Functional MRI with motor strip activation.

An adult with  top frontoparietal  glioma, by imaging and MRS parameters  with no neurological deficit so far needs surgery. Functional MRI (fMRI) is ordered to delineate the motor strips. Motor strips on both sides are equally and adequately  delineated , with the lesion anteriorly located in relation to the ipsilateral strip. In addition, supplementary motor activation area in parasagittal location is identified in posterior and medial location to the lesion. Case submitted by Dr MGK Murthy, Mr Sahadev and Abdul Hamid.

Teaching points

·         fMRI is preneurosurgical investigation to localize eloquent cortices controlling language, motor, and memory functions   based on BOLD sequences i.e.-Blood level Oxygen dependent sequence  studying the mapping of oxygen extraction

·         Motor mapping is fairly reliable and easy to perform even for cognitively impaired patients , by simply doing finger tapping

·         Ideal is to perform cued motor movements of fingers/feet/and/or  tongue  depending on the location of the lesion

·         Shows spatial relationship between tumor and  motor activation area, contralateral motor activation and supplementary motor activation

·         It could be decreased on the  side of the lesion depending on the mass effect and vascularity

·         MR report should be specific and brief,  for example- Motor strip on the side of the  lesion is  seen medial/lateral to and anterior/posterior  to the  lesion. Supplementary motor activation is noted /absent. Activity appears decreased / same  as contralateral activity. Preferably film should depict sagittal and axial images.

Functional MRI for Comatose Patients

For those of you not aware of the whole story, this is Terri's Fight for life: From The Guardian

Terri Schiavo, the severely brain-damaged woman whose condition sparked an epic legal, medical and political battle that has gripped America, died yesterday, 13 days after her feeding tube was removed by the wishes of her husband and the orders of several courts. News of her death prompted wailing and praying from supporters of her parents, who wanted to keep her alive, as both the US president, George Bush, and the Vatican expressed their concern at the circumstances of Ms Schiavo's death. Was she actually feeling anything or did she have no real consciousness?

Presently, the Functional Magnetic Resonance Imaging (fMRI) is the most promising tool not only to provide better diagnosis and predict outcome of brain injuries but also to communicate with the patient. The technique enables to communicate with the patient. We can ask him questions by telling him to think of playing tennis if he wants to say "yes", or imaging to walk through his home if he wants to say "no". We then directly see the reaction of brain activity in specific areas on the monitor. This technology will probably have profound implications for management of comatose patients. What do you think?