Ulnar nerve lesion at the wrist and sport: A report of 8 cases compared with 45 non-sport cases.

OBJECTIVE: Reporting clinical and electrodiagnostic characteristics of sport-related ulnar neuropathies at the wrist. PATIENTS AND METHODS: Eight sport-related and 45 non-sport-related cases from 53 ulnar neuropathies at the wrist cases over 14 years. RESULTS: Sport-related ulnar neuropathies at the wrist cases were due to cycling (5 cases), kayaking (2 cases), and big-game fishing (1 case). No patient had sensory complaints in ulnar digits, and all had motor impairment. Conduction across the wrist with recording on the first dorsal interosseous muscle was impaired in all cases, with conduction block in 5. Two cyclists showed bilateral ulnar neuropathies at the wrist. All cases recovered within 2 to 6 months with sport discontinuation. Distal lesions of the deep motor branch were more frequent in sport- than non-sport-related cases. CONCLUSIONS: The 8 sport-related ulnar neuropathies at the wrist cases involved the deep motor branch. Conduction study to the first dorsal interosseous muscle across the wrist is the key to electrodiagnostics. Bilateral cases in cyclists does not require wrist imaging.

Electrophysiological pattern of 53 cases of ulnar nerve lesion at the wrist.

OBJECTIVE: We aimed to evaluate the relative diagnostic sensitivity and specificity of different motor and sensory conduction electrodiagnostic (EDX) tests used to demonstrate ulnar neuropathy at the wrist (UNW). We also reported some data on associated nerve lesions and unusual causes of UNW. PATIENTS AND METHODS: A prospective case series was conducted in 53 cases of UNW and 100 cases of ulnar neuropathy at elbow (UNE). All cases underwent the same EDX examination according to a protocol defined in 1997. A few cases required additional conduction tests with coaxial needle recording. RESULTS: The diagnostic sensitivity of the distal motor latency (DML) to adductor digiti minimi (ADM) and sensory conduction was 42% and 19% respectively. The diagnostic sensitivity of the DML to first dorsal interosseous (FDI) was 66% and studying conduction across the wrist to search for conduction block (CB) improved the diagnostic sensitivity up to 90%. In 10% of cases, no EDX test of this protocol allowed locating the site of the UNL. The specificity of each test was 100% for controls, and varied from 100% for conduction block (CB), to 95% (DML to FDI) for UNE. CB at the wrist in UNW was 2.7times more frequent than at the elbow in UNE (57% vs. 22%; P<0.0001). Finally, we found three cases of isolated sensory UNW, 16 of sensory and motor UNW, and 34 of pure motor lesions. A median nerve lesion at the wrist coexisted in 22 cases. CONCLUSIONS: Improving UNW diagnosis requires systematic study of the ulnar motor conduction to FDI across the wrist, and in a few cases conduction tests with a coaxial needle recording.

A new electrode placement for recording the compound motor action potential of the first dorsal interosseous muscle.

OBJECTIVE: This paper describes a new electrode placement for recording compound muscle action potentials (CMAPs) of the first dorsal interosseous muscle (FDI) to determine the distal motor latency (DML) and study nerve conduction of the ulnar nerve across the wrist. METHODS: The DML to the FDI was evaluated bilaterally in 90 subjects after stimulation 1cm proximal to the distal wrist crease and at the palm. The CMAP was recorded with a pair of disposable surface electrodes fixed over the FDI and wrist. RESULTS: The CMAP never exhibited a positive initial deflection, with a gain of 0.5 mV per division. DML to the FDI was 2.65±0.26 ms (mean±SD), and CMAP amplitude was 14.7±3.3 mV. A prolonged DML was taken as 3.4 ms (mean+3 standard deviation [SD]). CONCLUSIONS: This new electrode placement offers more reproducible results for determining the DML to the FDI as it provides the shortest DML, and the tightest SD values. SIGNIFICANCE: This result is obtained through the respect of fundamental rules for CMAP recording, as it shows no positive wave at the onset of the CMAP of the FDI. Its use should improve the diagnosis of ulnar nerve lesions at the wrist and more especially of the deep motor branch.

A painless complete abdominal wall palsy with groin and thigh paresthesiae related to traffic accident injury.

