Early diagnosis of amyotrophic lateral sclerosis by threshold tracking and conventional transcranial magnetic stimulation.

BACKGROUND AND PURPOSE: Short-interval intracortical inhibition by threshold tracking (T-SICI) has been proposed as a diagnostic tool for amyotrophic lateral sclerosis (ALS) but has not been compared directly with conventional amplitude measurements (A-SICI). This study compared A-SICI and T-SICI for sensitivity and clinical usefulness as biomarkers for ALS. METHODS: In all, 104 consecutive patients referred with suspicion of ALS were prospectively included and were subsequently divided into 62 patients with motor neuron disease (MND) and 42 patient controls (ALS mimics) by clinical follow-up. T-SICI and A-SICI recorded in the first dorsal interosseus muscle (index test) were compared with recordings from 53 age-matched healthy controls. The reference standard was the Awaji criteria. Clinical scorings, conventional nerve conduction studies and electromyography were also performed on the patients. RESULTS: Motor neuron disease patients had significantly reduced T-SICI and A-SICI compared with the healthy and patient control groups, which were similar. Sensitivity and specificity for discriminating MND patients from patient controls were high (areas under the receiver operating characteristic curves 0.762 and 0.810 for T-SICI and A-SICI respectively at 1-3.5 ms). Paradoxically, T-SICI was most reduced in MND patients with the fewest upper motor neuron (UMN) signs (Spearman ρ = 0.565, p = 4.3 × 10-6 ). CONCLUSIONS: Amplitude-based measure of cortical inhibition and T-SICI are both sensitive measures for the detection of cortical involvement in MND patients and may help early diagnosis of ALS, with T-SICI most abnormal before UMN signs have developed. The gradation in T-SICI from pathological facilitation in patients with minimal UMN signs to inhibition in those with the most UMN signs may be due to progressive degeneration of the subset of UMNs experiencing facilitation.

Seizure detection using heart rate variability: A prospective validation study.

Although several validated seizure detection algorithms are available for convulsive seizures, detection of nonconvulsive seizures remains challenging. In this phase 2 study, we have validated a predefined seizure detection algorithm based on heart rate variability (HRV) using patient-specific cutoff values. The validation data set was independent from the previously published data set. Electrocardiography (ECG) was recorded using a wearable device (ePatch) in prospectively recruited patients. The diagnostic gold standard was inferred from video-EEG monitoring. Because HRV-based seizure detection is suitable only for patients with marked ictal autonomic changes, we defined responders as the patients who had a>50 beats/min ictal change in heart rate. Eleven of the 19 included patients with seizures (57.9%) fulfilled this criterion. In this group, the algorithm detected 20 of the 23 seizures (sensitivity: 87.0%). The algorithm detected all but one of the 10 recorded convulsive seizures and all of the 8 focal impaired awareness seizures, and it missed 2 of the 4 focal aware seizures. The median sensitivity per patient was 100% (in nine patients all seizures were detected). The false alarm rate was 0.9/24 h (0.22/night). Our results suggest that HRV-based seizure detection has high performance in patients with marked autonomic changes.

Seizure detection based on heart rate variability using a wearable electrocardiography device.

