Background Tremor-related quality of life is a multi-dimensional concept that reflects the physical, emotional and other health effects of tremor. Curiously, tremor-related quality of life has never been directly compared in patients with the two major tremor disorders, essential tremor (ET) and Parkinson’s disease (PD). We performed a head-to-head comparison of ET with PD patients. Methods The Quality of Life in Essential Tremor (QUEST) questionnaire was administered to 103 ET and 103 matched PD patients enrolled in a clinical-epidemiological study in New York. Results The QUEST total score and QUEST physical subscore were higher in ET than PD patients (both p<0.05). In relative terms, ET patients reported significantly more impairment than PD patients in multiple areas; PD patients reported more impairment than ET patients in one area (all p≤0.02). In absolute terms, tremor impacted on many aspects of quality of life in both diseases, including physical and psychosocial, and in one-third or more of PD patients, tremor sometimes, frequently or always interfered with numerous physical activities, including writing, using a typewriter/computer, fixing small things, dressing, eating, and holding reading material. Conclusions Tremor is a clinical entity that can have numerous effects on patients. While there were relative differences between the two major tremor disorders, ET and PD, in absolute terms, tremor impacted on several domains of quality of life, from physical to psychosocial, in a large proportion of ET and PD patients. Attempts to judge the efficacy of treatments for tremor, whether pharmacological or surgical, should consider its broad impact.

No abstract

The marginal shell of the anteroventral cochlear nucleus is anatomically and physiologically different from its central core. Previous studies suggest that neurons in the marginal shell are well suited to encode the intensity of acoustic stimuli. To investigate the projections of the marginal shell, a focal injection (<100 nl) of a mixture of biotinylated dextran amine (BDA) and 3H‐leucine was made into the marginal shell of the cat combined with injection of cholera toxin subunit‐B (CTB) into the cochleas. Following a 7‐day survival, the cats were perfused. Axons and swellings labeled with BDA and olivocochlear neurons labeled with CTB were immunocytochemically stained black and brown, respectively. 3H‐leucine labels were visualized by autoradiography. Labeled neural structures were examined via light microscopy. We found that swellings labeled with BDA, sometimes doubly labeled with BDA and 3H‐leucine, were in close apposition with dendrites and/or somata of olivocochlear neurons identified with CTB labeling. Double labeling with BDA and 3H‐leucine signifies that the label was anterogradely transported. The results support the conclusion that the anteroventral cochlear nucleus projects to medial olivocochlear neurons bilaterally and to lateral olivocochlear neurons ipsilaterally. Furthermore, the results are consistent with the interpretation that the marginal shell provides a source of the above‐mentioned projections. Together with information in the literature, the present anatomical results support a hypothesis that the marginal shell provides information about stimulus intensity as a part of a reflex (or feedback gain control) system comprising the cochlea, cochlear neurons, cochlear nucleus, medial olivocochlear neurons, and cochlear outer hair cells. J. Comp. Neurol. 420:127–138, 2000. © 2000 Wiley‐Liss, Inc.

Evidence-based data indicate that administration of botulinum toxin in several human conditions can alleviate refractory pain. The problems with some study designs and toxin dosage are critically reviewed.