帕金森病与阿尔茨海默病

普遍认为帕金森病和阿尔茨海默病是两个独立的、有着显著判别的疾病。但是,相当数量为证据表明,二者具有相互重叠的临床和神经病理特征、相似的病因和病变发生机制。因此,现在有人认为这两种疾病的部分病例可能是同一种神经元退行性变疾病的不同表现形式。本文拟对此作一介绍。     

轻度认知功能损害、阿尔茨海默病患者和健康对照者的枕区脑干听觉诱发电位的比较

背景轻度认知功能损害（mild cognitive impairment,MCI）患者枕叶异常的证据越来越多,这些患者也存在发展成阿尔茨海默病（Alzheimer s disease,AD）的高危险性。目的比较MCI患者、AD患者以及年龄匹配的健康对照者（normal control,NC）的枕区脑干听觉诱发电位特点。方法使用Nicolet Bravo脑诱发电位仪,用＂Click短声刺激,记录36例MCI、30例AD患者和45名健康对照者的脑干听觉诱发电位。比较脑干听觉诱发电位波III和波V的绝对潜伏期、绝对波幅的差异。结果 AD组的波III绝对潜伏期比MCI组、NC组的长[依次为5.12（0.36）ms、4.60（0.35）ms和4.71（0.35）ms;F=19.47,P〈0.001]。AD组的波III和波V的绝对波幅低于其他两组。MCI组的波V的绝对波幅低于健康对照组。结论枕区脑干听觉诱发电位有助于AD和MCI的诊断与鉴别诊断。     

Auditory and somatosensory evoked potentials (AEPs and SEPs) and ballistic movements in parkinson disease

In five patients with initial idiopathic Parkinson disease AEPs (early and late components of auditory evoked potentials), SEPs (somatosensory evoked potentials) and arm ballistic movements (abduction of the humerus) were studied. Experimental sessions were conducted before starting treatment (L-Dopa plus Carbidopa) and at two and six month intervals. Before treatment evoked potential abnormalities were found in four out of five patients; EMG patterns underlying ballistic arm abduction movements were altered in all patients; corresponding prolonged duration of initial movements and low mean velocities were found. After treatment AEP and SEP showed a reduction of previously observed abnormalities and both EMG patterns and kinematic variables consistently improved. It is suggested that the electrophysiological investigations employed in this preliminary study may be a useful tool in clinical and pharmacological researches on Parkinson disease.

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Sommario Sono stati studiati in 5 pazienti affetti da sindrome di Parkinson idiopatica iniziale gli AEPs (componenti precoci e tardive), i SEPs ed i movimenti balistici (abduzione dell'omero). Lo studio è stato condotto prima dell'inizio della terapia (L-Dopa+Carbidopa), e due e sei mesi dopo l'inizio della terapia. Anomalie dei potenziali evocati sono state riscontrate prima dell'inizio della terapia in 4 pazienti. I dati elettromiografici relativi ai movimenti balistici di abduzione del braccio erano alterati in tutti i pazienti ed erano caratterizzati da un ritardo nell'inizio del movimento e da una diminuizione della velocità media.Dopo la terapia si è rivelata una riduzione delle anomalie precedentemente riscontrate per gli AEPs ed i SEPs ed anche i patterns EMG e le variabili kinematiche sono apparse notevolmente migliorati. Dall'analisi di questi risulati sembra emergere la possibilità che queste metodiche neurofisiologiche possano essere utilizzate quale mezzo per controllare la progressione della sindrome e l'efficacia di eventuali trials farmacologici.

     

N30 somatosensory evoked potentials in patients with unilateral Parkinson's disease

The N30 component of the somatosensory evoked responses (SEP) was reported as absent or abnormally low in various basal ganglia disorders, including Parkinson's disease (PD), but its relationship to the more affected side in asymmetric disease has not been assessed systematically. In 14 patients with unilateral PD and 10 controls, SEP were performed by stimulating each upper limb and recording from the parietal and frontal contralateral cortex. N30 was symmetric in 4 patients and 4 controls; it was asymmetric in 2 controls and in 8 patients (in 4 the responses were of lower amplitude over the affected hemisphere); no response was elicited in 2 patients and 4 controls. In all patients SEP were recorded off medication; in 9 of them the test was repeated following administration of L-dopa and did not show any significant changes. In conclusion, the N30 was asymmetric in a similar proportion of PD patients and controls. No correlation was found between the affected side and N30 latencies or amplitudes; no change was seen following L-dopa administration as well. The motor deficits and SEP abnormalities in PD probably reflect pathologies in different anatomical structures or functional circuits.     