OBJECTIVE: To assess the feasibility and accuracy of seizure detection based on heart rate variability (HRV) using a wearable electrocardiography (ECG) device. Noninvasive devices for detection of convulsive seizures (generalized tonic-clonic and focal to bilateral tonic-clonic seizures) have been validated in phase 2 and 3 studies. However, detection of nonconvulsive seizures still needs further research, since currently available methods have either low sensitivity or an extremely high false alarm rate (FAR). METHODS: In this phase 2 study, we prospectively recruited patients admitted to long-term video-EEG monitoring (LTM). ECG was recorded using a dedicated wearable device. Seizures were automatically detected using HRV parameters computed off-line, blinded to all other data. We compared the performance of 26 automated algorithms with the seizure time-points marked by experts who reviewed the LTM recording. Patients were classified as responders if >66% of their seizures were detected. RESULTS: We recruited 100 consecutive patients and analyzed 126 seizures (108 nonconvulsive and 18 convulsive) from 43 patients who had seizures during monitoring. The best-performing HRV algorithm combined a measure of sympathetic activity with a measure of how quickly HR changes occurred. The algorithm identified 53.5% of the patients with seizures as responders. Among responders, detection sensitivity was 93.1% (95% CI: 86.6%-99.6%) for all seizures and 90.5% (95% CI: 77.4%-97.3%) for nonconvulsive seizures. FAR was 1.0/24 h (0.11/night). Median seizure detection latency was 30 s. Typically, patients with prominent autonomic nervous system changes were responders: An ictal change of >50 heartbeats per minute predicted who would be responder with a positive predictive value of 87% and a negative predictive value of 90%. SIGNIFICANCE: The automated HRV algorithm, using ECG recorded with a wearable device, has high sensitivity for detecting seizures, including the nonconvulsive ones. FAR was low during the night. This approach is feasible in patients with prominent ictal autonomic changes.

Utility of the H-reflex in diagnosing polyneuropathy.

INTRODUCTION: An absent Hoffman (H)-reflex, the electrophysiological equivalent of the Achilles reflex, is assumed to be one of the first detectable signs of polyneuropathy (PNP). In this study we compare the H- and Achilles reflexes in patients with suspected PNP to evaluate the diagnostic utility of the H-reflex. METHODS: Data from clinical examination and nerve conduction studies (NCS) were analyzed in patients with suspected PNP. RESULTS: The PNP diagnosis was confirmed by follow-up in 209 patients. The sensitivities of the H- and Achilles reflexes were similar (70.3% vs 71.8%), whereas the H-reflex had higher specificity (85.2% vs 70.5%) (P < .001). Adding H-reflex to the NCS protocol increased the diagnostic sensitivity from 80.9% to 87.6%. DISCUSSION: The H-reflex is a sensitive method that could provide added value to standard NCS in PNP diagnosis. The simplicity and high specificity make it superior to its clinical equivalent, the Achilles reflex.

Chronic Pain and Neuropathy Following Adjuvant Chemotherapy.

Objective: To determine symptoms and characteristics of chronic sensory neuropathy in patients treated with oxaliplatin and docetaxel, including patterns of somatosensory abnormalities, pain descriptors, and psychological functioning. Design: A retrospective cross-sectional study. Setting: A chronic pain research center. Subjects: Thirty-eight patients with chronic peripheral pain and/or dysesthesia following chemotherapy. Methods: Sensory profiles, psychological functioning, and quality of life were assessed using standardized questionnaires. In addition, standardized quantitative sensory testing and nerve conduction studies were carried out. Results: The sensory profiles and clinical symptoms were very similar in the two groups. Pricking, numbness, and burning were common descriptors in both groups, and the predominant finding was sensory loss to A beta-mediated sensory modalities with decreased mechanical and vibration detection thresholds. A high frequency of abnormalities in thermal sensory limen and the presence of paradoxical heat sensation seem to be sensitive markers of small fiber loss. Both groups had mainly sensory, axonal large fiber or mixed fiber polyneuropathy, which tended to be most severe in the oxaliplatin group. Conclusions: Both oxaliplatin-induced and docetaxel-induced polyneuropathies represent a significant problem that affects the daily life of the patients. Our results, defining the somatosensory phenotype, can improve the understanding of the pathophysiological mechanisms useful for future studies in the tailored treatment of prevention of chemotherapy-induced peripheral neuropathy and pain.

Involvement of distal sensory nerves in amyotrophic lateral sclerosis.

