Bilateral pallidotomy for treatment of Parkinson's disease induced corticobulbar syndrome and psychic akinesia avoidable by globus pallidus lesion combined with contralateral stimulation.

OBJECTIVE: Posteroventral pallidotomy (PVP) has proved to be an effective method for the treatment of Parkinson's disease. However, data on bilateral procedures are still limited. To assess the effects of bilateral globus pallidus (GPi) lesion and to compare it with a combination of unilateral GPi lesion plus contralateral GPi stimulation (PVP+PVS), an open blind randomised trial was designed. METHODS: A prospective series of patients with severe Parkinson's disease refractory to medical treatment, and severe drug induced dyskinesias, were randomised either to simultaneous bilateral PVP or simultaneous PVP+PVS. All patients were assessed with the core assessment programme for intracerebral transplantation (CAPIT), and a comprehensive neuropsychological and neuropsychiatric battery both before surgery and 3 months later. RESULTS: The severe adverse effects found in the first three patients subjected to bilateral PVP led to discontinuation of the protocol. All three patients developed depression and apathy. Speech, salivation, and swallowing, as well as freezing, walking, and falling, dramatically worsened. By contrast, all three patients undergoing PVP+PVS had a significant motor improvement. CONCLUSION: Bilateral simultaneous lesions within the GPi may produce severe motor and psychiatric complications. On the other hand, a combination of PVP+ PVS significantly improves parkinsonian symptoms not associated with the side effects elicited by bilateral lesions.

Theory of mind and pragmatic abilities in dementia.

OBJECTIVE: "Theory of Mind" (ToM) is the capacity to attribute mental states to oneself and to others and to interpret behavior in terms of mental states. Deficits in both ToM and pragmatic abilities have been described in patients with neurologic disorders, such as frontal lobe lesions and right hemisphere strokes, but have not been assessed in demented patients. METHODS: This study examined ToM and pragmatic abilities in a consecutive series of 34 patients with probable Alzheimer disease (AD) using a second-order false belief story, 11 short stories assessing understanding of social situations, and a test of pragmatic abilities assessing both indirect requests and-conversational implications. RESULTS: Sixty-five percent of AD patients with mild dementia could not pass a second-order false belief task, whereas no failures were found in a group of 10 age-comparable healthy controls. AD patients who did not pass the second-order false belief task had more severe deficits on tests of verbal anterograde memory, verbal comprehension, abstract thinking, and naming, as compared with AD patients who passed the task. AD patients also showed significantly more severe pragmatic deficits than age-comparable healthy controls, and there was a significant association between ToM and pragmatic deficits. On the other hand, there were no significant associations between ToM or pragmatic deficits, and behavioral problems frequently reported in AD such as depression, delusions, apathy, and irritability. CONCLUSIONS: This initial exploratory investigation demonstrated significant deficits in both ToM and pragmatic abilities in a consecutive series of AD patients with mild dementia.

Remote memory in Alzheimer's disease.

The authors examined the severity and type of deficits in remote memory in patients with probable Alzheimer's disease (AD). In the first study, 40 AD patients showed significantly more severe deficits on both the free-recall and the recognition sections of the Remote Memory Scale (which measures memory for famous people and well-known events) compared with normal control subjects. In the second study, 25 AD patients showed significantly more deficits on the free-recall section of the Autobiographical Memory Scale compared with normal control subjects. Remote memory deficits in AD may be related to both retrieval deficits and damage to memory traces.

Explicit and implicit learning in patients with Alzheimer disease and Parkinson disease with dementia.

OBJECTIVE: To examine the differential impairment of implicit and explicit memory systems in cortical and subcortical dementias. BACKGROUND: Whereas verbal priming was reported to be impaired in patients with Alzheimer Disease (AD), patients with Parkinson Disease (PD) may be relatively more impaired on tasks of motor skill learning. METHODS: We examined 15 patients with Alzheimer disease, 10 patients with Parkinson disease and dementia (PD-D), 15 patients with PD but no dementia, and 24 age-comparable normal control subjects with a neuropsychologic battery that included tests of explicit memory (Buschke Selective Reminding Test, Benton Visual Retention Test, Digits Span), and tests of implicit memory (Word-Stem Completion task and the Maze Test). RESULTS: AD and PD-D groups showed similar deficits on all measures of explicit memory, and performed significantly worse than PD patients without dementia and normal control subjects. On the other hand, there were no significant between-group differences in any of the measures of implicit memory. CONCLUSIONS: Our study demonstrated preserved implicit learning in the context of severe explicit learning deficits in patients with dementia, but could not demonstrate a different profile of memory deficits between so-called cortical and subcortical dementias.

Neuropsychological correlates of apathy and depression in patients with dementia.

OBJECTIVE: To investigate the association between apathy and depression, and specific cognitive deficits in AD. BACKGROUND: Apathy and depression are frequent behavioral disorders in patients with AD. However, the neuropsychological correlates of these disorders have rarely been examined. METHODS: A comprehensive neuropsychological and psychiatric evaluation was carried out in 72 patients with AD with apathy and depression, 29 patients with AD with apathy only, 31 patients with AD with depression only, and 52 patients with AD with neither apathy nor depression (control group). RESULTS: Patients with apathy had significantly lower scores on tests of verbal memory, naming, set shifting, and verbal fluency compared with patients without apathy. The association of depression and apathy produced significantly more severe deficits compared with apathy only on a test of abstract thinking. Finally, depression in the absence of apathy was not associated with more severe cognitive impairments compared with the AD control group. CONCLUSIONS: Apathy, but not depression, is associated with significantly more severe frontal lobe related cognitive deficits in AD.

Unilateral radiofrequency lesion versus electrostimulation of posteroventral pallidum: a prospective randomized comparison.

