Effects Of The Dopaminergic Agent Amantadine On Brain Function Of Vegetative State With TBI Patients:a Study Using PET/CT(Two Cases Report)

Patients with severe traumatic brain injury often survive in disorders of consciousness,the level of consciouness in these patients decides whether the clinical treatment and home care for them or not.The accurate evaluation of brain function is the basis for subsequent clinical treatment.The increasing use of neuroimaging techniques indicates that PET/CT?positron emission tomography / X-ray computer the imager?can quantitatively show the change of brain function and corresponding residual activity area by using radioactive tracer,and further provides the clinical objective evidence for the diagnosis.On the other hand,Patients who suffer from TBI often live with the change of neurotransmitters,the role of these neurotransmitters on the recovery of brain function raises more and more attention.Amantadine,a dopamine receptor agonist,can affect the catecholamine synthesis,accumulation,release and uptake in the central nervous system,which can directly influence the brain neurons,not only can promote the release of dopamine,but also inhibit its absorption.In recent years,some researchers have found that amandatine can accelerate the recovery of patients with consciousness disorders.We collected two cases who were in vegetative state suffering from traumatic brain injury,and treated with amandatine.We also measured the change of the cerebral glucose metabolism using PET/CT before and after the drug intervention.The first case was 26-year-old male,who was in vegetative state after craniocerebral injury operation for 12 weeks,with the pre-treatment GCS score of 6?eye opening response: 3,verbal response: 1,motor response: 2?.The second case was 45-year-old male,who was left with disturbance of consciousness after the removal of intracerebral hematoma for 16 weeks,with the pre-treatment GCS score of 6?eye opening response: 3,verbal response: 1,motor response: 2?.Both of the patients were receiving only inpatientcomprehensive rehabilitation for 4 weeks,including positioning,passive range of motion,splinting,sensory stimulation and early mobilization techniques.Then the patients received amantadine at a dose of 200mg/day for 2 weeks,then in the 3rd week,the dose was increased to 300mg/day.Another 3 weeks,the dose was adjusted to 400mg/day.The Coma Recovery Scale-Revised?CRS-R?score,which consists of auditory function,visual function,motor function,verbal function,communication,and arousal,was obtained every 7 days to assess the consciousness improvement of the patients in the two stages.Then monitored the corresponding change of the global cerebral glucose metabolic using ¹⁸F-FDG-PET/CT after 6-week drug treatment and made the comparsion with the pre-treatment's.The results showed that both of the patients had improvement in the CRS-R score,and one case progressed into minimally consciousness state,both of them showed the improvement of global cerebral glucose metabolism as well.We can speculate that amantadine may accelerate the recovery of the consciousness in vegetative state,possibly by increasing the brain glucose metabolism in the specific functional area which affects the consciousness recovery.