INTRODUCTION: The diagnostic criteria for amyotrophic lateral sclerosis (ALS) require normal sensory nerve conduction studies (NCS) or abnormal NCS only in the presence of neuropathy of identified etiology. In this study, we investigated the presence and extent of involvement of Aß sensory fibers in ALS. METHODS: Distal sensory NCS [antidromic dorsal sural (DS) and orthodromic medial plantar (MP)] and conventional sensory NCS (unilateral median sensory and bilateral sural nerves) were performed in 16 definite and 2 probable ALS patients (based on Awaji criteria) and 31 controls. RESULTS: Abnormal conventional sensory NCS were found in 8 (44.4%) ALS patients and 1 (3.2%) control subject (P = 0.002), whereas abnormal distal sensory NCS were found in 12 (66.7%) ALS patients and 3 (9.6%) controls (P < 0.0001). CONCLUSION: Distal sensory NCS were more often abnormal than conventional sensory NCS in ALS. Muscle Nerve 54: 1086-1092, 2016.

The artificial somato-autonomic reflex arch does not improve lower urinary tract function in patients with spinal cord lesions.

PURPOSE: The artificial somato-autonomic reflex arch (Xiao procedure) was proposed as treatment for neurogenic bladder dysfunction. We investigated the effects of the procedure on lower urinary tract function. MATERIALS AND METHODS: Seven and 3 patients with a median age of 46 years (range 19 to 64) had AIS A and B spinal cord injury, respectively. In these patients an anastomosis was created between the ventral (motor) part of L5 and the ventral part of the S2 root. Urodynamics were performed and a standard questionnaire was completed at baseline and 18 months postoperatively. RESULTS: Artificial reflex arch stimulation did not initiate voiding or increase bladder pressure. Maximum bladder capacity did not change significantly from baseline to followup (median 427.5 ml, range 168 to 581 vs 498.5, range 271 to 580, p = 0.09). Likewise, bladder compliance did not significantly differ at baseline and followup (median 16.9 ml/cm H2O, range 15.0 to 65.0 vs 25.1, range 17.5 to 50.0, p = 0.95). No difference was found in awareness of bladder emptying, incontinence episodes, bladder emptying method or medication use for neurogenic bladder dysfunction. The only statistically significant change was a decreased incidence of leakage at followup on urodynamics (p = 0.03). Postoperatively decreased genital sensation and erectile dysfunction developed in 1 patient and another experienced a minor cerebrovascular accident with no long-term complications. CONCLUSIONS: In contrast to earlier findings, creation of an artificial somato-autonomic reflex arch in patients with spinal cord injury had no clinically relevant effect on lower urinary tract function.

High-resolution ultrasound in ulnar neuropathy at the elbow: A prospective study.

INTRODUCTION: We examined the role of ultrasound in diagnosing and localizing ulnar neuropathy (UN) at the elbow. METHODS: Forty-one patients referred for UN and 43 healthy subjects were included. Cross-sectional area (CSA) of the ulnar nerve was measured by ultrasound at 5 locations across the elbow and at the wrist. Patients underwent near-nerve conduction studies (N-NCS). RESULTS: Ultrasound (US) had a sensitivity of 80.5%, N-NCS had a sensitivity of 70.7%, and combined sensitivity was 85.4% in diagnosing UN. Using N-NCS as a reference standard, US reached a sensitivity of 93.1% and a specificity of 50.0% in diagnosing UN, and a sensitivity of 77.3% and a specificity of 42.9% in localizing UN at the elbow. There was a reduction in mean CSA at 3-month follow-up. CONCLUSIONS: N-NCS and US are complementary methods and have the potential to increase the sensitivity for diagnosing and localizing UN at the elbow.

Peripheral nervous system involvement in chronic spinal cord injury.

