By M. Hengley. Tabor College.
Still buy discount cozaar 25 mg online, substantial changes in the body and can impart significant side effects generic cozaar 25 mg overnight delivery. At another extreme purchase cozaar 50mg, some efficacy and that keep them in contact with clinicians habit reversal therapy involves the application of cognitive who can monitor their overall medical condition discount 25mg cozaar with mastercard. Ulti- and behavioral therapy principles to TS (136), analogous mately, it is critically important for these alternative treat- to the successful use of these therapies in the treatment of ments to be tested in controlled trials, in which their tolera- OCD. Although studies with habit reversal therapy are only bility, safety, and efficacy can be established in an objective now being completed, initial results appear promising, of- manner. Unfortunately, the cost of such studies is often fering the possibility of a true, 'nonpharmacologic' ap- prohibitive, and they are generally not a high priority for proach to this disorder. Conceptually, once it is effectively funding from the pharmaceutical industry. Clinicians learned, habit reversal therapy may be easy to apply over a should ask patients and parents whether alternative thera- period of years, to a variety of different types of tics. Proponents of As is true with most neuropsychiatric conditions, comorbid- rTMS emphasize that the procedure can be administered on ity of TS with affective disorders deserves special attention, an outpatient basis, at relatively low cost, without apparent owing to the insidious and often profound morbidity im- significant side effects. More heroic efforts for intractable parted by depression. Comorbid affective illness accompa- TS and OCD have included psychosurgical interventions, nying TS is generally sensitive to standard pharmacothera- Chapter 117: Tourette Syndrome and Related Tic Disorders 1693 pies for these disorders. These can often be used in matched control tissue is also being collected, to diminish combination with anti-tic regimens, but the possibility of variability across different studies. These systematic efforts, iatrogenic depression from dopamine antagonists should al- combined with the judicious but timely distribution of ways be considered, because this may dictate a reduction in brain tissue for studies, should help to overcome many of neuroleptic dose rather than the addition of an antidepres- the limitations of past TS neuropathologic studies. As with comorbid OCD or ADHD, it appears that ity to utilize this material effectively and to interpret the comorbid depression can often cause a worsening of tics in information that it provides depends entirely on our TS, and there are reports of severe, refractory, mood-depen- progress in understanding the complex interconnections dent tics in comorbid TS and depression that show dramatic within CSPT circuitry. Although we have useful maps of the sensitivity to electroconvulsive therapy (138,139). Whereas major thoroughfares within CSPT circuitry, we will need more representative epidemiologic data are necessary, the to be equally knowledgeable regarding the detailed input- lifetime prevalence of comorbid mood disorders in TS pa- output relationships of functionally and neurochemically tients seen in specialty clinics may be as high as 70%, com- distinct striatal subterritories. Important pathologic find- parable to that reported in patients with OCD (140). Neuroimaging efforts in TS will focus on two strategies FUTURE DIRECTIONS that have been so informative in studies of OCD: pretreat- ment versus posttreatment repeated measures and on-line Several lines of inquiry are positioned to make major ad- behavioral or psychophysiologic probes in conjunction with vances in our understanding of the etiology and treatment functional imaging. Nonpharmacologic treatment effects of TS, based on the tremendous progress that has already on regional brain metabolism or brain activation may be been made in each of these areas: studied before and after habit reversal therapy, similar to The clinical 'phenotype' of TS has been particularly well such studies using cognitive and behavior therapy in OCD characterized. Appropriate on-line probes for fMRI studies must tics, sensory phenomena in TS are relatively less well under- be carefully developed. Optimally, these probes should stood and are more difficult to study. A full understanding either (a) detect deficits in patients with TS, or (b) in healthy of the TS phenotype will clearly enhance research efforts, persons, selectively activate relevant brain substrates, includ- by permitting stratification in measures from all levels of ing the basal ganglia or frontal circuitries. Event-related analysis, from genetics to neuropsychology. Detailed clinical fMRI techniques appear especially promising as investiga- characterization, and the experimental analysis that it facili- tors seek to identify the sequence of neural events that pre- tates, will also be important in clarifying the potentially cede and follow tics. This issue has tremendous im- the most promising regions is planned. Verification and portance, because these two 'types' of TS are not generally extension of this work within several extended TS families (and often cannot be) segregated in genetic, neuroimaging, are also anticipated. Parallel efforts will continue in targets or other biological measures in this disorder. For example, of opportunity, including informative chromosomal trans- it may not be appropriate to generalize to all forms of TS the locations.
