Chronic benign pain

Chronic benign pain (CBP) can be defined as a type of unpleasant sensory experience that arises from inflammation, visceral stress or damage, or other such pathophysiologic process(es), and that is not associated with a metastatic process. A patient's complaint of pain should be taken seriously by the practitioner, both in terms of the discomfort evoked and the likelihood that the potential cause of the pain requires diagnostic evaluation. This article reviews the diagnosis and treatment of the following common conditions associated with CBP syndromes: fibromyalgia, lower back pain syndrome, sickle-cell disease, reflex sympathetic dystrophy syndrome, and peripheral neuropathies.     

Cerebrospinal fluid findings in chronic cerebral-organic psychiatric axis syndrome

Retrospective examinations of liquors from 136 children with a chronic brain-organic psychic axis syndrome following brain damage during infancy yielded pathological findings in 75.7% of the cases. These included changes in total protein content, slight increases in cell counts and the occurrence of monocytic forms of stimulus, but rarely changes in the pattern produced by electrophoresis of the liquor. Combinations of these pathological findings are rare, so that it is not possible to elaborate a typical liquor syndrome for this group of patients.     

An investigation of repetition and language processing in a case of conduction aphasia

A study is reported of a single case of conduction aphasia. A battery of tasks designed to investigate the parameters of the patient's severe repetition deficit is supplemented by tests of several language functions. The results provide extensive information on a wide range of the patient's language abilities and are used to evaluate the adequacy of four models that have been offered to account for conduction aphasia. An argument is made in support of the suggestion that the syndrome of conduction aphasia should be divided into two subgroups based on patients' ability to select and realize phonemes in speech output. It is concluded that the best explanation for the disorder of patients with repetition deficit but without significant speech output problems is the hypothesis that repetition ability is compromised by a pathological limitation of auditory-verbal short-term memory. This hypothesis is extended to account for the pattern of results obtained in the language tasks.     

Effects of caffeine on the trigeminal blink reflex

The acoustic startle and trigeminal blink reflexes share the same motor output. Since caffeine has been shown to augment the startle reflex, it was proposed that caffeine would also increase the trigeminal blink reflex. In 6 humans, the effects of caffeine (100 mg) on the trigeminal blink reflex were investigated. Reflex blinks were elicited by stimulation of the supraorbital branch of the trigeminal nerve. Following ingestion of caffeinated coffee, reflex blinks increased in amplitude and duration and occurred at a shorter latency than reflex blinks following ingestion of decaffeinated coffee. Since the blink reflex is a brainstem reflex, these results suggest that the psychomotor effects of caffeine facilitate brainstem processing.     

Measurement of muscle reflex time in radicular disorders of the lumbosacral region]

The results of studies performed by the authors show that time measurements of proprioceptive muscular reflexes (triceps surae and tibialis posterior reflexes) may be considered a valuable addition to methods of topical diagnosis of radicular disturbances in the lumbosacral region. The reflexes were tested in twenty normal subjects. There were found an intraindividual constancy of the respective reflex time with a maximum deviation of 2 ms as well as a lateral variability up to 1.3 ms. Radicular compressions resulted in an increase in reflex time by 2 to 66 ms or failure of the reflex potential to be recorded. The pathological cases were compared with clinical and neurological studies, positive myelographies using radiopaque substances, and results of surgical operations. Compared with the results of surgical operations, changes in reflex time indicated damage to the reflex arc in ninety percent of the cases.     

Crib death: a biobehavioral phenomenon?

