Neurological examination of the upper limb: a study of construct validity.

OBJECTIVE: We have previously demonstrated that neurological individual findings and patterns can be reliably assessed in the examination of the upper limb and also that they are related to pain, weakness, and/or numbness/tingling. This study aimed to study further aspects of the construct validity of the neurological examination. METHODS: Blinded to patient-characteristics, two examiners assessed the function of 16 muscles, the sensibility in 7 territories, and the nerve-mechanosensitivity at 20 locations in 82 upper limbs. Based on anatomical patterns and pre-designed algorithms, one or both examiners rated neuropathy as "possible" or "definite" in 40 limbs and also determined the location( s). We developed and tested hypotheses on anatomically and regionally related locations of nerve afflictions (a selective vulnerability of neurons, double and multiple crush, and a tendency to regional spread) and examined the stability of the internal structure of the constructs in different situations. The interrelations of findings were analyzed by hypothesis testing and factor analyses, and the homogeneity of location profiles was analyzed by a conditional likelihood test. RESULTS: Out of 30 limbs with related locations of neuropathy, the findings of each examiner correlated positively (gamma > 0.35) in 22/25, respectively. The patterns of the interrelations identified by the two examiners were similar, with no evidence of any heterogeneity of location profiles for either examiner. CONCLUSIONS: This study supports the validity of the physical examination. However, feasibility of its application requires the demonstration of further aspects of construct validity and a favorable influence on patient-management and/or prevention.

Fatal occupational accidents in Danish fishing vessels 1989-2005.

The purpose of the study was to study the circumstances and incidence rates of fatal accidents in inspection obligated and non-inspection obligated Danish fishing vessels to identify areas for prevention. Information about the fatalities came from maritime authority reports, including vessel disaster reports, post mortem reports, maritime inquiries and police reports. The person- and vessel years at risk came from the Danish Directorate of Fisheries. During the period 1989-2005, 114 fatalities occurred. Sixty-one of the fatalities occurred in 36 vessel disasters mainly caused by foundering/capsizing due to stability changes in rough weather and collisions; 39 fatal occupational accidents mainly occurred on the larger inspection obligated trawlers during fishing. In the remaining 14 other fatal accidents, the main causal factors were difficult embarking/disembarking conditions by darkness in foreign ports and alcohol intoxication. In the period 1995-2005, the overall incidence rate was 10 per 10,000 fishermen per year with no down-going trend during that period. The fatal accident rates are still too high, despite the efforts to reduce the risk. Increased focus on regular and repeated safety training for all fishermen and improved safety measures are needed, especially in the underscored areas of sea disasters concerning small vessels and occupational accidents on big vessels. Better registration of time at risk for fishermen is needed to validate the effect of the safety measures.

Major differences in rates of occupational accidents between different nationalities of seafarers.

OBJECTIVES: Earlier studies and statistics have shown that merchant seafarers from the South East Asia had considerable lower accident rates when compared with seafarers from Western Europe. The purposes of the study were to investigate whether the earlier observations were sustained if further sources on occurrence of accidents were used and to identify specific causes of excess accident rates among certain nationalities. METHODS: Occupational accidents aboard Danish merchant ships during one year were identified from four different sources. These included accidents reported to the maritime authorities, accidents reported to a mutual insurance company, files on medical costs reimbursed by the government and finally, accidents in which there has been contact to the radio medical service. Time at risk aboard was obtained from a register on all employment periods aboard merchant ships. RESULTS: A total of 943 accidents causing personal injury to a seafarer directly caused by work aboard were identified. Among these accidents, 499 had taken place aboard cargo ships in international trade. Only these were used in the detailed analysis. The accident rate for all identified accidents aboard cargo ships were 84 accidents per 1,000 years aboard. The crude incidence rate ratio (IRR) for East European seafarers was 0.88 and for South East Asians 0.38 using West European seafarers as reference. In a Poisson regression analysis, the IRR for South East Asians was 0.29 (0.22-0.38). In an analysis including only more serious accidents, IRR for South East Asians rose to 0.36 (0.26-0.48). DISCUSSION: This study indicates that seafarers from South East Asia, mainly the Philippines, may have a genuine lower risk of occupational accidents in comparison with seafarers from Western and Eastern Europe. Differences in approach to safety and risk taking between South East Asian and European seafarers should be identified and positives attitudes included in accident preventing programmes. Main messages Seafarers from South East Asia, mainly the Philippines, seem to have a genuine lower risk of occupational accidents in comparison with seafarers from Western and Eastern Europe. POLICY IMPLICATIONS: Differences in approach to safety and risk taking between South East Asian and European seafarers should be identified and positives attitudes included in accident preventing programmes.

