Clinical data: 28 yr old lady suspected of branistem death shows on MRI , bilateral Trans cerebral vein, cortical veins sign, Loss of intra arterial flow signal voids on T2WI (LIFSV), loss of flow signal in dural sinuses conforming to brainstem death .
Teaching points by Dr MGK Murthy, Dr Srujana
MRI technologist: Mr Murali
1.Brain death or Brainstem death is defined as "complete irreversible cessation of all brain functions including Brainstem". However criterion varies from country to country as it is political/ ethical/ religious/ societal based .
2. USA/UK/Germany etc apply Clinical criteria, while France/ japan/ netherlands make technical exams mandatory, with Korea making EEG absolutely essential(though false + ve of EEG could be as high as 20%)
India has enacted legislation in 1994 (some states are yet to adapt the law) based on UKs "Brain stem death &Transplant of Human organs (THO) " with a team of 4 experts consisting of Medical administrator , Neuro physician/Neurosurgeon(or surgeon&anaesthetist), Medical Officer in charge of the case , and a specialist, mandatory to declare .
Criteria include deeply comatose/ on Ventilator/All brainstem reflexes absent(pupillary/Dolls head/Corneal/vestibulo -ocular/gag/cough &no motor response to any of the cranial nerves stimulation etc)/ specific core temp abnormality (normal 32.2 to 36.0 Degrees celsius) with Mandatory Apneic diffuse Oxygenation test (for spontaneous respiration response)
3. As of now technical tests are not mandatory, however not contraindicated .
4. Four vessel angiography is gold standard amongst the tests , however not practical.
CT Angiography/CT Perfusion/MRAngiography are variably used with EEG and Radionuclide scintigraphy with TC99 at places . MRI is considered by many, to be most practical and reliable with T2WI/DW/SW/FFE/TOFMRA accepted as standard sequences both for reliable findings and rapidity.Classical findings include Loss of intra arterial flow signal voids on T2WI (LIFSV)/Tonsilar herniation/Diffuse cortical hyper intensity/swelling of sulci on DW/Diffuse hemispheric hyper intensity on DW/Bilateral trans cerebral vein sign (parallel or perpendicular to lateral ventricles)/ Bilateral Cortical veins sign/ reduced ADC values .
5. Being an evolving subject with organ transplantation picking up rapidly in our country, the issue along with criteria/ technical exams etc are expected to change in the near future