INTRODUCTION: Upper motor neuron disorders are believed to leave the peripheral nervous system (PNS) intact. In this study we examined whether there is evidence of PNS involvement in spinal cord injury (SCI). METHODS: Twelve subjects with chronic low cervical or thoracic SCI were included prospectively. Needle electromyography was done in 10 different muscles in each subject bilaterally. Nerve conduction studies (NCS) were conducted in the fibular, tibial, and femoral motor and fibular and sural sensory nerves. RESULTS: Half the subjects had widespread abnormal spontaneous activity (SA), and the amount of SA correlated inversely with reflex activity and nerve length. Fibular nerve entrapment across the knee was seen in 6 subjects, and sciatic nerve entrapment was seen in 1. Apart from entrapment neuropathies, NCS changes were found predominantly in motor nerves. CONCLUSION: The presence of widespread electrophysiologic changes outside entrapment sites indicates that SCI has a significant impact on the entire PNS, affecting the motor part predominantly.

Heart rate variability analysis indicates preictal parasympathetic overdrive preceding seizure-induced cardiac dysrhythmias leading to sudden unexpected death in a patient with epilepsy.

Evidence for seizure-induced cardiac dysrhythmia leading to sudden unexpected death in epilepsy (SUDEP) has been elusive. We present a patient with focal cortical dysplasia who has had epilepsy for 19 years and was undergoing presurgical evaluation. The patient did not have any cardiologic antecedents. During long-term video-electroencephalography (EEG) monitoring, following a cluster of secondarily generalized tonic-clonic seizures (GTCS), the patient had prolonged postictal generalized EEG suppression, asystole, followed by arrhythmia, and the patient died despite cardiopulmonary resuscitation. Analysis of heart rate variability showed a marked increase in the parasympathetic activity during the period preceding the fatal seizures, compared with values measured 1 day and 7 months before, and also higher than the preictal values in a group of 10 patients with GTCS without SUDEP. The duration of the QTc interval was short (335-358 msec). This unfortunate case documented during video-EEG monitoring indicates that autonomic imbalance and seizure-induced cardiac dysrhythmias contribute to the pathomechanisms leading to SUDEP in patients at risk (short QT interval).

Threshold tracking transcranial magnetic stimulation and neurofilament light chain as diagnostic aids in ALS.

OBJECTIVE: There is a need for sensitive biomarkers in amyotrophic lateral sclerosis (ALS), to enable earlier diagnosis and to help assess potential treatments. The main objective of this study was to compare two potential biomarkers, threshold-tracking short-interval cortical inhibition (T-SICI), which has shown promise as a diagnostic aid, and neurofilament light chains (NfL). METHODS: Ninety-seven patients with ALS (mean age 67.1 ± 11.5 years) and 53 ALS mimics (aged 62.4 ± 12.9) were included. Mean disease duration was 14 months ±14.1. Patients were evaluated with revised ALS functional rating score (ALSFRS-R), Penn upper motor neuron score (UMNS), muscle strength using the Medical Research Council (MRC) score and examined with T-SICI, quantitative electromyography (EMG), and NfL measured in spinal fluid. RESULTS: NfL increased with increasing UMNS (rho = 0.45, p = 8.2 × 10-6) whereas T-SICI at 2.5 ms paradoxically increased toward normal values (rho = 0.53, p = 1.9 × 10-7). However, these two measures were uncorrelated. Discrimination between ALS patients and mimics was best for NfL (area under ROC curve 0.842, sensitivity 84.9%, specificity 83.5%), compared with T-SICI (0.675, 39.6%, 91.8%). For the patients with no UMN signs, NfL also discriminated best (0.884, 89.3%, 82.6%), compared with T-SICI (0.811, 71.4%, 82.6%). However, when combining NfL and T-SICI, higher AUCs of 0.854 and 0.922 and specificities of 93.8 and 100 were found when considering all patients and patients with no UMN signs, respectively. INTERPRETATION: Both T-SICI and NfL correlated with UMN involvement and combined, they provided a strong discrimination between ALS patients and ALS mimics.

Source localization of rhythmic ictal EEG activity: a study of diagnostic accuracy following STARD criteria.

