Quantitative Muscle Ultrasonography in Carpal Tunnel Syndrome

OBJECTIVE: To assess the reliability of quantitative muscle ultrasonography (US) in healthy subjects and to evaluate the correlation between quantitative muscle US findings and electrodiagnostic study results in patients with carpal tunnel syndrome (CTS). The clinical significance of quantitative muscle US in CTS was also assessed. METHODS: Twenty patients with CTS and 20 age-matched healthy volunteers were recruited. All control and CTS subjects underwent a bilateral median and ulnar nerve conduction study (NCS) and quantitative muscle US. Transverse US images of the abductor pollicis brevis (APB) and abductor digiti minimi (ADM) were obtained to measure muscle cross-sectional area (CSA), thickness, and echo intensity (EI). EI was determined using computer-assisted, grayscale analysis. Inter-rater and intra-rater reliability for quantitative muscle US in control subjects, and differences in muscle thickness, CSA, and EI between the CTS patient and control groups were analyzed. Relationships between quantitative US parameters and electrodiagnostic study results were evaluated. RESULTS: Quantitative muscle US had high inter-rater and intra-rater reliability in the control group. Muscle thickness and CSA were significantly decreased, and EI was significantly increased in the APB of the CTS group (all p<0.05). EI demonstrated a significant positive correlation with latency of the median motor and sensory NCS in CTS patients (p<0.05). CONCLUSION: These findings suggest that quantitative muscle US parameters may be useful for detecting muscle changes in CTS. Further study involving patients with other neuromuscular diseases is needed to evaluate peripheral muscle change using quantitative muscle US.

Clinical profile of Guillain Barre syndrome in a tertiary care centre.

Background: This study was done to know about the clinical profile of Guillain Barre syndrome in a tertiary care centre and to correlate certain clinical features with outcome at discharge and thereby to identify a poor outcome group in early stages. Methods: 33 patients admitted in the medical wards were included in the study based on the diagnostic criteria modified by Asbury. Detailed history and physical examination as per a structured profroma was taken and necessary lab investigations were done including CSF study and electrodiagnostic study. Results: The factors affecting the outcome at discharge were 1. Requirement of mechanical ventilation 2. Features of axonopathy in electrodiagnostic studies 3. Decreased CMAP (<10% of lower limit of normal) 4. Presence of cranial nerve involvement 5. Presence of autonomic involvement. Conclusion: There is a high percentage of Miller Fisher variant of GBS this study. Older age is not found to have adverse effect on outcome at discharge in this study. Axonal variant of GBS is found to have a bad outcome. Requirement of mechanical ventilation was found to be a factor adversely affecting outcome. Cranial nerve involvement and autonomic involvement adversely affects the outcome at discharge.

Quantitative Evaluation of Median Nerve Motor Function in Carpal Tunnel Syndrome Using Load Cell : Correlation with Clinical, Electrodiagnostic, and Ultrasonographic Findings

OBJECTIVE: Major complaints of carpal tunnel syndrome (CTS) are sensory components. However, motor deficit also impedes functional status of hand. Contrary to evaluation of sensory function, the objective, quantitative evaluation of median nerve motor function is not easy. The motor function of median was evaluated quantitatively using load cell and its correlation with findings of electrodiagnostic study (EDS) was evaluated. METHODS: Objective motor function of median nerve was evaluated by load cell and personal computer-based measurement system. All of the measurement was done in patients diagnosed as having idiopathic CTS by clinical features and EDS findings. The strength of thumb abduction and index finger flexion was measured in each hand three times, and the average value was used to calculate thumb index ratio (TIR). The correlation of TIR with clinical, EDS, and ultrasonographic findings were evaluated. RESULTS: The TIR was evaluated in 67 patients (119 hands). There were 14 males and 53 females, mean age were 57.6 years (range 28 to 81). The higher preoperative nerve conductive studies grade of the patients, the lower TIR was observed [p<0.001, analysis of variance (ANOVA)]. TIR of cases with thenar atrophy were significantly lower than those without (p<0.001, t-test). TIR were significantly lower in patients with severe median nerve swelling in ultrasonography (p=0.042, ANOVA). CONCLUSION: Measurements of median nerve motor function using load cell is a valuable evaluation tool in CTS. It might be helpful in detecting subclinical motor dysfunction before muscle atrophy develops.

