Acute Motor Axonal Neuropathy

05 November 2004

Term first used in 1993 for Chinese paralytic illness

Chinese Paralytic Illness

Average age 4.5 yrs

30% preceding diarrhea especially Campylobacter in summer months

symmetrical & flaccid weakness

normal sensory exam

no autonomic dysfunction

reflexes preserved, sometimes hyperreflexic

electrophysiology:         normal DML, CV but reduced CMAP amplitudes

                                    normal SNAP & if F detectable were normal

                                    H reflex not done

normal CSF in first week

necropsy:          extensive chromatolysis of anterior horn cells

Wallerian like degeneration of ventral roots & motor fibres in periph nerves and mild demyelinating changes

Dorsal root & ganglia normal

Serology:          ODR>3 for IgG for C. jejuni (normal ODR<2)

If patient survived, very good outcome

Acute motor neuropathy (GBS without sensory loss)

More rapid onset of weakness

Earlier nadir

Initially predominantly distal weakness

Sparing of cranial nerves

Preserved and even hyperreflexia noted in this form of GBS (no study with H reflex)

No sensory signs

67% elevated GM1 compared to 28% GBS

electrophysiology similar to above and abundant denervation on EMG

better response to immune globulin compared to plasma exchange (Dutch study)