PURPOSE: Although precise identification of the seizure-onset zone is an essential element of presurgical evaluation, source localization of ictal electroencephalography (EEG) signals has received little attention. The aim of our study was to estimate the accuracy of source localization of rhythmic ictal EEG activity using a distributed source model. METHODS: Source localization of rhythmic ictal scalp EEG activity was performed in 42 consecutive cases fulfilling inclusion criteria. The study was designed according to recommendations for studies on diagnostic accuracy (STARD). The initial ictal EEG signals were selected using a standardized method, based on frequency analysis and voltage distribution of the ictal activity. A distributed source model-local autoregressive average (LAURA)-was used for the source localization. Sensitivity, specificity, and measurement of agreement (kappa) were determined based on the reference standard-the consensus conclusion of the multidisciplinary epilepsy surgery team. Predictive values were calculated from the surgical outcome of the operated patients. To estimate the clinical value of the ictal source analysis, we compared the likelihood ratios of concordant and discordant results. Source localization was performed blinded to the clinical data, and before the surgical decision. KEY FINDINGS: Reference standard was available for 33 patients. The ictal source localization had a sensitivity of 70% and a specificity of 76%. The mean measurement of agreement (kappa) was 0.61, corresponding to substantial agreement (95% confidence interval (CI) 0.38-0.84). Twenty patients underwent resective surgery. The positive predictive value (PPV) for seizure freedom was 92% and the negative predictive value (NPV) was 43%. The likelihood ratio was nine times higher for the concordant results, as compared with the discordant ones. SIGNIFICANCE: Source localization of rhythmic ictal activity using a distributed source model (LAURA) for the ictal EEG signals selected with a standardized method is feasible in clinical practice and has a good diagnostic accuracy. Our findings encourage clinical neurophysiologists assessing ictal EEGs to include this method in their armamentarium.

Standardized computer-based organized reporting of EEG: SCORE.

The electroencephalography (EEG) signal has a high complexity, and the process of extracting clinically relevant features is achieved by visual analysis of the recordings. The interobserver agreement in EEG interpretation is only moderate. This is partly due to the method of reporting the findings in free-text format. The purpose of our endeavor was to create a computer-based system for EEG assessment and reporting, where the physicians would construct the reports by choosing from predefined elements for each relevant EEG feature, as well as the clinical phenomena (for video-EEG recordings). A working group of EEG experts took part in consensus workshops in Dianalund, Denmark, in 2010 and 2011. The faculty was approved by the Commission on European Affairs of the International League Against Epilepsy (ILAE). The working group produced a consensus proposal that went through a pan-European review process, organized by the European Chapter of the International Federation of Clinical Neurophysiology. The Standardised Computer-based Organised Reporting of EEG (SCORE) software was constructed based on the terms and features of the consensus statement and it was tested in the clinical practice. The main elements of SCORE are the following: personal data of the patient, referral data, recording conditions, modulators, background activity, drowsiness and sleep, interictal findings, "episodes" (clinical or subclinical events), physiologic patterns, patterns of uncertain significance, artifacts, polygraphic channels, and diagnostic significance. The following specific aspects of the neonatal EEGs are scored: alertness, temporal organization, and spatial organization. For each EEG finding, relevant features are scored using predefined terms. Definitions are provided for all EEG terms and features. SCORE can potentially improve the quality of EEG assessment and reporting; it will help incorporate the results of computer-assisted analysis into the report, it will make possible the build-up of a multinational database, and it will help in training young neurophysiologists.

Spontaneous electromyographic activity of the tongue in amyotrophic lateral sclerosis.