Diagnostic distribution of non-traumatic upper limb disorders: vibrotactile sense in the evaluation of structured examination for optimal diagnostic criteria.

BACKGROUND: Upper limb disorders (ULDs) are common, and so are the difficulties in specific diagnoses of these disorders. Prior studies have shed light on the nerves in the diagnostic approach beside disorders related to muscles, tendons and joints (MCDs). OBJECTIVE: The study aimed to compare the distribution of upper limb disorders, and the vibration perception threshold (VPT) in different diagnostic groups according to 1) A-criteria: the SALTSA consensus criteria, including MCDs and four peripheral neuropathies, and 2) B-criteria: including MCDs and 10 different neuropathy diagnoses--re-defined in an attempt to refine diagnostic criteria of peripheral neuropathy in respect of different MCDs; and further to discuss the impact of the presented criteria. METHODS: 161 patients--recruited from 21 general practitioners--were examined by the same examiner according to the two sets of diagnostic criteria. VPT measurements were conducted in all patients. RESULTS: Three patients did not fulfill the criteria of any ULD diagnosis. A/B criteria were fulfilled for 181/183 upper limbs, respectively, out of which 29.3%/163.3% were neuropathy diagnoses alone, 23.8%/10.9% MCD alone, and 46.9%/25.7% were categorized as neuropathy in combination with MCD diagnoses. The overall agreement on presence of neuropathy was high (75%), but on focal level there was a large discrepancy. According to the A-criteria, patients with symptoms located at wrist and shoulder were primarily defined with wrist diagnoses, and only few had concomitant shoulder diagnoses. In contrast, the B-criteria primarily defined neuropathy located at the shoulder, often concomitantly with neuropathy of the radial and the median nerve at the elbow, but seldom at the wrist level. In MCDs defined by both sets of criteria--Rotator cuff syndrome and medial/lateral epicondylitis--the A-criteria defined more MCDs than the B-criteria, the B diagnoses typically constituted only a part of the A diagnoses and additionally defined neuropathy. The B-criteria showed more significant VPT findings than the A-criteria concerning the discrimination between limbs with and contralateral limbs without diagnoses as well as between diagnostic groups with and without neuropathy. CONCLUSIONS: The VPT findings suggest the B-criteria to be superior to A-criteria for differentiating between patients with and without neuropathy. This study shows that neuropathy is extensive in ULDs when specific diagnostic criteria are used. Additionally it suggests the importance of a critical revision of the current diagnostic criteria of upper limb neuropathy, and the differential diagnoses concerning the MCDs. Management and prevention is highly dependent on correct diagnoses.

Diagnostic accuracy of the neurological upper limb examination II: relation to symptoms of patterns of findings.

BACKGROUND: In a sample of patients in clinical occupational medicine we have demonstrated that an upper limb neurological examination can reliably identify patterns of findings suggesting upper limb focal neuropathies. This further study aimed at approaching the diagnostic accuracy of the examination. METHODS: 82 limbs were semi-quantitatively assessed by two blinded examiners (strength in 14 individual muscles, sensibility in 7 homonymous territories, and mechanosensitivity at 10 locations along nerves). Based on the topography of nerves and their muscular and sensory innervation we defined 10 neurological patterns each suggesting a localized nerve affliction. Information on complaints (pain, weakness and/or numbness/tingling) collected by others served as a reference for comparison. The relation between the presence of pattern(s) and complaints was assessed by kappa-statistics. Sensitivity, specificity, and positive/negative predictive values were calculated, and pre-test odds were compared to post-test probability. RESULTS: The two examiners identified pattern(s) suggesting focal neuropathy in 34/36 out of 38 symptomatic limbs, respectively (kappa = 0.70/0.75), with agreement in 28 limbs. Out of 44 non-symptomatic limbs the examiners agreed on absence of any pattern in 38 limbs. With concordance between the examiners with regard to the presence or absence of any pattern, the sensitivity, specificity, positive and negative predictive values were 0.73, 0.86, 0.93 and 0.90, respectively. While the pre-test odds for a limb to be symptomatic amounted to 0.46 the post-test probability was 0.81. For each examiner the post-test probability was 0.87 and 0.88, respectively. CONCLUSION: The improved diagnostic confidence is an indication of one aspect of construct validity of the physical examination. For determination of clinical feasibility of the examination further studies are required, most importantly 1) studies of validity by means of comparison with additional references and 2) studies of the potential benefit that can be attained from its use.

Vibrotactile sense in patients with different upper limb disorders compared with a control group.