Pitfalls in Using Electrophysiological Studies to Diagnose Neuromuscular Disorders

Electrodiagnostic testing is used widely for the full characterization of neuromuscular disorders and for providing unique information on the processes underlying the pathology of peripheral nerves and muscles. However, such testing should be considered as an extension of anamnesis and physical examination, not as pathognomonic of a specific disease entity. There are many pitfalls that could lead to erroneous interpretation of electrophysiological study results when the studies are not performed properly or if they are performed in the presence of anatomical aberrations. The diagnostic reliability of electrodiagnostic studies can be improved and the associated pitfalls overcome if the physician is familiar with all of those possible pitfalls. In this article we discuss the most common and important pitfalls associated with electrodiagnostic medicine.

Survey on the Diagnostic Process of Amyotrophic Lateral Sclerosis

OBJECTIVE: To emphasize the need for precise diagnosis of amyotrophic lateral sclerosis (ALS), a progressive and degenerative disease of upper and lower motor neurons that often present initially with weakness at the upper or lower extremities, and frequently misdiagnosed as myelopathy, radiculopathy, peripheral neuropathy or arthropathy that may ultimately lead to unnecessary treatments including surgical procedures. METHOD: We retrospectively reviewed medical records of 331 ALS patients who visited our hospital between 1998 and 2008. Symptoms at onset, progression of disease, radiologic findings, surgeries prior to diagnosis of ALS, outcome after surgery or conservative treatments, and electrodiagnostic study results were reviewed. RESULTS: Among the 331 patients with ALS, 34 (10.3%) had a history of surgical procedure and 37 (11.1%) underwent conservative treatment prior to diagnosis of ALS. 34 patients with a mean disease duration at diagnosis of 20.0+/-14.9 months, had surgery for symptoms that were later attributable to ALS. In 30 of the 34 patients, symptoms did not resolve after the intervention. 37 patients with a mean disease duration at diagnosis of 16.6+/-14.3 months, underwent conservative treatments such as physical therapy prior to diagnosis of ALS. Only in one patient (2.7%), symptoms improved after conservative treatment. CONCLUSION: In the absence of a single confirmatory study for the diagnosis of ALS, clinical findings may be misinterpreted, leading to an erroneous diagnosis. Therefore, closer and more careful follow-up is necessary for patients with limb weakness in the absence of sensory symptoms, or bulbar abnormalities such as dysarthria and dysphagia.

The Value of Electrodiagnostic Studies Performed before and after Microvascular Decompression

OBJECTIVE: To evaluate the usefulness of electrodiagnostic studies in hemifacial spasm patients by comparing abnormal muscle response (AMR) and irregular bursting discharge (IBD) before and after the surgery of hemifacial spasm. METHOD: Fifty nine patients who had been diagnosed with hemifacial spasm and underwent microvascular decompression (MVD) were chosen. The AMR was carried out in three different ways; 1) abnormal response of orbicularis oris when stimulating the supraorbital branch of trigeminal nerve (AMR1), 2) abnormal response of mentalis when stimulating the zygomatic branch of facial nerve (AMR2) and 3) abnormal response of orbicularis oculi when stimulating the marginal mandibular branch of facial nerve (AMR3). We identified the correlation between the loss of IBD and the AMR results per each method, the results of the electrodiagnostic studies according to the onset duration, and the point of follow up time. RESULTS: The AMR and IBD decreased or disappeared after the surgery. AMR which had a significant statistical correlation with the changes of IBD, were AMR2 and AMR3. No definite changes were seen regarding the onset duration. According to the studies done during the follow up period, there was a significant reduction in lateral spread and IBD as the length of the follow up period lengthened. CONCLUSION: Investigation of pre- and postoperative electrodiagnostic study, especially abnormal muscle response (facio- facial reflex) is very helpful in predicting the outcome of operation and the overall prognosis.

Comparison of Fixed Distance Stimulation and Distal Wrist Crease Stimulation in Median Motor Conduction Study