INTRODUCTION: Detection of denervation in muscles in the craniobulbar area is important to assure widespread lower motor neuron involvement in the diagnosis of amyotrophic lateral sclerosis (ALS). The value of spontaneous activity analysis in needle electromyography (EMG) of the tongue has been questioned in the recent literature. METHODS: Spontaneous activity in the tongue and sternocleidomastoid (SCM) muscles was reviewed retrospectively in 17 ALS patients. RESULTS: Needle EMG showed spontaneous activity in the tongue in 14 of 17 patients (82%) and in 6 patients of 17 (35%) in SCM. Spontaneous EMG activity in the tongue was found in patients with and without bulbar symptoms. CONCLUSIONS: Needle EMG is a valuable method for assessing clinical and subclinical involvement of the tongue in patients with bulbar and limb onset ALS. Adequate relaxation of the tongue is a prerequisite for proper spontaneous activity recording.

Lifestyle risk factors for ulnar neuropathy and ulnar neuropathy-like symptoms.

INTRODUCTION: We examined whether lifestyle factors differ between patients with ulnar neuropathy confirmed by electroneurography (ENG) and those with ulnar neuropathy-like symptoms with normal ulnar nerve ENG. METHODS: Among patients examined by ENG for suspected ulnar neuropathy, we identified 546 patients with ulnar neuropathy and 633 patients with ulnar neuropathy-like symptoms. These groups were compared with 2 separate groups of matched community referents and to each other. Questionnaire information on lifestyle was obtained. The electrophysiological severity of neuropathy was also graded. We used conditional and unconditional logistic regression. RESULTS: Responses were obtained from 59%. Ulnar neuropathy was related to smoking, adjusted odds ratio (OR) 4.31 (95% confidence interval [CI] 2.43-7.64) for >24 pack-years. Ulnar neuropathy-like symptoms were related to body mass index ≥30 kg/m(2), OR 1.99 (95% CI 1.25-3.19). Smoking was associated with increased severity of ulnar neuropathy. CONCLUSIONS: Findings suggest that smoking specifically affects the ulnar nerve.

Differential effects of a 5% lidocaine medicated patch in peripheral nerve injury.

INTRODUCTION: We examined the effect of topical lidocaine on the function of small and large fibers in patients with peripheral neuropathic pain due to traumatic or postoperative nerve injury. METHODS: In an open-label study, 24 patients were treated with a 5% lidocaine patch for up to 12 weeks. We recorded contact heat evoked potentials (CHEPs) and performed quantitative sensory testing (QST) before and after treatment with the contralateral side as control. RESULTS: Twenty-one patients (mean age 47.6 ± 13.5 years) completed the study. Lidocaine increased cold pain threshold (P = 0.04) and reduced CHEP amplitude (P = 0.007) with no effect on other QST parameters. Patients responding to treatment had less cold detection deficit on the affected side and had a larger increase in cold pain detection threshold following treatment than nonresponders. CONCLUSIONS: Controlled trials are warranted to further understand the mechanisms mediating the effects of topical lidocaine.

Electrohysterography of labor contractions: propagation velocity and direction.

OBJECTIVE: Electrohysterographic assessment of the propagation velocity of uterine depolarization has been introduced as a promising predictor of preterm labor. Therefore, the objectives of this study were to characterize the uterine electrohysterographic signals during labor and to determine the propagation velocity and propagation direction of electrohysterographic signals. DESIGN: Descriptive study. SETTING: Department of Obstetrics and Gynecology, Aarhus University Hospital, Denmark. POPULATION: Eight women in active labor at term. METHODS: Electrohysterograms (three channels) were recorded using surface electrodes placed abdominally along the vertical median axis with an inter-electrode distance of 6.5-11.2 cm. In total, 89 contractions were analyzed. RESULTS: Electrohysterographic characteristics: The duration of the contractions was 61.0 ± 18.0 s (mean ± SD). The median frequency of the power spectrum density was 0.51 (0.44; 0.51) Hz (median; 10th; 90th percentile). The greatest signal magnitude was obtained by the electrode in the centermost position. The propagation velocity: 2.15 (0.66; 13.8) cm/s in the upper part and 1.53 (0.58; 6.7) cm/s in the lower part of the uterus. Propagation direction: Both downward (58%) and upward (42%) propagation of the electrohysterographic signals occurred. Moreover, downward and upward propagations were recorded simultaneously in the upper and lower part of the uterus, suggesting a multidirectional propagation pattern. CONCLUSIONS: Labor contractions, expressed by electrohysterographic signals, propagate both in the downward and upward direction, a phenomenon that must be taken into account when determining the propagation velocity for preterm labor diagnostics.

