Search PubMedSearch

PubMed · 2688608

[Persistent alpha-vegetative state].

Abstract

After briefly reviewing the concepts of "coma" and "alpha-coma", we report the case of a patient with presumable Pick's disease who spent several weeks in a vegetative state with a normal and reactive EEG in the alpha range in the later stages of her illness. We (a) emphasize some implications of the appearance of the eyes in such patients, b) stress the importance of distinguishing alpha activity from true alpha rhythm and (c) suggest the category "alpha-coma" should include only those individuals bearing evidence of disorders of the junctional tegmentum of the pons and midbrain. In a complementary way, we propose that patients in a persistent vegetative state displaying normal EEG should be separately classified as persistent "alpha-vegetative state".

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R Oliveira-Souza, D L Gusmão, W M Figueiredo, J R López, J S Mello, S A Ribeiro, H Alvarenga. 1989. [Persistent alpha-vegetative state].. https://doi.org/10.1590/s0004-282x1989000200014

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Anxiogenic effects of caffeine in patients with anxiety disorders.

The effects on measures of anxiety from two doses of oral caffeine (250 and 500 mg) and placebo were compared in 12 patients with generalized anxiety disorder (GAD), 12 patients with panic disorder, and 12 normal subjects. Caffeine produced significantly less decrease in electroencephalographic alpha wave activity, greater decrease in N1-P2 auditory evoked potential amplitude, and greater increased in skin conductance level, systolic and diastolic blood pressure, critical fusion flicker frequency, and self-ratings of anxiety and sweating in patients with GAD than in normal patients. Patients with panic disorder showed different reactivity than normal patients did with respect to electroencephalographic alpha waves, N2 latency, N2-P2 auditory evoked potential amplitude, and physical tiredness but were less reactive than patients with GAD on several variables. It is concluded that patients with GAD are abnormally sensitive to caffeine and that the data support the view that panic disorder is a separable disorder from GAD.

Alpha Rhythm

A 10 Hz "alpha-like" rhythm in the visual cortex of the waking cat.

Rhythms at about 10 Hz were recorded from the primary visual cortex of the cat (anterior part of area 18), with characteristics close to those of the alpha rhythm in man: frequency band (7-14 Hz), localization and reactivity to visual stimulation. Coherence analysis of this activity with the "mu" rhythms on the somatosensory cortex showed that although both types develop in the same overall behavioural situations (quiet waking and/or expectancy of an event to occur), they are independent.

Alpha Rhythm

Alpha rhythm and the pineal gland.

Alpha rhythm is classically described as a bilateral posterior rhythm of substantially constant frequency in the range of 8-13 Hz which is enhanced by mental relaxation and blocked by attention. Since the full expression of alpha rhythm has been shown to occur coincident with puberty, it is possible that the establishment of alpha rhythm is subject to neuroendocrine influences which govern psychosexual maturation. There is ample evidence to indicate that the pineal gland is implicated in cerebral maturation and psychosexual development. Nocturnal plasma melatonin levels have been shown to decline progressively throughout childhood reaching a nadir at puberty. Since administration of melatonin has been reported to block alpha rhythm, it is proposed that the progressive decline in melatonin secretion during childhood facilitates the maturation of the alpha rhythm. Consequently, the presence of alpha rhythm could be used as a neurophysiological marker for the activity of the pineal gland and disorders associated with absent or delayed maturation of the alpha rhythm such as autism, dyslexia, personality disorders, epilepsy, Tourette's syndrome, and schizophrenia might be related to disturbances of pineal melatonin functions in early life. Moreover, since the EEG patterns associated with cerebral immaturity (i.e., slowing, absence of alpha activity) are more pronounced in the left hemisphere, this hypothesis implies differential influence of the pineal gland on hemispheric maturation potentially accounting for the vulnerability of the left hemisphere to cerebral insults.

Alpha Rhythm