Dysphagia predicts poor outcome in late-stage Parkinson's disease

BACKGROUND

Few data exist on the rate of clinical progression for Parkinson's disease (PD) patients who have entered a late stage of the disease.

OBJECTIVE

Study the clinical progression of a late-stage PD (LSPD) population over one year follow-up.

METHODS

50 LSPD patients (Schwab and England ADL Scale <50 or Hoehn Yahr Stage >3 in MED ON) underwent an extensive clinical assessment at baseline and after one year and an acute levodopa test at baseline.

RESULTS

Mean age of LSPD patients (female 46%) was 77.5 ± 5.9 years and mean disease duration was 15.5 ± 6.5 years. At baseline, 76% had levodopa-induced motor complications (MC), usually non-troublesome, 68% were demented, 54% had psychosis and 68% depression. Caregiver distress was high. l-dopa responsiveness was mild (18% ± 12 of improvement on MDS-UPDRS-III). After one-year, 20% of the patients were dead, institutionalized or HY 5. MDS-UPDRS-motor mean score worsened 7.2 ± 10.3 points although there was heterogeneity between patients, and there was a global worsening of non-motor symptoms, mostly in cognition/mood, urinary and gastrointestinal domains. Nevertheless, MC improved despite similar levodopa equivalent dose. Functional independence and quality of life worsened. Dysphagia severity at baseline predicted a poor outcome (death, institutionalization or HY 5) (Hazard ratio 2.3, 95% CI 1.12-4.4; p = 0.01), whereas magnitude of l-dopa response of LSPD patients did not.

CONCLUSIONS

LSPD patients still present a significant, although heterogeneous, motor and non-motor progression over 1 year. Dysphagia severity predicts the occurrence of additional disease severity milestones and its management must be prioritized.

Adjunctive Therapies in Parkinson's Disease: How to Choose the Best Treatment Strategy Approach

End-of-dose motor fluctuations are regarded as one of the core troublesome symptoms by patients with Parkinson's disease (PD). Treatment of levodopa (L-dopa)-induced motor fluctuations is still an unmet medical need. L-dopa is the gold standard in the treatment of motor PD symptoms; notwithstanding, a wide range of adjunct therapies are currently available for the treatment of end-of-dose motor fluctuations. Additionally, device-aided therapies, such as deep brain stimulation, L-dopa-carbidopa intestinal gel infusion, and on-demand injection or continuous apomorphine infusion, may be considered when oral treatments are not sufficient to control motor fluctuations. In spite of the several evidence-based reviews and guidelines available, there is no agreement on which add-on therapy should be started first or its optimal timing. Equally challenging is the choice and timing between device-aided therapies. Herein, we propose a general overview of oral and device-aided treatments for PD patients with end-of-dose motor fluctuations, offering two possible algorithms that can guide clinicians during the therapeutic decision process.

Speech and Voice Response to a Levodopa Challenge in Late-Stage Parkinson's Disease

BACKGROUND

Parkinson's disease (PD) patients are affected by hypokinetic dysarthria, characterized by hypophonia and dysprosody, which worsens with disease progression. Levodopa's (l-dopa) effect on quality of speech is inconclusive; no data are currently available for late-stage PD (LSPD).

OBJECTIVE

To assess the modifications of speech and voice in LSPD following an acute l-dopa challenge.

METHOD

LSPD patients [Schwab and England score <50/Hoehn and Yahr stage >3 (MED ON)] performed several vocal tasks before and after an acute l-dopa challenge. The following was assessed: respiratory support for speech, voice quality, stability and variability, speech rate, and motor performance (MDS-UPDRS-III). All voice samples were recorded and analyzed by a speech and language therapist blinded to patients' therapeutic condition using Praat 5.1 software.

RESULTS

24/27 (14 men) LSPD patients succeeded in performing voice tasks. Median age and disease duration of patients were 79 [IQR: 71.5-81.7] and 14.5 [IQR: 11-15.7] years, respectively. In MED OFF, respiratory breath support and pitch break time of LSPD patients were worse than the normative values of non-parkinsonian. A correlation was found between disease duration and voice quality (R = 0.51; p = 0.013) and speech rate (R = -0.55; p = 0.008). l-Dopa significantly improved MDS-UPDRS-III score (20%), with no effect on speech as assessed by clinical rating scales and automated analysis.

