Depression in Parkinson's disease is not accompanied by more corticotropin-releasing hormone expressing neurons in the hypothalamic paraventricular nucleus.

BACKGROUND: Depression is frequently encountered in Parkinson's disease (PD). In addition, more than half of the PD patients have a disturbed dexamethasone suppression test, which is associated with increased activity of corticotropin-releasing hormone (CRH) neurons. We recently found an increase in CRH neuron number, CRH-messenger RNA, and vasopressin colocalization in CRH neurons in the paraventricular nucleus (PVN) of depressed patients, which may be involved in the pathogenesis of depression. METHODS: The number of neurons expressing CRH was determined in the PVN of 6 depressed PD patients with a high score (> or = 13) on the Hamilton Depression Rating Scale, 6 nondepressed PD patients, and 6 controls. RESULTS: The three groups did not differ in the number of neurons expressing CRH. CONCLUSIONS: We hypothesize that activation of CRH neurons in the PVN, as we recently observed in idiopathic depression, does not play an essential role in depression in PD.

Primary cerebellar nocardiosis and alveolar proteinosis.

We report a patient with known asymptomatic pulmonary alveolar proteinosis (PAP) who developed a cerebellar gait disorder and dysarthria caused by an isolated cerebellar nocardial abscess. To our knowledge only 1 patient with PAP and isolated central nervous system nocardia infection has previously been reported. In this early report, diagnosis was established at autopsy. In our patient the clinical and MRI examinations of this cerebellar abscess are described and specific features leading to earlier diagnosis and successful treatment are presented.

Neurofibrillary tangles and neuropil threads as a cause of dementia in Parkinson's disease.

Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common age-related degenerative disorders of the human brain. Both diseases involve multiple neuronal systems and are the consequences of cytoskeletal abnormalities. In AD susceptible neurons produce neurofibrillary changes, while in Parkinson's disease, they develop Lewy bodies. In AD six developmental stages can be distinguished on account of the predictable manner in which the neurofibrillary changes spread across the cerebral cortex. During the course of PD numerous limbic determined parts of the brain undergo specific lesions regulating endocrine and autonomic functions. In general, the extranigral destructions are in themselves not sufficient to produce overt intellectual deterioration. Fully developed Parkinson's disease with concurring incipient Alzheimer's disease is likely to cause impaired cognition.

Consensus guidelines for the clinical and pathologic diagnosis of dementia with Lewy bodies (DLB): report of the consortium on DLB international workshop.

Recent neuropathologic autopsy studies found that 15 to 25% of elderly demented patients have Lewy bodies (LB) in their brainstem and cortex, and in hospital series this may constitute the most common pathologic subgroup after pure Alzheimer's disease (AD). The Consortium on Dementia with Lewy bodies met to establish consensus guidelines for the clinical diagnosis of dementia with Lewy bodies (DLB) and to establish a common framework for the assessment and characterization of pathologic lesions at autopsy. The importance of accurate antemortem diagnosis of DLB includes a characteristic and often rapidly progressive clinical syndrome, a need for particular caution with neuroleptic medication, and the possibility that DLB patients may be particularly responsive to cholinesterase inhibitors. We identified progressive disabling mental impairment progressing to dementia as the central feature of DLB. Attentional impairments and disproportionate problem solving and visuospatial difficulties are often early and prominent. Fluctuation in cognitive function, persistent well-formed visual hallucinations, and spontaneous motor features of parkinsonism are core features with diagnostic significance in discriminating DLB from AD and other dementias. Appropriate clinical methods for eliciting these key symptoms are described. Brainstem or cortical LB are the only features considered essential for a pathologic diagnosis of DLB, although Lewy-related neurites, Alzheimer pathology, and spongiform change may also be seen. We identified optimal staining methods for each of these and devised a protocol for the evaluation of cortical LB frequency based on a brain sampling procedure consistent with CERAD. This allows cases to be classified into brainstem predominant, limbic (transitional), and neocortical subtypes, using a simple scoring system based on the relative distribution of semiquantitative LB counts. Alzheimer pathology is also frequently present in DLB, usually as diffuse or neuritic plaques, neocortical neurofibrillary tangles being much less common. The precise nosological relationship between DLB and AD remains uncertain, as does that between DLB and patients with Parkinson's disease who subsequently develop neuropsychiatric features. Finally, we recommend procedures for the selective sampling and storage of frozen tissue for a variety of neurochemical assays, which together with developments in molecular genetics, should assist future refinements of diagnosis and classification.

Olanzapine in the treatment of dopaminomimetic psychosis in patients with Parkinson's disease.

We studied the effect of olanzapine (1 to 15 mg/d) in 15 nondemented parkinsonian patients with drug-induced psychosis. Psychotic symptoms decreased significantly during treatment, and there was no worsening of extrapyramidal symptoms. These results suggest that olanzapine is a well-tolerated and effective treatment for drug-induced psychosis in nondemented patients with Parkinson's disease.

New aspects of pathology in Parkinson's disease with concomitant incipient Alzheimer's disease.