Identification of diagnostic evoked response potential segments in Alzheimer's disease

Evoked response potentials (ERPs) to brief flashes of light were analyzed for constituent features that could be used to distinguish individuals with Alzheimer's disease (AD, n = 15) from matched control subjects (n = 17). Statistical k nearest-neighbor methods distinguished AD from control with a maximum sensitivity of 29% and false alarm rate of 12%. The comparable sensitivity/false-alarm values for a statistical projection pursuit method and an extended projection pursuit method, which selectively identify discriminative features for classification, were 75%/18% and 100%/6%, respectively. The results demonstrate that combinations of selected ERP time segments across different electrodes contain signal features that discriminate AD from control subjects with high sensitivity and specificity.     

Subthalamic somatosensory evoked potentials in Parkinson's disease.

Deep brain stimulation (DBS) of subthalamic nucleus (STN) is an effective treatment for advanced Parkinson's disease. It also provides an opportunity to record neural activity from the human basal ganglia. In this study, to investigate the involvement of the human STN in sensory functions, we recorded somatosensory evoked potentials (SEPs) elicited by contralateral median-nerve stimulation, from STN electrodes implanted for DBS in patients with Parkinson's disease. We suggest that the STN N18 component of SEPs in Parkinson's disease is a mainly local field potential elicited by muscle afferent input to the nucleus.     

视觉诱发电位在视神经脊髓炎中的诊断价值

目的探讨视觉诱发电位在视神经脊髓炎中的诊断价值。方法应用棋盘格反转模式对32例健康人和30例视神经脊髓炎患者进行视觉诱发电位检测,比较测量数据。结果视觉诱发电位的异常率为93.33%,P100峰潜伏期与对照组相比有显著性差异(P<0.01),P100波峰无显著性差异(P>0.01)。结论视觉诱发电位对视神经脊髓炎的早期诊断和病情程度判断具有一定的价值。     

Cortical visual evoked potentials recorded after optic tract near field stimulation during GPi-DBS in non-cooperative patients

Object

Neurophysiologic monitoring during deep brain stimulation (DBS) interventions in the globus pallidus internum (Gpi) for the treatment of Parkinson's disease or primary dystonia is generally based upon microelectrode recordings (MER); moreover, MER request sophisticated technology and high level trained personnel for a reliable monitoring. Recordings of cortical visual evoked potentials (CVEPs) obtained after stimulation of the optic tract may be a potential option to MER; since optic tract lies just beneath the best target for Gpi DBS, changes in CVEPs during intraoperative exploration may drive a correct electrode positioning.

Patients and methods

Cortical VEPs from optic tract stimulation (OT C-CEPs) have been recorded in seven patients during GPi-DBS for the treatment of Parkinson's disease and primary dystonia under general sedation. OT C-VEPs were obtained after near-field monopolar stimulation of the optic tract; recording electrodes were at the scalp. Cortical responses after optic tract versus standard visual stimulation were compared.

Results

After intraoperative near-field OT stimulation a biphasic wave, named N40-P70, was detected in all cases. N40-P70 neither change in morphology nor in latency at different depths, but increased in amplitude approaching the optic tract. The electrode tip was positioned just 1 mm above the point where OT-CVEPs showed the larger amplitude. No MERs were obtained in these patients; OT CVEPs were the only method to detect the Gpi before positioning the electrodes.

Conclusions

OT CVEPs seem to be as reliable as MER to detail the optimal target in Gpi surgery: in addition they are less expensive, faster to perform and easier to decode.     

Olfactory bulb changes in Alzheimer's disease

Summary Olfactory bulbs in cases of Alzheimer's disease and age-matched controls have been examined by means of combining silver staining of pathological filaments with pigment-Nissl staining of the cell bodies. Neuritic plaques were found in the anterior olfactory nucleus. Neurofibrillary tangles and neuropil threads occurred in the anterior olfactory nucleus and in all layers of the olfactory bulb except the outer fibrous layer. The tangle-bearing neurons of the olfactory bulb were identified as tufted cells, outer granule cells, and two different types of nerve cells forming the rostral part of the anterior olfactory nucleus.Supported by grants from the Deutsche Forschungsgemeinschaft     

Neurochemical markers in the cerebrospinal fluid of patients with Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis and normal controls

Summary Several neurotransmitter markers were investigated in the cerebrospinal fluid (CSF) from patients with Alzheimer's disease (AD) (n=27), Parkinson's disease (PD) (n=35) and ALS (n=26) and from control subjects (n=34) to compare the possible alterations in the biochemical profiles of these different neurodegenerative diseases. The main proportion of the patients represented an early phase of the illness at the time of the diagnosis. Correlations of the degree of dementia and the stage of the disease with CSF measures were evaluated. The CSF levels of somatostatin like-immunoreactivity (SLI) were significantly reduced in AD patients when compared with those of normals and ALS patients. The CSF concentrations of homovanillic acid (HVA) were significantly decreased for PD patients and the decrease focused on the nondemented patients. A trend of decreasing HVA values towards the most advanced stage of Parkinson's disease assessed by Webster's scale was also displayed. The content of 3-methoxy-4-hydroxyphenylglycol (MHPG) in the CSF was higher for ALS patients than for other groups. The lowest 5-hydroxy-indoleacetic acid (5HIAA) levels were observed in the PD group and the lowest acetylcholinesterase (AChE) activities were found in the PD patients with the most severe disease. Changes in CSF measures were too subtle to be beneficial for diagnostic purposes, but adequate for reflecting the different neurochemical profiles of these three degenerative neurological disorders.     

