What is the role of muscle receptors in proprioception?

The role of muscle afferents is discussed in terms of their contribution to kinesthesia, the senses of position and movement of the limbs. It is argued that muscle spindles are not well suited as position sensors, on several grounds. Yet we know from muscle vibration experiments that they do contribute to kinesthesia. A number of recent experiments have shown that positional information is of particular significance to the central nervous system. In other experiments it has been demonstrated that a disturbance to kinesthesia follows fatigue from exercise. Fatigue of elbow flexor muscles led subjects to make significant positional errors in a forearm matching task. The size of the errors correlated with the fall in force from fatigue. These data suggest that we derive a positional cue from the effort required to hold a limb against the force of gravity. A challenge for the future will be to reveal how the centrally derived sense of effort and peripherally derived afferent information interact to give us our kinesthetic sense.     

What is the role of procedural justice in civil commitment?

OBJECTIVE: To determine best practice management strategies in the clinical application of civil commitment. METHOD: All relevant literature on the topics of 'civil commitment', 'coercion' and 'procedural justice' were located on MEDLINE and PsychLIT databases and reviewed. Literature on the use of Ulysses contracts and advance directives in mental health treatment was integrated into the findings. RESULTS: Best practice evidence that guides management strategies is limited to the time of enactment of civil commitment. Management strategies involve enhancing the principles of procedural justice as a means of limiting negative patient perception of commitment. In the absence of evidence-based research beyond this point of enactment, grounds for the application of the principles of procedural justice are supported by reference to ethical considerations. Ulysses contracts provide an additional method for strengthening procedural justice. CONCLUSIONS: Procedural justice principles should be routinely applied throughout the processes of civil commitment in order to enhance longer term therapeutic outcomes and to blunt paternalism.     

The role of neurotensin in central nervous system pathophysiology: what is the evidence?

The peptide neurotensin has been studied for more than 30 years. Although it is widely distributed in the central and peripheral nervous systems, neurotensin has been more intensely studied with regard to its interactions with the central dopamine system. A number of claims have been made regarding its possible implication in many diseases of the central nervous system, including schizophrenia. In this review, we describe briefly the basic biology of this neuropeptide, and then we consider the strengths and the weaknesses of the data that suggest a role for neurotensin in schizophrenia, drug abuse, Parkinson's disease, pain, central control of blood pressure, eating disorders, cancer, neurodegenerative disorders and inflammation.     

What is the role of the hippocampus and parahippocampal gyrus in the persistence of tinnitus?

The hippocampus and parahippocampal gyrus have been implicated as part of a tinnitus network by a number of studies. These structures are usually considered in the context of a “limbic system,” a concept typically invoked to explain the emotional response to tinnitus. Despite this common framing, it is not apparent from current literature that this is necessarily the main functional role of these structures in persistent tinnitus. Here, we highlight a different role that encompasses their most commonly implicated functional position within the brain—that is, as a memory system. We consider tinnitus as an auditory object that is held in memory, which may be made persistent by associated activity from the hippocampus and parahippocampal gyrus. Evidence from animal and human studies implicating these structures in tinnitus is reviewed and used as an anchor for this hypothesis. We highlight the potential for the hippocampus/parahippocampal gyrus to facilitate maintenance of the memory of the tinnitus percept via communication with auditory cortex, rather than (or in addition to) mediating emotional responses to this percept.     

The cerebellum in dystonia - Help or hindrance?

Dystonia has historically been considered a disorder of the basal ganglia. This review aims to critically examine the evidence for a role of the cerebellum in the pathophysiology of dystonia. We compare and attempt to link the information available from both clinical and experimental studies; work detailing cerebellar connectivity in primates; data that suggests a role for the cerebellum in the genesis of dystonia in murine models; clinical observation in humans with structural lesions and heredodegenerative disorders of the cerebellum; and imaging studies of patients with dystonia. The typical electrophysiological findings in dystonia are the converse to those found in cerebellar lesions. However, certain subtypes of dystonia mirror cerebellar patterns of increased cortical inhibition. Furthermore, altered cerebellar function can be demonstrated in adult onset focal dystonia with impaired cerebellar inhibition of motor cortex and abnormal eyeblink classical conditioning. We propose that abnormal, likely compensatory activity of the cerebellum is an important factor within pathophysiological models of dystonia. Work in this exciting area has only just begun but it is likely that the cerebellum will have a key place within future models of dystonia.     

What are the determinants of quality of life in people with cervical dystonia?

BACKGROUND: Little is known about the quality of life in patients with cervical dystonia, although pain and depression are relatively common. OBJECTIVE: To test the hypothesis that an individual's ability to cope with the disease will modify the association of intrinsic, extrinsic, and disease related factors with quality of life. METHODS: Patients with cervical dystonia diagnosed by a movement disorder specialist were recruited from seven European countries. Data on quality of life (SF-36), measures of coping, and intrinsic, extrinsic, and disease related factors were collected by a self completed postal questionnaire. RESULTS: 289 patients (101 men and 188 women), mean age 55 years, completed the questionnaire. Both physical and mental quality of life scores were predicted by self esteem and self deprecation, educational level, employment status, social support, response to botulinum toxin, disease severity, social participation, stigma, acceptance of illness, anxiety, and depression. In multivariable analyses, the strongest predictors were anxiety and depression. Severe depression was associated with a 19.1 point decrement in the physical summary score (95% confidence interval, -31.7 to -6.6; p = 0.003); however, disease duration and severity remained predictors. CONCLUSIONS: Care for patients with cervical dystonia must not only focus on reducing the severity of the dystonia but also on the psychological wellbeing of the patient. Interventions aimed at treating depression or anxiety, especially of a cognitive nature, may have a large impact on improving quality of life.