INTRODUCTION: No case of complete unilateral abdominal wall palsy, occurring after a traffic accident, was found in the literature data. We report one case. CASE REPORT: A 32-year-old woman was treated for a large abdominal hernia by mesh prosthesis nine years after a traffic accident injury. Surgery led to an iatrogenic lesion of the right lateral femoral cutaneous nerve (LFCN). During the electrodiagnostic examination for the LFCN lesion, abdominal wall palsy was diagnosed. Analysis of the patient's history and clinical, electrophysiological, and imaging data revealed that this abdominal wall palsy was related to a tear of the T10 to L2 anterior roots, plexus or nerves, a consequence of the violent deceleration during the car crash. CONCLUSION: This report highlights the importance of clinical examination, electrodiagnosis and imaging in diagnosing abdominal wall palsy.

Accessory nerve lesion after cervicofacial lift: clinical and electrodiagnostic evaluations of two cases.

Two cases of accessory nerve lesion are reported that occurred within 2.5 weeks and 4.5 weeks, respectively, after surgery for cervicofacial lift. The patients were referred for electrodiagnostic examination because of persistent and unexplained unilateral shoulder pain and disability, 6 and 5 months, respectively, after face lift. In both cases clinical examination revealed severe right-shoulder weakness related to trapezius palsy, without trapezius muscle atrophy in the first case and with trapezius atrophy in the second. Electrodiagnosis revealed bilateral accessory nerve lesions in the first case and a unilateral lesion in the second case. Recovery for both cases was progressive but delayed, and both were evaluated 11 and 10 months, respectively, after the first evaluation. Clinical and especially electrodiagnostic findings suggested that the accessory nerve lesion was related to conduction block in the first case and severe axonal loss in the second case.

[Entrapment neuropathies involving the ulnar nerve at the wrist (and into the hand) and the peroneal nerve]. / Neuropathies compressives du nerf ulnaire au poignet (et dans la main) et du nerf fibulaire commun. Données récentes.

We report our experience with patients who underwent surgery for entrapment neuropathies involving the ulnar nerve at the wrist and into the hand and the peroneal nerve. For the ulnar nerve, the cause of the lesion was identified in all patients, generally a cyst which had developed in the Guyon canal. The patients usually recovered completely. For the peroneal nerve, there was a wide variety of causes, with mucoid cysts frequently involved. Recovery was often incomplete, because of the very marked initial axonal damage. We emphasized the need for rapid diagnosis and surgical treatment.

Complete fatty degeneration of lumbar erector spinae muscles caused by a primary dysferlinopathy.

Magnetic resonance imaging of the thoracolumbar spine showed complete fatty degeneration of the lumbar erector spinae muscles in a woman who had complained of chronic lower back pain for 5 years and of progressive weakness of the lower limbs for 1 year. Neuromuscular examination of the lower limbs showed no obvious anomaly, and there was no camptocormia. Serum creatine kinase levels were increased (six- to ninefold); electrodiagnostic examination revealed no activity at rest or during effort in the erector spinae muscles and was normal in proximal and distal muscles of the limbs. Muscle computed tomography revealed mild fatty degeneration of thigh and gastrocnemius muscles, and histopathology of the deltoid muscle showed dystrophic features and complete lack of dysferlin. Molecular analysis identified a homozygous disease-causing mutation in the gene encoding dysferlin. Because there were no similar cases in the family, the final diagnosis was sporadic limb-girdle muscular dystrophy type 2B. Overall, this case report shows that the lumbar and lower thoracic of erector spinae muscles may display complete fatty degeneration without the occurrence of camptocormia, with primary dysferlin deficiency as a possible cause.

Sonography and electrodiagnosis in carpal tunnel syndrome diagnosis, an analysis of the literature.

We present a review of the international literature concerning sonography for the diagnosis of carpal tunnel syndrome (CTS). Analysis of the results and comparison with electrodiagnostic data provide a sensible albeit personal view on the relevance of sonography and whether it competes or is complementary to electrodiagnosis (EDX). Although EDX is considered as the gold standard for CTS diagnosis, one author chose surgical results to define CTS. The normal and threshold mean values for sonography are particularly variable from one study to another. The standard deviation (S.D.), when compared to mean values, makes normal and abnormal data overlap considerably and produces many false negatives when the specificity is high, and many false positives when the sensitivity is high. In fact, sonography is non-interpretable in only 10 to 15% of the population, and it affirms the median nerve lesion at the wrist in 55% of cases when EDX does it in more than 90% with common tests. Further more the specificity of sonography leads to a false positive diagnosis in 1 case out of 5 versus 1 out of 40 with EDX. The main conclusion is that there is no competition but rather a complementarity between sonography and EDX: sonography is certainly an efficient imaging technique but cannot replace proper EDX performed for upper limb paresthesiae. Namely, sonography can answer only one out of the 8 questions a complete EDX answer: Are sonographic images compatible with a median nerve lesion at the wrist? The answer to this solely question can be obtain with a partial EDX using a single conduction test (motor or sensitive), then duration and cost will be comparable to sonography but will be both more sensitive and specific. Finally, one must kept in mind that the final aim of all examinations in CTS is to determine the cause(s) of upper limb paresthesiae, not simply if there is a median nerve lesion at wrist or not.

