The frequency, clinical correlates, and mechanism of anosognosia after stroke.

OBJECTIVE: To review the frequency, clinical correlates, and mechanism of anosognosia after stroke. METHODS: We searched the most recent relevant literature on anosognosia after stroke and carried out a critical analysis of the main findings. RESULTS: Anosognosia is present in about 10% of acute stroke patients and its diagnosis is relatively simple. Nevertheless, a valid and reliable standardization of diagnostic instruments and criteria for research purposes is more difficult to achieve. This limitation may partially account for various instruments available to assess anosognosia and the different strategies used to diagnose this phenomenon. Anosognosia is a fleeting phenomenon and chronic cases are infrequent. There is a robust association between anosognosia and right-hemisphere lesions involving cortical (insular, temporal, and parietal lobes) and subcortical structures (thalamus and basal ganglia). The main clinical correlates of anosognosia are the presence of neglect, cognitive deficits, previous strokes, and older age. Anosognosia has a negative impact on the rehabilitation of stroke patients. The mechanism of anosognosia remains unknown but was explained as owing to psychological denial, disconnection between left and right hemispheres, and dysfunction of a system that monitors the intention to move and actual movements. CONCLUSION: Anosognosia is a relatively frequent complication of acute stroke and may become an excellent model to understand the mechanism of human awareness.

In vivo proton magnetic resonance spectroscopy in patients with mood disorders: a technically oriented review.

Proton MR spectroscopy (1HMRS) has been extensively used among mood disorders patients. A review of the published literature in 1HMRS studies of mood disorders was carried out for the period 1991 to July 2006. Of 71 1HMRS studies, 77.5% were done at 1.5T and 66.2% used single voxel sequences (SVS), implying limitations of spectral resolution and anatomic coverage, respectively. In all, 47.9% of studies relied on creatine (Cr) as internal signal standard, although Cr changes were reported in major depression (MD). Most reported metabolic alterations related to mood state affected the left frontal lobe. Depressed adult and pediatric MD patients had reduced glutamate (Glu) in frontal lobe regions, which reversed with successful treatment. A consistent reduction of N-acetyl-aspartate (NAA) was reported in the hippocampal formation among bipolar disorder (BD) patients, along with an increment in frontal Glu. The differences in results of 1HMRS studies in mood disorders reflect heterogeneity of technical factors and subject selection. Future studies should benefit from higher spectral resolution and more extensive anatomic coverage as well as standardized data-processing protocols and subject selection criteria.

White matter volume and cognitive dysfunction in early Huntington's disease.

BACKGROUND: Structural abnormalities of the striatum and cognitive impairments have consistently been shown in patients with Huntington's disease (HD). Fewer studies have examined other cerebral structures in early HD and potential associations with cognition. METHOD: Ten patients with early HD and 10 matched control subjects underwent magnetic resonance imaging to provide quantitative measures (volumes) of cortical gray and white matter and the caudate, putamen, and thalamus. Patients completed the Unified Huntington's Disease Rating Scale, including three cognitive tasks. RESULTS: Although striatal volumes were clearly reduced, white matter was also morphologically abnormal. Cortical gray matter volume was not significantly correlated with cognitive performance. However, the cognitive tasks were most highly correlated with cerebral white matter and, to a lesser degree, striatal volume. CONCLUSIONS: Cerebral white matter volume may be an important variable to examine in future studies of HD.

Repetitive transcranial magnetic stimulation as treatment of poststroke depression: a preliminary study.

BACKGROUND: Depression has a significant impact on poststroke recovery and mortality. There are a proportion of patients with poststroke depression (PSD) who do not respond to antidepressants. Repetitive Transcranial Magnetic Stimulation (rTMS) might be a safe and effective alternative in these refractory cases. METHODS: We conducted a randomized, parallel, double-blind study of active versus sham left prefrontal rTMS in patients with refractory PSD. After discontinuing antidepressants, patients were randomly assigned to receive 10 sessions of active (10 Hz, 110% of the motor threshold, 20 trains of 5 seconds duration) or sham left prefrontal rTMS. Efficacy measures included HAM-D scores, response and remission rates. Patients completed a neuropsychological battery at baseline and after completing the protocol. RESULTS: When compared with sham stimulation, 10 sessions of active rTMS of the left dorsolateral prefrontal cortex were associated with a significant reduction of depressive symptoms. This reduction was not influenced by patient's age, type or location of stroke, volume of left frontal leukoaraiosis or by the distance of the stimulating coil to the prefrontal cortex. However, there was a significant positive correlation between the percentage of reduction of Ham-D scores and frontal gray and white matter volumes. There were no significant changes in cognitive functioning between the active and the sham stimulation groups. In addition, there were few and mild adverse effects that were equally distributed among groups. CONCLUSIONS: Taken together, these preliminary findings suggest that rTMS may be an effective and safe treatment alternative for patients with refractory depression and stroke.

Regional cerebral blood flow changes during visually induced subjective sadness in healthy elderly persons.

This study examined regional cerebral blood flow (rCBF) changes associated with visually induced sad affect in healthy elderly persons. Subjects viewed sadness-laden, happiness-laden, and emotionally neutral image sets while rCBF was recorded using [(15)O] water PET. The sad image set included human faces and scenery/objects ("scenes"). To control for secondary sensory processing, the neutral and happy comparison sets included exclusively either human faces or scenes. During the sad condition, the ventral prefrontal and temporal cortices were more active compared with happy and neutral scenes conditions and the thalamus was more active compared with happy and neutral faces conditions. Ventral prefrontal cortex and thalamus were associated with processing of sad visual stimuli, whether compared with neutral or happy stimuli. The specific findings associated with sad affect were contingent on the comparison stimuli content (scenes or human faces), not affect (i.e., comparison with neutral or happy conditions).

Problemas neuropsiquiátricos pós-AVC: diagnóstico, fisiopatologia e tratamento / Post-stroke neuropsychiatric problems: diagnosis, pathophysiology and treatment

Resumo: Depressäo é o transtorno psiquiátrico mais comum ocorrendo como conseqüência de acidente vascular cerebral (AVC). Aproximadamente entre 40 e 50 por cento destes pacientes iräo apresentar depressäo no primeiro mês após um AVC agudo. Depressäo pós-AVC pode ter um efeito significativo na reabilitaçäo para atividades de vida diária e funcionamento cognitivo nestes pacientes. Antidepressivos têm se mostrado eficazes no tratamento de depresäo pós-AVC. Estimulantes centrais e eletroconvulsoterapia (ECT) também parecem eficazes em estudo näo-controles. Mania é uma complicaçäo rara de AVC. Seus mecanismos ainda säo desconhecidos, e o tratamento é baseado em drogas que säo eficazes no tratamento da mania primária. O tratamento do transtorno bipolar pós-AVC também segue os critérios para tratamento do transtorno bipolar primário. Lítio é o tratamento principal, que também pode ser associado a antipsicóticos ou outros estabilizadores do humor, como o valproato de sódio ou carbamazepina. Outros problemas psiquiátrico associados com AVC incluem a ansiedade pós-AVC, a psicose pós-AVC e o riso e choro patológico. Ansiedade responde às drogas ansiolíticas, como os bensodiazepínicos. Existem duas formas básicas de abordar os pacientes com psicose pós-AVC. Uma destas formas utiliza terapia anticonvulsivante, e a outra utiliza antipsicóticos. Nortriptilina e citalopram têm se mostrado drogas eficazes em estudos duplo-cego, controlados, para o tratamento de riso e choro patológicos pós-AVC