In developed countries, more children under 1 year of age die of crib death (sudden infant death syndrome, SIDS) than of all other causes combined. Researchers and clinicians have proposed many possible causes of SIDS, but the abrupt, unexpected death of some babies remains mysterious and frightening. Although infant behavior may explain some of these deaths, scant attention has addressed behavioral characteristics of babies who die without medical explanation. Any explanation of SIDS must account for the fact that most SIDS deaths occur at 2 to 5 months of age, acknowledging that a protective mechanism appears to spare babies before 2 months but then disappears. The respiratory occlusion reflex serves as an initial defense against smothering and can provide such an explanation. Infantile reflexes wane, after providing opportunities for learned responses to be acquired. During this well-documented neurobehavioral transition from subcortical to cortically mediated responding, some babies, viable for the first 2 months, may become especially vulnerable if they fail to acquire sufficiently strong defensive behaviors needed to prevent occlusion after the waning of the life-preserving reflex. Recent success of back-to-sleep directives, urging that babies sleep on their backs to avoid smothering, supports this hypothesis.     

The Interrater Reliability of Subjective Assessments of the Babinski Reflex

The Babinski reflex is a clinical diagnostic tool; however, the interrater reliability of this tool is currently greatly contested. A comparison between rater groups with objective measurements of the Babinski reflex was therefore conducted. Fifteen recorded Babinski reflexes were assessed by 12 neurologists and 12 medical students as being either pathological or nonpathological. Kinematic and electromyographic variables were collected and used to assess which aspects of the Babinski reflex predict classification. Substantial interrater agreement within the neurologist and student groups (κ = .72 and .67, respectively) was shown; however, there were some differing aspects between what neurologists and students used to assess the reflex as determined by objective kinematic measurements.     

The functional role of consciousness: A phenomenological approach

In this paper, a theoretical account of the functional role of consciousness in the cognitive system of normal subjects is developed. The account is based upon an approach to consciousness that is drawn from the phenomenological tradition. On this approach, consciousness is essentially peripheral self-awareness, in a sense to be duly explained. It will be argued that the functional role of consciousness, so construed, is to provide the subject with just enough information about her ongoing experience to make it possible for her to easily obtain as much information as she may need. The argument for this account of consciousness' functional role will proceed in three main stages. First, the phenomenological approach to consciousness as peripheral self-awareness will be expounded and endorsed. Second, an account of the functional role of peripheral perceptual awareness will be offered. Finally, the account of the functional role of peripheral self-awareness will be obtained by straightforward extension from the functional role of peripheral perceptual awareness. This revised version was published online in June 2006 with corrections to the Cover Date.     

On the Conceptual Foundations of Anti-Realism

The central premise of Michael Dummett's global argument for anti-realism is the thesis that a speaker's grasp of the meaning of a declarative, indexical-free sentence must be manifested in her uses of that sentence. This enigmatic thesis has been the subject of a great deal of discussion, and something of a consensus has emerged about its content and justification. The received view is that the manifestation thesis expresses a behaviorist and reductive theory of meaning, essentially in agreement with Quine's view of language, and motivated by worries about the epistemology of communication. In the present paper I begin by arguing that this standard interpretation of the manifestation thesis is neither particularly faithful to Dummett's writings nor philosophically compelling. I then continue by reconstructing, from Dummett's texts, an account of the manifestation thesis, and of its justification, that differ sharply from the received view. On my reading, the thesis is motivated not epistemologically, but conceptually. I argue that connections among our conceptions of meaning, assertion, and justification lead to a conclusion about the metaphysics of meaning: we cannot form a clearly coherent conception of how two speakers can attach different meanings to a sentence without at the same time differing in what they count as justifying assertions made with that sentence. I conclude with some suggestions about how Dummett's argument for global anti-realism should be understood, given my account of the manifestation thesis. This revised version was published online in August 2006 with corrections to the Cover Date.     

Neuroleptic malignant syndrome--3 case reports

An account is given of three patients who exhibited a malignant neuroleptic syndrome after the administration of neuroplegics. Like other authors, we identified typical elicitation factors and clinical characteristics. In one case a catatonic dilemma with lethal issue was observed. In the final case dealt with in this paper, the renewed application of neuroplegics following the termination of the malignant neuroleptic syndrome was tolerated without complications, whereas in the case of an epileptic patient with damage to the brain, the malignant neuroleptic syndrome returned upon dosage increase.     

Brain mechanisms in fatal cardiac arrhythmia.

