Neuroplasticity and Rehabilitation Strategies

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Neuroplasticity and Rehabilitation Strategies

• Robert K. Shin M.D.
• VA MS Center of Excellence
• Assistant Professor
• Departments of Neurology and Ophthalmology
• University of Maryland School of Medicine

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Neuroplasticity?

• The ability of cortex to reorganize in response
  to injury

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Question

• Is the brain compensating for damage from MS in
  order to maintain normal function?

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Functional MRI

• BOLD contrast analysis
• Oxyhemoglobin
• Deoxyhemoglobin
• Alternating periods of task vs. rest
• Activated regions determined statistically

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Reddy et al. Neurology 200054236-244
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A dynamic cortical response?

• Initially increased activation of contralateral
  sensorimotor cortex
• Ipsilateral activation seen initially as well
• Activation gradually reduced as patient recovered

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Clinically isolated syndrome

• 16 consecutive patients with a CIS suggestive of
  multiple sclerosis
• 15 age- and sex-matched controls
• Functional MRI during finger flexion
• Rocca et al. NeuroImage 200318847-855

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Rocca et al. NeuroImage 200318847-855
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A response to cortical pathology?

• Decreased NAA found in clinically stable CIS
  patients
• Increase in activation of somatomotor cortex
  correlated with worsening brain damage

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Another puzzle

• Optic neuritis causes vision loss and prolonged
  VEPs
• Vision in optic neuritis almost always recovers
• VEPs frequently remain abnormal

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Question

• Is the brain somehow compensating for impaired
  optic nerve function?

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Recovery from optic neurits

• 7 patients who had recovered from optic neuritis
• 7 controls
• Functional MRI during photic stimulation
• Werring, et al. JNNP 200068441-449

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Werring, et al. JNNP 200068441-449
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Functional reorganization?

• Only occipital activation seen in controls
• Additional extra-occipital areas were activated
  in patients who had recovered from optic neuritis

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Attention and memory

• 22 patients with RR-MS
• 22 age-matched controls
• Functional MRI study
• Paced Auditory Serial Addition Test (PASAT)
• Recall task

Mainero, et al. NeuroImage 200421858-867
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PASAT
Mainero, et al. NeuroImage 200421858-867
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Recall
Mainero, et al. NeuroImage 200421858-867
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T2 LL
Mainero, et al. NeuroImage 200421858-867
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An adaptive mechanism?

• Altered activation during cognitive tasks in MS
  patients
• Activation increases as T2 lesion load increases
• But activation is greater in patients with better
  function

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Conclusions

• Functional MRI activity is altered in MS patients
• These changes appear to be an adaptive response
  to brain damage

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Implications for rehabilitation?

• Can functional MRI be used to prognosticate?
• Can cortical plasticity be enhanced?
• Proprioceptive stimulation
• Forced use
• Neurotrophic factors
• Increased neurotransmitter release