[Management of secondary normal pressure hydrocephalus and assessment of cortical reorganization using fMRI]

We assessed the motor recovery and cortical reorganization associated with intracranial pressure (ICP) control in a secondary normal pressure hydrocephalus (sNPH) patient. A 32-year-old man with sNPH resulting from a head injury presented with left hemiplegia. A ventricular-peritoneum shunt (VP shunt) was surgically inserted for the sNPH using a Codman Hakim Programmable Valve, and his ICP was controlled according to the ventricular size by CT scanning. The motor function of the patient was evaluated by functional MRI (fMRI) during ICP control in our hospital. The fMRI was performed at 3.0 T with timed dorsal flexion-extension movement of the foot. After 3 months of shunt valve pressure control, the primary sensorimotor cortex (SM1) was activated during the affected (left) foot movement, an area that had not been able to be activated just after admission. His walking ability also recovered markedly to the point of free independent walking. The motor function of the affected lower extremity appeared to recover to almost the some degree the original motor area after control of the ICP. This finding may reflect functional reorganization of the motor pathway following ICP normalization.