Unilateral subthalamic nucleus deep brain stimulation contralateral to thalamic stimulation in Parkinson disease

The effects of unilateral subthalamic nucleus (STN) stimulation contralateral to thalamic stimulation in Parkinson disease (PD) have not been previously reported. We are reporting a patient who developed left arm tremor in 1994, at age 62, as her first PD symptom. She underwent right thalamic DBS surgery in 1999 that resulted in complete resolution of left arm tremor. Her PD symptoms progressed and she developed severe motor fluctuations and disabling dyskinesias. In 2003, she underwent left STN electrode implantation. Left STN stimulation improved contralateral motor scores in the medication OFF state, and allowed for reduced medication doses and less dyskinesia. However, there was no significant improvement in activities of daily living (ADL), motor scores in the medication ON state, gait, or postural stability.     

Neuropsychological outcomes after thalamic deep brain stimulation for essential tremor

IntroductionNon-motor DBS outcomes have received little attention in ET relative to PD. This study examines neuropsychological outcomes in ET following thalamic VIM DBS.MethodsFifty patients completed neuropsychological evaluations preoperatively and approximately seven months postoperatively. Cognition and mood changes were analyzed at the group level and individual level. Additional associations with treatment, disease, and demographic characteristics were assessed.ResultsSignificant cognitive decline was not observed at the group level. At the individual level, 46% of patients demonstrated at least subtle overall cognitive decline (≥1SD on at least one test within at least two domains). Mild decline (≥1SD) was seen in 10%–29.17% of patients on individual tests across all cognitive domains, with highest rates in verbal memory. Substantial cognitive decline (≥2SD) occurred in less than 9% of the sample across all tests. Factors related to cognitive decline included higher DBS parameter settings, older age of ET onset, intracranial complications, and inability to reduce ET medications postoperatively. Depression and anxiety did not change when accounting for questionnaire items that could be falsely elevated by tremor.ConclusionSubstantial cognitive decline after VIM DBS is rare in patients with ET. However, subtle decrements can occur across cognitive domains and particularly in verbal memory. DBS parameter settings may relate to cognitive decline. Further research is needed to better understand possible associations with electrode lateralization and other variables that could also relate to disease progression and test-retest effects. Symptoms of depression and anxiety remain stable.     

Neuropsychological predictors of patient-reported cognitive decline after deep brain stimulation in Parkinson’s disease

Background: Deep brain stimulation (DBS) is effective for treatment of motor complications of dopaminergic therapy in Parkinson’s disease (PD) but occasionally has been associated with multidomain cognitive decline. Patient- and caregiver-reported cognitive decline are clinically meaningful and increasingly recognized as important to consider when evaluating therapeutic interventions for PD.

Objective: The objective was to assess presurgical neuropsychological and clinical factors associated with PD patient- and caregiver-reported cognitive decline in two or more domains after DBS.

Method: A single telephone survey was used to assess patient- and caregiver-reported cognitive decline in five domains at both one and four months after DBS surgery. Decline in two or more domains was considered multidomain cognitive decline (MDCD). Baseline demographic, clinical, and neuropsychological factors were compared in those with or without MDCD. Preoperative neuropsychological measures were evaluated as risk factors and regressed on the presence of MDCD, with demographic covariates, using multiple logistic regression.

Results: Preoperative performance in verbal recognition memory, language knowledge, and verbal processing decline were associated with postoperative, patient-reported MDCD in the first four weeks. MDCD at four months after DBS was associated with worse preoperative verbal reasoning, verbal recall, and semantic verbal fluency. Caregiver-reported MDCD one month after DBS was associated with poorer baseline verbal memory recognition accuracy/discriminability, visuospatial problem solving, and constructional praxis.

Conclusion: Poor presurgical performance in verbal memory recognition, language processing, and visuospatial performance is associated with patient- or caregiver-reported decline following DBS surgery. Posterior cortical dysfunction seems to portend significant self-reported cognitive decline following deep brain stimulation.     

