Influence of Demographic Factors on Nerve Ultrasound of Healthy Participants in a Multiethnic Asian Population.

BACKGROUND: High-resolution nerve ultrasound provides morphological information of peripheral nerves. We aimed to determine the normal ultrasonographic reference values of nerve cross-sectional area (CSA) in multiethnic Malaysian healthy participants. METHODS: Nerve ultrasound of the median, ulnar, radial, tibial, fibular, and sural nerves was performed in 84 healthy participants at anatomical-defined locations. The CSA at each scanned site was measured by tracing circumferentially inside the hyperechoic rim of each nerve. Comparisons were made between genders and ethnic groups. Correlations with age, ethnicity, gender, height, weight, and body mass index (BMI) were evaluated. RESULTS: CSA values and reference ranges in healthy participants were generated. Nerve CSA was significantly different in different gender (P = 0.002-0.032) and ethnic groups (P = 0.006-0.038). Men had larger nerve CSA than women, and Malay participants had larger nerve CSA compared to other ethnic groups. Nerve CSA had significant correlations to age, height, weight, and BMI (r = 0.220-0.349, P = 0.001-0.045). CONCLUSION: This study provides normative values for CSA of peripheral nerves in a multiethnic Malaysian population, which serves as reference values in the evaluation of peripheral nerve disorders. The ethnic differences in nerve CSA values should be considered during nerve ultrasound.

Determining the Utility of the Guillain-Barré Syndrome Classification Criteria.

BACKGROUND AND PURPOSE: Several variants of Guillain-Barré syndrome (GBS) and Miller Fisher syndrome (MFS) exist, but their frequencies vary in different populations and do not always meet the inclusion criteria of the existing diagnostic criteria. However, the GBS classification criteria by Wakerley and colleagues recognize and define the clinical characteristics of each variant. We applied these criteria to a GBS and MFS cohort with the aim of determining their utility. METHODS: Consecutive GBS and MFS patients presenting to our center between 2010 and 2020 were analyzed. The clinical characteristics, electrophysiological data, and antiganglioside antibody profiles of the patients were utilized in determining the clinical classification. RESULTS: This study classified 132 patients with GBS and its related disorders according to the new classification criteria as follows: 64 (48.5%) as classic GBS, 2 (1.5%) as pharyngeal-cervical-brachial (PCB) variant, 7 (5.3%) as paraparetic GBS, 29 (22%) as classic MFS, 3 (2.3%) as acute ophthalmoparesis, 2 (1.5%) as acute ataxic neuropathy, 2 (1.5%) as Bickerstaff brainstem encephalitis (BBE), 17 (12.9%) as GBS/MFS overlap, 4 (3%) as GBS/BBE overlap, 1 (0.8%) as MFS/PCB overlap, and 1 (0.8%) as polyneuritis cranialis. The electrodiagnosis was demyelinating in 55% of classic GBS patients but unclassified in 79% of classic MFS patients. Anti-GM1, anti-GD1a, anti-GalNAc-GD1a, and anti-GD1b IgG ganglioside antibodies were more commonly detected in the axonal GBS subtype, whereas the anti-GQ1b and anti-GT1a IgG ganglioside antibodies were more common in classic MFS and its subtypes. CONCLUSIONS: Most of the patients in the present cohort met the criteria of either classic GBS or MFS, but variants were seen in one-third of patients. These findings support the need to recognize variants of both syndromes in order to achieve a more-complete case ascertainment in GBS.

Diagnosis of Guillain-Barré syndrome and validation of the Brighton criteria in Malaysia.

