Aggressive Acquired Demyelinating Neuropathy Caused by NF-155: Initially Treatment-Resistant.

OBJECTIVES: Anti-neurofascin-155 IgG4 (NF-155) antibody disease has previously been associated with a subset of patients with chronic inflammatory demyelinating polyradiculoneuropathy. We report a case of NF-155 positive polyneuropathy that initially presented as an acute inflammatory demyelinating polyradiculoneuropathy. The patient responded appropriately to treatment but subsequently progressed over a 3-month period, resulting in quadriplegia, areflexia, and oculobulbar paralysis. METHODS: Case report and literature review. RESULTS: A 40-year-old male presented with acute bilateral arm and thigh weakness, areflexia, and distal sensory loss. Treatment with intravenous immunoglobulin (IVIg) for acute acquired demyelinating neuropathy resulted in initial improvement but subsequent decline. Lack of response to additional IVIg and plasmapheresis (PLEX) prompted testing for NF-155. Treatment with rituximab and steroids resulted in virtually complete recovery. CONCLUSIONS: Early testing for nodal and paranodal proteins is indicated in patients who present with acute acquired demyelinating neuropathy but fail to respond to conventional treatments, such as IVIg or PLEX. Identification of nodal and paranodal antibodies should prompt treatment with rituximab and steroids to increase likelihood of recovery.

Prospective, Randomized, Double-Blinded, Sham-Controlled Pilot Study of Intraneural Facilitation as a Treatment for Carpal Tunnel Syndrome.

Objective: To perform a pilot study to assess the efficacy of intraneural facilitation, a novel manual technique, in the treatment of carpal tunnel syndrome (CTS). Design: Patients with clinical and electrodiagnostic evidence of CTS were randomized into intraneural facilitation or sham groups. Setting: Electrodiagnostic laboratory in a university medical center. Participants: Patients referred to our electrodiagnostic laboratory were screened based on nerve conduction studies that were diagnostic for distal median neuropathy at the wrist or CTS. A total of 14 participants were enrolled; 4 participants withdrew prior to randomization, with the remaining 10 participants (N=10) divided equally between treatment and control groups. There was a 9:1 female-to-male sex ratio and average duration of symptoms was 28.5 months. Interventions: Treatment was performed twice weekly for 3 weeks. Main Outcome Measures: Primary outcomes were the Boston Carpel Tunnel Questionnaire (BCTQ) and Boston Functional Status Scale at enrollment and at 1 week and 3 months after completion of intervention. A secondary outcome was ultrasonography (US) of the median nerve performed at baseline and 1 week after intervention. Results: Ten participants completed the trial, 5 each in the treatment and 5 each in the sham groups. The total percentage change in BCTQ and Boston Functional Status Scale scores decreased at baseline, 1 week, and 3 months after intervention. However, there was no difference between control and intraneural facilitation group. Within-group differences showed nonstatistically significant differences for all the groups except for the BCTQ questionnaires after 3 months of intraneural facilitation therapy was completed (P=.043) compared with baseline. Between-group differences showed large effects for the BCTQ questionnaires (d=1.933) and wrist to forearm ratio (WFR) 1 week after completion of intervention. Conclusions: This pilot study suggests that intraneural facilitation might improve symptoms and possibly function but did not improve median nerve cross-sectional area or WFR in CTS at follow-up evaluation 3 months after completion of intervention.

Ischemic stroke segmentation in multi-sequence MRI by symmetry determined superpixel based hierarchical clustering.

Automated estimation of ischemic stroke evolution across different brain anatomical regions has immense potential to revolutionize stroke treatment. Multi-sequence Magnetic Resonance Imaging (MRI) techniques provide information to characterize abnormal tissues based on their anatomy and physical properties. Asymmetry of the right and left hemispheres of the brain is an important cue for abnormality estimation but using it alone is susceptible to occasional error due to self-asymmetry of the brain. A precise estimate of the symmetry axis is therefore essential for accurate asymmetry identification, which holds the key to the proposed method. The proposed symmetry determined superpixel based hierarchical clustering (SSHC) method initially estimates the lesion from inter-hemispheric asymmetry. This asymmetry further determines the thresholding parameter for hierarchically clustering the superpixels leading to an automated and accurate lesion delineation. A multi-sequence MRI based pipeline also combines the estimations from individual sequences. SSHC is evaluated on different sequences of the Loma Linda University (LLU) dataset with 26 patients and the Ischemic Stroke Lesion Segmentation (ISLES'15) dataset with 28 patients. SSHC eliminates the need for manual determination of threshold for combining the superpixel clusters and is more reliable as it derives the information from the quick estimation of asymmetry. SSHC outperforms the state-of-the-art resulting in a high Dice similarity score of 0.704±0.27 and a recall of 0.85±0.01 which are 6% and 35% respectively higher than the challenge winning method. SSHC thus demonstrates a promising potential in the automated detection of (sub-)acute adult ischemic stroke.

Prior muscle activation affects the compound muscle action potential.

