Costanza Pazzaglia

Carpal Tunnel Syndrome: ultrasound, neurophysiology, clinical and patient-oriented assessment

OBJECTIVE The aim of this study is twofold. First, to assess the relationships between the cross-sectional area (CSA) of the median nerve (MN) calculated at ultrasound (US) and: (1) patients perception of his/her symptoms and hand function; (2) clinical severity of CTS; (3) neurophysiological classification; (4) hand distribution of symptoms. Second, to assess the sensitivity of ultrasonography (US) and neurophysiology in the diagnosis of CTS using clinical measures as gold standard. METHODS We performed a prospective study by using multidimensional assessment: clinical (Historic and Objective scale, Hi-Ob), neurophysiological, patient-oriented measures (Boston Carpal Tunnel Questionnaire, BCTQ) and high-resolution US. The dominant hands of 54 consecutive patients who were referred to our neurophysiologic laboratory with clinical signs of CTS (43 females, mean age 53.3, range 30-80, SD: 13.1) were examined. RESULTS A statistically significant correlation was found between the CSA of the MN at wrist and (1) hand function (according to BCTQ, r=0.35, p=0.01), (2) clinical scale (Hi-Ob scale, r=0.51, p<0.00007), (3) neurophysiologic classification (r=0.80, p<0.0000001), and (4) hand distribution of symptoms (p=0.017). Neurophysiology showed higher sensitivity than US but in one of 3 cases with normal neurophysiological results, US showed data suggestive of CTS. CONCLUSIONS A positive correlation exists between US findings and all the conventional measures of CTS severity. The sensitivity of the combination of US and neurophysiology is higher than the sensitivity of neurophysiology or US alone. US is a useful complementary tool for CTS assessment. SIGNIFICANCE Information on the contribution of US in CTS and the interpretation of severity measurements in CTS.

Intra- and internerve cross-sectional area variability: new ultrasound measures.

Introduction: Nerve involvement in immune‐related neuropathies is non‐homogeneous, and therefore characterization of ultrasound (US) abnormalities is difficult. We developed two measures to quantify US abnormalities in immune‐related neuropathies. Methods: Intranerve cross‐sectional area (CSA) variability for each nerve was calculated as: maximal CSA/minimal CSA. Internerve CSA variability for each patient was calculated as: maximal intranerve CSA variability/minimal intranerve CSA variability. Six patients underwent US evaluation of the median, ulnar, and fibular nerves, and the abnormalities were scored with our newly developed measures. Results: The new measures were applicable to all nerves and patients. The highest degree of intra‐ and internerve CSA variability was observed in multifocal motor neuropathy, consistent with the asymmetric characteristics of this neuropathy. Conclusions: The application of intra‐ and internerve CSA variability measures allows us to quantify the heterogeneity of nerves and nerve segments and identify different US patterns in diverse immune‐related neuropathies. Muscle Nerve, 2012

Sonographic measurement of cross-sectional area of the median nerve in the diagnosis of carpal tunnel syndrome: Correlation with nerve conduction studies

Purpose. To assess the usefulness of sonographic measurement of the median nerve cross-sectional area (CSA) in the diagnosis of carpal tunnel syndrome (CTS) and grading of its severity using nerve conduction (NC) studies as the standard. Method. The CSA of the median nerve was measured at the tunnel inlet and outlet using the ellipse formula and automatic tracing in 72 hands with suspicion of CTS. Result. The lack of inter-reader reliability led to excluding CSA measurements obtained at the tunnel outlet. Based on the receiver operating characteristic curves, the following cut-off points for the CSA of the median nerve at the tunnel inlet was selected: 9.8 mm and 12.3 mm2 for the ellipse formula and 11 and 13 mm2 for automatic tracing. For the ellipse formula, a CSA less than or equal to 9.8 mm2 excluded CTS whereas a CSA greater than or equal to 12.3 mm2 was diagnostic of CTS with measurements between 9.8 and 12.3 mm2 being indeterminate and requiring NC studies. For automatic tracing, the cutoff value of 11 mm2 was excluded because of the high percentage of false negatives, whereas CSAs greater than or equal to 13 mm2 were diagnostic of CTS. There were no statistically significant differences in CSA measurements between the various degrees of CTS severity determined by NC studies. Conclusion. Sonographic measurement of median nerve CSA at the tunnel inlet is a good alternative to NC studies as the initial diagnostic test for CTS, but it cannot grade the severity of CTS as well as NC studies.

Contribution of ultrasound in a neurophysiological lab in diagnosing nerve impairment: A one-year systematic assessment

OBJECTIVE To evaluate the usefulness of a combination of electromyography (EMG) and ultrasound (US) assessments in diagnosing nerve trunk involvement. We hypothesised that in some cases, when the clinical or neurophysiological picture is unclear, the simultaneous study of the peripheral nervous system through both US and EMG may provide pathologic information not obtainable through EMG alone, and this may influence therapeutic decisions. METHODS In 2005, we performed a prospective study in 77 consecutive patients with involvement of a single nerve trunk, using a combination of EMG and US in the same session. We divided the diagnostic contribution of US into four categories: diagnostic, confirming, inconclusive and misdiagnostic. RESULTS In about a quarter of the patients, US provided results confirming the clinical neurophysiological diagnosis. In another quarter of the cases, US was very helpful in modifying diagnosis and therapy. In most of these cases, the contribution of US was important for the detection of tumors or cysts, thus showing the cause of nerve involvement. In half of the cases the US results were inconclusive, and in one case US was misdiagnostic. CONCLUSIONS The combination of EMG and US performed in the same session (or in collaboration with an ultrasound examiner) may be useful for diagnosis and determination of appropriate therapy. SIGNIFICANCE Diagnosis of mononeuropathies is improved through a combined functional and morphological evaluation of the nerve by using EMG and US.

