关键词:
ACh, acetylcholine
AEP, auditory evoked potential
ANS, autonomic nervous system
ARAS, ascending reticular activating system
BAEP, brainstem auditory evoked potential
BSRF, brainstem reticular formation
CBF, cerebral blood flow
CSF, cerebrospinal fluid
DAI, diffuse axonal injury
DTPS, diffuse thalamic projection system
EAA, excitatory amino acid
ECS, electroconvulsive shock
ECT, electroconvulsive therapy
EEG, electroencephalogram
EP, evoked potential
FVEP, flash visual evoked potential
GSA, generalized seizure activity
HRP, horseradish peroxidase
ICP, intracranial pressure
MRI, magnetic resonance imaging
PASAT, paced auditory serial addition task
PDS, paroxysmal depolarization shift
PVS, persistent vegetative state
REM, rapid eye movement
SEP, somatosensory evoked potential
TBI, traumatic brain injury
TTX, tetrodotoxin
摘要:
Cerebral concussion is both the most common and most puzzling type of traumatic brain injury (TBI). It is normally produced by acceleration (or deceleration) of the head and is characterized by a sudden brief impairment of consciousness, paralysis of reflex activity and loss of memory. It has long been acknowledged that one of the most worthwhile techniques for studying the acute pathophysiology of concussion is by the recording of neurophysiological activity such as the electroencephalogram (EEG) and sensory evoked potentials (EPs) from experimental animals. In the first parts of this review, the majority of such studies conducted during the past half century are critically reviewed. When potential methodological flaws and limitations such as anesthetic protocols, infliction of multiple blows and delay in onset of recordings were taken into account, two general principles could be adduced. First, the immediate post-concussive EEG was excitatory or epileptiform in nature. Second, the cortical EP waveform was totally lost during this period. In the second parts of this review, five theories of concussion which have been prominent during the past century are summarized and supportive evidence assessed. These are the vascular, reticular, centripetal, pontine cholinergic and convulsive hypotheses. It is concluded that only the convulsive theory is readily compatible with the neurophysiological data and can provide a totally viable explanation for concussion. The chief tenet of the convulsive theory is that since the symptoms of concussion bear a strong resemblance to those of a generalized epileptic seizure, then it is a reasonable assumption that similar pathobiological processes underlie them both. Further, it is demonstrated that EPs and EEGs recorded acutely following concussive trauma are indeed the same or similar to those obtained following the induction of a state of generalized seizure activity (GSA). According to the present incarnation of the convulsive theor