Consistency of clinical diagnosis of dementia in NEDICES: A population-based longitudinal study in Spain.

BACKGROUND: Few longitudinal studies have verified the clinical diagnosis of dementia based on clinical examinations. We evaluated the consistency of the clinical diagnosis of dementia over a period of 3 years of follow-up in a population-based, cohort study of older people in central Spain. METHODS: Individuals (N = 5278) were evaluated at baseline (1994-1995) and at follow-up (1997-1998). The evaluation included a screening questionnaire for dementia and a neurological assessment. RESULTS: Dementia screening consisted of a 37-item version of the Mini-Mental State Examination (MMSE) and the Pfeffer Functional Activities Questionnaire (FAQ). Study neurologists investigated those participants who screened positively (N = 713) as well as 843 who had screened negatively to test the sensitivity of the screening instruments or because they had a positive screening for other chronic neurological diseases. We detected 295 patients among those who screened positive and 13 among those who screened negatively. Three years follow-up evaluation demonstrated 14 diagnostic errors at baseline (4.5%) leading to a final number of 306 patients with dementia. The corrected prevalence of dementia was 5.8% (95% confidence interval [CI] 5.2-6.5). CONCLUSIONS: The diagnosis of dementia was highly accurate in this population-based, Spanish cohort study, and our prevalence figures agree with other European surveys. Given the high cost and difficulties of population rescreening and its relatively low yield, we conclude that a single 2-phase investigation (screening followed by clinical examination) provides accurate information for most population-based prevalence studies of dementia.

Who was Cajal?

After a brief introduction, a series of Cajal's own thoughts and recollections of his difficult childhood and adolescence are literally transcribed. They clearly represent the astonishing achievements of an equally astonishing child who was born in a tiny village of the Pyrenees mountains. Even today, visitors find it very difficult to understand how it was possible for a child to free himself from a medieval atmosphere and climb to the highest scientific level: to be awarded with the Nobel Prize in Medicine.

[Giving up life in the labyrinth]. / Dejar de vivir en el laberinto.

A brief historic survey of the labyrinth, from prehistoric images carved in stone, to gardens, Renaissance drawings and architectonic constructions will presented. The metaphor of the labyrinths, which began with Theseus killing the Minotaur with the help of Ariadne, can be applied to all: scientific investigation, artistic creation, wickedness, theology ... to life. In these eculiar and chaotic designs, structural simplicity and functional complexity coincide and therefore may produce repeated erroneous decisions. To wander successfully through these labyrinths, caution and repeated decision-makings are required to enable the traveller to reach the desired and elusive center. In each instant, decisions are made in our mind as a consequence of complex cerebral systems, activated by stimuli which originate in the intimate regions of the mind, the most complex labyrinth of all. These types of mental labyrinths are immaterial, without paths or walks, where each successive decision made facing multiple bifurcations, causes the mental traveller to advance until reaching the center. This center deceptively becomes the entrance to another of the innumerable and unknown mental labyrinths that the intimate life proposes.

[Decision making: biological bases and limitations]. / Toma de decisiones: bases y limitaciones biológicas.

In the human brain, simple molecules and complex circuits are constantly making decisions which are indispensable for our survival and also to accomplish a variety of daily activities such as walking, memorizing, conversing, composing music, painting or poetry.... All are the result of the integration of many neural systems that perceive many and simultaneous visual, tactile, auditory and/or mental stimuli. Once synthetized, they are immediately transmitted to the corresponding executive systems, thus completing the fascinating functional loop of decision-making: a) perception of stimuli or information which originate in the environment, b) selection and elaboration of the decision which is considered more appropriate or attractive according to personal experience or intuition and c) execution. If these neural nets have been damaged or haven failed to develop the mechanisms of facilitation or inhibition that govern them become unbalanced. If inhibition is reduced, excessive and violent behaviour is expressed as in patients suffering from manic phases. Conversely, if inhibition is excessive, decision making mechanisms are not operative. In either case, behaviour is not "reasonable" and does not follow prototypical patterns. All these processes must be the consequence of a constant molecular activity full of micro-decisions whose effectiveness depends on the histological and biochemical integrity of the neurons. This microenvironment is responsible for all types of decisions of all forms of life and represents one of the fundamental successes of evolution.

[They thought; therefore, they spoke]. / Pensaban luego hablaron.