CONCLUSION

Speech is severely affected in LSPD. Although l-dopa had some effect on motor performance, including axial signs, speech and voice did not improve. The applicability and efficacy of non-pharmacological treatment for speech impairment should be considered for speech disorder management in PD.

Acute response of non-motor symptoms to subthalamic deep brain stimulation in Parkinson's disease

BACKGROUND

Subthalamic deep brain stimulation (STN-DBS) is an established treatment for the motor complications of Parkinson's disease (PD) and may have beneficial effects on non-motor symptoms (NMS). However, the acute effect of STN stimulation on NMS has only been explored in small PD cohorts with short post-surgical follow-up.

OBJECTIVE

To study NMS response to an acute stimulation challenge in an STN-DBS PD population with a medium/long-term post-surgical follow-up.

METHODS

32 STN-DBS PD patients were tested twice (MED OFF/STIM OFF and MED OFF/STIM ON). MDS-UPDRS-III, blood pressure (BP) assessment, a visual analogue scale for pain and fatigue and State Trait Anxiety Scale score were evaluated during both stimulation conditions. NMS were assessed with MDS-UPDRS-I, Non-Motor Symptoms Scale, Geriatric Depression Scale and the Neuropsychiatric Inventory scale.

RESULTS

Mean (SD) age was 62.5 (±13.3) years, mean disease duration 18.7 (±5.1) years, mean post-surgical follow-up 4.6 (±1.3) years, and the mean reduction of levodopa equivalent daily dose after surgery was 58.9% (±25.4%). Mean (SD) motor response to stimulation was 40% (15%). STN stimulation significantly improved anxiety (mean 18% ± 19%, P < 0.005) and fatigue (mean 25% ± 51%; P < 0.05), while pain, although improved did not reach statistical significance. With stimulation ON, BP significantly decreased during orthostatism (P < 0.05) and there was a significant increase in asymptomatic orthostatic hypotension (P < 0.05).

CONCLUSIONS

Acute STN stimulation improves anxiety and fatigue but decreases orthostatic BP in PD, several years after surgery. These effects should be considered when assessing long-term effect of DBS.

Response of non-motor symptoms to levodopa in late-stage Parkinson's disease: Results of a levodopa challenge test

BACKGROUND

Non-motor symptoms (NMS) are extremely common among late-stage Parkinson's disease (LSPD) patients. Levodopa (L-dopa) responsiveness seems to decrease with disease progression but its effect on NMS in LSPD still needs to be investigated.

OBJECTIVE

To assess the response of blood pressure (BP), pain, fatigue and anxiety to L-dopa in LSPD patients.

METHODS

20 LSPD patients, defined as Schwab and England ADL Scale <50 or Hoehn Yahr Stage >3 (MED ON) and 22 PD patients treated with subthalamic deep brain stimulation (advanced PD group) underwent an L-dopa challenge. BP and orthostatic hypotension (OH) assessment, a visual analogue scale (VAS) for pain and fatigue and the Strait Trait Anxiety (STAI) were evaluated before and after the L-dopa challenge.

RESULTS

Systolic BP dropped significantly after L-dopa intake (p < 0.05) in LSPD patients, while there was no change in pain, fatigue or anxiety. L-dopa significantly improved (p < 0.05) pain and anxiety in the advanced PD group, whereas it had no effect on BP or fatigue. L-dopa-related adverse effects (AEs), namely OH and sleepiness, were more common among LSPD patients. 40% and 65% of LSPD patients were not able to fill out the VAS and the STAI, respectively, while measurement of orthostatic BP was not possible in four LSPD patients.

CONCLUSIONS

This exploratory study concludes that some non-motor variables in LSPD do not benefit from the acute action of L-dopa while it can still induce disabling AEs. There is a need for assessment tools of NMS adapted to these disabled LSPD patients.

