that this treatment significantly delays disease onset by more than two weeks while survival was not affected. Further research is necessary to determine whether non-psychotropic cannabinoids might be useful in ameliorating symptoms in ALS.

Age Factors↗
PubMed2005

Characterization of genetically defined types of Charcot-Marie-Tooth neuropathies by using magnetic resonance neurography.

OBJECT: Charcot-Marie-Tooth (CMT) disease is a collection of related genetic disorders affecting peripheral nerves with an incidence of one in every 2500 individuals. A diagnosis of CMT disease has classically relied on a medical history, examination, and measurement of nerve conduction velocities. Advancements in genetic testing and magnetic resonance (MR) imaging techniques may provide clinicians with a more precise diagnostic armamentarium. The authors investigated MR neurography as a possible method to characterize CMT subtypes. METHODS: The authors performed MR neurography to evaluate sciatic nerves in the mid-thigh area of seven patients with genetically defined subtypes of CMT, one patient with chronic inflammatory demylinating polyneuropathy, and one patient without neuropathy. The authors correlate their findings with normal nerve conduction velocities (NCVs) and present their results as a descriptive case series. Although MR neurography could not be used to distinguish subtypes of CMT disease on nerve area or fascicle number, it appears to characterize phenotypic features and disease progression noninvasively in patients with some subtypes. CONCLUSIONS: In conjunction with NCV measurements, MR neurography may be useful in the diagnosis of CMT neuropathies and in monitoring disease progression.

Adult↗
PubMed2005

Microscale surgery on single axons.

OBJECTIVE: The lack of meaningful axon regeneration after central nervous system damage and poor functional recovery after serious peripheral nervous system nerve injuries have been long-standing problems of substantial interest to both neurosurgeons and neurobiologists. As an alternative to strategies that seek to promote the regeneration of adult axons, our research group has taken advantage of advances in microtechnology to develop a paradigm of direct axon repair involving the substitution of damaged axon regions with healthy segments from donor axons. METHODS: This repair methodology uses a novel combination of microtechnology, electrokinetic axon manipulation, and the well-established biological principle of cell fusion. These three fields of research have been integrated in a multidisciplinary approach to develop a solution for a significant clinical problem that currently has no specific treatment. RESULTS: The findings reported here provide some initial proof of principle for the core technologies we intend to use for axon repair. Functional recovery from nerve damage of course is clinically challenging, and many obstacles would need to be overcome before such axon repair procedures can be contemplated for therapeutic use. We identify some of the clinical issues that must be addressed for microtechnology-assisted axon repair to transition from the realm of research into actual surgical settings. CONCLUSION: It is hoped that each advance in axon repair technology will spur additional research to provide us with a comprehensive understanding on how best to pursue neurosurgical intervention at the microscale.

Animals↗
PubMed2004

Inflammatory mediators and growth factors in the spinal cord of G93A SOD1 rats.

Amyotrophic lateral sclerosis (ALS) is a devastating motor neuron disease. One mechanism involved in ALS pathology is neuroinflammation. Neuroinflammation is mediated by soluble pro-inflammatory molecules such as cytokines, prostaglandins and nitric oxide. Studies on transgenic mice demonstrated the expression of pro-inflammatory mediators in early stages of murine ALS. Recently a transgenic rat model became available. Since species differences in regard to cytokine expression have been reported in other disease models we set out to validate the neuroinflammatory hypothesis in the ALS-transgenic rat. We investigated the expression of inflammatory mediators and growth factors in the spinal cord by semi-quantitative RT-PCR. We found that several pro-inflammatory mediators are up-regulated at asymptomatic and end-stages, whereas VEGF, a neuroprotective factor was down-regulated.

Amyotrophic Lateral Sclerosis↗
PubMed2004

Blocking of up-regulated ICAM-1 does not prevent macrophage infiltration during Wallerian degeneration of peripheral nerve.

Circulating blood monocytes infiltrate into distal degenerating nerve and differentiate into activated macrophages that remove degenerating axonal and myelin debris and promote axonal regeneration. The cellular and molecular mechanisms responsible for this monocyte-macrophage recruitment remain largely unknown. Cell adhesion molecules which mediate monocyte and endothelial cell interactions, such as the endothelial cell adhesion molecule intercellular adhesion molecule-1 (ICAM-1) interaction with the monocyte adhesion molecules Mac-1 (complement receptor type 3) and LFA-1 (lymphocyte function-associated antigen-1), have been shown to play a critical role in mediating the transendothelial migration of circulating monocytes into nonneural tissues following various types of injury. This study investigated whether these cell adhesion molecules also play a critical role in mediating monocyte-macrophage infiltration during Wallerian degeneration of peripheral nerve. Following sciatic nerve transection, Mac-1- and LFA-1-positive macrophages in distal degenerating nerve increased in number at 2 days and peaked at 14 days before declining. The number of ICAM-1-immunostained blood vessels increased maximally at 1 day before declining to baseline levels by 14 days. Three days following nerve transection, the intensity of ICAM-1 immunostaining on intraneural blood vessels was maximal and then decreased to baseline levels by 14 days. To test the role of ICAM-1 in mediating monocyte-macrophage recruitment, we used two complementary experimental strategies following a sciatic nerve transection: (1) intravenous administration of a rat ICAM-1-blocking monoclonal antibody and (2) ICAM-1 knockout mice. In both cases, the number of infiltrating monocytes-macrophages was above controls, which is opposite to what has been shown to occur in other tissues following injury.

