Ryan Felling, M.D.
One day the 17-year-old suffered fatigue and headache, the next her whole body felt sore. Her pediatrician, suspecting something viral at play, sent her home. But days later she returned describing a “knife-like” pain shooting down her back, tingling and weakness in the left side of her face and numbness in her hands, feet and buttocks. Also, at school she felt dizzy and had to hold on to a wall to walk down a corridor. What was going on?
Her pediatrician promptly sent her to a local hospital, where ED physicians learned she had camped in the woods the previous fall and was hospitalized for H1N1 pneumonia a year earlier. They conducted CT and cerebral spinal fluid (CSF) studies and referred her to Hopkins Children’s neurology service. Due to the Bell’s palsy-like facial weakness, they considered Lyme disease, meningitis, and atypical migraine. But because of her diagnostic studies, including high CSF protein without white blood cells, number one on the differential list was Guillain Barre Syndrome, or GBS, an autoimmune disorder that often follows an infection and damages the myelin sheath covering nerves, causing nerve signals to slow down and the numbness, tingling and weakness.
“Her neurologic exam showed left upper and lower facial weakness, and she couldn’t close her left eye tight,” said pediatric resident Sean Barnes at a recent case conference. “Also, she couldn’t completely smile on the left side.”
So, Barnes asked fellow residents and pediatric neurologist Ryan Felling, what is the differential diagnosis for weakness and numbness in an adolescent? Was this a typical Guillain Barre Syndrome patient, does high-dose immunoglobulin therapy (IVIG) change the progression of symptoms, and when would you order nerve conduction studies?
Felling noted that the weakness and numbness can often be vague and misleading, particularly in children, and pediatricians need to consider causes like stroke, spinal cord compression, inflammation in the central nervous system, neuromuscular junction disorders like myasthenia gravis, toxic exposures resulting in neuromuscular junction failure, as well as peripheral neuropathy, nerve root injury and primary muscle disorders like myositis. The culprit in this case, Guillain Barre Syndrome, he added, tends to have a wide range of presentations. Diagnosis requires progressive weakness in two or more limbs due to neuropathy, areflexia – the absence of neurologic reflexes – a disease course less than four weeks, and the catchall exclusion of other causes. In addition to that, patients may present with one of several types of GBS, from the more familiar AIDP (acute inflammatory demyelinating polyneuropathy) and the less common AMSAN (acute motor sensory axonal neuropathy) to the fairly rare Miller Fisher Syndrome.
“The variability in presentation makes it tough to define a typical case of GBS,” Felling said.
The patient met the criteria for GBS and the pattern of symptoms getting worse very quickly, though weakness increasing over several days is common. Citing the patient’s balance problems, one participant at the conference raised the possibility of a cerebellar disorder. There weren’t any “true cerebellar findings,” Felling answered, though adding that many people with tactile sensory deficits can have balance problems: “Some patients describe the sensation of walking on pillows.”
There is no cure for GBS though plasmapheresis and IVIG have been shown to reduce the severity and duration of the disorder by blocking the antibodies that attack the nerve cells. In multiple studies, Felling noted, patients treated with IVIG improved more quickly than those treated with supportive management alone (Cochrane Database of Systematic Reviews 2010: Jun 16;(6);CD002063). Corticosteroids, he added, are of no benefit.
In this case the patient underwent nerve-conduction studies, which are often ordered to make sure there is no evidence of peripheral neuropathy as well as to classify the subtype of GBS. She was then treated with IVIG over five days and discharged with mild deficits, the most persistent of which was her facial droop. Felling was not surprised, describing the typical two-week onset of the disease, three-week plateau of symptoms, and six-to-eight week recovery. The good news, he noted, is that pediatric patients have a “universally better prognosis” than adults, citing a prospective study of 20 children with severe acute disease who all fully recovered following treatment with IVIG (Pediatric Neurology 2003:28;4;295). In adults, Felling added, disability persists in up to 20 percent of patients.
“In most cases,” Felling said, “children show a full recovery regardless of what subtype of GBS they had.”
The take-home message for community pediatricians?
"Be vigilant about children presenting with weakness or sensory problems even after a presumed viral illness," Felling noted, "as they may have an underlying neurologic disorder."