Clinical pharmacology review of opicapone for the treatment of Parkinson's disease

Two catechol-O-methyl transferase inhibitors are currently used as add-on therapy to levodopa for the amelioration of end-of-dose motor fluctuations in Parkinson's disease patients: entacapone, which has moderate efficacy and requires multiple dosing, and tolcapone, which has a poor safety profile. Opicapone (OPC) is a novel, long-acting, peripherally selective, once daily, third-generation catechol-O-methyl transferase inhibitor. Two Phase III clinical trials demonstrated OPC efficacy in reducing OFF-time by an average of about 60 min daily compared with placebo, without increasing ON-time with troublesome dyskinesias, with a good drug safety profile. In June 2016, the European Commission granted a marketing authorization valid throughout the European Union for OPC, indicated as adjunctive of levodopa decarboxylase inhibitors in adult patients with Parkinson's disease and end-of-dose motor fluctuations.

Quantitative Analysis Versus Visual Assessment of Neuromelanin MR Imaging for the Diagnosis of Parkinson's disease

BACKGROUND

Specific MR sequences have been able to identify the loss of neuromelanin in the substantia nigra (SN) of early stage Parkinson's disease (PD) patients. Since this technique may have a significant impact in clinical patient management, easy and widely available imaging analysis is needed for routine use.

OBJECTIVE

In this study we compared a quantitative analysis with a visual assessment of SN neuromelanin-sensitive MR images in early stage PD patients, in terms of pattern changes recognition and diagnostic accuracy.

METHODS

The inclusion criteria were untreated "de novo" PD patients or a 2-5 year PD duration; in addition, age matched controls were enrolled. These were studied with a high-resolution T1-weighted MR imaging sequence at 3.0 Tesla to visualize neuromelanin. The primary outcome was the comparison of quantitative width measurement with visual assessment by experienced neuroradiologists of SN neuromelanin sensitive MR images for PD diagnosis.

RESULTS

A total of 12 "de novo" PD patients, 10 PD patients with 2-5 year disease duration and 10 healthy controls were evaluated. We obtained a good accuracy in discriminating early-stage PD patients from controls using either a quantitative width measurement of the T1 high signal or a simple visual image inspection of the SN region.

CONCLUSIONS

Visual inspection of neuromelanin-sensitive MR images by experienced neuroradiologists provides comparable results to quantitative width measurement in the detection of early stage PD SN changes and may become a useful tool in clinical practice.

Clinical pharmacology review of safinamide for the treatment of Parkinson’s disease

Safinamide (Xadago™) is an oral α-aminoamide derivative marketed for the treatment of Parkinson’s disease (PD). The drug has both dopaminergic properties, namely highly selective and reversible inhibition of monoamine oxidase B, and nondopamimetic properties, namely selective sodium channel blockade and calcium channel modulation, with consequent inhibition of excessive glutamate release. In 2014, safinamide was approved in the European Economic Area, as “an add-on therapy to stable dose levodopa, alone or in combination with other PD therapies in mid- to late-stage-fluctuating PD patients.” In addition, evidence has been provided for safinamide in the treatment of motor symptoms in early PD patients. This article summarizes the pharmacological properties, development program, clinical indications for PD treatment, stratified according to several disease’s stages and the safety profile of safinamide. A meta-analysis of the most frequent adverse events among Phase III trials has been also performed.

Action verbal fluency in Parkinson’s patients

We compared the performance of 31 non-demented Parkinson´s disease (PD) patients to 61 healthy controls in an action verbal fluency task. Semantic and phonemic fluencies, cognitive impairment and behavioural dysfunction were also assessed. The mean disease duration of PD was 9.8 years (standard deviation (SD) = 6.13). There were no age (U = 899.5, p = 0.616), gender(chi-square = 0.00, p = 1.00) or literacy (U = 956, p = 0.96) differences between the two groups. A significant difference was observed between the two groups in the action verbal fluency task (U = 406.5, p < 0.01) that was not found in the other fluency tasks. The education level was the only biographical variable that influenced the action (verb) fluency outcomes, irrespective of disease duration. Our findings suggest a correlation between the disease mechanisms in PD and a specific verb deficit, support the validity of the action (verb) fluency as an executive function measure and suggest that this task provides unique information not captured with traditional executive function tasks.

