Dementia has been increasingly more recognized to be a common feature in patients with Parkinson's disease (PD), especially in old age. Specific criteria for the clinical diagnosis of dementia associated with PD (PD-D), however, have been lacking. A Task Force, organized by the Movement Disorder Study, was charged with the development of clinical diagnostic criteria for PD-D. The Task Force members were assigned to sub-committees and performed a systematic review of the literature, based on pre-defined selection criteria, in order to identify the epidemiological, clinical, auxillary, and pathological features of PD-D. Clinical diagnostic criteria were then developed based on these findings and group consensus. The incidence of dementia in PD is increased up to six times, point-prevelance is close to 30%, older age and akinetic-rigid form are associated with higher risk. PD-D is characterized by impairment in attention, memory, executive and visuo-spatial functions, behavioral symptoms such as affective changes, hallucinations, and apathy are frequent. There are no specific ancillary investigations for the diagnosis; the main pathological correlate is Lewy body-type degeneration in cerebral cortex and limbic structures. Based on the characteristic features associated with this condition, clinical diagnostic criteria for probable and possible PD-D are proposed.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/mds.21507

Clinical diagnostic criteria for dementia associated with Parkinson's disease.

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(13)60688-1.pdf

Delirium in elderly people

The incidence of epilepsy and of all unprovoked seizures was determined for residents of Rochester, Minnesota U.S.A. from 1935 through 1984. Age-adjusted incidence of epilepsy was 44 per 100,000 person-years. Incidence in males was significantly higher than in females and was high in the first year of life but highest in persons aged > or = 75 years. Sixty percent of new cases had epilepsy manifested by partial seizures, and two thirds had no clearly identified antecedent. Cerebrovascular disease was the most commonly identified antecedent, accounting for 11% of cases. Neurologic deficits from birth, mental retardation and/or cerebral palsy, observed in 8% of cases, was the next most frequently identified preexisting condition. The cumulative incidence of epilepsy through age 74 years was 3.1%. The age-adjusted incidence of all unprovoked seizures was 61 per 100,000 person-years. Age- and gender-specific incidence trends were similar to those of epilepsy, but a higher proportion of cases was of unknown etiology and was characterized by generalized onset seizures. The cumulative incidence of all unprovoked seizures was 4.1% through age 74 years. With time, the incidence of epilepsy and of unprovoked seizures decreased in children and increased in the elderly.

Incidence of Epilepsy and Unprovoked Seizures in Rochester, Minnesota: 1935–1984

https://tud.qucosa.de/api/qucosa%3A26871/attachment/ATT-0/

Cost of disorders of the brain in Europe 2010

The organization and possible functions of basal forebrain and pontine cholinergic systems are reviewed. Whereas the basal forebrain cholinergic neuronal projections likely subserve a common electrophysiological function, e.g. to boost signal-to-noise ratios in cortical target areas, this function has different effects on psychological processes dependent upon the neural network operations within these various cortical domains. Evidence is presented that (a) the nucleus basalis-neocortical cholinergic system contributes greatly to visual attentional function, but not to mnemonic processes per se; (b) the septohippocampal projection is involved in the modulation of short-term spatial (working) memory processes, perhaps by prolonging the neural representation of external stimuli within the hippocampus; and (c) the diagonal band-cingulate cortex cholinergic projection impacts on the ability to utilize response rules through conditional discrimination. We also suggest that nucleus basalis-amygdala cholinergic projections have a role in the retention of affective conditioning while brainstem cholinergic projections to the thalamus and midbrain dopamine neurons affect basic arousal processes (e.g. sleep-wake cycle) and behavioral activation, respectively. The possibilities and limitations of therapeutic interventions with procholinergic drugs in patients with Alzheimer's disease and other neurodegenerative disorders in which basal forebrain cholinergic neurons degenerate are also discussed.

