Inclusion Criteria:

• All patients must have clinically-defined ALS as defined by the World Federation of Neurology criteria
• Age greater than 18 years
• If female, must be post-menopausal or had a hysterectomy
• Permanent resident or citizen of the United States
• History of a chronic onset of a progressive motor weakness of greater than one year, but less than two years duration
• Must have vital capacity greater than 65% of predicated for age, gender, and body type
• Able to comply with protocol requirements, including MRI testing
• Can provide written informed consent

Exclusion Criteria:

• Any clinically significant medical condition (e.g., within six months of baseline, had myocardial infarction, angina pectoris, and/or congestive heart failure) that, in the opinion of the investigator, would compromise the safety of patient.
• Autoimmunity, including Crohn's disease, rheumatoid arthritis, psoriasis
• Malignancy including melanoma with the exception of localized skin cancers (with no evidence of metastasis, significant invasion, or re-occurrence within three years of baseline). Any other malignancy will not be allowed.
• Active systemic or local infection near the lumbar puncture site
• Other active systemic disease as defined by laboratory abnormalities
• Use of herbal medications or other unapproved drugs
• Enrolled in an investigational drug trial within 30 days of baseline visit
• Kokmen Short Test of Mental Status score <32
• Beck's Depression Inventory score >18
• Presence of a tracheostomy
• Ventilator dependent