Neuropsychological and quality of life outcome after thalamic stimulation for essential tremor

OBJECTIVE: To evaluate short-term effects of unilateral thalamic deep brain stimulation (DBS) on cognition, mood state, and quality of life in patients with essential tremor (ET). BACKGROUND: Unilateral thalamotomy and thalamic DBS are effective in alleviating refractory tremor contralateral to the side of surgery. Thalamotomy can lead to cognitive morbidity, and DBS might be a preferable surgical intervention given potential avoidance or reversibility of such morbidity. Although unilateral thalamic DBS is cognitively safe and leads to quality of life improvement in PD, its neurobehavioral effects in ET are unknown. METHODS: Forty patients with ET were administered a broad neuropsychological test battery, measures of mood state, and generic and disease-specific quality of life measures approximately 1 month before and 3 months after surgery (left hemisphere, 38 patients). RESULTS: Unilateral thalamic DBS was associated with significant improvements in tremor and dominant-hand fine visuomotor coordination. Statistically significant but clinically modest gains were observed on tasks of visuoperceptual and constructional ability, visual attention, delayed word list recognition, and prose recall. Only lexical verbal fluency declined significantly after surgery. Patients rated themselves as less anxious after surgery, and they perceived their quality of life as improved significantly. In particular, patients reported improved quality of life with respect to activities of daily living, stigma, emotional well-being, and communication. CONCLUSIONS: Unilateral thalamic DBS for ET is cognitively safe and associated with improvements in anxiety and quality of life in the near term and in the absence of operative complications. Patients were better able to carry out activities of daily living after surgery, and they reported improvement in several psychosocial domains of quality of life.     

Neuropsychological and quality of life outcomes 12 months after unilateral thalamic stimulation for essential tremor

OBJECTIVES: To evaluate the one year cognitive, mood state, and quality of life (QoL) outcomes of unilateral thalamic deep brain stimulation (DBS) for essential tremor (ET). METHODS: 40 patients diagnosed with ET completed comprehensive neuropsychological assessments about one month before and three and 12 months after DBS electrode implantation. Data were subjected to multivariate analyses, and significant results were further analysed using univariate techniques. RESULTS: Analyses revealed statistically significant improvements on a cognitive screening measure and in aspects of fine visuomotor and visuoperceptual functions, verbal memory, mood state, and QoL. No group-wise declines in cognition were observed, but more patients showed declines than improvements on language and visual memory tests. Semantic verbal fluency declined significantly in four (10%) of the patients. In these four patients, diminished lexical verbal fluency was present at baseline. CONCLUSION: Cognitive, mood, and QoL outcomes after one year of DBS for ET are favourable; there were no overall deleterious effects on cognition, and DBS was accompanied by a significant reduction in anxiety and improvements in quality of life. However, preoperative verbal fluency diminution may predispose to further fluency declines after DBS.     

Neuropsychological performance before and after partial or complete insulectomy in patients with epilepsy

Resection of the insular cortex is becoming more frequent as it is increasingly recognized that a nonnegligible proportion of surgical candidates with drug-resistant epilepsy have an epileptogenic zone that involves the insula. In the last decades, however, the insula has been proposed to be involved in several neuropsychological functions, and there is a lack of documentation on whether partial or complete insulectomy results in permanent cognitive impairments in this clinical population. In this study, we conducted standard preoperative and postoperative neuropsychological assessments in 18 patients undergoing epilepsy surgery that included the removal of the insula in the right (n = 13) or the left (n = 5) hemisphere. Postoperative testing was conducted at least five months after surgery. Cognitive impairments were common and heterogeneous prior to surgery, with language and verbal memory impairments being especially frequent among patients in whom epileptic seizures originated from the left hemisphere. After surgery, declines and improvements occurred on a variety of outcomes, although new deficits were relatively infrequent among patients who had obtained normal performance at baseline. Statistical comparisons between preoperative and postoperative assessments revealed significant deterioration of only one outcome – the color naming condition of the Stroop test – which relies on oro-motor speed and lexical access. These findings suggest that partial or complete resection of the insular cortex in patients with drug-refractory epilepsy can be conducted without major permanent neuropsychological impairments in a vast majority of patients. However, small decrements in specific cognitive functions can be expected, which should also be taken into account when considering the surgical option in this clinical population.     

