The value of sensory nerve conduction studies in the diagnosis of Guillain-Barré syndrome

Clinical Spectrum and Prognosis in Patients With Acute Nutritional Axonal Neuropathy

BACKGROUND AND OBJECTIVES

To describe the clinical, micronutrient, and electrophysiologic spectra and prognosis in patients with acute nutritional axonal neuropathy (ANAN).

METHODS

Patients with ANAN were identified between 1999 and 2020 by a retrospective review of our EMG database and electronic health records and categorized on clinical and electrodiagnostic grounds, as pure sensory, sensorimotor, or pure motor; and by risk factor (alcohol use disorder, bariatric surgery, or anorexia). Laboratory abnormalities were recorded including thiamine, vitamin B6, B12, and E, folate, and copper. Ambulatory and neuropathic pain status at last follow-up were recorded.

RESULTS

Of 40 patients with ANAN, 21 had alcohol use disorder, 10 were anorexic, and 9 had recently undergone bariatric surgery. Their neuropathy was pure sensory in 14 (7 with low thiamine), sensorimotor in 23 (8 with low thiamine), and pure motor in 3 (1 with low thiamine). Vitamin B1 was most commonly low (85%), followed by vitamin B6 (77%) and folate (50%). The risk factor and neuropathy type were not associated with a particular micronutrient deficiency. Of the 37 patients who were seen in follow-up, only 13 (35%) were walking independently, and only 8 (22%) were pain free at the last follow-up visit at a mean of 22 months (range 2-88 months) from onset.

DISCUSSION

The spectrum of ANAN is wide, ranging from: (1) a pure sensory neuropathy with areflexia, limb and gait ataxia, neuropathic pain, and unevocable sensory responses to (2) a motor axonal neuropathy with low-amplitude motor responses without conduction slowing, block, or dispersion, and (3) a mixed sensorimotor axonal polyneuropathy. Specific micronutrient deficiencies or risk factors do not predict neuropathy subtype. The subgroup of patients with ANAN with documented thiamine deficiency also range from pure sensory to pure motor, and only a minority have Wernicke encephalopathy. We do not know whether coexistent micronutrient deficiencies may help explain the wide clinical spectrum of thiamine-deficient ANAN. The prognosis of ANAN is guarded due to residual neuropathic pain and slow recovery of independent ambulation. Therefore, early recognition of patients at risk is important.

Sural nerve involvement in Guillain-Barré syndrome: Clinical and prognostic implications. A prospective cohort

BACKGROUND

Sural sparing is common in Guillain-Barré syndrome (GBS). However, one third of patients have sural nerve compromise. Its clinical implications associated factors and short-term prognosis are still unknown. The objective of this study is to identify if sural nerve compromise is associated with a worse prognosis and to describe clinical and electrophysiological characteristics in Guillain-Barré syndrome.

MATERIALS AND METHODS

We prospectively analyzed patients with Guillain-Barré diagnosis with vs without sural nerve compromise. All patients underwent nerve conduction studies within the first 3 days of hospital admission. Clinical and electrophysiological characteristics were compared between groups.

RESULTS

174 patients were included in this study. Acute inflammatory demyelinating polyneuropathy was the predominant variant (43.7 %). Thirty percent of patients had sural nerve involvement. In the comparative analysis between affected vs unaffected sural groups, age ≥50 years and Guillain-Barré disability score ≥3 demonstrated a statistically significant difference. Regarding short-term recovery period for independent walking, there was no significant difference. In the multivariate analysis, age ≥50 years was identified as independent factors for sural nerve compromise on admission.

CONCLUSION

sural nerve compromise occurs in 30 % of patients with GBS and is not associated with a worse functional prognosis. Age ≥50 years was identified as an independent factor for sural nerve compromise.

Sural Sparing Pattern and Sensory Ratio as Electrodiagnostic and Prognostic Markers in Pediatric Guillain-Barré Syndrome

BACKGROUND

We aimed to evaluate the presence of sural sparing pattern (SSP) and sensory ratio in pediatric Guillain-Barré syndrome (GBS), their distribution to subtypes, and their relationship with demographic and clinical features with a focus on the disability and muscle strength.

METHODS

This single-center retrospective study was conducted on pediatric GBS patients of both sexes with 2 years follow-up and two nerve conduction studies in which SSP and sensory ratio were calculated. Three subgroups of SSP were formed by separate calculation of median (SSP-m) and ulnar (SSP-u) and both median and ulnar sensory nerve action potentials (SNAPs; SSP-total). Muscle strength and disability were evaluated with the Medical Research Council (MRC) sum score and Hughes functional grading scale (HFGS), respectively.

RESULTS

SSP total was identified in 70.6% (n: 24) of the patients, while sensory ratio >1 was observed in 20 (66.7%) patients. Patients with SSP-m, SSP-u, SSP-total, or sensory ratio >1 had higher HFGS scores, while patients with SSP-m, SSP-u, or SSP-total had lower MRC sum scores. SSP parameters were significantly associated with muscle strength and disability scores in acute motor axonal neuropathy patients.