Three different short-interval intracortical inhibition methods in early diagnosis of amyotrophic lateral sclerosis.

Objectives: To compare the utility of conventional amplitude measurements of short-interval intracortical inhibition (A-SICI) with two threshold-tracking (T-SICI) methods, as aids to early diagnosis of amyotrophic lateral sclerosis (ALS). The new parallel threshold-tracking method (T-SICIp) was compared with the previously used serial tracking method (T-SICIs). Methods: 112 consecutive patients referred with the suspicion of ALS and 40 healthy controls were prospectively included. Based on clinical follow-up, patients were divided into 67 patients with motor neuron disease (MND) comprising progressive muscular atrophy (PMA) as well as ALS, and 45 patient controls. SICI was recorded from first dorsal interosseus muscle using the three different protocols. Results: MND patients had significantly reduced T-SICIp, T-SICIs and A-SICI, compared with healthy controls and patient controls, while healthy and patient controls were similar. Paradoxically, T-SICIp was least affected in MND patients with the most upper motor neuron (UMN) signs (Spearman ρ = 0.537, P < 0.0001) whereas there was no correlation for T-SICIs or A-SICI. T-SICIp also provided the best discrimination between patient controls and MND as determined by the receiver operating characteristic (ROC) curves. For patients with no UMN signs, area under ROC curve for 2-3ms inter-stimulus intervals was 0.931 for T-SICIp, 0.771 for T-SICIs and 0.786 for A-SICI. Conclusions: SICI is a sensitive measure for detection of cortical involvement in ALS patients. T-SICIp has higher sensitivity and specificity than T-SICIs and A-SICI, particularly in patients without any upper motor neuron signs.

Ulnar neuropathy and ulnar neuropathy-like symptoms in relation to biomechanical exposures assessed by a job exposure matrix: a triple case-referent study.

OBJECTIVES: We aimed to evaluate relations between occupational biomechanical exposures and (1) ulnar neuropathy confirmed by electroneurography (ENG) and (2) ulnar neuropathy-like symptoms with normal ENG. METHODS: In this triple case-referent study, we identified all patients aged 18-65 years, examined with ENG at a neurophysiological department on suspicion of ulnar neuropathy, 2001-2007. We mailed a questionnaire to 546 patients with ulnar neuropathy, 633 patients with ulnar neuropathy-like symptoms and two separate groups of community referents, matched on sex, age and primary care centre (risk set sampling). The two patient groups were also compared to each other directly. We constructed a Job Exposure Matrix to provide estimates of exposure to non-neutral postures, repetitive movements, hand-arm vibrations and forceful work. Conditional and unconditional logistic regressions were used. RESULTS: The proportion who responded was 59%. Ulnar neuropathy was related to forceful work with an exposure-response pattern reaching an OR of 3.85 (95% CI 2.04 to 7.24); non-neutral postures strengthened effects of forceful work. No relation was observed with repetitive movements. Ulnar neuropathy-like symptoms were related to repetitive movements with an OR of 1.89 (95% CI 1.01 to 3.52) in the highest-exposure category (≥2.5 h/day); forceful work was unrelated to the outcome. CONCLUSIONS: Ulnar neuropathy and ulnar neuropathy-like symptoms differed with respect to associations with occupational biomechanical exposures. Findings suggested specific effects of forceful work on the ulnar nerve. Thus, results corroborated the importance of an electrophysiological diagnosis when evaluating risk factors for ulnar neuropathy. Preventive effects may be achieved by reducing biomechanical exposures at work.