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Brain Imaging in Trials of Restorative Therapies for Stroke
Several restorative therapies for stroke are under investigation including neuro-
trophic factors, stem cell transplants, small molecules, intensive physiotherapy,
robotics, neuroprosthetics, electromagnetic brain stimulation, and mental exercises.
Measures of CNS injury and function can be used in many different ways to assist
in clinical trials of these therapies. Brain imaging can be a useful approach to select
patients and evaluate the effi cacy of treatment as well as progress of recovery fol-
lowing stroke (Cramer 2009 ).
Brain imaging parameters might be used to guide treatment decisions for sub-
jects in a clinical trial. For example, serial imaging measures can be used to indi-
vidualize details of therapy such as defi ning dose and duration of treatment, for an
individual patient. PET and SPECT have been used to determine response of post-
stroke patients to hyperbaric oxygen and help in the decision whether to use hyper-
baric oxygen and level of pressure depending on the response to a test treatment
(Jain 2009). Imaging measures might also serve as biomarkers of treatment effect.
Such data might provide insight into treatment mechanism, which might second-
arily guide features of restorative trial design. Changes in laterality or size of motor
system activation, revealed by fMRI studies in response to a motor-based therapy,
might guide entry criteria to exclude patients with massive motor system injury, and
refi ne restorative stroke trial design.
Decisions for Evacuation of Intracerebral Hemorrhage
Intracerebral hemorrhage (ICH) usually has poor prognosis, which is not altered by
surgical evacuation of the hematoma in most cases. Vasculopathic changes associ-
ated with the APOE ε2 allele might have a role in the severity and clinical course of
lobar ICH. Screening of patients who have ICH to identify the ε2 variant might
allow identifi cation of those at increased risk of mortality and poor functional out-
comes (Biffi et al. 2011 ).
Decisions for Revascularization Procedures in Chronic
Post- stroke Stage
Patients who have not recovered from stroke in a year despite various treatments
and have fi xed neurological defi cits are usually referred to as being in a chronic
post-stroke stage. Because penumbra zone surrounding the cerebral infarct may
contain dormant neurons even after a year following the stroke onset, various treat-
ments have been attempted to activate these neurons with the aim of improving
cerebral function. Hyperbaric oxygen (HBO) is one of these treatments. Some of
these patients undergo extracranial-intracranial (EC/IC) bypass procedure, usually
12 Personalized Management of Neurological Disorders