CONCLUSION

Both SSP and sensory ratio can be used for diagnostic and prognostic purposes. Disability and muscle strength are associated with SSP and sensory ratio in pediatric GBS.

[Very-early and early neuroelectrophysiological features of childhood Guillain-Barré syndrome]

OBJECTIVES

To study the very-early and early neuroelectrophysiological features of childhood Guillain-Barré syndrome (GBS) and their association with clinical diagnosis.

METHODS

A retrospective analysis was performed on the neuroelectrophysiological data of 43 children with GBS. According to the interval from onset to neuroelectrophysiological examination, the children were divided into a very-early examination group with 18 children (an interval from onset to the examination of ≤7 days) and an early examination group with 25 children (an interval from onset to the examination of 7 to ≤14 days). The children with acute flaccid paralysis, matched for the examination time of GBS children, were enrolled as the control group. The abnormal rates of neuroelectrophysiological parameters were compared between the above groups. According to the results of the H reflex test, the GBS children were divided into an abnormal H reflex group and a normal H reflex group, and related clinical data were compared between the two groups.

RESULTS

Compared with the control group, the very-early and early examination groups had a significantly higher abnormal rate of H reflex (P<0.05), while there was no significant difference in the abnormal rates of F wave, motor nerve conduction, and sensory nerve conduction (P>0.05). Compared with the normal H reflex group, the abnormal H reflex group had a significantly shorter interval from onset to the time of confirmed diagnosis (P<0.05).

CONCLUSIONS

Absence of the H reflex is a valuable parameter of neuroelectrophysiological abnormalities in the early stage of GBS and can help with the diagnosis of GBS.

Sural-sparing pattern: A study against electrodiagnostic subtypes of Guillain–Barre syndrome

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This study investigated sural-sparing in GBS patients who underwent extensive sensory NCS protocol.

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Sural-sparing was less obvious in axonal than demyelinating GBS based on the number of affected upper-limb SNAPs.

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Extended sensory NCS (bilateral or serial) is worth detecting sural-sparing as a supportive EDX feature of GBS.

Objective

To study sural-sparing pattern in Guillain–Barre syndrome (GBS) and compare it among GBS’s electrodiagnostic subtypes, classified by two recent criteria.

Methods

This study retrospectively reviewed clinical data and electrodiagnostic studies (EDXs) of 88 GBS patients diagnosed in a tertiary care hospital (2010–2019).

Results

Overall, 79/88 (89.8%) and 36/45 (80%) patients had bilateral sensory nerve conduction studies (NCS) in the first EDX and follow-up EDX, respectively. Sural-sparing occurred in all subtypes (50% overall occurrence rate), most commonly in demyelination. There was no statistically significant difference in sural-sparing occurrence rates between demyelinating and axonal GBS; however, sural-sparing in axonal GBS tended to show a lower number of abnormal upper-limb sensory nerve action potentials (SNAPs) than demyelinating GBS. Shifting between sural-sparing and no sural-sparing occurred in approximately-one-fourth of patients receiving serial studies. Follow-up EDX additionally discovered 20% of all sural-sparing. Unilateral EDX could have omitted up to 30% of sural-sparing.

Conclusions

Sural-sparing is less obviously manifested in axonal than demyelinating GBS, with respect to the number of affected upper-limb SNAPs. Extended sensory NCS is worth in detecting sural-sparing as a supportive electrodiagnostic GBS feature.

Significance

This report showed one different character of sural-sparing (number of affected upper-limb SNAPs) between demyelinating and axonal GBS.

Analysis of Clinical Symptoms of Guillain–Barré Syndrome Induced by Heat Stroke: Three Case Reports and Literature Review

Background

Heat stroke is a potentially fatal condition that is caused by elevated core temperature. Guillain–Barré syndrome (GBS) induced by heat stroke is extremely rare and has only been reported in few case reports. The purpose of this case study was to evaluate the clinical symptoms, neuroelectrophysiological and imageological features of GBS after heat stroke.

Methods

We reviewed our hospital records and previously published reports to find the cases of GBS after heat stroke. The clinical, imageological, and electrophysiological profiles, treatment and prognosis were presented and analyzed.

Results

We retrieved three cases of GBS induced by heat stroke from our hospital, which presented as lesions on multiple cranial and peripheral nerves and albuminocytologic dissociation in the cerebrospinal fluid. All of these patients had disorders of consciousness at the early stage of heat stroke and a “pseudo-recovery period” after they recovered from coma after heat stroke. After immunoglobulin administration and immunoregulation therapy, these patients' neurological deficiencies were relieved significantly. But there are still disabilities and almost totally reliant on others.

Conclusions

The number of the cases of GBS induced by HS reported in this study has been the most in the recent 5 years. Clinicians should pay attention to patients with heat stroke with sustained coma and the sudden quadriplegia. Early, exact and timely diagnosis and treatment of GBS need to be performed, to accelerate recovery and improve prognosis.