Substantia nigra neuromelanin magnetic resonance imaging in de novo Parkinson's disease patients

BACKGROUND

Depigmentation of the substantia nigra (SN) and locus coeruleus (LC) is a conspicuous pathological feature of Parkinson's disease (PD) and is related to the loss of neuromelanin, whose paramagnetic properties result in high signal on specific T1-weighted magnetic resonance imaging (MRI). Recent studies have suggested that neuromelanin decrease in the SN and LC of PD patients may emerge as a possible diagnostic biomarker. The SN neuromelanin signal in de novo and early stage PD patients was studied to assess its diagnostic accuracy. This is the first study based on a semi-automated MRI analysis of the neuromelanin signal in de novo PD patients.

METHODS

The inclusion criteria were untreated de novo PD and a 2-5 year disease duration; in addition, age matched healthy controls were enrolled. These were studied with a high-resolution T1-weighted MRI sequence at 3 T to visualize neuromelanin. The primary outcome was SN high signal area, length and neuromelanin/midbrain ratio obtained with semi-automated methods.

RESULTS

A total of 12 de novo PD patients and 10 PD patients with a 2-5 year disease duration were evaluated. The area, length of the SN T1 high signal and the SN neuromelanin/midbrain ratio were markedly decreased in the PD groups compared with age-matched controls, with a substantial overlap between the two PD groups.

CONCLUSIONS

Neuromelanin-sensitive MRI techniques can discriminate PD patients from healthy individuals with high sensitivity and specificity. Our findings are consistent with recent findings showing that PD neuromelanin changes remain stable during the course of the disease.

Subthalamic deep brain stimulation effects on odor identification in Parkinson's disease

BACKGROUND AND PURPOSE

Olfactory dysfunction is common in Parkinson's disease (PD) and it is one of the earliest non-motor symptoms. A few studies have suggested that deep brain stimulation of the subthalamic nucleus (STN-DBS) could improve olfactory function. Our aim was to evaluate the acute effect of bilateral STN-DBS on a commonly used smell test in PD patients.

METHODS

Fifteen PD patients who underwent bilateral STN-DBS and 15 controls were recruited. Patients and controls were tested for odor identification.

RESULTS

No statistical differences were documented between ON and OFF STN-DBS acute stimulation concerning olfaction. Controls presented a better performance for olfactory identification than patients.

CONCLUSIONS

Our exploratory study did not support that bilateral STN-DBS could have an acute effect on olfactory function in PD patients.

[Health-economic burden of Parkinson's disease in Portugal: a cohort study]

INTRODUCTION

Parkinson's disease (PD) is a common neurodegenerative disorder with a considerable socioeconomic burden. Health-economic evaluations of PD in the Southern European countries are limited.

AIM

To evaluate the costs of PD in an outpatient cohort in Portugal.

PATIENTS AND METHODS

49 consecutive PD patients were recruited at the neurological outpatient clinic of the University of Lisbon between October 2004 and December 2005. Clinical status was evaluated using the Unified Parkinson's Disease Rating Scale and the Hoehn and Yahr stages. Costs were assessed from the societal perspective using health-economic questionnaires. Human capital approach was used to estimate indirect costs. Health-related quality of life was evaluated by means of the EQ-5D.

RESULTS

Direct costs were 2,717 euros (95% CI = 1,147-3,351) per patient for a six-month period. Main contributors to the direct costs included drugs (544 euros; 95% CI = 426-6,940) and hospitalizations (690 euros; 95% CI = 229-1,944). Indirect costs amounted to 850 euros (95% CI = 397-1,529), whereas patient expenditures constituted 12% of direct costs. Assistance by family and other relatives played a major role. In general, costs were lower than in other Western countries.

CONCLUSIONS

The economic burden of PD in Portugal is considerable. Important cost components include medications and hospitalizations. More research is needed in order to describe a comprehensive health service patterns in Portugal and to guide health policy decisions more effectively.

Flunitrazepam in combination with alcohol engenders high levels of aggression in mice and rats

RATIONALE

Higher doses of benzodiazepines and alcohol induce sedation and sleep; however, in low to moderate doses these drugs can increase aggressive behavior.

OBJECTIVES

To assess firstly the effects of ethanol, secondly the effects of flunitrazepam, a so-called club drug, and thirdly the effects of flunitrazepam plus alcohol on aggression in mice and rats.