We aimed to evaluate the key diagnostic features of Guillain-Barré syndrome (GBS) in Malaysian patients and validate the Brighton criteria. This was a retrospective study of patients presenting with GBS and Miller Fisher syndrome (MFS) between 2010 and 2019. The sensitivity of the Brighton criteria was evaluated. A total of 128 patients (95 GBS, 33 MFS) were included. In the GBS cohort, 92 (97%) patients presented with symmetrical limb weakness. Reflexes were depressed or absent in 90 (95%) patients. Almost all patients (94, 99%) followed a monophasic disease course, with 5 (5%) patients experiencing treatment-related fluctuations. Cerebrospinal fluid (CSF) albuminocytological dissociation was seen in 62/84 (73%) patients. Nerve conduction study (NCS) revealed neuropathy in 90/94 (96%) patients. In GBS patients with complete dataset (84), 56 (67%) patients reached level 1 of the Brighton criteria, 21 (25%) reached level 2, 3 (4%) reached level 3, and 4 (5%) reached level 4. In MFS, the clinical triad was present in 25 (76%) patients. All patients had a monophasic course. CSF albuminocytological dissociation was present in 10/25 (40%) patients. NCS was normal or showed sensory neuropathy in 25/33 (76%) patients. In MFS patients with complete dataset (25), 5 (20%) patients reached level 1 of the Brighton criteria, 14 (56%) reached level 2, 2 (8%) reached level 3, and 4 (16%) reached level 4. Inclusion of antiganglioside antibodies improved the sensitivity of the Brighton criteria in both cohorts. In the Malaysian cohort, the Brighton criteria showed a moderate to high sensitivity in reaching the highest diagnostic certainty of GBS, but the sensitivity was lower in MFS.

Nerve ultrasound can distinguish chronic inflammatory demyelinating polyneuropathy from demyelinating diabetic sensorimotor polyneuropathy.

Diabetic patients with poor glycaemic control can demonstrate demyelinating distal sensorimotor polyneuropathy (D-DSP) on electrophysiology. Distinguishing D-DSP from chronic inflammatory demyelinating polyneuropathy (CIDP) can be challenging. In this study, we investigated the role of nerve ultrasound in differentiating the two neuropathies. Nerve ultrasound findings of D-DSP patients (fulfilling the electrophysiological but not clinical criteria for CIDP) were compared with non-diabetic CIDP patients (fulfilling both criteria). We studied 108 and 95 nerves from 9 D-DSP and 10 CIDP patients respectively. CIDP patients had significantly larger cross-sectional areas of the median nerve at the mid-arm (17.0 ±â€¯12.5 vs 8.7 ±â€¯2.6; p = 0.005), ulnar nerve at the wrist (7.3 ±â€¯3.1 vs 4.1 ±â€¯1.0; p = 0.001), mid forearm (8.8 ±â€¯5.3 vs 5.5 ±â€¯1.5; p = 0.002) and mid-arm (14.5 ±â€¯14.1 vs 7.5 ±â€¯1.9; p = 0.013), and radial nerve at mid forearm (4.1 ±â€¯2.4 vs 1.2 ±â€¯0.4; p < 0.001). In comparison to D-DSP, CIDP patients had markedly larger nerves at the proximal and non-entrapment sites of the upper limbs, suggesting that nerve ultrasound is useful in differentiating the two neuropathies.

Serial peripheral nerve ultrasound in Guillain-Barré syndrome.

OBJECTIVE: To assess the longitudinal changes of nerve ultrasound in Guillain-Barré syndrome (GBS) patients. METHODS: We prospectively recruited 17 GBS patients and 17 age and gender-matched controls. Serial studies of their nerve conduction parameters and nerve ultrasound, documenting the cross-sectional areas (CSA), were performed at admission and repeated at several time points throughout disease course. RESULTS: Serial nerve ultrasound revealed significantly enlarged CSA in median, ulnar and sural nerves within the first 3 weeks of disease onset. Longitudinal evaluation revealed an improvement in the nerve CSA with time, reaching significance in the ulnar and sural nerves after 12 weeks. There was no significant difference between the demyelinating and axonal subtypes. There was also no significant correlation found between nerve CSA and neurophysiological parameters or changes in nerve CSA and muscle strength. CONCLUSION: In GBS, serial studies of peripheral nerve ultrasound CSA are helpful to detect a gradual improvement in the nerve size. SIGNIFICANCE: Serial nerve ultrasound studies could serve as a useful tool in demonstrating nerve recovery in GBS.