Objective: To define clinically an unusual acute paralytic syndrome with features distinctive from those of the Guillain-Barré syndrome and similar to those described in Chinese children and young adults.
Design: Case series.
Setting: University medical centers.
Patients: Three North American men (mean age, 29 years) who presented with acute symmetric weakness and muscle cramps after a preceding gastrointestinal tract illness. These patients had no sensory symptoms, developed no respiratory insufficiency or facial weakness, and had normal to brisk muscle stretch reflexes.
Results: Results of serial nerve conduction studies were normal except for low-amplitude motor potentials. Needle electromyography revealed diffuse denervation potentials. Cerebrospinal fluid showed an elevated protein level and, in one case, a mild pleocytosis. A sural nerve biopsy specimen in one patient was normal; muscle biopsy specimens showed denervation atrophy.
Conclusion: These cases resemble those described in Chinese children and young adults and may represent a postviral monophasic process affecting the anterior horn cell or distal motor nerve terminal. Further pathologic correlation will be required to identify the exact site of the lesion. Differentiation is important when considering modes of treatment.