The long thoracic nerve conduction study revisited in 2006.

OBJECTIVE: To compare the reliability and feasibility of recording long thoracic nerve (LTN) conductions either with surface or needle electrodes. METHODS: The nerve conduction studies were carried out bilaterally on 40 control subjects. The LTN was first stimulated at the axilla and recorded with surface electrodes located on the 7th or 8th digitations of the serratus anterior (SA), then stimulated at Erb's point and recorded with a needle inserted in the 6th or 7th digitations of the SA. For each method, the latency and amplitude of the motor action potential were recorded. RESULTS: Responses were recorded on both sides for each patient. With surface recording, the mean latency was 2.2 +/- 0.30 ms, and the mean amplitude was 5.3 +/- 2.4 mV. With needle recording, the mean latency was 3.65 +/- 0.45 ms, and the mean amplitude was 8.95 +/- 4 mV. CONCLUSIONS: This study demonstrates that both techniques are reliable, feasible, and correlate well. SIGNIFICANCE: Our study shows surface recording of nerve conduction should be favored because it is non-traumatic, less uncomfortable for the patient, and less prone to pitfalls. Nevertheless, in pathological cases, both techniques should be used at initial and follow-up examinations in order to better assess axonal loss and nerve conduction impairment.

Meralgia paresthetica: clinical and electrophysiological diagnosis in 120 cases.

We report the results of clinical and electrophysiological examinations in 131 cases of meralgia paresthetica (MP) among 120 unselected patients, 69 men and 51 women, aged 15-81 years. All patients experienced permanent or intermittent pain, and all but one had permanent sensory impairment of the thigh. The lateral aspect of the thigh was solely involved in 88 cases and the anterior aspect was also or exclusively involved in 32 cases. The right thigh was involved 62 times and the left 58 times. Symptom duration varied from 2 weeks to 20 years. The initial diagnosis was meralgia paresthetica in 47 cases (39%), root disease in 35 cases, and osteoarthritis in 6 cases; no diagnosis was proposed in the 32 remaining cases. Two cases had undergone previous spine surgery for disk herniation, with no benefit. A precise cause could explain the lateral femoral cutaneous nerve (LFCN) lesion in 46 cases, the other 74 cases being considered idiopathic (25% of patients were obese). Only one case required surgery to relieve symptoms. LFCN conduction was studied orthodromically, distally from the anterior superior iliac spine. The side-to-side amplitude ratio (ssRatio) was greater than 2.3 in 118 of 120 patients (98.3%) and was a better index to confirm a lesion of the LFCN than SNAP amplitude, which was abnormal (less than 3 microV) in 88 cases (73.3%). Only two of the 11 bilateral cases had an ssRatio lower than 2.3 (they were both 2.0). An ssRatio of 2.3 or more and a SNAP amplitude lower than 3 microV provided a specificity of 98.75% or more. The mean axonal loss was 88%. These clinical and electrophysiological data highlight the central role the neurophysiologist should play in diagnosing MP by means of an LFCN conduction study.

[Idiopathic lumbosacral plexopathy]. / Plexopathie lombo-sacrée idiopathique.

INTRODUCTION: Lumbosacral plexopathy is the equivalent in the lower limbs of neuralgic amyotrophy (also known as Parsonage-Turner syndrome) in the upper limbs. It is well-known in patients with diabetes mellitus, when it is known as Bruns-Garland syndrome. CASE: We report the case of a 47-year-old woman who developed a unilateral neuropathy of the leg, neither radicular nor truncal in origin. The slow continuous improvement was not affected by any of the treatments administered. DISCUSSION: Lumbosacral plexopathy is characterized by intense pain in one or both legs, associated with motor and sensory deficits. Recovery is usually slow (6 to 36 months) and often incomplete. The electrodiagnostic examination shows important acute motor and sensory axonal loss, characterized by denervation and low-amplitude sensory action potential. Treatment generally combines analgesics with narcotic agents, neuropathic pain medication, short-term corticosteroids, and rehabilitation. In the most severe cases, long-term corticosteroids and other immunosuppressive agents may be required. This diagnosis cannot be reached until all other radicular, plexal and truncal origins have been ruled out.

Symptoms of thoracic outlet syndrome in women with carpal tunnel syndrome.