All functions that characteristically define each form of life are the consequence of the unpredictable process of evolution. The appearance around 300,000 years ago of a complex system of language allowed the homo sapiens to verbally express his thoughts, feelings and experiences in a narrative manner. Thus began the great and continuous development of knowledge and the subsequent post-biological improvement of cognitive functions as a consequence of the stimulation of brain plasticity. This complex process vas not rapid. Important structural and functional craneofacial and pharyngo-laryngeal changes were necessary. Some were already present four million years ago in the australopitecus and became more efficient in homo erectus to reach the definite dimensions of modern humans 125,000 years ago in the homo sapiens-sapiens. From then on a continuous, productive and interactive relationship between the ability to think and the capacity to speak was established. New anonymous ideas invent their corresponding words which, in turn, create more complex sequential thoughts. The fundamental contribution of language in the development of human intelligence raises the question fo which of the two functions preceded the other or whether they both evolved simultaneously. Is it possible to assume that if the pharyngo-laryngeal structures ad not evolved at all, the brain would have invented another type of language?

Apolipoprotein E genotype in Spanish patients of Alzheimer's or Parkinson's disease.

Blood donors of the Madrid area show a 6% frequency of apolipoprotein E genotype carrying allele epsilon 4. This frequency is smaller than other populations of Caucasian origin. This proportion decreases to 4% in a selected sample of healthy individuals of ages > 60 years. The frequency (34%) of the allele epsilon 4 was significantly increased in patients of late onset Alzheimer's disease, similarly to other populations. An earlier age of onset of the dementia is observed in the patients of late-onset Alzheimer's disease carrying the allele epsilon 4. No increased frequency in allele epsilon 4 frequency was found in patients of early-onset Alzheimer's disease. Patients of Parkinson's disease do not show any differences in the frequency of the alleles of apolipoprotein E when compared with healthy individuals.

Acute headache of recent onset and subarachnoid hemorrhage: a prospective study.

Twenty-seven patients with acute severe headache of recent onset were prospectively recruited in the Emergency Room. Mean duration of headache was 61 hours. CT scan disclosed subarachnoid bleeding in 4 patients and spinal tap revealed subarachnoid hemorrhage (SAH) in 5 patients with normal CT scan. In most SAH cases pain was bilateral, very intense and involving the occipital region. Four of these patients had doubtful or no nuchal rigidity and in one, pain improved while in the Emergency Room. In every case with an intense acute severe headache of recent onset CT scan and (if normal) a lumbar puncture are warranted to help rule out a SAH.

[Metachromatic leukodystrophy: an exceptional cause of dementia in the adult]. / Leucodistrofia metacromática: una causa excepcional de demencia en el adulto.

Hereditary metabolic diseases are an exceptional cause of neurological disorders in adults. Metachromatic leukodystrophy is a hereditary alteration of the metabolism of myelin which may be manifested in adults as intellectual deterioration. A case of metachromatic leukodystrophy presented in adulthood is presented with cognitive deterioration and behavioral alterations as the only clinical manifestation. The patient was a 28 year old male studied for dementia of one year of evolution. Computerized tomography and cranial magnetic resonance demonstrated diffuse and symmetric involvement of the periventricular white matter. The visual evoked potentials were involved while the brain stem auditory potentials were normal. Study of the speed of nerve conductions was compatible with demyelinating neuropathy. The diagnosis of metachromatic leukodystrophy was confirmed by enzyme study revealing very diminished levels of aryl-sulfatase A. Although it is exceptional the adult form of metachromatic leukodystrophy should be included in the differential diagnosis of dementia. Computerized tomography and cranial magnetic resonance together with neurophysiologic studies are the principle procedures orienting diagnosis to this disease.

Prevalence of neurological diseases in Madrid, Spain.

A pilot study to demonstrate the feasibility of measuring prevalence and prevalence ratios of major neurological disorders was successfully carried out in an urban area of Madrid, Spain, in a population of 961 subjects. The most frequent disorders identified were migraine, epilepsy and peripheral neuropathy.

Psychological disturbances and folic acid in chronic epileptic outpatients.

The relationship between serum folate level and psychological disturbances was studied in a series of 95 chronic epileptic outpatients. All were nondrinkers. Serum folic acid in all cases and vitamin B12 in 83 cases were determined by radioimmunoassay. Only three factors were significantly related with psychological disturbances: serum levels of folic acid were significantly lower and the mean corpuscular volume of the erythrocytes was significantly higher in disturbed patients, particularly in those with the most severe psychiatric syndromes, and the incidence of disturbances was significantly higher in patients treated with three or more drugs. Conversely, variables such as number or type of seizures, duration of epilepsy, duration of treatment, presence of structural neurological lesions, previous mental retardation, or focal temporal lobe disturbances in the EEG did not show any statistical relationship to the presence of psychological disturbances. No relevant relationship was found between serum vitamin B12 and psychological disturbances.