Behavioral disturbances have been reported with subthalamic (STN) deep brain stimulation (DBS) treatment in Parkinson's disease (PD). We report correlative functional imaging (fMRI) of mood and motor responses induced by successive right and left DBS. A 36-year-old woman with medically refractory PD and a history of clinically remitted depression underwent uncomplicated implantation of bilateral STN DBS. High-frequency stimulation of the left electrode improved motor symptoms. Unexpectedly, right DBS alone elicited several reproducible episodes of acute depressive dysphoria. Structural and functional magnetic resonance imaging (fMRI) imaging was carried out with sequential individual electrode stimulation. The electrode on the left was within the inferior STN, whereas the right electrode was marginally superior and lateral to the intended STN target within the Fields of Forel/zona incerta. fMRI image analysis (Analysis of Functional NeuroImages, AFNI) contrasting OFF versus ON stimulation identified significant lateralized blood oxygen level-dependent (BOLD) signal changes with DBS (P < 0.001). Left DBS primarily showed changes in motor regions: increases in premotor and motor cortex, ventrolateral thalamus, putamen, and cerebellum as well as decreases in sensorimotor/supplementary motor cortex. Right DBS showed similar but less extensive change in motor regions. More prominent were the unique increases in superior prefrontal cortex, anterior cingulate (Brodmann's area [BA] 24), anterior thalamus, caudate, and brainstem, and marked widespread decreases in medial prefrontal cortex (BA 9/10). The mood disturbance resolved spontaneously in 4 weeks despite identical stimulation parameters. Transient depressive mood induced by subcortical DBS stimulation was correlated with changes in mesolimbic cortical structures. This case provides new evidence supporting cortical segregation of motor and nonmotor cortico-basal ganglionic systems that may converge in close proximity at the level of the STN and the adjacent white matter tracts (Fields of Forel/zona incerta).

RÉSUMÉ: Marqueurs cognitifs de la progression de la maladie d'Alzheimer. Cette revue constitue un sommaire de la littérature sur l'utilisation de batteries de tests cognitifs pour suivre la progression de la maladie d'Alzheimer (MA). Les études publiées en anglais ont été identifiées par une recherche PubMed (1983PubMed ( -2004. Elles étaient incluses s'il s'agissait d'études longitudinales sur des patients atteints de MA probable, diagnostiquée selon les critères du National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association ou du Manuel diagnostique et statistique des maladies mentales III/IV; et si la validité et la fiabilité des techniques utilisées pour les évaluations successives étaient bien établies. Les études longitudinales sur la progression de la MA rapportent des taux annuels de progression très variables. Il n'est pas clair si cette observation est attribuable à l'évolution de la maladie chez des sous-groupes de patients ou à des taux de déclin en relation avec les stades de la maladie. Conclusions: Nous suggérons qu'une combinaison de tests cognitifs appropriés à différents stades de la maladie tels le Mattis Dementia Rating Scale et le Severe Impairment Battery, ainsi que des méthodes statistiques appropriées tenant compte de la variabilité individuelle du taux de déclin puissent évaluer la progression de la MA et pourraient être utiles dans les études futures.

Seventeen patients diagnosed with Parkinson's disease completed a complex computer-based task that involved planning and management while also performing an attention-demanding secondary task. The tasks were performed concurrently, but it was necessary to switch from one to the other. Performance was compared to a group of healthy age-matched control participants and a group of young participants. Parkinson's patients performed better than the age-matched controls on almost all measures and as well as the young controls in many cases. However, the Parkinson's patients achieved this by paying relatively less attention to the secondary task and focusing attention more on the primary task. Thus, Parkinson's patients can apparently improve their performance on some aspects of a multidimensional task by simplifying task demands. This benefit may occur as a consequence of their inflexible exaggerated attention to some aspects of a complex task to the relative neglect of other aspects. (JINS, 2008, 14, 257-265.)

Unconditioned reward and conditioned reinforcing effects may reflect an isomorphic motivational process because increased conditioned reinforcing effects were seen with increased amounts of saccharin consumed in taste and place conditioning. Reinforcing effects in place conditioning leveled off as saccharin unconditioned consumption reached maximum amounts of approximately 140 mg/rat. Posttrial consumption, but not intraperitoneal injection, of saccharin significantly enhanced conditioned place and taste preferences as well as conditioned taste aversions. Saccharin's memory-improving effects in both aversive and appetitive conditioning suggest a process separate from the reward-reinforcement process. Independent of effects on blood glucose, the motivational property of saccharin's sweet taste undergoes differential central processing to mediate reward-reinforcement versus memory improvement processes.

The tegmental pedunculopontine nucleus (TPP) of the brainstem has been identified as a critical substrate for both opiate and food reward in nondeprived rats. In this study of rats, TPP lesions blocked saccharin-conditioned place preferences, in both the presence and the absence of water deprivation. TPP lesions also attenuated the unconditioned intake of saccharin and water over several hours after recovery from food and water deprivation. TPP lesions did not block saccharin preferences over water in short-duration tests. The researchers propose that the absence of a lesion effect may reflect previously conditioned discriminations. TPP lesions had no effect on the ability of posttrial presentations of a 3.2% saccharin solution to improve lithium-chloride-conditioned taste aversions. TPP lesions dissociate 2 behavioral processes elicited by saccharin: One mediates unconditioned-reward-conditioned-reinforcing effects, and another mediates the memory-improving effect.

A 22 year old woman with recently diagnosed systemic lupus erythematosus presented with subacute progressive areflexic paraparesis, electrophysiologically identified as a pure axonal polyradiculopathy. Sural nerve biopsy disclosed necrotising vasculitis. A striking radiological feature was marked enhancement of the cauda equina with gadolinium. (J Neurol Neurosurg Psychiatry 1999;66:658-661)

In conditioning paradigms, morphine has both rewarding and aversive motivational properties. The rewarding motivational property is preferentially associated with places, whereas the aversive property is preferentially associated with tastes. We used this preferential associability of stimuli in combination with a higher order conditioning procedure to ask how the motivational effects of morphine are represented in memory. First-order conditioning involved the pairing of a novel taste or distinct place with an intraperitoneal injection of morphine (15 mg/kg) in two separate groups ofrats. As expected, conditioned taste aversions developed in one group and conditioned place preferences developed in the other. Second-order conditioning involved pairing the first-order taste conditioned stimulus (eS) with a distinct place es in the absence of morphine in one group and pairing the first-order place es with a distinct taste es in the absence of morphine in the other group. Ifthe first-order taste es, for example, elicits from memory a representation of the entire motivational spectrum of morphine, then the second-order place cues might be expected to reveal conditioned place preferences on the basis of differential associability findings. However, if the first-order taste es calls up only a representation of morphine's aversive effects, then second-order conditioned place aversions would be expected. We found that the firstorder taste es produced second-order conditioned place aversions. Similarly, in the other group, the first-order place es produced second-order taste preferences. In other words, only conditioning within one motivational system was observed. We propose that the first-order stimulus conditioned to morphine represents in memory only that single motivational effect of morphine to which the first-order conditioned stimulus is preferentially associable.Opiates, along with other psychoactive drugs, have both rewarding and aversive motivational properties (Sherman,

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