OBJECTIVE: To determine optimal stimulation site for median motor conduction study, we compared fixed distance (7 cm proximal to the recording electrode) stimulation method and distal wrist crease stimulation method. METHOD: Nerve conduction studies were performed in 65 hands of 36 healthy adults without neurologic abnormality. Median motor responses were recorded from abductor pollicis brevis (APB) with the stimulations at the point 7 cm proximal to the recording electrode and at the distal wrist crease. The distal latencies and onset-to-peak amplitudes were measured and compared between two techniques. The distal latencies were also compared to that of ulnar compound muscle action potential (CMAP) obtained with fixed distance stimulation (7 cm proximal to the recording electrode). And we measured median nerve actual length from distal wrist crease to APB muscle motor point by anatomic dissection of 12 hands. RESULTS: The distal latencies of median CMAP to APB with 7 cm fixed distance stimulation and distal wrist crease stimulation were 2.91+/-0.37 ms and, 2.75+/-0.41 ms respectively. The differences were statistically significant. The distal latency of ulnar CMAP was 2.50+/-0.32 ms. Differences in distal latencies between ulnar CMAPs and not only 7 cm fixed distance median stimulation but also distal wrist crease median stimulation were also statistically significant. The mean length of median nerve from distal wrist crease to APB motor point was 5.91+/-0.77 cm. CONCLUSION: We suggest that the median motor nerve conduction study using distal wrist crease stimulation was an easier and more rapid procedure than fixed distance median motor nerve conduction study.

The Analysis of Treatment with Acyclovir and Prognostic Factors on Idiopathic Facial Mononeuropathy Using Sunnybrook Scale

BACKGROUND: Based on a recent study showing that the reactivation of HSV-1 may be one of the possible pathogenesis of idiopathic facial mononeuropathy, antiviral therapy has been suggested as a good treatment modality. However, the efficacy of antiviral therapy is still controversial. This argument may be caused by the absence of a reliable system of grading facial nerve paralysis. We performed this study to investigate the therapeutic effects of an antiviral agent and possible prognostic factors using the Sunnybrook scale. METHODS: Patients with idiopathic facial mononeuropathy were divided as two groups according to the treatment regimens (Acyclovir & Steroid vs. Steroid only). Clinical efficacy was evaluated using the House-Brackmann grading system and Sunnybrook scale. Electrodiagnostic studies including the blink reflex, facial nerve conduction study, and facial nerve excitability test were performed. The clinical improvement rate between the two groups and the usefulness of the electrodiagnostic studies as prognostic factors were analyzed. RESULTS: No significant differences of the clinical improvement rate was revealed with a 70% improvement rate for the Acyclovir treatment group and 84% for the steroid only group. Among electrodiagnostic studies, the compound muscle gamma action potential (CMAP) amplitude (=0.637, p=0.000) and nerve excitability =0.688, gamma test (p=0.000) on 2 weeks showed significant correlations to the final Sunnybrook score. There is good correlation between the two facial nerve grading systems. CONCLUSIONS: Acyclovir may not be effective in the recovery of idiopathic facial mononeuropathy. CMAP amplitude and nerve excitability tests on 2 weeks may provide valuable prognostic factors. The Sunnybrook scale may be useful as a facial grading system.

Long-term Follow-up of Idiopathic Facial Palsy

OBJECTIVE: The purpose of this study was to observe clinical characteristics and electrodiagnostic findings of idiopathic facial palsy and to follow up beyond 1 year after onset. METHOD: From February 2002 to July 2003 the authors analyzed 103 cases that could be followed up after 1 year since diagnosed as idiopathic facial palsy by electrodiagnostic study which was performed at approximately 2 weeks after the onset time. The patients were classified by House- Brackmann (H-B) facial nerve grading system on their first visits and followed up by telephone interview using H-B system. Treatment method, age, sex, medical history and symptoms were noted. In addition, the blink reflex, nerve conduction study and needle electromyography (EMG) were done. RESULTS: When degree of degeneration (% degeneration) was greater than 90% at approximately 2 weeks after the onset or motor unit action potentials were not detected in at least one among the four tested muscles, patients did not gain satisfactory facial function after 1 year. CONCLUSION: Methods related to prognosis of idiopathic facial palsy were compared with side to side evoked potential amplitude and needle EMG. This methods would be helpful to explain its prognosis.

Diagnostic Usefulness of Electrodiagnostic Study and Magnetic Resonance Imaging to Preganglionic Brachial Plexopathy

OBJECTIVE: This study aims at evaluating the usefulness of the electrodiagnostic study (EDx) and the magnetic resonance imaging (MRI), which are performed before surgical operation of brachial plexus injury. METHOD: We reviewed 57 cases of brachial plexopathy diagnosed with surgical findings. EDx and MRI were performed to the patients before surgery. Based upon intraoperative findings, we evaluated the occurrence of preganglionic root injury and subsequently each injured spinal root level. RESULTS: EDx and MRI for preganglionic root injuries showed 92.1% and 78.9% of diagnostic sensitivity and 63.2% and 42.9% of diagnostic specificity, respectively. The followings were about each injured spinal root level. EDx showed that the sensitivities of C5, C6, C7, C8, T1 were 91.4%, 91.4%, 92.6%, 96%, 95.8%, and their specificities were 59.1%, 59.1%, 56.7%, 68.8%, 66.7%. MRI showed that the sensitivities were 47.4%, 57.9%, 58.3%, 75%, 66.7%, and their specificities were 57.1%, 71.4%, 78.6%, 85.7%, 85.7%. CONCLUSION: As for preganglionic brachial plexopathy, EDx was more useful than MRI to diagnose preganglionic root injury and determine the level of injured spinal root.