Alzheimer's disease and Parkinson's disease are the most common age-related degenerative disorders of the human brain. Both diseases involve multiple neuronal systems and are the consequences of cytoskeletal abnormalities which gradually develop in only a small number of neuronal types. In Alzheimer's disease, susceptible neurons produce neurofibrillary tangles and neuropil threads, while in Parkinson's disease, they develop Lewy bodies and Lewy neurites. The specific lesional pattern of both illnesses accrues slowly over time. Presently available data support the view that fully developed Parkinson's disease with concurring incipient Alzheimer's disease is likely to cause impaired cognition.

Pattern of brain destruction in Parkinson's and Alzheimer's diseases.

Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common age-related degenerative disorders of the human brain. Both diseases involve multiple neuronal systems and are the consequences of cytoskeletal abnormalities which gradually develop in only a small number of neuronal types. In AD, susceptible neurons produce neurofibrillary tangles (NFTs) and neuropil threads (NTs), while in PD, they develop Lewy bodies (LBs) and Lewy neurites (LNs). The specific lesional pattern of both illnesses accrues slowly over time and remains remarkably consistent across cases. In AD, six developmental stages can be distinguished on account of the predictable manner in which the neurofibrillary changes spread across the cerebral cortex. The pathologic process commences in the transentorhinal region (clinically silent stages I and II), then proceeds into adjoining cortical and subcortical components of the limbic system (stages III and IV - incipient AD), and eventually extends into association areas of the neocortex (stages V and VI - fully developed AD). During the course of PD, important components of the limbic system undergo specific lesions as well. The predilection sites include the entorhinal region, the CA2-sector of the hippocampal formation, the limbic nuclei of the thalamus, anterior cingulate areas, agranular insular cortex (layer VI), and - within the amygdala - the accessory cortical nucleus, the ventromedial divisions both of the basal and accessory basal nuclei, and the central nucleus. The amygdala not only generates important projections to the prefrontal association areas but also exerts influence upon all non-thalamic nuclei which in a non-specific manner project upon the cerebral cortex and upon the nuclei regulating endocrine and autonomic functions. All these amygdala-dependent structures themselves exhibit severe PD-specific lesions. In general, the extranigral destructions are in themselves not sufficient to produce overt intellectual deterioration. Similarly, AD-related pathology up to stage III may be asymptomatic as well. Fully developed PD with concurring incipient AD, however, is likely to cause impaired cognition. Presently available data support the view that the occurrence of additional lesions in the form of AD stage III (or more) destruction is the most common cause of intellectual decline in PD.

Pharmacokinetics and clinical efficacy of rectal apomorphine in patients with Parkinson's disease: a study of five different suppositories.

The pharmacokinetics and clinical effects of apomorphine after rectal administration were determined in five patients with idiopathic Parkinson's disease (PD). Three different pharmaceutical formulations were tested: a rectal solution of apomorphine (10 or 15 mg), a gelatin suppository (25 and 50 mg), and a Witepsol-H15 suppository (50 and 100 mg). The pharmacokinetics of apomorphine were determined by measuring plasma concentrations using a sensitive and specific high-performance liquid chromatography method. The mean bioavailability varied between 14.7% and 40.2%, which was the bioavailability until the end of clinical benefit. Also, despite the differences in dose, the values of the Cmax were similar, with average values of 12.7-25.6 ng/ml. Wide differences in Tmax were observed, with values varying between 16 min for the enema and 127.5 min for the Witepsol-H15 100-mg suppository. The time course of the clinical effect was determined by assessing the time needed for walking a 25-m course and by calculating a tremor and dyskinesia score. Onset of effect was similar for each of the preparations, with an average onset time of 14-28 min. Significant differences with respect to the duration of the effect were observed. The duration of effect after administration of the Witepsol-H15 100-mg suppository was 156 +/- 43 min versus 50 +/- 13 min after rectal administration of the apomorphine solution. These results show that rectal administration of apomorphine may present an alternative to subcutaneous administration. The sustained-release properties of the Witepsol-H15 suppositories are especially of interest in the treatment of on-off fluctuations in PD.

Gene expression of the nicotinic acetylcholine receptor alpha 4 subunit in the frontal cortex in Parkinson's disease patients.

Cognitive impairment in Parkinson's disease is accompanied by a marked decrease of cerebrocortical nicotinic receptors. To study the putative site of impaired receptor synthesis, frontal cortices of Parkinson patients with cognitive dysfunction have been screened for the expression of the nicotinic receptor alpha 4 subunit gene. Quantitative assessment of alpha 4 mRNA-expressing neurons did not show significant differences between patients and controls. Therefore, decreased nicotinic receptor sites cannot be attributed to alterations at the transcriptional level of the alpha 4 gene. Alternative causes have to be searched for at the translational and/or postranslational level.

'Lewy body disease': clinico-pathological correlations in 18 consecutive cases of Parkinson's disease with and without dementia.

