Fellow’s Corner: Refusal to Walk? Consider the Nerves

Gina Chang, MD, MPH

Case: A 3-year-old girl is admitted to the general pediatrics service for 2 days of refusal to walk. Parents report that she has become increasingly less active and now cries when placed in a standing position, stating that her back and legs hurt. There is no history of trauma, and she does not currently have fever or other symptoms of infection, though she had a few days of low-grade fever with rhinorrhea and cough about 2 to 3 weeks ago.

On her admission exam, there is no obvious joint swelling or tenderness to palpation along her back or legs. She moves all her extremities spontaneously with full passive range of motion. When made to stand, she takes a few steps, but starts to cry, will not walk further, and then sits down. Complete blood count, electrolytes, liver function panel, creatine kinase, C-reactive protein, erythrocyte sedimentation rate, and X-rays of her back, hips, and legs are normal.

Neurology is consulted, and on neurologic exam, the patient sits independently, slightly fussy but with an otherwise normal mental status. Cranial nerves are normal, and she has normal muscle bulk and tone. She moves all extremities at least antigravity and against some resistance, but further confrontational testing is limited by age. On sensory exam, she has limited response to tickling or pinching of her feet or legs. Deep tendon reflexes are absent throughout. Plantar responses are down-going bilaterally. Coordination is age-appropriate without dysmetria. She has a narrow-based gait but appears hesitant and unsteady. Lumbar puncture is performed, and CSF is notable for a white blood cell (WBC) count of 3 cells/uL and an elevated protein of 220 mg/dL. MRI of the brain and spinal cord demonstrates diffuse thickening and gadolinium enhancement of the cauda equina nerve roots.

Discussion: Diagnoses to consider include musculoskeletal injury, toxic synovitis, arthritis, acute cerebellar ataxia, spinal cord lesion (such as transverse myelitis), anterior horn cell lesion (such as acute flaccid myelitis), toxic/metabolic neuropathies (due to agents such as lead, mercury, organophosphates, and others), myositis, and Guillain-Barré syndrome (GBS).

GBS is an acute inflammatory polyradiculopathy classically characterized by rapidly progressive ascending symmetric weakness and areflexia. However, in pre-school aged children, the most common presenting symptoms are refusal to walk and leg pain. These symptoms, coupled with exam findings of sensory deficits and areflexia, and CSF demonstrating albuminocytologic dissociation (elevated protein with normal WBC), make GBS the most likely diagnosis for this case.

It is critical to consider GBS early with the young child refusing to walk, because weakness can progress to involve the respiratory muscles, leading to the need for ventilatory support in 15% to 20% of children. Autonomic dysfunction (dysrhythmias, blood pressure instability, bladder dysfunction) is quite common, occurring in one-half of patients. Cranial nerves may be involved in some variants of GBS, such as Miller-Fisher syndrome, which can make the diagnosis more challenging.

The time course of GBS is fairly rapid—2 to 4 weeks to nadir for most patients. As in our patient, GBS is preceded by a respiratory or gastrointestinal infection in approximately two-thirds of cases. While GBS has been associated with some vaccinations, particularly influenza, risk of GBS following influenza infection is far greater than risk following the vaccine.

Supportive studies in the diagnosis of GBS include lumbar puncture to evaluate for albuminocytologic dissociation and lumbar spine MRI, which may demonstrate contrast enhancement of the nerve roots. Electrodiagnostic studies (electromyography [EMG] and nerve conduction studies [NCS]) are typically reserved for cases where the diagnosis is unclear.

Treatment for GBS consists of supportive care and immunotherapy. While data are limited in children, adding intravenous immunoglobulin (IVIG) is thought to shorten time to recovery. Plasma exchange may be used in patients with more severe manifestations. Recovery occurs over weeks to months. Long-term prognosis in children is excellent: >90% of children recover ambulatory function within 6 months. Recurrence is rare. Live vaccines (MMR, VZV) should be delayed for 11 months following IVIG administration to ensure optimal immune response.

Reference and Selected Reading

Asbury AK, Cornblath DR. Assessment of current diagnostic criteria for Guillain-Barré syndrome. Ann Neurol. 1990;27(Suppl):S21–S24.

Roodbol J, et al. Recognizing Guillain-Barre syndrome in preschool children. Neurology. 2011 Mar 1;76(9):807-10.

El-Bayoumi MA, et al. Comparison of intravenous immunoglobulin and plasma exchange in treatment of mechanically ventilated children with Guillain Barré syndrome: a randomized study. Crit Care. 2011;15(4):R164.

Kwong JC, et al. Risk of Guillain-Barré syndrome after seasonal influenza vaccination and influenza health-care encounters: a self-controlled study. Lancet Infect Dis. 2013;13(9):769-76.

Kawasaki disease. In: Red Book. 2015 Report of the Committee on Infectious Diseases. Elk Grove, IL: American Academy of Pediatrics; 2015:494-500.

Hughes RA, et al.; Quality Standards Subcommittee of the American Academy of Neurology. Practice parameter: immunotherapy for Guillain- Barré syndrome: report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2003;61(6):736-40.

Rosen, BA. Guillain-Barré syndrome. Pediatrics in Review. 2012;33(4):164-171.