Clinical and Electrodiagnostic Findings of Failed Back Surgery Syndrome

OBJECTIVE: To analyze the clinical and electrodiagnostic findings of patients with failed back surgery syndrome after lumbar disc operation. METHOD: We investigated 28 patients with back and/or lower limb pain and weakness who were underwent lumbar spine operation. Seven patients who had undergone surgery due to spinal infection or fracture were excluded. Twenty-one patients included 7 female and 14 male patients with ages 20~63 years, and the mean age was 44.4 years. The following data were evaluated: clinical symptoms, neurological examination, duration from operation to first visit, preoperative diagnosis, operation number and site, electrodiagnostic studies, radiologic studies (simple radiographs, epidurography, CT, MRI), and psychological evaluations (SCL-MPD). RESULTS: The time of the visit after the operation varied between one month and 15 years (mean 48.5 months). Electrodiagnostic study revealed lumbar radiculopathy in 18 patients and the most common level was at the fifth lumbar root. All eight patients who undergone epidurography showed filling defect or indentation. Psychologic evaluations were performed on five patients and they revealed high scores in depression and somatization. CONCLUSION: Clinical and electrodiagnostic findings of lumbar radiculopathy, abnormal epidurographic findings and psychological results after lumbar disc operation were related to the causes of failed back surgery syndrome.

Effect of Local Cooling on the Electrodiagostic Parameters in Patients with Carpal Tunnel Syndrome

OBJECTIVE: To evaluate the effect of local cooling on the parameters of electrodiagnostic study of the patients with carpal tunnel syndrome. METHOD: Twenty subjects with carpal tunnel syndrome and fifteen normal subjects were enrolled. The latency and conduction velocity of median motor and sensory nerves at wrist and elbow were measured with the different skin temperature at 32 degrees C as a baseline, and at 20 degrees C after cooling of mid-palm area by cold water immersion. RESULTS: The distal motor and sensory onset latencies were prolonged, and the sensory nerve conduction velocity was decreased after local cooling in both the patients and normal control group (p<0.01). The differences of distal motor and sensory onset latencies, and sensory nerve conduction velocity between before and after local cooling were statistically significant in patients group (p<0.01) compared with control group. CONCLUSION: These results showed that the patients with carpal tunnel syndrome reacts differently to temperature changes compared with normal control in electrodiagnostic study.

Clinico-radiologic Findings of the Whole Spine in Patients with Chronic Low Back Pain

OBJECTIVE: The purpose of this study was to evaluate the whole spine of the patients with chronic low back pain. METHOD: The cervico-thoraco-lumbar spine were evaluated in 128 patients with chronic low back pain. We analyzed radiologic and clinical findings of the cervico-lumbar spine and electrodiagnostic findings. RESULTS: Most of all cases showed abnormal findings in plain radiography and electrodiagnostic study. The radiologic findings were as follow: cervical X-ray with straightening of cervical lordotic curve in 85 cases; thoracic X-ray with scoliosis in 55 cases; lumbar X-ray with disc space narrowing in 85 cases. The electrodiagnostic study revealed lumbosacral radiculopathy in 87 cases. There were significant positive relationship between increased lumbosacral angle and straightening of cervical lordotic curve, and between lumbar scoliosis and thoracic scoliosis. CONCLUSION: Cervico-thoracic spinal abnormalities were shown in most of the patients with chronic low back pain. Therefore, The evaluation of whole spine would be needed comprehensive rehabilitation approach for the patients with chronic low back pain.