One of the characteristic histological features of Parkinson's disease (PD), with or without dementia, is the presence of Lewy bodies (LBs) in the brainstem and neocortical and limbic structures. They are often accompanied by Alzheimer type pathology (ATP). In the present retrospective study the clinical features and post-mortem findings of 18 consecutive and unselected PD patients were compared, with special reference to the frequent but not exclusive association of LBs with ATP in Lewy body disease (LBD). LBD is the term applied to a particular pattern of neuronal degeneration associated with LBs. In this study of idiopathic PD patients ATP seems to be the major determinant of the cognitive decline in most patients. Cortical Lewy Bodies (CLBs) were present in all patients reviewed, whether or not dementia was present. It was not possible to distinguish a specific pattern in the cognitive or psychopathological symptoms of dementia that would differentiate LBD from Alzheimer's disease (AD). Although in most cases hippocampal CA2-3 ubiquitin immunoreactive neurites were observed, here again there was no correlation with the presence of dementia.

Nigral and extranigral pathology in Parkinson's disease.

This article reviews data on the internal organization, neuronal types, and interconnections of limbic and motor components of the human brain, and the specific lesions which a few of them undergo during the course of Parkinson's disease (neuronal loss associated with the development of Lewy bodies and Lewy neurites). The severe involvement of nigral neuromelanin-laden projection cells has received particular attention during the past decades. This lesion interferes with normal function of the striatum and probably contributes to many of the motor dysfunctions characteristically occurring in Parkinson's disease. The similarly severe involvement of several areas and nuclei outside of the substantia nigra has often escaped notice. However, the pathology of Parkinson's disease cannot be completely described unless changes in these extranigral areas are taken into account. Interpretation of the characteristic lesional pattern is facilitated by combining schemata of both the limbic and motor systems. This approach reveals a key role by the amygdala and related structures in extranigral pathology. Severe lesions occur in the central amygdaloid nucleus, in nuclei projecting to the cerebral cortex in a non-specific manner, and in nuclei regulating endocrine and autonomic functions. It is suggested that extranigral lesions contribute to the development of behavioral changes and autonomic dysfunction.

Clozapine in the treatment of tremor in Parkinson's disease.

Tremor at rest is a classic symptom of Parkinson's disease that causes significant disability and distress for the patient and is generally only weakly responsive to conventional treatment, like anticholinergic and dopaminergic medication. This study describes the treatment with Clozapine in patients with Parkinson's disease, who despite optimal antiparkinson medical therapy still have a major disabling tremor at rest. Clozapine is an "atypical" neuroleptic agent, producing fewer extra pyramidal side effects common to conventional antipsychotic drugs. Clozapine, however, has as its most serious complication agranulocytosis, and hence all patients taking Clozapine must undergo blood tests at least several times a month. Under these frequent blood monitoring conditions, in this study Clozapine produced a substantial alleviation of parkinsonian tremor in 17 of 23 patients (73%). The beneficial response was reached with a relative low dose of Clozapine (18 mg./day), while previous antiparkinson medication was kept unchanged. The improvement of tremor at rest was noticeable generally within 2 weeks of beginning Clozapine therapy. No tolerance to the antitremor efficacy of Clozapine was seen during study-period of at least 6 months. Leucopenia developed in one patient, other major adverse events were hypersalivation and day-time drowsiness. These findings confirm the substantial antitremor efficacy of Clozapine in Parkinson's disease.

Pharmacokinetics of apomorphine in Parkinson's disease: plasma and cerebrospinal fluid levels in relation to motor responses.

In this study, we measured the relationship between plasma and cerebrospinal fluid (CSF) apomorphine levels and their clinical effects in two patients with Parkinson's disease (PD). After subcutaneous injection of apomorphine, serial samples of plasma and lumbal CSF were taken and serial scoring of motor responses was done using the Webster Rating Scale. The ratio of the highest level of apomorphine in CSF and plasma was 0.036 for patient A and 0.025 for patient B. The time lag between the highest level of apomorphine in plasma and CSF was 20 min for patient A and 10 min for patient B. Plasma levels of apomorphine correlated weakly with clinical motor responses. However, we could establish a highly strong correlation between apomorphine CSF levels and clinical motor responses: 0.93 and 0.89 for patients A and B, respectively. We conclude that a two-compartment pharmacokinetic model explains the clinical effects of apomorphine better than does a one-compartment model. In a two-compartment model, clinical effect can clearly be correlated to apomorphine levels in the central compartment.

Amygdala pathology in Parkinson's disease.

The amygdala undergoes severe pathological changes during the course of Parkinson's disease (PD). Lewy bodies and Lewy neurites are distributed in a specific manner throughout the nuclear complex. The lesional pattern displays only minor interindividual variation. The most prominent changes occur in the accessory cortical and central nuclei. The cortical, accessory basal and granular nuclei show less severe alterations, while the basal and lateral nuclei, as well as the intercalated cell masses, generally remain uninvolved. The amygdala receives a broad range of afferents, allowing integration of exteroceptive information with interoceptive data. It generates major projections to the isocortex (the prefrontal cortex in particular), limbic system (hippocampus and entorhinal region) and centers regulating endocrine and autonomic functions. The specific lesional pattern seen in PD destroys part of the nuclear gray matter and its connections and, thus, may likely contribute to the development of behavioral changes and autonomic dysfunctions.