The rostral mesencephalon in Parkinson's disease and Alzheimer's disease

Summary The rostal mesencephalon at the level of the posterior commissure was studied by light microscopy in two patients with idiopathic Parkinson's disease, one patient with Alzheimer's disease, and one patient with senile dementia of Alzheimer's type. In the Parkinsonian cases, the rostral part of the nucleus of Edinger Westphal disclosed Lewy bodies in 3% of the neurons, neurofibrillary degeneration in 2% of the neurons, and a 54% neuronal loss. In Alzheimer's disease, 2% of Edinger Westphal neurons contained neurofibrillary degeneration, whereas in senile dementia of Alzheimer's type only rare neurofibrillary degeneration was evident in this nucleus. Neuronal loss was not apparent in the nucleus of Edinger Westphal in either of the Alzheimer's cases. The pathologic changes observed in this presumably cholinergic nucleus resemble in some respects changes reported in the cholinergic centers of the basal forebrain in these diseases.In addition, the central gray matter and pretectal region in Parkinson's disease contained a patchy increase in astroglia, some with scant reactive cell bodies; however, Lewy bodies were limited to that part of the central gray matter corresponding to the nucleus of Darkschewitsch. A few neurofibrillary tangles were present in the nucleus of Darkschewitsch in both diseases.     

Effects of carnosine on olfactory bulb EEG, evoked potentials and DC potentials

Carnosine is a dipeptide found in great quantities in the primary olfactory nerve and has been suggested to be the neurotransmitter of the olfactory receptor axons. The aim of the present study was to describe some of its electrophysiological actions in the olfactory bulb (OB) of rabbits under anesthesia. Carnosine as a 10% solution in amounts of 2-5 microliter was injected to the OB at the level of the glomerular layer by means of a pipette attached to a Hamilton syringe. Average evoked potentials (AEPs) on the stimulation of the lateral olfactory tract (LOT-AEP), electroencephalographic (EEG) activity and slow potential (DC) recordings were obtained. The LOT-AEPs were analyzed by fitting damped sine waves to them. The parameters of amplitude, frequency, decay rate, phase and rise rate were measured and statistically compared to the values obtained prior to the carnosine injection. An increase in frequency and decreases in the phase and the decay rate of the AEP were found. Carnosine also produced a sustained oscillation in the EEG and a surface negative, deep positive shift in the DC recording. The changes were maximal within the first minute after injection and lasted 2-7 min. Tyrodes' solution, which was used as the carnosine vehicle, did not produce any changes, nor did beta-alanine, which is one of the constituents of carnosine, at equivalent osmotic concentrations. It is concluded that carnosine has an excitatory action on the mitral/tufted cells, and that this effect is obscured by a secondary increase in granule cell (inhibitory) activity.     

Event-Related Potentials in Senile Dementia of Alzheimer's Type, Multiinfarct Dementia and Parkinson's Disease

Abstract: We investigated event-related potentials (P300) in three types of demented patients. Fourteen patients with senile dementia of Alzheimer's type (SDAT), 15 with multiinfarct dementia (MID), 8 with Parkinson's disease with dementia and 29 normal controls participated in this study. We measured the latencies of N100 and P300 at Pz after odd-ball paradigm stimulation. N100 peaks were within the normal range in all patients. However, P300 peaks were significantly delayed in all demented patients. There were no statistical differences in the mean latencies of P300 in each demented group. P300 latencies were found to be negatively correlated with Hasegawa's dementia scale. These results suggest that regardless of its cause dementia has similar influences on the P300 latency and P300 may be a useful means to assess the degree of dementia.     