OBJECTIVE: To evaluate the frequency of symptoms and signs suggestive of thoracic outlet syndrome (TOS) in women aged 60 years or less, with unambiguous carpal tunnel syndrome (CTS). METHODS: The CTS was clinically and electrodiagnostically defined in 100 upper limbs. Clinical and electrophysiological symptoms and signs suggestive of TOS, true neurogenic TOS (NTOS) and disputed NTOS were tested in each upper limb. The 100 idiopathic median nerve lesions at the wrist occurred in 61 successive and unselected women. Women with ulnar nerve entrapment, root lesions and polyneuropathies were excluded. The main outcome measures were clinical symptoms and signs suggestive of TOS and NTOS as electrodiagnostic evaluation of the lower brachial plexus. RESULTS: In the 100 upper limbs with definite CTS, no major symptoms and signs suggestive of TOS and NTOS were found. On the contrary, moderate and mild clinical symptoms and signs suggestive of disputed NTOS were frequently found, even if no electrodiagnostically definite major or minor lower brachial plexus lesion was found. CONCLUSIONS: This study demonstrates the low specificity of clinical symptoms and signs suggestive of disputed NTOS, as they were frequently found in women with unselected and unambiguous CTS, despite no patients had definite lower brachial plexus lesion. SIGNIFICANCE: Our study shows why CTS can easily be misdiagnosed as disputed NTOS, and stresses the importance of systematic electrodiagnosis with median, ulnar, and medial antebrachial cutaneous nerve conduction studies, in order to rule out CTS, ulnar nerve, root lesion, and to establish lower brachial plexus lesion before treating NTOS.

Frequency of neurogenic thoracic outlet syndrome in patients with definite carpal tunnel syndrome: an electrophysiological evaluation in 100 women.

OBJECTIVE: The aim of this work was to evaluate the frequency of lower brachial plexus lesions as true neurogenic thoracic outlet syndrome (NTOS) in women with carpal tunnel syndrome (CTS). METHODS: This was a prospective and descriptive study. The CTS was clinically and electrodiagnostically defined in each patient. The conduction of ulnar and medial antebrachial cutaneous nerves (MABCN) was bilaterally studied to evaluate the function of lower brachial plexus. One hundred women with 176 median nerve lesions at wrist were studied. Patients with ulnar nerve lesion at elbow or wrist were excluded. The sensory nerve action potential (SNAP) of ulnar nerve was abnormal when the interside amplitude ratio was greater than 1.66 or when its amplitude was smaller than 8 microV. The SNAP of MABCN was abnormal when the interside amplitude ratio was greater than 1.66 with both techniques (antidromic and orthodromic) or when its amplitude was smaller than 8 and 6 microV for non-obese patients, respectively, less and more than 60 years old. RESULTS: The mean SNAP amplitude of ulnar and MABC nerves was normal compared with control subjects, and none of the 100 women with CTS had an abnormal interside amplitude ratio for one or both nerves. In 7-10 cases, all of which were either obese or elderly patients, SNAP amplitude of MABCN was decreased, but the interside amplitude ratio remained normal. CONCLUSIONS: On the basis of tests considered quite sensitive (70%) and specific (100%), the occurrence of true NTOS is lower than 1/100 in woman with definite CTS. SIGNIFICANCE: These results demonstrate that there is no appreciable link between CTS and true NTOS. There is no need for the systematic MABCN testing had in CTS patients.

Medial antebrachial cutaneous nerve conduction study, a new tool to demonstrate mild lower brachial plexus lesions. A report of 16 cases.

OBJECTIVE: This was to demonstrate the ability to electrodiagnosed mild lower brachial plexus lesion only through abnormal medial antebrachial cutaneous nerve (MABCN) conduction study. METHODS: We report 16 cases of unilateral, atypical pains and paresthesias of the upper limbs without motor deficit or atrophy. Patients were referred as carpal tunnel syndrome in 12 cases. All patients had needle examination of the impaired upper limb from C5 to T1. Motor and sensory conductions of median and ulnar nerves were bilaterally studied. MABCN was antidromically (16 cases) and orthodromically (9 cases) studied at the elbow in the both sides. MABCN abnormality was defined by an interside amplitude ratio of the sensory nerve action potential equal or greater than 2 (mean + 3 SD). RESULTS: No patient had a definitive and accurate diagnosis, before MABCN abnormality determination. MABCN testing was abnormal in all the 16 cases with a mean interside amplitude ratio of 7.2 (mean + 25 SD), when all other motor and sensory nerve conductions were normal. All except four patients showed normal needle examination from C5 to T1. In 5 cases, an obvious cause (traumatic and neoplastic) explained the mild lower brachial plexus lesion. In 2 cases, a mild neurogenic thoracic outlet syndrome (NTOS) was confirmed by surgical findings. In the 9 other cases, the mild lower brachial plexus lesion defined by MABCN findings, was without cause and was considered as a mild NTOS. CONCLUSIONS AND SIGNIFICANCE: These 16 cases, support a new electrodiagnostic pattern to define a mild lower brachial plexus lesion: comparatively low or low MABCN SNAP amplitude, normal median and ulnar SNAP/Compound motor action potential amplitudes and normal or slightly reduced interference pattern in some C8-T1 innervated muscles. This pattern can be found in patients with 'carpal tunnel syndrome like' symptoms who have normal electro-diagnostic examination, or in patients with clinical features suggesting a lower brachial plexus lesion.