Neuropsychological function in patients with end-stage heart failure before and after cardiac transplantation

This study was performed to examine cognitive function in patients with end-stage heart failure, to identify possible cardiovascular factors associated with cognitive function, and to evaluate changes in cognitive function in a subgroup of patients who received heart transplantation. An extensive battery of neuropsychological tests were given to 62 patients with end-stage cardiac failure as part of their evaluation for cardiac transplantation. Most patients were consecutive referrals, not selected because of cognitive complaints. A small subgroup of transplanted (n = 7) and non-transplanted (n = 4) patients received a repeat neuropsychological examination. At initial examination, approximately 50% of the patients met criteria for impairment in reference to normal control values. Higher stroke volume index and cardiac index and lower right atrial pressure were correlated with better cognitive function. In the subgroup of patients re-examined, the transplanted patients demonstrated significantly improved cognitive function, whereas the non-transplanted subjects were unchanged. These data indicate that in patients with end-stage heart failure there is a high prevalence of impaired cognitive function which is related to measures of cardiovascular efficiency. Preliminary evidence suggests that these impairments may be partially ameliorated by cardiac transplantation.     

P3 after acoustic and somatosensory stimulation in patients with Huntington disease]

Sixteen Huntington patients (HD) (mean age 43.7 years) were studied and compared to 12 risk people for Huntington disease (HR) (mean age 31.2 years) and 25 normal people (mean age 33.2 years). A simple auditory or somatosensory paradigm was used requiring counting of the rare target stimulus. For the normal subjects, most of the recordings showed a slightly earlier latency for the P3 component of the ERPs with the auditory paradigm (P3A). For the HD, a clear P3 was observed in both modalities in 8 patients, in 5 cases no P3 for both stimuli and in 3 cases no P3 for the somatosensory paradigm (P3S) only. The mean value of the P3A latencies was increased compared to the normal control group and after the age effect correction. The mean value of the P3S is significantly more increased compared to the normal group and the "expected" value, according the P3A latencies. This dissociation is constant in all HD when the P3S is recorded and could be due to the fact that the endogenous component is also related to the stimulus modality (increased difficulty and/or subclinical abnormality in the somatosensory modality).     

Neuropsychological changes after subthalamic nucleus stimulation: a 12 month follow-up in nine patients with Parkinson's disease

Deep brain stimulation of the subthalamic nucleus has been recognized as one of the most promising techniques to decrease 'off' motor symptoms and motor fluctuations, allowing a reduction of drug therapy and limiting side effects of drug therapy. However, there is still open debate on the possible consequences of chronic subthalamic stimulation on general cognitive performance. A general amelioration of cognitive performance, in particular of executive functions has been reported but results are not homogeneous. We studied nine patients with Parkinson's Disease for 12 months following surgery for deep stimulation, studying their cognitive performances, paying particular attention to linguistic tests and selective alternating words production. Our results may be consistent with a slowing of cognitive activity, with a reduction of quantitative production, but with an increase in control of linguistic production, which is more precise and definite. We discuss the possible significance of these results, fully aware that only nine patients were involved, and that the potential for generalization is seriously limited, with a particular overview on the frontal-subthalamic pathway, which in our opinion is responsible for the results we observed.     

Neuropsychological changes after subthalamic nucleus stimulation: a 12 month follow-up in nine patients with Parkinson's disease

Deep brain stimulation of the subthalamic nucleus has been recognized as one of the most promising techniques to decrease ‘off’ motor symptoms and motor fluctuations, allowing a reduction of drug therapy and limiting side effects of drug therapy. However, there is still open debate on the possible consequences of chronic subthalamic stimulation on general cognitive performance. A general amelioration of cognitive performance, in particular of executive functions has been reported but results are not homogeneous. We studied nine patients with Parkinson's Disease for 12 months following surgery for deep stimulation, studying their cognitive performances, paying particular attention to linguistic tests and selective alternating words production. Our results may be consistent with a slowing of cognitive activity, with a reduction of quantitative production, but with an increase in control of linguistic production, which is more precise and definite. We discuss the possible significance of these results, fully aware that only nine patients were involved, and that the potential for generalization is seriously limited, with a particular overview on the frontal-subthalamic pathway, which in our opinion is responsible for the results we observed.     