Various data suggest that this subcircuit is critical for of dopamine transmission in the PFC have generally re- the formation of learned associations with rewarding stimuli vealed that the actions of dopamine are state-dependent 25 mg cozaar. The second connection is among the amygdala order 50 mg cozaar, This is reflected by distinct electrophysiologic effects of do- VTA discount cozaar 50 mg on-line, and nucleus accumbens discount 25mg cozaar free shipping. Although this subcircuit is pamine when pyramidal cells in the cortex are relatively important in unconditioned responses to most drugs of active or inactive (e. Although the effects of dopamine tioned stimuli to obtain reward, as well as cue-induced drug are state-dependent, dopamine clearly has the capacity to relapse (114). Although both circuits probably contribute modulate excitatory glutamatergic projections to the nu- to stimulus-induced drug relapse, the relative role of each cleus accumbens and VTA (105–107). Thus, the long-term may depend on the type of stimulus. For example, relapse alterations in PFC dopamine transmission by repeated drug precipitated by a low dose of drug, especially a drug known use change corticofugal glutamate transmission. More- The last decade has witnessed the emergence of a number of over, the blockade of glutamate receptors in the nucleus seminal developments in our understanding of the circuitry accumbens inhibits the expression of behavioral sensitiza- mediating addiction. Primary among these is that there ex- tion to cocaine, as well as the capacity of systemic cocaine ists substantial overlap in the circuits mediating behavioral to elicit drug craving using a reinstatement model of craving responses to non-drug and drug reward (Figs. ACKNOWLEDGMENT The second critical development is that neuroplasticity to drug reward arises from an interaction between the molecu- This work was supported in part by USPHS grants MH- lar site of drug action and environmental stimuli associated 40817, DA-11809, and DA-03906. In this way, cortical and allocorti- cal circuitry important in learning and memory is recruited and undergoes neuroplastic alterations in response to drugs of abuse. The studies outlined in this chapter describe REFERENCES changes in neurotransmission and cell signaling that may 1. J be critical in changing the functional status of the circuit Neuropsychiatry Clin Neurosci 1997;9:482–497. Neuroadaptations involved in amphet- and neurochemical neuroadaptations, it is also important amine and cocaine addiction. Drug addiction: a model 117), which show that akin to normal learning, repeated for the molecular basis of neural plasticity. Neuron 1993;11: exposure to psychostimulants or opioids produces morpho- 995–1006. Although neurobiologists during cue-induced cocaine craving. Ann NYAcad Sci 1992; how these alterations result in a change in the function of 654:400–415. What is the role of dopamine in highly interconnected and topographically organized (35, reward: hedonic impact, reward learning, or incentive salience? Thus, a change in the function of a cell group in one 7. Cocaine craving and nucleus is likely to impact on the status of neurons in other paranoia: a combination of pharmacology and learning. Predicting and experimentally evaluating these sec- try Ann 1998;28:569–576. Addiction, dopamine, and the molecular mechanisms of memory. This arena can be approached from molecular ior produced by chronic amphetamine administration: a review technologies at one end and imaging studies at the other. The imaging experiments help to define functional subcir- Brain Res Rev 1986;11:157–198. Using pharmacologic and genetic manip- self-administration. The neu- ulations these specific cellular neuroadaptations can be eval- ropharmacological basis of reward.