METHODS

Exhaustive behavioral records of confrontations between a male resident and a male intruder were obtained twice a week, using CF-1 mice and Wistar rats. The salient aggressive and non-aggressive elements in the resident's repertoire were analyzed. Initially, the effects of ethanol (1.0g/kg), and secondly flunitrazepam (0; 0.01; 0.1; and 0.3mg/kg) were determined in all mice and rats; subsequently, flunitrazepam or vehicle, given intraperitoneally (0; 0.01; 0.1; and 0.3mg/kg) was administered plus ethanol 1.0g/kg or vehicle via gavage.

RESULTS

The most significant finding is the escalation of aggression after a moderate dose of ethanol, and a low dose of flunitrazepam. The largest increase in aggressive behavior occurred after combined flunitrazepam plus ethanol treatment in mice and rats.

CONCLUSIONS

Ethanol can heighten aggressive behavior and flunitrazepam further increases this effect in male mice and rats.

5-HT(1B) receptors, ventral orbitofrontal cortex, and aggressive behavior in mice

RATIONALE

Systemic injections of 5-HT(1B) receptor agonists have been shown to have specific anti-aggressive effects in aggressive individuals. One site of action for these drugs is the 5-HT(1B) receptors in the ventral orbitofrontal cortex (VO PFC), an area that has been implicated in the inhibitory control of behavior and is a terminal region for 5-HT projections.

OBJECTIVE

To assess the anti-aggressive effects of the 5-HT(1B) receptor agonist CP-94,253 when microinjected into the VO PFC (0.1, 0.56, and 1.0 microg/0.2 microl) or into the infralimbic prefrontal cortex (IL PFC; 1.0 microg/0.2 microl) in separate groups of aggressive resident male mice. To confirm the 5-HT(1B) receptor as the critical site of action for the anti-aggressive effects, the 5-HT(1B/D) antagonist GR-127,935 was microinjected at 10.0 microg/0.2 microl into the VO PFC. After recovery from surgery, the anti-aggressive effects of microinjected CP-94,253 were studied during 5-min resident-intruder confrontations that were recorded and analyzed.

RESULTS

Microinjections of CP-94,253 (0.56 and 1.0 microg/0.2 microl) dose-dependently reduced the frequency of attack bites and sideways threats. This effect was behaviorally specific because non-aggressive motor activities were not significantly altered by the drug. In the IL vmPFC or in an area lateral to the VO PFC, CP-94,253 (1.0 microg/0.2 microl) did not have significant behavioral effects.

CONCLUSIONS

The results highlight the 5-HT(1B) receptors in the VO PFC as a particularly important site for the inhibition of species-typical aggressive behavior in male mice.

The European Multiple System Atrophy-Study Group (EMSA-SG)

Introduction. The European Multiple System Atrophy-Study Group (EMSA-SG) is an academic network comprising 23 centers across Europe and Israel that has constituted itself already in January 1999. This international forum of established experts under the guidance of the University Hospital of Innsbruck as coordinating center is supported by the 5th framework program of the European Union since March 2001 (QLK6-CT-2000-00661). Objectives. Primary goals of the network include (1) a central Registry for European multiple system atrophy (MSA) patients, (2) a decentralized DNA Bank, (3) the development and validation of the novel Unified MSA Rating Scale (UMSARS), (4) the conduction of a Natural History Study (NHS), and (5) the planning or implementation of interventional therapeutic trials. Methods. The EMSA-SG Registry is a computerized data bank localized at the coordinating centre in Innsbruck collecting diagnostic and therapeutic data of MSA patients. Blood samples of patients and controls are recruited into the DNA Bank. The UMSARS is a novel specific rating instrument that has been developed and validated by the EMSA-SG. The NHS comprises assessments of basic anthropometric data as well as a range of scales including the UMSARS, Unified Parkinson's Disease Rating Scale (UPDRS), measures of global disability, Red Flag list, MMSE (Mini Mental State Examination), quality of live measures, i.e. EuroQoL 5D (EQ-5D) and Medical Outcome Study Short Form (SF-36) as well as the Beck Depression Inventory (BDI). In a subgroup of patients dysautonomic features are recorded in detail using the Queen Square Cardiovascular Autonomic Function Test Battery, the Composite Autonomic Symptom Scale (COMPASS) and measurements of residual urinary volume. Most of these measures are repeated at 6-monthly follow up visits for a total study period of 24 months. Surrogate markers of the disease progression are identified by the EMSA-SG using magnetic resonance and diffusion weighted imaging (MRI and DWI, respectively). Results. 412 patients have been recruited into the Registry so far. Probable MSA-P was the most common diagnosis (49% of cases). 507 patients donated DNA for research. 131 patients have been recruited into the NHS. There was a rapid deterioration of the motor disorder (in particular akinesia) by 26.1% of the UMSARS II, and - to a lesser degree - of activities of daily living by 16.8% of the UMSARS I in relation to the respective baseline scores. Motor progression was associated with low motor or global disability as well as low akinesia or cerebellar subscores at baseline. Mental function did not deteriorate during this short follow up period. Conclusion. For the first time, prospective data concerning disease progression are available. Such data about the natural history and prognosis of MSA as well as surrogate markers of disease process allow planning and implementation of multi-centre phase II/III neuroprotective intervention trials within the next years more effectively. Indeed, a trial on growth hormone in MSA has just been completed, and another on minocycline will be completed by the end of this year.