Intravenous injection of histamine to rabbits was used as a prototype in an investigation of the mechanism of sudden death due to anaphylaxis and other causes. The "dive" reflex, bradycardia due to activation of the ophthalmic branch of the fifth cranial nerve, was induced in thirty-seven of the animals while they inhaled a very small amount of cigarette smoke. Associated with the resulting bradycardia were lowered blood pH and increased serum content of lactic acid and potassium and increased peripheral arterial constriction with elevation of diastolic blood pressure. Intravenous injection of 1 ml of histamine in the presence of the dive reflex induced potentially fatal ventricular arrhythmia, but no cardiac disturbance when administered while the dive reflex was inactive, thereby strongly suggesting that sudden death in anaphylaxis may involve an overzealous response to a normally protective neural reflex.     

An equilibrium-point model for fast, single-joint movement: II. Similarity of single-joint isometric and isotonic descending commands

The model for isotonic movements introduced in the preceding article in this issue is used to account for isometric contractions. Isotonic movements and isometric contractions are analyzed as consequences of one motor program acting under different peripheral conditions. Differences in isotonic and isometric EMG patterns are analyzed theoretically. Computer simulation of the EMG patterns was performed both with and without the inclusion of possible effects of reciprocal inhibition. A series of experiments was performed to test the model. The subjects made fast isotonic movements that were unexpectedly blocked at the very beginning in some of the trials. The observed differences in the EMG patterns between blocked and unblocked trials corresponded to the model's predictions. The results suggest that these differences are due to the action of a tonic stretch reflex rather than to preprogrammed reactions. The experimental and simulation findings, and also the data from the literature, are discussed in the framework of the model and the dual-strategy hypothesis. They support the hypothesis that the motor control system uses one of a few standardized subprograms, specifying a small number of parameters to match a specific task.     

The Charles Bonnet syndrome: 'phantom visual images'.

The Charles Bonnet syndrome is a condition in which individuals experience complex visual hallucinations without demonstrable psychopathology or disturbance of normal consciousness. An analysis of the sixty-four cases described in the literature reveals that the syndrome can occur at any age though it is more common in elderly people. Reduction in vision, due to peripheral eye pathology as well as pathology within the brain, is associated with the syndrome. Individual hallucinatory episodes can last from a few seconds to most of the day. Episodes can occur for periods of time ranging from days to years, with the hallucinations changing both in frequency and in complexity during this time. The hallucinations may be triggered or stopped by a number of factors which may exert their effect through a general arousal mechanism. People, animals, buildings, and scenery are reported most often. These images may appear static, moving in the visual field, or animated. Emotional reaction to the hallucinations may be positive or negative. Several theories have been proposed to account for the hallucinations. This paper highlights the sensory deprivation framework, with particular emphasis on the activity in the visual system after sensory loss that produces patterns of nerve impulses that, in turn, give rise to visual experience.     

Brain mechanisms in fatal cardiac arrhythmia

Intravenous injection of histamine to rabbits was used as a prototype in an investigation of the mechanism of sudden death due to anaphylaxis and other causes. The “dive” reflex, bradycardia due to activation of the ophthalmic branch of the fifth cranial nerve, was induced in thirty-seven of the animals while they inhaled a very small amount of cigarette smoke. Associated with the resulting bradycadia were lowered blood pH and increased serum content of lactic acid and potassium and increased peripheral arterial constriction with elevation of diastolic blood pressure. Intravenous injection of 1 ml of histamine in the presence of the dive reflex induced potentially fatal ventricular arrhythmia, but no cardiac disturbance when administered while the dive reflex was inactive, thereby strongly suggesting that sudden death in anaphylaxis may involve an overzealous response to a normally protective neural reflex.     

