Phenomenology Of Pdd And Td

The term tardive dyskinesia covers a wide range of abnormal movements. Early descriptions emphasized that TD typically involves face, mouth, and muscles of mastication. However, Jeste and Wyatt (1982, footnote, p. 51) comment that this early emphasis may have biased many subsequent descriptions. In their own catalog of the phenomenology of TD, abnormal movements could occur in any part of the motor apparatus, including tongue, lips and face, neck and trunk, upper or lower limbs, and even the...

Other Disorders Involving The Basal Ganglia

The disorders which have been the focus in Part II of this book are those whose primary pathological basis is known or strongly suspected as having a location in the basal ganglia (usually in the striatum). For these disorders, basic pathology (or neuro-chemical pathology) correlates well with their various symptom profiles. Hence, these disorders can be defined as distinct entities. They can then be the subject of theoretical analysis, to establish why, in terms of causal reasoning, the...

Neuropathology And Pathophysiology Of Disorders Of The Basal Ganglia

The primary objective of Part II of this monograph, dealing with disorders of the basal ganglia, is to show how the symptoms of these disorders can be incorporated into the theory of basal ganglionic function, described in Part I, so far based mainly on evidence from the normal brain. As a start, it is necessary to summarize the basic neuropathological processes underlying some of the major disorders of the basal ganglia. Mainly, the essential pathology is degenerative cell loss of a variety of...

Inflexibility Of Adjustments Of Posture And Gait In Parkinsons Disease

The previous section was concerned with selection of dimensions for attention and of behavior-related cell assemblies. Behavioral output should include automatic adjustments of gait or posture, normally thought of as motor functions. In Parkinson's disease there are, besides the classic motor symptoms, many abnormalities in gait and posture. Often these normal functions and their abnormalities in Parkinson's disease are spoken of in terms of postural reflexes. However, there are several...

Huntingtons Disease

In developing arguments for the basic theory of the basal ganglia, reference has already been made to Huntington's disease. The differential loss of striatal neurons of origin of the indirect versus direct pathways, leading respectively to hyper- versus hypokinetic symptoms, was important evidence contributing to the postulated opposite behavioral roles of those two pathways through the basal ganglia. Here, some further discussion is added on to the details of motor and other phenomenology of...

Dopaminergic And Cholinergic Receptor Subtypes

In Section 9.5 (see also Figure 9.2), it was proposed that therapy for psychosis with D2-blocking drugs is an indirect effect. It was suggested that it depends first on activation of cholinergic neurons, which leads to increased ACh release, and then activation of M4 muscarinic receptors on other striatal cells. This in turn leads to reduction in cAMP formation, itself mediating the abnormal synaptic plasticity supposed to be involved in active phases of psychosis. As part of the same...

Direct Connections From Basal Ganglia To Brain Stem And Their Role In Parkinsonian Akinesia And Rigidity

Two symptoms given prominence in descriptions of Parkinson's disease akinesia and rigidity are improved little by thalamotomy, unlike the symptom of tremor (see Section 8.6), although all three symptom classes are alleviated by STN lesions. Akinesia and rigidity are often associated in Parkinson's disease, and appear to represent a subtype different from that in which tremor predominates (see Section 8.1). Jellinger (1999) suggests, on the basis of neuropathological studies, that in this...

The Goad And The Halter In Parkinsons Disease

Oliver Sacks is of the clear opinion that the above-mentioned symptoms are not the core features of Parkinson's disease. In the introduction to Awakenings, he mentions that the very first qualities of Parkinson's disease to be described were festination and pulsion. In objective terms these consist of hurried movements (e.g., of gait or in writing), although the hurried movements may become smaller and smaller in amplitude and so come to an uncontrolled halt. Subjectively they are often...