Rivastigmine for dementia associated with Parkinson's disease

BACKGROUND

Cholinergic deficits are prominent in patients who have dementia associated with Parkinson's disease. We investigated the effects of the dual cholinesterase inhibitor rivastigmine in such patients.

METHODS

Patients in whom mild-to-moderate dementia developed at least 2 years after they received a clinical diagnosis of Parkinson's disease were randomly assigned to receive placebo or 3 to 12 mg of rivastigmine per day for 24 weeks. Primary efficacy variables were the scores for the cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog) and Alzheimer's Disease Cooperative Study-Clinician's Global Impression of Change (ADCS-CGIC). Secondary clinical outcomes were the scores for the Alzheimer's Disease Cooperative Study-Activities of Daily Living, the 10-item Neuropsychiatric Inventory, the Mini-Mental State Examination, Cognitive Drug Research power of attention tests, the Verbal Fluency test, and the Ten Point Clock-Drawing test.

RESULTS

A total of 541 patients were enrolled, and 410 completed the study. The outcomes were better among patients treated with rivastigmine than among those who received placebo; however, the differences between these two groups were moderate and similar to those reported in trials of rivastigmine for Alzheimer's disease. Rivastigmine-treated patients had a mean improvement of 2.1 points in the score for the 70-point ADAS-cog, from a baseline score of 23.8, as compared with a 0.7-point worsening in the placebo group, from a baseline score of 24.3 (P<0.001). Clinically meaningful improvements in the scores for the ADCS-CGIC were observed in 19.8 percent of patients in the rivastigmine group and 14.5 percent of those in the placebo group, and clinically meaningful worsening was observed in 13.0 percent and 23.1 percent, respectively (mean score at 24 weeks, 3.8 and 4.3, respectively; P=0.007). Significantly better outcomes were seen with rivastigmine with respect to all secondary efficacy variables. The most frequent adverse events were nausea (affecting 29.0 percent of patients in the rivastigmine group and 11.2 percent of those in the placebo group, P<0.001), vomiting (16.6 and 1.7 percent, P<0.001), and tremor (10.2 and 3.9 percent, P=0.01).

CONCLUSIONS

In this placebo-controlled study, rivastigmine was associated with moderate improvements in dementia associated with Parkinson's disease but also with higher rates of nausea, vomiting, and tremor.

[Cardiac effects of acute poisoning with tricyclic antidepressants: systematic review of the literature -- Part IV]

Tricyclic antidepressant overdose is a frequent diagnosis in the emergency room. It is responsible for a significant percentage of hospital admissions for observation and treatment. This is due to its cardiac (as well as neurologic) toxicity, and the difficulty in predicting its clinical gravity. The authors present this paper with two objectives in mind: 1) information about a common and significant cardiological emergency; 2) presentation of the methodology concerning systematic reviews of the literature. In this fourth article (the last in a series), we present the prevention and management of tricyclic antidepressant overdose (in the three previous articles--published in previous issues of the Revista--we discussed the epidemiological aspects as well as the clinical presentation and the diagnosis, and the prognosis). Note: this is the fourth and last article on the cardiac toxicity of tricyclic antidepressant overdose.