Animals↗
PubMed2004

Diagnosis of carpal tunnel syndrome: electrodiagnostic and MR imaging evaluation.

In clinically classic carpal tunnel syndrome (CTS) without symptoms or signs to suggest other disorders that can mimic CTS, it remains somewhat controversial as to whether performing nerve conduction studies is necessary or cost-effective. MR imaging reliably depicts normal carpal tunnel anatomy. It can also identify pathologic nerve compression and mass lesions, such as ganglion cysts, that compress nerves. Currently, MR imaging is most commonly used to image patients with ambiguous electrodiagnostic studies and clinical examinations. MR diffusion-weighted imaging of peripheral nerves might prove to be the most sensitive imaging sequence for the detection of early nerve dysfunction. Electrodiagnostic studies are likely to remain the pivotal diagnostic examination in patients with suspected CTS for the foreseeable future. With advances in both software and hardware, however, high-resolution MR imaging of peripheral nerves will become faster, cheaper, and likely more accurate, possibly paving the way for an expanded role in the diagnosis of this common syndrome.

Carpal Tunnel Syndrome↗
PubMed2004

MR neurography: diagnostic utility in the surgical treatment of peripheral nerve disorders.

Advances in MR imaging have improved the visualization of normal and pathologic peripheral nerve structures in various clinical settings. Peripheral nerve imaging has the potential to dramatically change the diagnosis and treatment of peripheral nerve pathology and lead to an improved understanding of peripheral nerve pathophysiology. Currently, MR imaging serves as a problem-solving tool when additional anatomic information is needed to clarify ambiguous electrodiagnostic and clinical examinations. The next major advance in MR imaging of peripheral nerves will likely be the transition from anatomic to physiologic imaging with higher resolution as better phased-array surface coils and higher-field-strength magnets become available. Finally, MR neurography should remain complementary to the clinical examination and electrodiagnostic studies in the evaluation of peripheral nerve disorders.

Electrodiagnosis↗
PubMed2004

Endocannabinoids accumulate in spinal cord of SOD1 G93A transgenic mice.

Approximately 2% of amyotrophic lateral sclerosis (ALS) cases are caused by mutations in the super oxide dismutase 1 (SOD1) gene and transgenic mice for these mutations recapitulate many features of this devastating neurodegenerative disease. Here we show that the amount of anandamide (AEA) and 2-arachidonoylglycerol (2-AG), two endocannabinoids that have neuroprotective properties, increase in spinal cord of SOD1(G93A) transgenic mice. This increase occurs in the lumbar section of spinal cords, the first section to undergo neurodegeneration, and is significant before overt motor impairment. Our results show that chronic neurodegeneration induced by a genetic mutation increases endocannabinoid production possibly as part of an endogenous defense mechanism.

Age Factors↗
PubMed2003

Assessing disease onset and progression in the SOD1 mouse model of ALS.

SOD1 transgenic mice are the most widely used animal model of amyotrophic lateral sclerosis (ALS). In addition to providing valuable insights into the pathogenesis of ALS, these animals are used intensively in many laboratories as an in vivo model for investigating novel therapeutic interventions towards this devastating motorneuron disease. Such pre-clinical studies require objective and reliable quantification of the clinical phenotype of individual mice, most importantly of the neuromuscular abnormalities. Here we compare four parameters of the clinical phenotype: motor signs, body weight, rotarod performance and paw grip endurance for their usefulness in monitoring the SOD1 mouse model. We found that paw grip endurance is a sensitive and inexpensive alternative to the widely used rotarod test.

Age of Onset↗
PubMed2003

Mapping dermatomes during selective dorsal rhizotomy: case report and review of the literature.

BACKGROUND: Studies suggest that the pattern of dermatomal segmental innervation in any given patient, may differ from the classic dermatomal maps first described in the 1890s. Such variability may limit the effectiveness of selective dorsal rhizotomy for treatment of neurogenic pain. CASE DESCRIPTION: A 46-year-old male presented with a 27-year history of intractable pain in his left arm after being shot during the Vietnam War; multiple surgical and medical therapeutic modalities failed to produce durable pain relief. The patient underwent selective dorsal rhizotomy, with intraoperative dermatomal and mixed somatosensory evoked potential recordings. Pre- and postrhizotomy recordings were compared, effectively mapping this patient's dermatomal pattern. At 4 years' follow-up, the patient remains pain free. CONCLUSION: Intraoperative monitoring of somatosensory evoked potentials during dorsal rhizotomy for neurogenic pain can be used to establish the degree to which an individual's pattern of segmental innervation conforms to the traditionally described dermatomes.

Evoked Potentials, Somatosensory↗