Current surgical treatment of Parkinson's disease

There has been a renaissance in the surgical management of Parkinson's disease. This has been due to long-term effects of levodopa and a better understanding of the basal ganglia and its circuitry. Ablative surgery and neurostimulation are the only realistic surgical options at present. Although surgical treatments, such as ablation and stimulation are effective, they are not useful for stopping the progression or restoring the system. Neural transplantation helps restore the system by using a number of techniques. Targets mostly used are in the thalamus, globus pallidus and subthalamic nucleus. A number of factors must be considered including patient's age, disability and his wishes. Globus pallidus stimulation might be preferable for patients who suffer from dyskinesia as a major source of disability. Pallidotomy might be appropriate in cases where frequent stimulator adjustments are impractical. Subthalamic nucleus stimulation is more suitable for patients with significant off periods and in younger patients in whom it may be desirable to maintain intact circuitry. Fetal neural transplantation, stem cell transplantation, xenotransplantation, adrenal medullary transplantation and transplantation of genetically engineered cells are at various stages of development and research. Ethical issues surrounding these process are likely to arouse strong emotions and have to be carefully considered

Basic principles and interpretations of electroencephalography [Workshop 1]

At the end of the workshop, the participant will be able to: 1. Understand the principles of EEG recording. 2. Identify commonly encountered EEG artifacts. 3. Recognize normal awake and sleep EEGs in children and adults. 4. Interpret some common abnormal EEG patterns. Electroencephalography [EEG] is the science relating to the electrical activity of the brain. The background electrical activity of the human brain was first analyzed in a systematic fashion by the German Psychiatrist Hans Berger [1929]. Since then, EEG has been used in clinical practice to disclose non-epileptiform and epileptiform cortical dysfunction. EEG recording. EEG is recorded with scalp electrodes. The recordings may be bipolar or unipolar. Bipolar records show fluctuations in potentials between 2 electrodes and the unipolar record show potential difference between cortical electrodes and theoretically in-different electrodes. A digital EEG machine allows any section of the record to be completely reformatted namely, viewed with any Montage, Gain, Filter or Timebase. The standard placement recommended by the American EEG society for use in the International 10-20% system is for 21 electrodes [Figure 1]. The standard numbering system in the 10-20 system places odd-numbered electrodes on the left and even numbered electrodes on the right, with the letter designating the anatomic area. Montage. The term montage refers to the particular combination of electrodes examined at a particular point of time. In most instances, multiple montages are more useful than a single montage for long periods. The function of the montage is to record from all areas of the scalp and also to record activity in such a manner that it is easily perceived by the reader. The principal montages are longitudinal bipolar "Double Banana", coronal bipolar, circumferential bipolar, laplacian, common average referencial and ear [A1, A2] referential. It should be mentioned here that bipolar runs provide better localized focal or regional features, while the morphology of the widespread phenomena appear best on referential montages. Physiological basis of EEG [EEG generator]. The activity recorded in the EEG is mostly that of the most superficial layers of the cortical gray matter. The potential changes in the cortical EEG are due to current flow in the fluctuating dipoles formed on the dendrites of the cortical cells and the cell bodies [Figure 2] namely current to flow through the volume conductor between "source" at the soma and basal dendrites and the "sink" at the apical dendrites sustaining excitatory postsynaptic potential [EPSPs]. Figure 2 illustrates current paths taking increasingly remote curving routes. The zero potential surface is located halfway between the positive and negative poles of the dipole. To understand how electrical potentials are recordable on the scalp generated by populations of the pyramidal neurons, it can be easily understandable by the solid angle concept of the volume conduction theory. In this, the potential generated by a dipole layer in a volume conductor [brain and its environs] is proportional to the solid angle subtended by the dipole layer at the point of the measurement [Figure 3]. EEG interpretations. EEG interpretation requires a structured approach to ensure that important information is not lost or data misinterpreted. Prior to the interpretation, the only clinical data known to the reader should be the age of the patient. In evaluating an EEG pattern or event, one should answer the following: Is it an artifact

Current surgical treatment of Parkinson's disease

There has been a renaissance in the surgical management of Parkinson's disease. This has been due to long-term effects of levodopa and a better understanding of the basal ganglia and its circuitry. Ablative surgery and neurostimulation are the only realistic surgical options at present. Although surgical treatments, such as ablation and stimulation are effective, they are not useful for stopping the progression or restoring the system. Neural transplantation helps restore the system by using a number of techniques. Targets mostly used are in the thalamus, globus pallidus and subthalamic nucleus. A number of factors must be considered including patient's age, disability and his wishes. Globus pallidus stimulation might be preferable for patients who suffer from dyskinesia as a major source of disability. Pallidotomy might be appropriate in cases where frequent stimulator adjustments are impractical. Subthalamic nucleus stimulation is more suitable for patients with significant off periods and in younger patients in whom it may be desirable to maintain intact circuitry. Fetal neural transplantation, stem cell transplantation, xenotransplantation, adrenal medullary transplantation and transplantation of genetically engineered cells are at various stages of development and research. Ethical issues surrounding these process are likely to arouse strong emotions and have to be carefully considered

Lewy body dementia

Lewy body is an intracytoplasmic inclusion1 seen classically in Parkinson's disease, mainly in the substantia nigro locus cereleus and dorsal motor nucleus of the vagus. Cases designated as diffuse Lewy body disease demonstrate widespread cortical and subcortical Lewy body formation. The fact that diffuse Lewy Body disease is possibly the second most common cause of dementia after Alzhemer's disease and is not generally recognized2. Dementia with Lewy bodies or Lewy body dementia is designated to patients with dementia. Parkinsonism an frequent symptoms such as hallucination. This article reviews recent advances in the clinical, with dementia, Parkinsonism and frequent symptoms such as hallucination. This article reviews recent advances in the clinical pathological, genetic and pharmacological features at Lewy body disorders and their relationship at Azlheimer's remains sources of intense debate