Central cholinergic systems and cognition

Changes in the cholinergic, serotonergic, noradrenergic, dopaminergic, GABAergic and somatostatinergic neurons were investigated to determine their roles in Alzheimer's disease (AD). Markers for these systems were analyzed in postmortem brain samples from 20 patients with AD and 14 controls. In the CSF study, markers for the cholinergic neurons (choline esterase, ChE) and for the somatostatinergic neurons (somatostatin-like immunoreactivity, SLI) were assayed for 93 and 75 probable AD patients and 29 and 19 controls, respectively. Activity of choline acetyltransferase (CAT) was decreased by 50-85% in four cortical areas and hippocampus in patients with AD, but not in other areas of the brain, indicating a profound deficit in the function of cholinergic projections ascending from the nucleus basalis to the cerebral cortex and hippocampus in AD. Muscarinic receptor binding was reduced by 18% in the frontal cortex but not in other areas of the brain in AD. Serotonin (5HT) concentrations were reduced (by 21-37%) in hippocampal cortex, hippocampus and striatum; and 5HT metabolite levels were lowered (by 39-54%) in three cortical areas, thalamus and putamen in AD patients. Concentrations of noradrenaline (NA) were reduced (18-36%) in frontal and temporal cortex and putamen. These data imply that serotonergic and noradrenergic projections are also affected in AD but less than the cholinergic neurons. Dopamine (DA) concentrations in AD patients were reduced by 18-27% in temporal and hippocampal cortex and hippocampus, while HVA, the metabolite of DA, was unaltered. Glutamic acid decarboxylase activity was not altered in AD. SLI was decreased (28-42%) in frontal, temporal and parietal cortex, but not in thalamus and putamen in patients with AD. Frontal tangle scores correlated most strongly with cortical CAT activity reduction and less so with decreases of 5HT, NA and DA, indicating a closer correlation with the cholinergic changes and severity of AD than with other neurotransmitter deficiencies. ChE activity and SLI were reduced by 20% and 35%, respectively, in CSF of the whole group of AD patients as compared to the controls. Comparison of CSF findings between four subgroups of dementia severity indicated that the SLI was already reduced in the group of mildest AD (-31%), while ChE activity was not. Although ChE activity in CSF declined in relation to dementia severity, however, the maximal reduction was only modest (-30%). On the other hand, SLI in CSF showed only a slight further reduction (up to -41%) as the dementia become more severe.(ABSTRACT TRUNCATED AT 400 WORDS)

Neurotransmitter changes in Alzheimer's disease: implications to diagnostics and therapy.

EEG findings in 62 patients with senile dementia of alzheimer type (SDA), 22 patients with multi-infarct dementia (MID) and 90 controls of same age and sex were studied. The SDA patients differed significantly from the controls in EEG normality, over-all disturbance, dominant occipital, rhythm, accentuation of theta and delta, fluctuations in alertness, paroxysmal activity and H-reaction. Even the least severely affected SDA patients differed significantly from the controls in all EEG variables except paroxysmal activity. With increasing degree intellectual impairment in the SDA group the dominant occipital rhythm became slower. The MID group differed from the controls in all EEG parameters including asymmetric findings. The EEG findings of the SDA patients differed significantly from those of the MID patients only in asymmetric findings which were more common in the MID patients. 29% of the normal elderly people had EEG alterations, Abnormalities were mild. Asymmetric findings, mainly theta activity in left temporal region were common. H-reaction (occipital driving response greater than or equal to 18 c/s) was well preserved in the controls. EEG is valuable in differentiation of dementia patients from normal elderly people, but differentiation between MID and SDA is not reliable by using EEG, only.

EEG findings in senile dementia and normal aging

Longitudinal EEG spectral analysis in early stage of Alzheimer's disease

In Finland, only limited data exist on the epidemiology of epilepsy in adults. This prompted us to study the incidence and prevalence of epilepsy in a population over 15 years of age, residing in Eastern Finland. In a retrospective study, various medical data sources were used to identify and reexamine all patients with established or suspected epileptic seizures during 1960-1979. A total of 1,233 patients with active epilepsy were identified. Mean annual incidence of epilepsy was 24/100,000. Age-specific incidence ratios tended to increase with advancing age. Prevalence of active epilepsy was 629/100,000. Both prevalence and incidence were higher in males than in females. Age-specific prevalence of active epilepsy increased until 40-50 years of age, and declined in the oldest age groups. Of the various seizure types, highest prevalence ratios were observed for partial secondarily generalized seizures, complex partial seizures, and tonic-clonic seizures. Prevalence of partial seizures and generalized seizures had a different age-related pattern.

Paavo Riekkinen

Papers

Neurotransmitter changes in Alzheimer's disease: implications to diagnostics and therapy.

EEG findings in senile dementia and normal aging

Longitudinal EEG spectral analysis in early stage of Alzheimer's disease

Incidence and Prevalence of Epilepsy in Adults in Eastern Finland

Dopaminergic system and monoamine oxidase-B activity in Alzheimer's disease.