INTRODUCTION: This study was performed to evaluate the effect of prior voluntary activation of a muscle on the subsequently-recorded compound muscle action potential (CMAP). METHODS: The CMAPs from the hypothenar, thenar, and extensor digitorum brevis muscles were recorded in 6 healthy volunteers at rest and for up to 30 min following 5 separate epochs of up to 20 s of voluntary muscle activation. RESULTS: There was consistent, significant (P < 0.02) enhancement of the negative area, amplitude, and duration of the CMAP after activation. The enhancement was maximal, up to 144% of baseline, within about 1 min post-activation; thereafter, the CMAP gradually returned to baseline over about 15 min. DISCUSSION: Activation of a muscle within several minutes prior to testing enhances the subsequently-recorded CMAP. This observation highlights prior muscle activation as a physiological variable that influences the size of the CMAP during motor nerve conduction studies. Muscle Nerve, 2019.

MRI based objective ischemic core-penumbra quantification in adult clinical stroke.

Objective and non-invasive quantification of ischemic stroke and differentiation of salvageable from non-salvageable tissue is critical to treatment planning. However current Magnetic Resonance Imaging(MRI) techniques are time consuming and rely on manual detection methods. Computer aided preliminary screening of the injured tissue could assist neuroradiologists in performing more detailed analysis of the lesion components. An established Hierarchical Region Splitting (HRS) method was extended to segment lesions from adult patients who suffered a clinical stroke using diffusion- and perfusion weighted image (DWI-PWI) maps and associated computed maps. Apart from lesion quantification PWI-DWI based HRS was also able to automatically quantify core (irrecoverable) the penumbra (potentially recoverable) which helped to estimate salvageable tissue. The PWI-DWI/HRS results were validated by comparing with manually demarcated ground truth in terms of performance indices like lesion volume (82.1% accuracy), sensitivity (78.8%), specificity (99.3%) and similarity (78.54%) for a dataset of 10 acute adult stroke patients. Data sets were classified into severe, moderate and mild injuries based on total lesion volume. Proposed PWI-DWI/HRS method demonstrated accuracy close to manual lesion demarcation with high performance indices for core and penumbra in severe and moderate classes.

Peripheral Nerve Injuries in Sport.

Sport-related peripheral nerve injuries (SRNIs) can occur in virtually any sport whether or not enjoyed by an amateur or in the career of a professional athlete. The diagnosis of SRNIs can be difficult, especially when trying to differentiate nerve injury from musculoskeletal pain. Clinicians should be able to recognize when a significant SRNI occurs and how to initiate a diagnostic and treatment pathway and referral to a specialist. This article reviews SRNIs and their specific sports, how to diagnose SRNIs, and how to select conservative or surgical management of these injuries.

Effects of a Novel Therapeutic Intervention in Patients With Diabetic Peripheral Neuropathy.

OBJECTIVE: To determine the effect of a novel therapeutic intervention called intraneural facilitation on balance measures and a neuropathy scale in patients with diabetic peripheral neuropathy. DESIGN: Prospective pre- and posttest, single group clinical trial. SETTING: Outpatient physical therapy clinic. PARTICIPANTS: Patients with diabetic peripheral neuropathy (N=13). INTERVENTION: Subjects received 10 sessions of intraneural facilitation. MAIN OUTCOME MEASURES: The modified Total Neuropathy Scale, the NeuroCom SMART Balance Master system computerized dynamic posturography (CDP) that includes the Sensory Organization Test (SOT) and the limits of stability (LOS), and the Activities-specific Balance and Confidence (ABC) scale. RESULTS: Subjects in this study showed significant improvement in the modified Total Neuropathy Scale, SOT, and 1 component in the LOS test (movement velocity). There were no significant differences in the ABC scale or in 4 components of the LOS test, which were reaction time, end point excursion, maximum excursion, and directional control. CONCLUSIONS: Intraneural facilitation improved objective balance measures and neuropathy symptoms in patients with diabetic peripheral neuropathy. Further study is needed to determine long-term benefits of this intervention.

Hoffmann sign: clinical correlation of neurological imaging findings in the cervical spine and brain.

STUDY DESIGN: Retrospective validity study. OBJECTIVE: To investigate the relationship between Hoffmann sign and radiographical evidence of cervical spinal cord compression and brain lesions. SUMMARY OF BACKGROUND DATA: Clinical significance of Hoffmann sign remains controversial with conflicting reports regarding its sensitivity and specificity and its usefulness. METHODS: Patients were divided into 2 groups according to the presence of Hoffmann sign on physical examination. Imaging studies were blindly examined by 2 observers for possible cervical and brain lesions. The sensitivity, specificity, positive predictive value, negative predictive value, as well as accuracy for Hoffmann sign as it relates to cervical spinal cord compression and brain pathology, were calculated. RESULTS: Of the 91 patients with a positive Hoffmann sign, 32 (35%) showed severe cervical cord compression and/or myelomalacia. Forty-seven of these patients had brain imaging studies, and 5 (10%) had positive findings. There were 80 patients in the negative Hoffmann sign or control group. Twenty-one (27%) of them had severe cervical cord compression and/or myelomalacia. Twenty-three of these control patients underwent neurological imaging of the brain, and 2 (8%) had positive findings. Hoffmann sign was found to have 59% sensitivity, 49% specificity, 35% positive predictive value, and 72% negative predictive value for cervical cord compression. For brain pathology, sensitivity was 71%, specificity 33%, positive predictive value 10%, and negative predictive value 95%. CONCLUSION: Hoffmann sign has too low a positive predictive value to be relied upon as a stand-alone physical examination finding and is not a reliable screening tool for solely predicting the presence of cervical spinal cord compression or brain pathology. LEVEL OF EVIDENCE: 2.

