There is evidence suggesting that stem cells harvested from the bone marrow and transplanted into the brain may be effective in slowing down the progression of parkinsonism. Mesenchymal stem cells are able to produce growth factors that provide support to diseased nervous cells.

In this study mesenchymal stem cells will be harvested from the bone marrow, cultivated in a test tube so that they multiply and then infused into the arteries that supply blood to the brain in 20 patients suffering from a rare form of parkinsonism, Progressive Supranuclear Palsy. Each patient will undergo two infusions, one with the stem cells and one without, at an interval of 6 months. The sequence of the two infusions will be assigned randomly; patients and assessors will not know the sequence (double-blind). Patients will be followed-up for up to 1 year after the last infusion, with regular assessments to assess safety, efficacy on motor and cognitive functions, and effects on the brain by neuroimaging techniques.

The study has a preliminary phase with 5 patients all given stem cell therapy alone, designed to assess safety

Inclusion Criteria:

diagnosis of 'probable Progressive Supranuclear Palsy - Richardson's disease subtype' according to current diagnostic criteria (Litvan et al. 1996 and 2003)

• age at onset at least 40 years;
• disease duration 12 months to 8 years;
• supranuclear ophthalmoplegia;
• postural instability or falls within 3 years from disease onset
• positive MRI for PSP criteria (Quattrone et al, 2008)
• Stable pharmacological treatment for at least 90 days
• Lack of response to chronic levodopa (at least 12-month treatment).
• Able to stand in upright posture without assistance for at least 30 seconds
• Written informed consent (including video taping)

Exclusion Criteria:

• Idiopathic Parkinson's disease;
• Cerebellar ataxia
• Symptomatic autonomic dysfunction
• Evidence of any other neurological disease that could explain signs;
• History of repeated strokes with stepwise progression of parkinsonian features;
• History of major stroke;
• Any history of severe or repeated head injury;
• A history of encephalitis;
• A history of neuroleptic use for a prolonged period of time or within the past 6 months;
• Street-drug related parkinsonism;
• Significant other neurological disease on CT-scan/MRI;
• Oculogyric crises;
• Major signs of corticobasal degeneration;
• Signs of Lewy body disease;
• Other life-threatening disease likely to interfere with the main outcome measure;
• Any clinically significant laboratory abnormality, with the exception of cholesterol, triglycerides and glucose;
• Renal failure (serum creatinine more than 300 mM/l);
• Transaminase elevation more than twice the upper limit of normal;
• Any concomitant disorder associated with bone marrow function impairment
• Any concomitant disorder that requires chronic treatment with immunosuppressors, anti-inflammatory agents, and/or growth factors
• dementia (MMSE < 24 according to Folstein 1975 or defined according to DSM-IV TR criteria)
• any other disorder that could interfere with the evaluation of treatment or that could make intra-arterial infusion inadvisable
• any other features that, according to the investigator, could reduce adherence to protocol procedures or prevent rapid access in case of emergency;
• women of child-bearing age
• participation in another clinical trial with experimental treatment in the last 30 days
• brain MRI evidence of severe vascular abnormalities, space-occupying lesions or normal pressure hydrocephalus