Microelectrode-guided posteroventral pallidotomy (PVP) has shown to be an effective method in the treatment of a group of patients with advanced Parkinson's disease. A nonlesioning approach by means of deep brain electrodes connected to a programmable neuropacemaker has also been used to inhibit the internal segment of globus pallidus (posteroventral stimulation [PVS]) reporting comparable clinical efficacy to the one obtained with the ablative method. Nevertheless, no controlled studies have been performed to compare the efficacy of both procedures. A prospective series of 13 patients with a clinical indication for globus pallidus surgery was randomized either to a pallidotomy or stimulator implantation, and comparisons on motor and neuropsychologic measurements were made on a 3-month follow-up basis. Primary measurements of efficacy showed a comparable effect on Unified Parkinson's Disease Rating Scale and activities of daily living score after both procedures. Secondary measurements of efficacy showed that although both techniques improve hand tapping score and dyskinesia score, the bilateral improvement in the former was greater after PVS whereas the latter improved more significantly after PVP. No significant changes in neuropsychologic parameters were observed after either PVP or PVS. Side effects and surgery complications occurred in six of 13 patients (three after PVP and three after PVS): they were mild, transient, and unrelated to optic tract injury. In conclusion, the short-time effect and safety of both procedures is comparable.

Prevalence and correlates of the catastrophic reaction in Alzheimer's disease.

We examined the prevalence of the catastrophic reaction (CR) in 146 patients with Alzheimer's disease. Sixteen percent showed a CR during the neuropsychological evaluation. A factor analysis of the CR scale demonstrated an anxious/angry factor that was significantly associated with higher irritability scores and a longer duration of illness, as well as a depressive factor that was significantly associated with more severe cognitive impairments and older age.

Cognitive functions in major depression and Parkinson disease.

OBJECTIVE: To investigate the importance of major depression in the production of cognitive deficits in patients with Parkinson disease (PD). DESIGN: A comprehensive neuropsychological and psychiatric assessment was conducted in 19 patients with PD and major depression, 31 patients with PD without depression, 27 patients with major depression but without PD, and 12 age-comparable healthy controls. SETTING: Outpatient clinic. RESULTS: Patients with major depression (with or without PD) had significantly more severe cognitive deficits than both healthy controls and patients with PD without depression on tests of verbal fluency and auditory attention, while patients with PD and major depression had significantly more severe deficits on tasks of abstract reasoning and set alternation compared with the other 3 groups. CONCLUSIONS: Major depression in patients with PD is associated with significant deficits on specific cognitive tasks. While some of these deficits may be explained by the presence of major depression, frontal lobe-related cognitive impairments may result from an interaction between neuropathologic factors in PD and the mechanism of major depression.

Prospective longitudinal study of depression and anosognosia in Alzheimer's disease.

BACKGROUND: The aim was to examine the longitudinal evolution of depression and anosognosia in patients with probable Alzheimer's disease (AD). METHOD: Sixty-two of a consecutive series of 116 AD patients that were examined with a structured psychiatric interview had a follow-up evaluation between one and two years after the initial evaluation. RESULTS: At the initial evaluation 19% of the 62 patients had major depression, 34% had dysthymia, and 47% were not depressed. After a mean follow-up of 16 months, 58% of patients with major depression at the initial evaluation were still depressed, whereas only 28% of patients with initial dysthymia and 21% of the non-depressed patients were depressed at follow-up. During the follow-up period, all three groups showed similar declines in cognitive status and activities of daily living. At the initial evaluation, 39% of the patients had anosognosia, and there was a significant increment of anosognosia during the follow-up period. CONCLUSIONS: While dysthymia in AD is a brief emotional disorder, major depression is a longer-lasting mood change. Anosognosia is another prevalent disorder among AD patients, and increases with the progression of the illness.

Anosognosia and procedural learning in Alzheimer's disease.

Awareness of cognitive deficits may rely on the implicit learning of intellectual limitations, and anosognosia in Alzheimer's disease (AD) may result from deficits in implicit learning. To examine this hypothesis, a consecutive series of 55 patients with probable AD were divided into groups with mild (n = 13), severe (n = 12), or no anosognosia (n = 30) and were assessed with a neuropsychological battery that included tests of declarative and procedural learning. Whereas there were no significant between-group differences in tests of declarative learning (the Buschke Selective Reminding Test and the Benton Visual Retention Test), patients with severe anosognosia showed a significantly worse performance on procedural learning (as measured with the Maze Learning Test) and a test assessing set shifting abilities (the Wisconsin Card Sorting Test) than AD patients without anosognosia. The authors' results suggest that deficits in procedural learning and anosognosia in AD may result from dysfunction in habit-learning systems.

Neuropsychological and psychiatric differences between Alzheimer's disease and Parkinson's disease with dementia.

OBJECTIVE: To examine neuropsychological and neuropsychiatric differences between patients with probable Alzheimer's disease and patients with Parkinson's disease and dementia. METHODS: Thirty three patients with probable Alzheimer's disease and 33 patients with Parkinson's disease and dementia were matched for age, sex, and mini mental state examination scores and given a battery of neuropsychological and neuropsychiatric tests. RESULTS: Patients with Parkinson's disease with dementia had a significantly higher prevalence of major depression than patients with Alzheimer's disease; patients with Alzheimer's disease showed more severe anosognosia and disinhibition than patients with Parkinson's disease. Whereas no significant between group differences were found on tests of memory and language, demented patients with Parkinson's disease had a significantly greater impairment on a test of visual reasoning than patients with Alzheimer's disease. CONCLUSION: There were significant psychiatric differences between patients with Alzheimer's disease and demented patients with Parkinson's disease, but neuropsychological differences were restricted to a single cognitive domain.