, Kee Duk Park, Kyoung Gyu Choi To observe the developmental maturation of brainstem auditory evoked potential(BAEP) for neonates by obtaining the normative data of each BAEP component in our own electrophysiological laboratory.
We reviewed 129 BAEP recordings in neonates ranging in gestational age from 33 weeks to 44 weeks. The BAEP recording were analyzed into latency(wave I,III,V), interpeak latency(I-III,III-V,I-V) and amplitude ratio(I/V) at 75dB sensation level clicks according to gestational age.
The latencies of each BAEP component decreased with maturation. Interpeak latency of waveI-V(central conduction time)also decreased with increasing age during 33-40 weeks of gestational age.
These results provided the concept of abnormal in neonatal BAEPs and opportunity of functional evaluation about the auditory or brainstem maturation in pathologic conditions.
Citations
, Kee Duk Park To construct the neural network model in the striatum that can explain the clin-ical effect of Parkinson disease.
We use an approach to studying the function of neural systems that is based on the use of a class of computer models known as parallel distributed processors(PDPs).And the focus of this study is the nigrostriatal dopaminergic effects on the corticostriatal fibers and the striatal medium spiny neurons.
A model that explains hypokinesia in Parkinson disease is presented for the opation of the striatum.
In order to study the brain funcion and mechanism of physiopathology, te-stable theories that consider brain as a whole system are needed. We think neural network model with PDPs would be an important field in neuroscience in near future.
, Ki Duk Park Present knowledge of brain mechanism is mainly based on anatomical and physiological studies. Such studies are however insufficient to understand the information processing of thebrain. The present new focus on neural network studies is the most likely candidate to fill thisgap. We made a simulation of striaum by neural network model, which is capable of limitedgeneralization and completion and possesses characteristic property of brain such as termedgrceful degradation.
Eight hundred and eighty four autopsy brains from patients with clinically diagnosed Alzheimer's disease were examined pathologically. Six hundred ninety eitht(79.96%) of the 884 cases fullfilled histological criteria for Alzheimer's disease, with or withour additional fndings, such as substantia nigral degeneration, cerebellar degeneration, Parkinson's disease or cerebral infarcts. One hundred and eighty six cases(20.04%) were diagnosed as other neurodegenerative disease such as Parkinson's disease, non-specific cortical degeneration or Pick's disease. Degenerative changes in the substantia nigra were common in patients with Alzheimer's disease than has been reported for the general aged population. Brain atrophy was severer in presenile type of Alzheimer's disease than in senile type of Alzheimer's disease.
Aphasia is a language disorder due to damage of the language center in the dominant hemisphere. I studied 42 patients whose main neurologic symptom was aphasia. In 42 aphasia patients, motor aphasia appeared in 13 pts(30.9%), sensory aphasia in 11 pts(26.1%), conduction aphasia in 5 pts(11.9%), anomic aphasia in 4 pts(9.5%), global aphasia in 4 pts(9.5%), transcortical motor aphasia in 3 pts(7.4%), transcortical sensory aphasia in 2 pts(4.7%). The most common associated pathologic condition was hypertension(85.7%) and the others were hypertriglyceridemia(42.9%), cardiac arrythmia(38.1%), transient ischemic attack(14.5%), seizure(9.5%) and hypotension(7.4%). The most common combined neurologic symptom was motor hemiparesis(26.22%), and the others were dysphagia, sensory hemianesthesia, ocular motor diturbance, agraphia, alexia, acaculia, finger agnosia and apraxia. The anomic aphasia and transcortical aphasia had best prognosis and the global aphasia had worst prognosis.
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