[Anterior interosseous nerve lesions revisited in 2004]. / Les atteintes du nerf interosseux antérieur en 2004.

When the anterior interosseous nerve (AIN) is involved, a motor deficit of the distal pinch appears. It usually occurred suddenly, with or without pain and the deficit may be complete or partial. Other nerve lesions and some precipitating conditions can be noticed and are important to assess the exact mechanism of the nerve lesion. Partial AIN lesion is frequently misdiagnosed as tendon rupture. The electrodiagnostic examination should always study the pronator quadratus or another muscle innervated by the AIN, the AIN conduction and the motor and sensory median nerve conduction. Thus electrodiagnosis will always assess the AIN lesion and precise its axonal or compressive mechanism. Mononeuritis as neuralgic amyotrophy is the most frequent cause of AIN palsy and never requires surgery. Traumatic lesions are less frequent and usually recover spontaneously. Thus, surgery is rarely required before 12 to 18 months except when no recovery occurs after trauma.

Somatosensory evoked potentials for the electrodiagnosis of meralgia paresthetica.

The aim of this study was to evaluate the diagnostic utility of somatosensory evoked potential (SSEP) studies of the lateral femoral cutaneous nerve (LFCN) in assessing patients with meralgia paresthetica. Twenty-one consecutive patients with unilateral meralgia paresthetica, as defined clinically (sensory impairment of lateral aspect of the thigh) and electrodiagnostically (abnormal sensory nerve conduction), and 21 control subjects were studied with two SSEP methods. SSEPs were elicited by stimulation of the LFCN below the anterior superior iliac spine (ASIS stimulation) and by cutaneous stimulation of the lateral aspect of the distal third of the thigh (thigh stimulation). Abnormalities were defined by the SSEP interside latency difference, interside amplitude ratio, or an absent response. The SSEP with ASIS stimulation had a sensitivity of 5% and a specificity of 95%, whereas with thigh stimulation it had a sensitivity of 52% and a specificity of 76%. Overall, SSEP after ASIS stimulation had no diagnostic value. Recording of the SSEP after thigh stimulation is recommended in obese patients only when sensory nerve conduction cannot be determined.

Isolated sensory manifestations in neuralgic amyotrophy: report of eight cases.

A series of eight patients with isolated clinical and electrophysiological sensory deficit related to neuralgic amyotrophy (NA) is reported. NA was diagnosed by clinical and electrodiagnostic features and disease course. Imaging and laboratory investigations excluded other disorders. The results showed mild to severe involvement of eight individual sensory nerves: lateral antebrachial cutaneous nerve lesions in three instances and partial lesions of the median nerve in five cases. Our findings suggest that isolated clinical and electrodiagnostic sensory involvement in NA is not exceptional but rather is unrecognized. The pattern of these nerve lesions agrees with the most typical pattern of NA, which is a mononeuritis or mononeuritis multiplex. The present study also shows that the spectrum of NA is diverse and may vary from pure motor to pure sensory deficit, according to the nature of the involved nerve fibers.

Anterior interosseous nerve and multifocal motor neuropathy.

We report the case of a 47-year-old woman with a left anterior interosseous nerve palsy. Surgical release of the anterior interosseous nerve was initially proposed, but electrodiagnostic evaluation demonstrated that the neuropathy was due not to compression or to neuralgic amyotrophy but to a proximal conduction block. At that time, the conduction block could be defined only by indirect electrodiagnostic criteria. A multifocal motor neuropathy with persistent conduction block was subsequently diagnosed, and the patient was treated with intravenous immunoglobulins. The efficacy of this treatment and the subsequent disclosure of conduction block in the right posterior interosseous and peroneal nerves definitively confirmed the multifocal motor neuropathy.