A case series of post-infectious chikungunya myeloradiculoneuropathy.

Chikungunya fever is an arboviral illness caused by chikungunya virus (CHIKV) and transmitted by the bite of Aedes aegypti and Aedes albopictus. It is an RNA virus belonging to the genus Alphavirus and family Togaviridae. We present a case series of three patients with chikungunya illness developing para/post-infectious myeloradiculoneuropathy.These patients developed neurological symptoms in the form of bilateral lower limb weakness with sensory and bowel involvement after the recovery from the initial acute episode of chikungunya fever. Clinical examination findings suggested myeloradiculoneuropathy with normal Magnetic Resonance Imaging of the Spine, with the nerve conduction study showing sensorimotor axonal polyneuropathy. All the patients were treated with 1 g of methylprednisolone once a day for five days, and case 2 was given intravenous immunoglobulin also. In the follow-up, cases 1 and 2 showed complete recovery without recurrence, and case 3 did not show improvement at one month.

Ultrasonography evaluation of the normal ulnar nerve in adult: Comparison of the cross-sectional area at elbow extension and flexion.

BACKGROUND: Cross-sectional area (CSA) measurement of the ulnar nerve in the adult population by using ultrasonography (US) at elbow extension and flexion has previously been reported, but not much evidence showed a significant difference between elbow extension and flexion position. PURPOSE: To compare the ulnar nerve CSA between elbow extension and flexion position. METHODS: A comparative cross-sectional study was conducted by involving 36 healthy adults with normally functioning ulnar nerve proven by Nerve Conduction Study (NCS) or Electroneurography. The ulnar nerve CSA was measured on each elbow by using US at the level of the medial epicondyle, 2 cm distal and 2 cm proximal from the medial epicondyle. RESULTS: The average ulnar nerve CSA at the medial epicondyle, 2 cm distal and proximal to the medial epicondyle at elbow extension respectively were 5.95 ±â€¯0.74 mm2, 6.27 ±â€¯0.92 mm2, and 5.92 ±â€¯0.73 mm2. At elbow flexion, the average ulnar nerve CSA at the positions was 5.70 ±â€¯0.83 mm2, 5.23 ±â€¯0.87 mm2, dan 5.73 ±â€¯0.71 mm2 respectively. The CSA of the ulnar nerve at elbow extension was significantly larger compared to the flexion position in the three areas observed in this study (p < 0.001). CONCLUSION: The CSA of the ulnar nerve at elbow extension position was larger compared to the flexion position. Elbow position should be considered in measuring CSA of the ulnar nerve.

Temporal dispersion in demyelination of POEMS syndrome and Castleman disease.

OBJECTIVE: We detailed the electrophysiological patterns of peripheral nerve temporal dispersion across spectrum of POEMS syndrome and Castleman disease (CD). METHODS: Compound muscle action potentials (CMAP) duration of 3 patients with POEMS syndrome and 2 with hyaline vascular type CD without clonal plasma cell dyscrasia were retrospectively analysed. RESULTS: Median and ulnar nerves distal CMAP duration were prolonged in all patients irrespective of plasma cell dyscrasia or M protein. All lower limbs distal CMAP responses were absent. Greatest distal CMAP duration prolongation was observed in median nerves for POEMS syndrome (17.0 ms, 158% upper limit normal) and in ulnar nerves for CD (9.8 ms, 47% upper limit normal). Distal/proximal CMAP duration ratio of <0.7 were seen in 33% of median and ulnar nerves studied among POEMS syndrome. Among nerves with ratio >0.7, all had distal CMAP duration prolongation (Range 7%-158% of upper limit normal). CONCLUSIONS: Abnormal distal CMAP dispersion is not uncommon in POEMS syndrome and CD without clonal plasma cell dyscrasia or M protein. POEMS syndrome has greater distal CMAP duration in median and ulnar nerves, particularly in median nerve that can reach up to 150% of upper limit normal, compared to <50% in CD. SIGNIFICANCE: Detailed electrophysiological analysis of distal CMAP duration may help in distinguishing POEMS syndrome and CD.

Impact of technical variations on the ring-finger test for carpal tunnel syndrome.