[Cardiac effects of acute poisoning with tricyclic antidepressants: systematic review of the literature -- Part III]

Tricyclic antidepressant overdose is a frequent diagnosis in the emergency room. It is responsible for a significant percentage of hospital admissions for observation and treatment. This is due to its cardiac (as well as neurologic) toxicity, and the difficulty in predicting its clinical gravity. The authors present this paper with two objectives in mind: 1) information about a common and significant cardiological emergency; 2) presentation of the methodology concerning systematic reviews of the literature. In this third (of four) articles, the prognosis of tryciclic antidepressant overdose is presented (in the two previous articles--published in previous issues of the Revista--we discussed the epidemiological aspects as well as the clinical presentation and the diagnosis). In the remaining paper we will present its management, and prevention. Note: this is the third of a series of four articles on the cardiac toxicity of tricyclic antidepressant overdose; the final article will be presented in the October issue of the Revista.

[Cardiac effects of acute poisoning with tricyclic antidepressants: systematic review of the literature -- Part II]

Tricyclic antidepressant overdose is a frequent diagnosis in the emergency room. It is responsible for a significant percentage of hospital admissions for observation and treatment. This is due to its cardiac (as well as neurologic) toxicity, and the difficulty in predicting its clinical gravity. The authors present this paper with two objectives in mind: 1) information about a common and significant cardiological emergency; 2) presentation of the methodology concerning systematic reviews of the literature. In this second (of four) articles, the clinical presentation and diagnosis of tricyclic antidepressant overdose are presented (in the first article--published in the previous issue of the Journal--we discussed the epidemiological aspects). In the remaining two papers we will present its management, prognosis and prevention. NOTE: This is the second of a series of four articles on the cardiac toxicity of tricyclic antidepressant overdose; the next two articles will be presented in the September and October issues of the Revista.

[Cardiac effects of acute poisoning with tricyclic antidepressants: systematic review of the literature. Part I]

Tricyclic antidepressant overdose is a frequent diagnosis in the emergency room. It is responsible for a significant percentage of hospital admissions for observation and treatment. This is due to its cardiac (as well as neurologic) toxicity, and the difficulty in predicting its clinical gravity. The authors present the paper with two objectives in mind: 1) information about a common and significant cardiological emergency; 2) presentation of the methodology concerning systematic reviews of the literature. In this first (of four) articles, the epidemiology tricyclic antidepressant overdose is presented. In the remaining three papers we will present its clinical presentation, diagnosis, treatment, prognosis and prevention. Note: this is the first of a series of four articles on the cardiac toxicity of tricyclic antidepressant overdose; the next three articles will be presented in the July, August and September issues of the RPC.

The neural correlates of verb and noun processing. A PET study

The hypothesis that categorical information, distinguishing among word classes, such as nouns, verbs, etc., is an organizational principle of lexical knowledge in the brain, is supported by the observation of aphasic subjects who are selectively impaired in the processing of nouns and verbs. The study of lesion location in these patients has suggested that the left temporal lobe plays a crucial role in processing nouns, while the left frontal lobe is necessary for verbs. To delineate the brain areas involved in the processing of different word classes, we used PET to measure regional cerebral activity during tasks requiring reading of concrete and abstract nouns and verbs for lexical decision. These tasks activated an extensive network of brain areas, mostly in the left frontal and temporal cortex, which represents the neural correlate of single word processing. Some left hemispheric areas, including the dorsolateral frontal and lateral temporal cortex, were activated only by verbs, while there were no brain areas more active in response to nouns. Furthermore, the comparison of abstract and concrete words indicated that abstract word processing was associated with selective activations (right temporal pole and amygdala, bilateral inferior frontal cortex), while no brain areas were more active in response to concrete words. There were no significant interaction effects between word class and concreteness. Taken together, these findings are compatible with the view that lexical-semantic processing of words is mediated by an extensive, predominantly left hemispheric network of brain structures. Additional brain activations appear to be related to specific semantic content, or, in the case of verbs, may be associated with the automatic access of syntactic information.