Brain Transplant

(NOVA, 12/15/1992, copyright PBS)

  1. the two most common degenerative diseases of aging
    1. Parkinson's disease
      1. symptoms (signs)
        1. resting tremor
        2. slowness (poverty) of movement
        3. cogwheel rigidity
        4. slow, shuffling gait
        5. loss of facial expression (masked face)
      2. l-dopa therapy has been most successful but has side effects (concept of the "therapeutic window")
        1. uncontrollable movements (athetosis)
        2. hallucinations
    2. Alzheimer's disease
  2. cell transplants
    1. adrenal cell transplants done in Mexico were claimed to alleviate Parkinson's disease, but this result could not be replicated elsewhere
    2. fetal cell (substantia nigra) transplants in monkeys reversed MPTP parkinsonism
      1. research in Sweden indicated that fetal cell transplants might be the only hope for patients with degenerative diseases such as Parkinson's and Alzheimer's disease
      2. strict ethical guidelines were established for operations in humans
      3. initial results were disappointing in older debilitated patients, so they decided to try a transplant in a younger patient with MPTP parkinsonism - after extensive screening, two candidates were chosen who were not so severely impaired that they could not be pretested
  3. fetal tissure grafts
    1. fetal tissue must be young - 6 to 8 weeks post fertilization
    2. tissue is implanted into the caudate nucleus and putamen
    3. the operation is carried out in two stages for implants on each side of the brain
    4. there was not much improvement after a year (in George's case), but by two years there was a dramatic improvement (although not complete recovery)
    5. PET scanning showed substantial recovery of dopamine in the basal ganglia, even though only 10% of the transplanted cells survived
    6. neuroprotection may be necessary in older patients with idiopathic parkinsonism to prevent the grafted cells from being killed off by the on-going disease process

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