However order cozaar 25 mg amex, address; however generic cozaar 25 mg with visa, there have been some attempts to examine the argument suggests that the use of a placebo is appropri- the consequences discount cozaar 50 mg amex, both short- and long-term cheap 25mg cozaar with amex, of receiving ate in cases when an effective treatment is not available. Overall, there problem remains in how to define effectiveness. The use of do not appear to be demonstratable deleterious effects of the term effective in this context is not necessarily identical to participating in short-term trials (6,7). The issue of lengthy the current use of effectiveness as differentiated from efficacy. If we define response tion of untreated psychosis is associated with poor outcome. In the case of outcome (8), but the effect was no longer evident in long- severe deficit symptoms or in patients who have proven term follow-up (9). Short-term clinical trials usually involve refractory to other drugs, the issue is less clear. Therefore, it is important to A particular problem arises when response to a proven recognize potential differences in consequences between effective treatment (or so-called gold standard) can vary brief delays and relatively long delays in treatment. Lavori enormously from trial to trial and in some cases be rather (5) argues that because assessments in placebo-treated pa- low, or when response to a placebo is generally high (4). The field would certainly benefit from more intent- already available, the question should not be is the new drug to-treat analyses as well as long-term follow-up of patients superior to placebo but rather is the new drug superior to who were involved in placebo-controlled trials. Unfortunately, given the nature Designs involving the treatment of patients who have of the diseases and the adverse effects associated with some failed on other treatments are another challenge. One could psychotropic drugs, a new drug could be superior in one argue that placebo controls are more acceptable in this con- domain and inferior in another, while being a very valuable text because there is no effective treatment. However, it is addition to the therapeutic armamentarium. The use of pla- usually the case that these patients have demonstrated some cebo controls can still be important to determine whether benefit from standard, albeit inadequate, treatment. There- or not in some domains a drug is inferior, but still better fore, the appropriate comparison would be the new treat- than a placebo, or whether its inferiority in one domain is ment versus standard treatment, with the only outcome of such that it would change the overall effectiveness equation. To provide an example, suppose drug A were somewhat The decision as to whether or not to use placebo or active less effective than drug B in controlling acute symptoms, controls or both in a particular trial is not an easy one. At the same There are complex issues that need to be considered, and time, drug B was associated with serious side effects that it is hoped that further knowledge involving the determi- might result in a substantial number of patients discontinu- nants of heterogeneity in response will facilitate more ra- ing the medication within a short period of time. Before approving drug A, we would want to be harm and not withhold effective treatment is a critical issue. Extensive use of rescue medication can make it diffi- (5) has emphasized, the data sets available from current cult to accurately assess the drug effect (even though use of placebo-controlled trials are usually 'heavily truncated, dif- rescue medication can be a telling outcome in and of itself). Here, too, carried forward (LOCF)' and that 'the interpretation of rates of utilization can be an important outcome measure, positive results in the context of badly truncated data re- yet at the same time the additional medication might have quires unverifiable assumptions, external to the observed other undesirable effects (e. To some extent, patient receives a potentially active compound and if re- this results from unfounded assumptions that we have good sponse occurs, crossover to a placebo takes place. If response data on dose-response relationships with drugs that have does not occur, the placebo phase is not required. In addi- cebo phase in this context helps to determine whether or tion, dosage requirements will vary depending on the popu- not the response to medication was a true drug effect or lation. For example, in schizophrenia, first-episode patients not. It is argued that this design has the advantage of each in general respond to lower doses than multiepisode pa- patient serving as his or her own control, allowing all pa- tients, and acute treatment usually requires higher doses tients to eventually receive active medication and increasing than maintenance treatment. Another design that is being increasingly utilized is the The applicability of this design varies depending on the adjunctive or add-on strategy. This is particularly useful nature of the disorder being studied, the time course of when subjects with partial or inadequate response are the response, and the vulnerability to relapse or symptom exac- focus of interest. Rather than switching participants from erbation once active treatment is replaced by a placebo. For the unsatisfactory treatment to a new treatment, partici- example, this design may be more informative in rapid cy- pants are randomized to an added placebo or added experi- cling bipolar patients (11) than in the context of an acute mental treatment. In this approach, no drug withdrawal is treatment trial in other disorders.
