may cause leg weakness (~80%), difficulty swallowing (27%) and difficulty breathing (17%) due to respiratory muscle paralysis, and possibly death from respiratory failure
symptoms appear most commonly within four hours of ingestion (onset range 10min to 18 hours, although half develop weakness within 2hrs and 75% develop weakness within 4 hours) and generally improves after 24hrs
distribution and severity of the weakness varies and can improve and re-emerge
most common sites of weakness are legs (~42%), hands (~37%), arms, face
80% had difficulty walking and 50% had inability to walk, often with rapid onset of fatigue on re-attempting activity
many describe the weakness coming in waves, each lasting minutes to an hour, but usually under 30min for each episode and may shift to different parts
~20% experience a fall or accident
7% had weakness lasting for 2 days, while 3% it lasted 3 days and rarely for over a week or several weeks