Function of Trapezius Muscle after Various Types of Neck Dissection

Radical neck dissection(RND) has been a standard treatment for the head and neck cancer with metastasis to the cervical lymphatics. The sacrifice of the spinal accessory nerve innervating trapezius muscles creates a definite deficit of the shoulder function. Therefore, the modified radical neck dissection(MRND) preserving one or more structures of the spinal accessory nerve, internal jugular vein or sternocleidomastoid muscle was introduced to minimize the postoperative morbidities. We studied the shoulder function by clinical examinations and electrodiagnosis for the various types of neck dissection in 39 cases of 24 patients and compared the results of each test according to the types of neck dissection. Correlation between the clinical parameter and electrodiagnostic results showed a statistical significancy. The functional results of trapezius muscle in the group of modified radical neck dissection were better than those of the radical neck dissection. The fact that 80% of the cases in the RND group presented incomplete denervation of the trapezius muscle, suggests the innervation of other nerves to this muscle. Forty five percents of the cases in the MRND group which presented partial denervation of the trapezius muscle, might be due to the damages during operations. To preserve the spinal accessory nerve, a careful manipulation of the nerve is required. Further studies including an anatomic dissection and intraoperative electrophysiologic evaluation of the trapezius muscle should be performed for the better rehabilitation outcomes.

Cold-sensitive Benign Focal Amyotrophy Confirmed by Electrodiagnostic Study: A case report

Benign focal amyotrophy (BFA) is a limited form of anterior horn cell disease with variable benign clinical appearance. Clinical symptoms of cold-sensitive BFA have been described but electrodiagnostic workup on these symptoms has not been done. A 28-year-old man suffering from cold-sensitive weakness and coordination disturbance of a hand underwent electrodiagnostic study while the subject was exposed to the cold. According to this study, the BFA with cold sensitivity may be classified as one type of BFA which can be confirmed by electrodiagnostic study.

A Case of Chronic Inflammatory Demyelinating polyradiculoneuropathy with Intestinal Pseudoobstruction / 대한내과학회지

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) represents an important acquired condition characterized by progressive, symmetrical, proximal and distal weakness. CIDP is characterized by sensory loss and weakness, areflexia, elevated CSF protein and electrodiagnostic evidence of multifocal demyelination with or without superimposed axonal degeneration. Some reports are made that an antecedent illness in the weeks preceding the onset of symptoms such as upper respiratory syndrome or flu-like illness, gastrointestinal syndrome etc., but intestinal pseudoobstruction as the main clinical feature in CIDP is an uncommon finding. The clinical course is variable. The condition is responsive to immunosuppressive therapy, especially prednisone and plasma exchange. We report a case of intestinal pseudoobstruction secondary to CIDP diagnosed by clinical features, electrodiagnostic study and nerve biopsy pathology.

The Clinical and Electrophysiological Study of the Suprascapular Nerve Palsy

The medical records of twenty-one patients with suprascapular nerve palsy were reviewed retrospectively. Nine patients had isolated suprascapular nerve lesions and twelve patients accompanied axillary nerve lesions. In trauma cases, combined nerve lesions were common and severe. In three cases isolated suprascapular nerve lesions were noted spontaneously. Isolated infraspinatus muscle lesions were noted in four cases which were due to compressions of suprascapular nerves at the spinoglenoid notch, and in one case from ganglionic cyst was diagnosed by ultrasonography. At initial examination, three patients showed complete and eighteen patients showed incomplete lesion. Eight patients with incomplete lesion and one patient with complete lesion were followed up. Seven patients with incomplete lesion showed regeneration between 1-7 months after injury. Therefore electrodiagnostic study is necessary to evaluate severity and level of nerve lesion and regeneration.

The Effect of Transcutaneous Electrical Nerve Stimulation and Microcurrent on the Electrodiagnostic Study

Due to lack of evidences on the central and peripheral mechanisms of electrical stimulation in vivo, the purpose of this study was to investigate the influence of afferent stimuli, transcutaneous electrical nerve stimulation and microcurrent, on the electrodiagnostic study of normal subjects. Electrodiagnostic study was performed before and after the application of afferent stimulion of the right popliteal fossa on 30 healthy female volunteers. After the transcutaneous electrical nerve stimulation, latencies of SEP, H-reflex, and F-wave, and H-amplitude changed significantly(P<0.01). After the microcurrent stimulation, latencies of SEP, H-reflex, and F-wave, and motor nerve conduction velocity changed significantly(P<0.01). The results of this study prove that transcutaneous electrical nerve stimulation and microcurrent may cause changes of the anterior horn excitability and the conduction of the nervous system in vivo. Microcurrent may have a different mechanism of action compared to transcutaneous electrical nerve stimulation by having more localized inhibitory effects on the peripheral nerve. However, further investigation is needed to assess their mechanisms of action and the precise relevance of stimulation parameters.