Caudate glucose metabolic rate changes with both drug and decreases in glucose metabolism in right anterior orbital behavior therapy for obsessive-compulsive disorder discount cozaar 25mg visa. De- creased metabolic activity in the left and right orbital frontal cortex predicted better response to paroxetine with greater reduction in OCDsymptom severity (Fig 50 mg cozaar visa. For example best 25mg cozaar, PET scans performed before and It should be noted purchase 50 mg cozaar with amex, however, that functional imaging after 10 weeks of treatment with either CBT or the SSRI, data sets have not been entirely consistent in OCDpatients fluoxetine have identified significant and comparable reduc- studied before and after treatment intervention. Benkelfat tions in right caudate glucose metabolism associated with and colleagues (149), for example, observed a significant reduction in OCD symptom severity (38,148) (Fig. Pathological correlations among orbital frontal tabolism but only the decrease in caudate metabolism was cortex, the caudate nucleus and the thalamus were observed associated with reduction in OCDsymptom severity. In in pretreatment OCDpatients but not in healthy volun- contrast, Swedo and co-workers (150) reported no change teers. These pathologic correlations were eliminated after in caudate metabolic activity after 2 months of clomipram- effective treatment with either SSRI or CBT. Subsequent ine treatment in OCDpatients with childhood onset of Chapter 113: Imaging and Neurocircuitry of OCD 1635 A FIGURE 113. Reprinted from Saxena S, Brody AL, Maidment KM, et al. Local- ized orbitofrontal and subcortical metabolic changes and predictors of response to paroxetine treatment in obsessive-compulsive disorder. Decreased baseline right orbitofrontal and anterior NEUROCHEMICAL STUDIES IN OCD cingulate metabolic rates, however, did predict better re- Neuronal Viability sponse to clomipramine treatment. Rubin and associates (151) also observed no caudate metabolic changes before To our knowledge, there have only been four neuroimaging and after SSRI treatment but found that decreased metabo- studies directly measuring brain chemistry in OCD. Proton lism in orbitofrontal cortex before treatment predicted magnetic resonance spectroscopy (1-H MRS), which can greater reduction in OCDsymptom severity. Like fMRI, there are tive ionizing radiation risks facilitating repeated study for no ionizing radiation risks, making it a particularly child- longitudinal follow-up with a neurodevelopmental perspec- friendly technique facilitating longitudinal monitoring of tive. This is an active area of investigation in our laboratory patients before and after treatment intervention. This is especially relevant in view of function than morphometric MRI assessment (79,153). Re- recent clinical neurodevelopmental models of OCD(88). Ebert and colleagues (154) also reported reduced less) likely to respond to a particular treatment (e. Recent advances allowing for the noninva- but not parietal white matter of adult OCDpatients. Volu- sive real-time measurement of brain activity provide an un- metric data for the regions of interest were not provided. Sample spectra for voxels (top) placed in the left medial thalamus (A) and left lateral thalamus (B). Individual peaks for choline compounds (Cho), creatine/phosphocreatine (Cr), and N-acetylaspartate (NAA) were resolved from the original spectrum, leaving a residual. NAA/ (Cr Cho) metabolite ratios by group (bottom) for left (A) and right (B) medial thalamus. Adapted from Fitzgerald KD, Moore GJ, Paulson LD, et al. Proton spectroscopic imaging of the thalamus in treatment-naive pediatric obsessive-compulsive disorder. Reduced NAA/Cho majority of axon terminals in the basal ganglia are gluta- Cr levels associated with OCDsymptom severity were matergic afferents (31,157,158), with the caudate nucleus observed in OCDpatients compared to controls (Fig. This is intriguing because the dorsomedial nucleus from ventral prefrontal cortex (15,159,160). Ablation of of the thalamus has been especially implicated in the patho- frontal cortex results in a dramatic reduction in caudate genesis of OCD(15). Becquet and associates Neuronal dysfunction or loss in specific fronto-striatal- (160) have shown that glutamate exerts a potent inhibitory thalamic circuits in OCDcould be related to excess brain effect on serotonin release in the caudate nucleus. Con- activity measured in this circuitry with functional neuroim- versely, serotonergic neurons can modulate glutamate re- aging (154). Moreover, reduced NAA levels in fronto-stria- lease (160) with stimulatory 5-HT2a receptors on GABAer- tal-thalamic regions may result from increased gluta- gic interneurons inhibiting glutamatergic projections from matergic afferent projections to the thalamus and striatum ventral prefrontal cortex to the striatum and thalamus (158).
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