Primary aim of the trial

1. to verify safety and tolerability of expanded human fetal neural stem cells
2. to verify safety and tolerability of a microsurgery human fetal neural stem cells transplantation model
3. to recognize each change in patient's quality of life

Secondary aim of the trial

1. assessment of the impact of human neural stem cells transplantation on the disability of ALS in a clinically significant and measurable way
2. Assessment of the impact of human neural stem cells transplantation on mortality (all causes)

18 patients diagnosed as definite ALS according to the El Escorial criteria will be recruited during two years. The patients will be divided into 3 groups with different severity. Each group will be less compromised than the group that went before them. Their breathing measurements must be at least 60%. Subjects will receive injections of the human foetal neural stem cells into the spinal cord. A variety of tests and examinations will take place every month for the first year and every three months for the next two in order to monitor the course of the disease and the adverse events.

Inclusion Criteria:

• Diagnosis of definite or possible ALS according to revised EL Escorial criteria
• Age: 20-75 years
• documented progression of disease during the last 6 months.
• Absence of concomitant diseases
• Adequate assurances of adherence to protocol
• The patient must be able to communicate verbally or with the use of non-verbal communication system

Group 1

• maximum score of 1 on walking item of ALS functional rating scale
• forced vital capacity > or equal to 60

Group 2

• forced vital capacity > or equal to 60
• ambulation difficulties (maximum score of 2 on walking item of ALS functional rating scale)

Group 3

• Independent ambulation (score 4 on a scale ALS-FRS)
• forced vital capacity > or equal to 70

Exclusion Criteria:

The presence of at least one of the following will lead to patient exclusion.

1. psychiatric diseases or other neurological diseases different from ALS
2. other systemic diseases
3. Neoplasms or other diseases reducing life expectancy
4. Antecedent polio infection
5. corticosteroids, immunoglobulin or immunosuppressive treatment
6. involvement in other clinical trials
7. 2 or more critical items in MMPI
8. neuropsychological evaluation suggestive of mental deterioration or cognitive sphere disturbance.
9. Impediments to MRI
10. patients unable to understand informed consent form and study aims.
11. women who are pregnant or childbearing potential for the duration of the study. Non-pregnant status will be documented by beta-HCG negative test 7 days before treatment start