Neuropsychological assessments before and after treatment in patients with anorexia nervosa and bulimia nervosa

In psychiatric patients the identification of cognitive deficits which predict a poor clinical outcome is important for the development of specific treatment strategies aimed at the amelioration of these impaired cognitive functions to increase the likelihood of full clinical remission. However, such attempts are absent in bulimia nervosa (BU), are scarce in anorexia nervosa (AN) and, furthermore, provide conflicting results. In the present prospective study we investigated the neuropsychological demands in 12 patients with AN and in 14 patients with BU before, during, and after a treatment period. At the initial testing session, both patients samples showed similar and impaired performance levels on tasks measuring attentional demands and problem solving abilities, while their mnemonic functions were preserved. At the final testing session, which took place 7 months thereafter, the impaired cognitive functions had improved to a similar degree in the AN and the BU subgroups. However, although the eating disorder symptomatology had ameliorated in parallel, no direct associations could be established with the initial neuropsychological demands and their rectification, respectively. On an individual level, 11 patients initially showed obvious cognitive deficits. However, the clinical characteristics of this subgroup differed not from that found in the 15 'good performers'. These findings indicate that the cognitive functions in the acute AN and BU are similarly impaired, but also ameliorate in a similar manner with clinical remission. Because no associations were obvious between cognitive and clinical rectifications, significant contributions of mediating factors (e.g., changes in metabolic brain turnover and in steroid hormones) are suggested.     

Pathological gambling after bilateral subthalamic nucleus stimulation in Parkinson disease

We describe a patient with advanced Parkinson's disease who developed pathological gambling within a month after successful bilateral subthalamic nucleus (STN) stimulation. There was no history of gambling. On neuropsychological testing, slight cognitive decline was evident 1 year after surgery. Stimulation of the most dorsal contact with and without medication induced worse performances on decision making tests compared with the more ventral contact. Pathological gambling disappeared after discontinuation of pergolide and changing the stimulation parameters. Pathological gambling does not seem to be associated with decision making but appears to be related to a combination of bilateral STN stimulation and treatment with dopamine agonists.     

Sleep electroencephalographic asymmetry in Parkinson's disease patients before and after deep brain stimulation

ObjectiveUnilateral manifestation of motor dysfunction is a prominent hallmark of Parkinson’s disease (PD). We investigated how the motor laterality of the disorder affects sleep neural asymmetry before and after Deep Brain Stimulation (DBS).MethodsTwenty-seven PD patients of the akinetic-rigid subtype were studied; 11 with right dominant (RD) and 16 with left dominant (LD) motor symptoms. Neuronal sleep asymmetry was computed as the difference of sleep slow-wave energy (SWE) between left and right hemispheres. We used linear mixed models to assess the relationship between symptomatic profile and SWE asymmetry.ResultsLD PD patients exhibited frontal electroencephalographic (EEG) asymmetry and motor laterality pre-DBS with increased SWE contralateral to their affected body side, which diminished post-DBS. The RD group did not exhibit neither neural asymmetry nor motor laterality pre- and post-DBS. There was a significant negative correlation between the motor laterality and sleep EEG asymmetry.ConclusionsOur results suggest evidence for a local use-dependent modulation of SWE as a result of the lateralized pathological motor profile. More bilateral motor symptoms and optimized treatment contribute to diminished sleep EEG asymmetry.SignificanceThese novel findings about the association between symptomatic motor laterality and sleep neural asymmetry may provide targeted therapeutic insights.     