OBJECTIVE: To assess if recording the sensory latencies of the median and ulnar nerves one-by-one (consecutive) or at the same time (simultaneous) in the ring-finger test for carpal tunnel syndrome (CTS) will show equivalent results or if it will lead to a different clinical classification of patients. METHODS: We assessed the limits of agreement between the simultaneous and the consecutive method based on the median- ulnar sensory latency difference derived by both methods in 80 subjects and compared the number of minimal CTS cases identified by the two methods. RESULTS: Limits of agreement ranged from -0.23 to 0.29 ms. A significantly higher proportion of subjects with minimal CTS (only detectable by using the comparison test) was found using the simultaneous method (n = 8 and 2, respectively; p = 0.03). CONCLUSION: The two methods have a poor to moderate agreement as indicated by the range of the limits of agreement (0.5 ms). SIGNIFICANCE: Even small methodological changes to the ring-finger test can lead to results with different clinical meaning in the same individual and one should be aware of which method was used when interpreting results.

Reversible conduction failure on the deep tendon reflex response recording in early Guillain-Barré syndrome.

OBJECTIVE: To describe the case of a patient with Guillain-Barré syndrome (GBS) showing early reversible conduction failure (RCF) detected by means of serial deep tendon reflex response (T-reflex) study. METHODS: A 36-year-old woman had a 5-day history of foot and hand paresthesias ascending to thighs and arms, throbbing interscapular and neck pain, mild to moderate tetraparesis, and areflexia. Nerve conduction studies (NCS) were performed on days 7 and 33 after onset. RESULTS: NCS showed an equivocal electrophysiologic pattern, just an isolated distal RCF being detected on the right radial nerve at initial examination. Motor latency on deltoid muscle after Erb's point stimulation was preserved. Sensory conduction velocities were normal or slightly slowed. Somatosensory evoked potentials from median and tibial nerves were normal. Initially, F-wave study demonstrated reversible abnormalities, consisting of multiple A waves and low F-wave persistence, minimal F-wave latencies being preserved. Biceps brachii T-reflex was normal, whereas Achilles T-reflex was absent bilaterally, appearing on the second study with normal T-wave morphology and latency, thus conforming to the requirements for RCF diagnosis. Soleus H-reflex was also initially absent. CONCLUSIONS: Serial T-reflex study is a useful technique for detecting early RCF of proximal nerve trunks in early GBS. SIGNIFICANCE: T-reflex is useful tool for GBS in association with NCS.

Influence of placement sites of the active recording electrode on CMAP configuration in the trapezius muscle.

OBJECTIVE: We investigated how the active electrode placement site influences compound muscle action potential (CMAP) configuration of the upper trapezius muscle (TM). METHODS: A nerve conduction study of the accessory nerve was performed, and the CMAPs obtained with two different placement sites, i.e., placement of the active recording electrode on the belly of the upper TM (CMAP-A) and placement of the electrode 2 cm behind the belly (CMAP-B), were compared. CMAPs were also obtained with the active recording electrode placed in the supraspinous fossa (CMAP-C). RESULTS: All CMAPs were recorded from 21 healthy volunteers. The mean peak-to-peak amplitude of CMAP-B was 3.4 mV higher than that of CMAP-A (11.0 ±â€¯4.0 mV vs. 14.4 ±â€¯4.9 mV; P < 0.01). The mean peak-to-peak amplitude of CMAP-C was 10.3 ±â€¯5.0 mV. CONCLUSIONS: CMAP of the upper TM was always higher when the active recording electrode was placed 2 cm behind the belly of the muscle. SIGNIFICANCE: When stimulating the accessory nerve, a current spread occurs to the C5 spinal nerve root and another CMAP originating from the supraspinatus muscle occurs in the supraspinous fossa. The volume conduction from the supraspinatus muscle affects the active recording electrode on the TM, resulting in an increase in CMAP amplitude.

Brachial Plexus Neuritis Associated With Anti-Programmed Cell Death-1 Antibodies: Report of 2 Cases.

Recently, guidelines have been outlined for management of immune-related adverse events occurring with immune checkpoint inhibitors in cancer, irrespective of affected organ systems. Increasingly, these complications have been recognized as including diverse neuromuscular presentations, such as demyelinating and axonal length-dependent peripheral neuropathies, vasculitic neuropathy, myasthenia gravis, and myopathy. We present 2 cases of brachial plexopathy developing on anti-programmed cell death-1 checkpoint inhibitor therapies (pembrolizumab, nivolumab). Both cases had stereotypic lower-trunk brachial plexus-predominant onsets, and other clinical features distinguishing them from Parsonage-Turner syndrome (ie, idiopathic plexitis). Each case responded to withholding of anti-programmed cell death-1 therapy, along with initiation of high-dose methylprednisiolone therapy. However, both patients worsened when being weaned from corticosteroids. Discussed are the complexities in the decision to add a second-line immunosuppressant drug, such as infliximab, when dealing with neuritis attacks, for which improvement may be prolonged, given the inherent slow recovery seen with axonal injury. Integrated care with oncology and neurology is emphasized as best practice for affected patients.