Differential involvement of A-delta and A-beta fibres in neuropathic pain related to carpal tunnel syndrome

ABSTRACT Carpal tunnel syndrome (CTS), a common entrapment neuropathy involving the median nerve at the wrist, frequently manifests with neuropathic pain. We sought information on pain mechanisms in CTS. We studied 70 patients with a diagnosis of CTS (117 CTS hands). We used the DN4 questionnaire to select patients with neuropathic pain, and the Neuropathic Pain Symptom Inventory (NPSI) to assess the intensity of the various qualities of neuropathic pain. All patients underwent a standard nerve conduction study (NCS) to assess the function of non‐nociceptive A&bgr;‐fibres, and the cutaneous silent period (CSP) after stimulation of the IIIrd and Vth digits, to assess the function of nociceptive A&dgr;‐fibres. In 40 patients (75 CTS hands) we also recorded laser‐evoked potentials (LEPs) in response to stimuli delivered to the median nerve territory and mediated by nociceptive A&dgr;‐fibres. We sought possible correlations between neurophysiological data and the various qualities of neuropathic pain as assessed by the NPSI. We found that the median nerve sensory conduction velocity correlated with paroxysmal pain and abnormal sensations, whereas LEP amplitude correlated with spontaneous constant pain. Our findings suggest that whereas paroxysmal pain and abnormal sensations reflect demyelination of non‐nociceptive A&bgr;‐fibres, spontaneous constant pain arises from damage to nociceptive A&dgr;‐fibres.

Contribution of ultrasound in the assessment of nerve diseases.

Background and purpose:  Recently, ultrasound (US) has been used to assess the peripheral nervous system; however, there is no real study about its possible significant role in routine practice. Our study aims to assess the contribution of US as a routine tool in a neurophysiological laboratory.

Predictive variables on disability and quality of life in stroke outpatients undergoing rehabilitation

The purposes of this study were: (1) to evaluate the relationship between disability and Quality of Life (QoL) in stroke outpatients undergoing rehabilitation and (2) to determine whether and how demographic and social features of the patient, duration of disease and concomitant diseases influence the disability and QoL of the stroke outpatients. We performed a prospective study using several conventional disability measurements (Barthel Index, Functional Independence Measure, Modified Rankin Scale and Deambulation Index) and a validated patient-oriented measurement of QoL (SF-36). Sixty-eight outpatients were evaluated consecutively. As expected, all disability measurements were related to Physical Function: patients with higher disability, according to the physician’s perspective, complained of higher deterioration of physical performance. Unexpectedly, patients with higher disability from the physician’s point of view perceive that they were not able to do some daily activities not only because of physical problems but also because of emotional problems, and complained of higher deterioration of mental health. Multivariate analysis showed that higher disability is associated with higher age, depression and lower educational level. Physical Composite Score appeared to be deteriorated in patients with lower educational level who lived with family; on the contrary, Mental Composite Score appeared deteriorated in patients with higher educational level who lived alone. The current study provides interesting data about the relationship, not always expected, between disability and QoL for stroke patients and about the influence of patients’ characteristics on disability and QoL. Our results showed that in a rehabilitation programme we should consider not only disability assessment but also QoL, which is more relevant for the patient.

Clinical usefulness of laser evoked potentials

Several papers were published since the first clinical applications of laser evoked potentials (LEPs) in disorders of the nociceptive system. While studies produced until five years ago were mostly addressed at identifying lesions of the nociceptive system, more recent papers used LEPs as an instrumental tool for the diagnosis of neuropathic pain. LEPs have also proved useful in demonstrating the pathophysiological mechanisms underlying different types of neuropathic pain (e.g., paroxystic and ongoing neuropathic pain). This is of utmost importance, as pain treatment should take physiopathological mechanisms, rather than etiology into account. Although there are still some limits for the routine use of LEPs as a diagnostic tool, this review of the literature demonstrates that LEP recording has become mandatory for the functional assessment of patients with hypoalgesia or neuropathic pain.

Systematic review of pregnancy-related carpal tunnel syndrome

The reported incidence of pregnancy‐related carpal tunnel syndrome (PRCTS) ranges from 0.8% to 70%, and little is known of its natural history. We systematically reviewed the reported incidence of PRCTS and evaluated its natural history. We identified 214 studies that fulfilled our selection criteria. Six publications fulfilled the inclusion criteria. Five fulfilled the incidence criteria, 3 fulfilled the natural history criteria, and 2 of the 6 publications satisfied both. The reported incidence of neurophysiologically confirmed PRCTS ranged from 7% to 43%, whereas the incidence of clinically diagnosed PRCTS ranged from 31% to 62%. Symptoms persisted in more than 50% of the patients after 1 year and in about 30% after 3 years. Our review suggests that variations in the reported incidence of PRCTS largely depend on the methods used to detect this syndrome. Our data also suggest that symptoms persist in a substantial number of patients 1 or more years after delivery. Muscle Nerve 42: 697–702, 2010

ULTRASOUND VISUALIZATION OF NERVE MORPHOLOGICAL ALTERATION AT THE SITE OF CONDUCTION BLOCK

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired autoimmune peripheral neuropathy. Neurophysiological investigations are the most important tool for establishing the diagnosis, as electrophysiological findings reveal a prominent demyelinating process, frequently resulting in conduction block. Previous studies performed with ultrasound (US) or magnetic resonance in CIDP and in other