Electrodiagnostic features of true neurogenic thoracic outlet syndrome.

INTRODUCTION: We report the electrodiagnostic (EDX) features of 32 patients with surgically verified true neurogenic thoracic outlet syndrome (TN-TOS). METHODS: Retrospective record review. RESULTS: We found uniform EDX evidence of a chronic axon loss process that affected the lower portion of the brachial plexus and disproportionately involved the T1 more than the C8 sensory and motor fibers. Because of this relationship, the medial antebrachial cutaneous sensory nerve (T1) and median motor (T1 > C8) study combination was abnormal in 89%, whereas response combinations that primarily assessed the C8 fibers were less frequently affected. CONCLUSIONS: The characteristic EDX features of TN-TOS are T1 > C8 nerve fiber involvement. A comprehensive EDX examination of the lower plexus with contralateral comparison studies is imperative to diagnose this disorder accurately.

The electrodiagnosis of cervical and lumbosacral radiculopathy.

This article reviews the usefulness of the electrodiagnostic examination in patients who have suspected cervical and lumbosacral radiculopathy. This study can verify the presence and severity of radiculopathy, determine which levels are involved, and provide an electrodiagnostic correlate to imaging abnormalities. A practical approach for conducting the nerve conduction portion and needle electrode examination in these patients is discussed.

Phrenic neuropathy due to neuralgic amyotrophy.

The authors reviewed the medical records of 33 patients diagnosed with idiopathic phrenic neuropathy and found that 17 patients had clinical features of neuralgic amyotrophy. They concluded that a careful clinical and electrodiagnostic evaluation may implicate neuralgic amyotrophy as a causative disease in patients with apparently isolated phrenic neuropathy.

Electrodiagnostic testing of nerves and muscles: when, why, and how to order.

The electrodiagnostic examination can provide essential information in cases of suspected peripheral nervous system disorders or injury. To optimize the yield of this test, one must have a basic understanding of how it works, when and how to order it, and its inherent limitations.

Infraclavicular brachial plexus injury following axillary regional block.

Infraclavicular brachial plexopathy is a potential complication of axillary regional block. We retrospectively reviewed 13 such injuries and found the median nerve most often affected, followed by combined median and ulnar neuropathies, and then by various combinations involving the median, ulnar, radial, and musculocutaneous nerves. All were axon-loss in type and most were severe in degree electrophysiologically. The clinical and electrodiagnostic features of these injuries are strikingly similar to those sustained after axillary arteriography, which has been associated with the medial brachial fascial compartment (MBFC) syndrome. This syndrome is characterized by the evolution of neurologic deficits and pain following hematoma formation within a compartment of the upper arm. Thus, we believe that this mechanism underlies most nerve injuries that result from axillary angiography or axillary regional block. This has important treatment implications, as timely surgical intervention may lead to improved outcome.

The medial brachial fascial compartment syndrome following axillary arteriography.

OBJECTIVE: To review clinical and electrodiagnostic features of the medial brachial fascial compartment syndrome, a complication of percutaneous axillary vessel puncture. METHODS: The authors reviewed electrodiagnostic examinations over a 20-year period. RESULTS: This syndrome presents with weakness, pain, and numbness during or following the percutaneous procedure. Injury is characterized by axon loss and involves terminal nerves of the infraclavicular brachial plexus-most often the median nerve alone, followed by combinations of the median, ulnar, radial, and musculocutaneous nerves. CONCLUSIONS: Early recognition of the medial brachial fascial compartment syndrome may lead to prompt surgical intervention, which, in turn, may prevent permanent nerve injury. Late diagnosis generally results in poor outcome and often results from delayed symptom onset and lack of overt compartment syndrome signs.

Comparison of surgical and electrodiagnostic findings in single root lumbosacral radiculopathies.

To identify the segmental innervation of L-2-S-1 muscles, we compared the preoperative electrodiagnostic examinations of 45 patients with single-level lumbosacral radiculopathies confirmed radiologically and surgically. The electrodiagnostic findings were classified as abnormal only by the needle examination and only if muscles demonstrated active denervation or a marked neurogenic motor unit potential firing pattern. In comparison to other surgical, intraoperative root stimulation, and clinical studies, we found several differences. Overall, there was little overlap among L-2-4, L-5, and S-1 radiculopathies. The tibialis anterior was predominantly L-5 innervated, the gastrocnemius (medial and lateral head) predominantly S-1 innervated, and the biceps femoris (short and long head) exclusively S-1 innervated. The two heads of biceps femoris were not affected in any patients with L-5 radiculopathy in whom they were examined. These findings help guide both the clinician and surgeon in the diagnosis and treatment of lumbosacral radiculopathies.