The smoke reflex in rabbits an example of autonomic control of cardiorespiratory function

This study was undertaken to elucidate aspects of autonomic behavior as reflected in the “smoke reflex” in rabbits. Allowing smoke to envelop the nostrils of a rabbit resulted in prompt apnea, bradycardia, diminution of peripheral pulse and elevation of systemic blood pressure. Atropine and vagotomy, or both, mitigated the bradycardia, but the combined effect of propranolol and vagotomy was required to abolish bradycardia. Phenoxybenzamine (dibenzyline) alone blocked only the peripheral vasoconstriction and pressor response. The combination of vagotomy, propranolol and phenoxybenzamine blocked all manifestations of the reflex with the exception of apnea. A classical concept holds that responses of the autonomie nervous system must be either distinctly adrenergic (sympathetic) or cholinergic (parasympathetic), and that visceral regulation is achieved by an antagonism between the two. This study introduces contrary evidence and demonstrates that in certain adaptive behavior there is a patterned response that includes activation of discrete elements of both cholinergic and adrenergic divisions, as well as inhibition of one component of the latter.     

‘Faultless’ ignorance: Strengths and limitations of epistemic definitions of confabulation

There is no satisfactory account for the general phenomenon of confabulation, for the following reasons: (1) confabulation occurs in a number of pathological and non-pathological conditions; (2) impairments giving rise to confabulation are likely to have different neural bases; and (3) there is no unique theory explaining the aetiology of confabulations. An epistemic approach to defining confabulation could solve all of these issues, by focusing on the surface features of the phenomenon. However, existing epistemic accounts are unable to offer sufficient conditions for confabulation and tend to emphasise only its epistemic disadvantages. In this paper, we argue that a satisfactory epistemic account of confabulation should also acknowledge those features which are (potentially) epistemically advantageous. For example, confabulation may allow subjects to exercise some control over their own cognitive life which is instrumental to the construction or preservation of their sense of self.     

Impaired shifting of attention in Balint's syndrome

We assessed the efficiency of attentional shifts across the horizontal and vertical axes of the visual field in a patient with Balint's syndrome caused by bilateral parieto-occipital infarctions. This was performed using an adaptation of Posner's peripheral cueing paradigm. In contrast to normal controls and patients with unilateral parietal lesions previously reported, this patient did not benefit from cues directing attention to the left or right visual field. She appeared to benefit only when the cues directed attention to the upper visual field. This suggests a defect in shifting attention that may occur following bilateral parietal lesions. We discuss the implications of these findings for the role of the parietal lobes in attentional processes and for our understanding of the behavioral abnormalities observed in Balint's syndrome.     

Electrophysiologic studies of patients with neural muscular atrophy

Various nerve conduction velocities, the terminal latency (TL) of facial nerve, the trigeminofacial reflex and fast auditory evoked potentials (FAEP) were investigated in 26 patients with peroneal muscular atrophy (22 with HMSN I and 4 with HMSN II). With the brain nerve status revealing no clinical abnormalities, 85.7% of HMSN I patients showed a longer-than-normal TL of the facial nerve, 66.6% had a prolonged early reflex component of trigeminofacial reflex and 22.7% pathological FAEPs. Normal neurophysiologic findings were obtained for brain nerves of HMSN II subjects. Subclinical involvement of the mid-group of brain nerves did not at all correlate with the impairment of extremity nerves and the duration of the disease. The present results reflect the heterogeneity of HMSN.     

The effect upon monaural sensitivity of continuous stimulation of the opposite ear

The threshold to a 1,000 c./sec. tone presented to the left ear was measured whilst the right ear was under continuous stimulation by a 400 c./sec. tone. Observations were made, on different groups of subjects, under three stimulus conditions and two conditions of attention. Thresholds were found to increase with increasing intensities of the continuous tone. Attention to that part of the field associated with the continuous stimulus produced no significant change, whether the continuous stimulus was present or not. There were no significant after-effects during ten minutes following the end of the continuous stimulus, though the results suggested a slow decrease in threshold.

Several explanations of the phenomenon are considered. Cross-hearing and the reflex contraction of the middle-ear muscles can be virtually excluded. Central inhibition or the central control of sensory end-organs can account for the results. A statistical hypothesis is also tenable.