We reviewed detailed clinical features of 266 patients with idiopathic cervical dystonia, commonly called spasmodic torticollis. Mean age at onset (41 years), female-to-male ratio (1.9:1), clustering of onset between ages 30 and 59 (70%), familial history of dystonia (12%), and remissions (9.8%) were similar to those found in previous studies. In contrast to the single prior large clinical study of this disorder, no predominance of right-handers or significant thyroid disease was found. Pain, which occurred in 75% of patients and contributed to disability score (p less than 0.01), distinguishes this syndrome from all other focal dystonias. Pain was also strongly associated with constant (vs. intermittent) head turning, severity of head turning, and presence of spasm. Eighty-three percent of patients had deviation of the head of greater than 75% of the time when sitting with the head unsupported (constant head deviation at rest). Of the 97% who had head turning, 81% also had head tilting in various combinations. The 23% with hand tremor had an older age at onset (mean, 46 vs. 41 years; p less than 0.05). An earlier age at onset (p less than 0.05) was seen in patients with a family history of dystonia (mean, 36 years), with trauma shortly preceding symptoms (mean, 36 years), with a change in the direction of head turning (mean, 30 years), and with remissions (mean, 33 years). Jerky movements or forced transient spasms of the head occurred in 62% of the patients, and these patients would be the ones for whom the designation "spasmodic torticollis" could logically apply.(ABSTRACT TRUNCATED AT 250 WORDS)
The nucleus accumbens (Acb) shell and core are essential components of neural circuitry mediating the reward and motor effects produced by activation of dopamine D2 or cannabinoid-1 (CB1) receptors. D2 receptors can form heterodimeric complexes with cannabinoid-1 (CB1) receptors and are also involved in control of the availability of both dopamine and endocannabinoids. Thus, the subcellular locations of D2 and CB1 receptors with respect to each other are implicit to their physiological actions in the Acb. We used electron microscopic immunocytochemistry to determine these locations in the Acb shell and core of rat brain. In each region, many neuronal profiles showed endomembrane and plasmalemmal distributions of one or both receptors. Approximately one-third of the labeled profiles were somata and dendrites, some of which showed overlapping subcellular distributions of D2 and CB1 immunoreactivities. The remaining labeled profiles were small axons and axon terminals containing CB1 and/or D2 receptors. Of the labeled terminals forming recognizable synapses, ~20% of those containing CB1 receptors contacted D2-labeled dendrites, while conversely, almost 15% of those containing D2 receptors contacted CB1-labeled dendrites. These results provide the first ultrastructural evidence that D2 and CB1 receptors in the Acb shell and core have subcellular distributions supporting both intracellular associations and local involvement of D2 receptors in making available endocannabinoids that are active on CB1 receptors in synaptic neurons. These distributions have direct relevance to the rewarding and euphoric as well as motor effects produced by marijuana and by addictive drugs enhancing dopamine levels in the Acb.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.