Motor Syndromes
- Brief facts about primary lateral sclerosis (PLS). Many other motor syndromes are laos mentioned.
- http://www.neuro.wustl.edu/neuromuscular/motor.html#pls

Primary Lateral Sclerosis - Emidicine.com
- Extensive article about primary lateral sclerosis (PLS).
- http://www.emedicine.com/NEURO/topic324.htm

Primary Lateral Sclerosis
- PLS information sheet compiled by the National Institute of Neurological Disorders and Stroke (NINDS).
- http://www.ninds.nih.gov/health_and_medical/disorders/primary_lateral_sclerosis.htm