Neuropsychological evaluation of children after ischemic cerebrovascular disease

The purpose of this study is to associate neuropsychological evaluation with neuroimaging results in children with cerebral tomography indicating ischemic cerebrovascular disease (ICVD). Neuroimaging, neurological exams and neuropsychological instruments were used to evaluate five children. The study revealed that the cognitive and perceptive skills in two children were normal and motor sequele in four cases. The rhythm, visual and speech receptive skills remained unchanged. In four cases the SPECT exam showed regions with hypoperfusion and in four cases the EEG was normal. Neuropsychological, neurological and image indication some degree of sequele demonstrating the importance of follow up of children who had suffered cerebrovascular disease.     

Levodopa withdrawal after bilateral subthalamic nucleus stimulation in advanced Parkinson disease

CONTEXT: Subthalamic nucleus (STN) stimulation may be effective in ameliorating parkinsonian symptoms even to the extent to permit levodopa withdrawal. OBJECTIVES: To analyze the efficacy of STN stimulation in patients with Parkinson disease (PD) and to determine if levodopa may be withdrawn after surgery. DESIGN: Before-after trial. SETTING: Referral center, hospitalized care. PATIENTS: Fifteen patients with advanced PD. INTERVENTIONS: Microelectrode-guided bilateral STN high-frequency stimulation. OUTCOME MEASURES: Before surgery patients were evaluated in off-medication and on-medication conditions. Dopaminergic drug dosages were reduced after surgery, aiming for complete withdrawal. Six months after surgery, patients were reeavaluated in off- and on-medication conditions, with the stimulation turned on and off. RESULTS: Total Unified Parkinson's Disease Rating Scale (UPDRS) motor score in the off-medication condition improved by 65.9%; and axial symptoms, bradykinesia, rigidity, and tremor improved by 65.8%, 60.4%, 66.1%, and 81.1%, respectively. UPDRS part II scores were reduced by 71.8% and Schwab and England scores improved by 45.3%. Levodopa was withdrawn in 8 patients and the overall levodopa dose was reduced 80.4%. "Off" time was reduced 89.7% and the severity of dyskinesias decreased 80.6% after surgery. All results reached significance (P<.001). Stimulation of the STN achieved antiparkinsonian effect similar to that of treatment with levodopa. No life-threatening adverse effects occurred. CONCLUSIONS: Bilateral STN stimulation safely improves all parkinsonian symptoms, decreases or eliminates the need for levodopa, and ameliorates motor fluctuations and dyskinesias. Complete withdrawal of levodopa is feasible with this technique and the overall motor effect of STN stimulation is quantitatively comparable to that obtained with levodopa.     

Initial cognitive dip after subthalamic deep brain stimulation in Parkinson disease

Although many studies have shown no significant change in global cognitive function after subthalamic brain stimulation (STN DBS) in patients with Parkinson disease (PD) and have concluded that STN DBS is generally safe from a cognitive standpoint, some studies have reported a decline in global cognitive function after STN DBS. Interestingly, in some studies, the decline in cognitive function appears to be greater during the initial short period after surgery (within 6 or 12 months after surgery) than the decline thereafter. To this end, we examined whether the rate of change in global cognitive function during the initial 6 months after STN DBS was different from the mean 6-month change that occurred between 6 and 36 months after surgery. Thirty-six PD patients who underwent bilateral STN DBS and were followed for more than 3 years were included. Change in Mini-Mental Status Examination (MMSE) score during the first 6 months after surgery was compared with the 6-month MMSE score change between 6 and 36 months after surgery. Mean MMSE change during the first 6 months after surgery was significantly greater than the mean 6-month MMSE change between 6 to 36 months after surgery. The levodopa equivalent daily dose at baseline and the score for Stroop Color-word test at baseline were significantly associated with the decline in MMSE score during the first 6 months after surgery. Our result showed that decline in global cognitive function was faster in the first 6 months after surgery, compared with that after 6 months.     

Cardiovascular autonomic responses in patients with Parkinson disease to pedunculopontine deep brain stimulation

Clinical Autonomic Research - Dysautonomia can be a debilitating feature of Parkinson disease (PD). Pedunculopontine nucleus (PPN) stimulation may improve gait disorders in PD, and may also result...