Attentional deficits in Alzheimer's, Parkinson's, and Huntington's diseases

Introduction – Attentional deficits have been shown in Alzheimer's disease but it is unknown whether this reflects disease specific impairment or is present in other neurodegenerative disorders. Material & methods – We administered a verbal dichotic listening task (free recall and selective allocation to the left or right ear) to 17 patients with Alzheimer's disease, 19 patients with Huntington's disease, 10 patients with idiopathic Parkinson's disease with clinical evidence of dementia (DemPD), 22 non-demented patients with Parkinson's disease (PD), and 22 healthy controls. Patients with dementia were matched for dementia severity and performance in the 3 recall conditions was used as a measure of attentional capacity. Results – Patients with dementia (Alzheimer and Huntington patients, DemPD) were less accurate than those without dementia (PD and normal subjects). Demented subjects performed at comparable levels regardless of specific diagnosis; likewise those without dementia also achieved similar levels. All groups had a right ear preference under the free recall condition. Alzheimer and Huntington patients showed consistent right ear preference under all recall conditions, while PD patients, like controls, could selectively allocate attention to the left under left ear recall, regardless of the presence of dementia. Conclusion - The findings suggest a double dissociation. Non-selective attentional processing is affected by dementia presence versus absence but not by specific disease, while selective attentional processing shows disease specific impairments, regardless of the presence of dementia.     

事件相关诱发电位对阿尔茨海默病与轻度认知功能障碍的诊断价值

目的 探讨事件相关诱发电位(event-related potentials,ERPs)对阿尓茨海默病(Alzheimer's disease,AD)和轻度认知功能障碍(mild cognitive impairment,MCI)的诊断价值.方法 前瞻性的研究130例受试者,分3组:AD组60例,MCI组35例,和正常...     

帕金森病早期多种诱发电位检测的临床诊断价值

目的 观察帕金森病早期体感诱发电位(SL-SEP)、脑干听觉诱发电位(BAEP)和视觉诱发电位(PR-VEP)的异常特征．寻找敏感可靠的诊断指标。方法 对一组52例Yahr分期为Ⅰ期的帕金森病人和一组40例年龄匹配的健康对照组进行三种诱发电位观测。结果帕金森病早期SLSEP异常率为69．2％；BAEP的异常率为32．7％：PR-VEP的异常率为30、7％，病例组SL-SEP各主波峰潜伏期、峰间潜伏期、P25和N30波幅与对照组比较差异有湿著性意义；病例组BAEPⅠ—ⅢIPL、Ⅲ—ⅤIPL、Ⅰ一Ⅲ／Ⅲ一Ⅴ比值和PR-VEP的P100PL与对照组比较差异无显著性意义．结论 在帕金森病的早期，皮层感觉处理过程已受到干扰：体感诱发电位中央前成份以及顶成份P25是一个敏感的诊断指标。     

Treatment of insomnia by concomitant therapy with Zopiclone and Aniracetam in patients with cerebral infarction, cerebroatrophy, Alzheimer's disease and Parkinson's disease

Abstract For insomniac patients, sleeping drags are used; in addition, concomitant therapy with other drugs has been tried in an effort to prevent a decrease in the effects due to long-term continuous use. This report presents the results of a study on the sleeping effects in nine aged patients with insomnia associated with cerebrovascular and non-cerebrovascular disorders who received concomitant therapy with Zopiclone and Aniracetam. The treatment in 7/9 cases (78%) was found to be effective, showing more than 50% prolongation of sleeping time, and in two cases (22%) was found to be ineffective. We discuss the mechanism of action referring to the literature.     

Magnetic resonance imaging and brain-stem auditory evoked potentials in neuro-Behcet's disease

We studied central nervous system lesions in patients with neuro-Behcet's disease using magnetic resonance imaging (MRI) of the brain and recording of brain-stem auditory evoked potentials (BAEPs). MRI revealed abnormal findings in seven of eight patients. MRI studies demonstrated extensive regions with high intensity signal in the brain stem and/or basal ganglia on T2-weighted images obtained during the acute stage of the disease in three patients. One of these patients had a strongly gadolinum-enhanced round lesion in the lower pons. In four of the other five patients with chronic disease, brain-stem atrophy was observed on T1-weighted images. Atrophic changes were more severe in the brain stem than in the cerebellum. Abnormal BAEPs were observed in three patients and consisted of prolongation of interpeak latency of waves III-V and defects of wave III or V. Abnormal BAEPs were recorded in patients with severe inflammatory changes or progression of atrophic changes in the brain stem. Our findings show that MRI and BAEPs are useful in detecting the presence and assessing the degree of neurological involvement in patients with neuro-Behcet's disease.     

阿尔茨海默病嗅觉障碍的研究

目的 :研究阿尔茨海默病 (AD)患者嗅觉障碍。方法 :配对的AD患者和正常老年人各 3 0例 ,分别行简易智能状态检查(MMSE)、日常生活活动量表 (ADL)、图片识别试验、气味感知阈值、图片介导的气味识别试验及气味再认记忆试验检查。结果 :AD组的气味感知、气味识别和气味再认记忆功能较正常对照组差 (P <0 0 1) ;相关分析显示 ,AD组患者的嗅觉障碍与MMSE总分密切相关 (P <0 0 5 ) ;结论 :AD患者的嗅觉功能全面受损 ,嗅觉障碍是疾病的早期症状 ,是认知障碍的简单反映