BACKGROUND: Upper limb disorders (ULDs) are common, and so are the difficulties with regard to their specific diagnoses. According to diagnostic consensus criteria, specific diagnoses include neuropathy and muscular- and connective-tissue disorders (MCDs). There is a need for valid objective diagnostic tools to reveal underlying mechanisms for specific diagnoses. OBJECTIVE: To investigate the possible differences in vibration perception threshold (VPT) and tolerance to suprathreshold stimulation (STS) between controls and specific diagnostic ULD patient groups with uni- and bilateral neuropathy and/or MCD. METHODS: In 161 ULD patients and 40 controls, the VPT of the median, ulnar, and radial nerves innervating the hand was examined by vibrometry using the "method of limits". The tolerance to STS of the anterior forearm was tested in 128 of the patients and all controls. RESULTS: The ULD patients in all diagnostic groups had significantly higher VPT (P<0.05) in all the nerves in limbs, with and without diagnoses compared with controls. Only patient groups defined with neuropathy demonstrated significantly higher VPT in the limb with diagnoses compared with the contralateral limb without diagnoses. The highest VPTs were found in the patient group with unilateral neuropathy and MCD, and for the radial nerve, VPT was significantly higher than that for patients with unilateral MCD alone. These findings were confirmed by almost similar findings in STS responses. CONCLUSIONS: The ULD patients generally demonstrated increased VPT compared with controls, indicating a neurogenous component independent of specific ULD diagnosis. Contralateral significant findings in limbs without diagnoses compared with controls indicate central neurogenous affection and/or the possibility of certain exposures elevating VPT before a positive status of a limb diagnosis is attained. Significantly higher VPT values in limbs with neuropathy diagnoses compared with limbs without and not in MCD alone, may indicate peripheral sensibilization or nerve affection only in the group with a specific diagnosis of neuropathy. These findings underline the importance of specific diagnoses among ULD patients.

Diagnostic accuracy of the neurological upper limb examination I: inter-rater reproducibility of selected findings and patterns.

BACKGROUND: We have previously assessed the reproducibility of manual testing of the strength in 14 individual upper limb muscles in patients with or without upper limb complaints. This investigation aimed at additionally studying sensory disturbances, the mechanosensitivity of nerve trunks, and the occurrence of physical findings in patterns which may potentially reflect a peripheral neuropathy. The reproducibility of this part of the neurological examination has never been reported. METHODS: Two blinded examiners performed a semi-quantitative assessment of 82 upper limbs (strength in 14 individual muscles, sensibility in 7 homonymous territories, and mechanosensitivity of nerves at 10 locations). Based on the topography of nerves and their muscular and cutaneous innervation we defined 10 neurological patterns each suggesting a focal neuropathy. The individual findings and patterns identified by the two examiners were compared. RESULTS: Strength, sensibility to touch, pain and vibration, and mechanosensitivity were predominantly assessed with moderate to very good reproducibility (median kappa-values 0.54, 0.69, 0.48, 0.58, and 0.53, respectively). The reproducibility of the defined patterns was fair to excellent (median correlation coefficient = 0.75) and the overall identification of limbs with/without pattern(s) was good (kappa = 0.75). CONCLUSION: This first part of a study on diagnostic accuracy of a selective neurological examination has demonstrated a promising inter-rater reproducibility of individual neurological items and patterns. Generalization and clinical feasibility require further documentation: 1) Reproducibility in cohorts of other composition, 2) validity with comparison to currently applied standards, and 3) potential benefits that can be attained by the examination.

Manual strength testing in 14 upper limb muscles: a study of inter-rater reliability.

BACKGROUND: Manual muscle testing has been termed a "lost art" and is often considered to be of minor value. The aim of this investigation was to study the inter-rater reliability of manual examination of the maximal voluntary strength in a sample of upper limb muscles. PATIENTS AND METHODS: The material consisted of a series of 41 consecutive patients (82 limbs) who had been referred to a clinic of occupational medicine for various reasons. Two examiners who were blinded as to patient-related information classified 14 muscles in terms of normal or reduced strength. In order to optimize the evaluation, the individual strength was assessed simultaneously on the right and left sides with the limbs in standardized positions that were specific for each muscle. Information on upper limb complaints (pain, weakness and/or numbness/tingling) collected by two other examiners resulted in 38 limbs being classified as symptomatic and 44 as asymptomatic. For each muscle the inter-rater reliability of the assessment of strength into normal or reduced was estimated by kappa-statistics. In addition, the odds ratio for the relation to symptoms of the definition in agreement of strength was calculated. RESULTS: The median kappa-value for strength in the muscles examined was 0.54 (0.25-0.72). With a median odds ratio of 4.0 (2.5-7.7), reduced strength was significantly associated with the presence of symptoms. INTERPRETATION: This study suggests that manual muscle testing in upper limb disorders has diagnostic potential.