Perception of different frequencies of cranial transcutaneous electrical nerve stimulation in normal and HIV-positive individuals.

Sine-wave transcutaneous electrical nerve stimulation (TENS) of varying frequencies applied across the cranium (ear to ear) has been demonstrated to evoke three different noncutaneous sensations in three discrete, nonoverlapping frequency bands in normal, healthy subjects. This report describes two studies which evaluate perception of these cranial TENS-evoked, frequency-dependent sensations in normal and HIV-positive individuals. In Exp. I, all of 50 normal, healthy subjects reported perceiving the same three noncutaneous sensations in the same three nonoverlapping frequency bands as long as stimulated and over repeated trials. In Exp. II, 34 HIV-positive individuals (14 asymptomatic, 9 ARC, 11 AIDS) who were free of neurological symptoms differed significantly from 10 normal, healthy controls, and from the norms observed in Exp. I, on perception of the three different TENS-evoked sensations. Also, inability to maintain perception of the stimulus over repeated trials, observed only in the HIV-positive individuals, increased significantly with severity of HIV infection.     

Family therapy approach to incapacitating migraine

A nine-year-old boy who suffered from intractable migraine was referred for psychiatric consultation and treatment after failing to respond to congeries of medications and diets, notwithstanding thorough investigations by neurologists, pediatricians, and other specialists. The decision for a family systems treatment approach resulted in the following defined objectives: (1) to investigate triggers for the headaches and to see if these could be reduced and/or eliminated, (2) to see if therapy would help the boy stay in school, (3) to examine, and if possible, change family rules of interaction and transaction, (4) to allow for more fun within the family (5) to allow for ventilation without retribution, and (6) to clarify the mother's role as a significant contributor to the family's interactions, shifting the focus from the father as the sole generator of family tension. The principal therapeutic tools which proved efficacious involved the following: (1) scrutiny of the maternal and paternal histories, and (2) analysis of triangulations within the family system, leading to (3) the formulation of therapeutic strategies, and (4) specific task assignments. A major intervention by the therapist was the specific strategy to have the family examine the rules of transaction which were in the metapsychological sense unarticulated.     

Hypothetical aspects of the preventive effectiveness of controlled reflex and stimulation therapy (exemplified by acupuncture and PuTENS) in migraine

On the basis of lang term therapeutical and experimental experience with acupuncture and punctual transcutaneous electrical nervestimulation (PuTENS) and in connection with the present neurophysiologically knowledge the results of reflextherapy and stimulatory-therapy in migrain are discussed. The established analgetic, vascular, musclerelaxing and reflectory effects of acupuncture may in part explain a causative influence on migraine. Trigger mechanisms siderably reduced and the vegetative state are favourable influenced.     

Asystem for cutaneous electrical stimulation mimicking touch

An electrical system is described which produces pain-free touch sensations similar to those from mechanical stimulation. The apparatus is inexpensive, easily constructed, and can be used with human or animal Ss.     

Vagus nerve stimulation: a new form of therapeutic brain stimulation

Although the vagus nerve has traditionally been considered to perform efferent functions, in reality it performs significant afferent functions as well, carrying information from the body, head, and neck to the brain. Preliminary studies examining this afferent activity led to the theory that vagus nerve stimulation (VNS) could successfully control seizure activity in persons who are refractory to antiepileptic medications. Unlike other forms of brain stimulation, VNS is unable to directly stimulate multiple discrete areas of the brain; however, through several pathways, it is able to relay sensory information to higher brain regions. An implantable VNS device known as the VNSTM NeuroCybernetic Prosthesis (NCP) System has been used in approximately 9,000 epilepsy patients in Europe and the United States since 1994. The implant has reduced seizure frequency by an average of 25% to 30%, with minimal side effects. Studies underway are also showing some degree of success in the management of treatment-refractory depression. The future efficacy of the implantable system in other disorders may depend on whether the implant can be more precisely focused to affect different brain regions. Research in this area is underway.     

Vagus nerve stimulation therapy in a patient with treatment-resistant depression: a case report of long-term follow-up and battery end-of-service

This is the first case report of a patient who received long-term (69-month) adjunctive vagus nerve stimulation (VNS) therapy for treatment-resistant depression (TRD) and reached VNS battery end-of-service (EOS). The patient is a 41-year-old female with depression who entered a study of adjunctive VNS therapy for TRD. Her Hamilton Rating Scale for Depression (HAM-D) scores dropped from a mean of 33.5 (pre-implantation baseline period) to 16 at the end of the 12-week acute-phase treatment period, and then fluctuated from <7 (normal range) to scores in the moderately depressed range (approximately 20) during long-term follow-up. Three and one-half years after VNS implantation, the patient's HAM-D scores began to increase from a score of 18 to a peak score of 27 approximately 16 months later (5-years post-implantation). The patient subsequently reported that she could no longer feel stimulation from the device and device interrogation 2 weeks later indicated battery EOS. The patient was hospitalized due to worsened depression, the pulse generator was replaced, and medication adjusted. HAM-D scores through the subsequent 9 months of follow-up returned to a pattern of fluctuations within the range noted during the long-term follow-up period prior to VNS battery EOS.     

Detection by the guinea pig of acoustic stimulation and of electrical stimulation of the brain

A threshold procedure using operant behavioral techniques with positive reinforcement was developed after initial efforts with avoidance behavioral procedures proved unsatisfactory. In the first of three experiments the operant threshold procedure was tested by determining masked auditory thresholds for trains of clicks. In a second experiment, similar techniques were used to measure thresholds for electrical stimulation of the brain. The last experiment, again an auditory problem, involved a determination of the absolute thresholds for trains of short noise bursts as a function of the time between bursts. Middle ear malfunction proved to be a more severe problem than had been anticipated on the basis of reports in the literature. The threshold procedure, however, seems to be adequate for determination of absolute or masked thresholds with auditory or electrical stimuli.     

Memory deficits during electrical stimulation of the speech cortex in conscious man

Cerebral zones supporting language and recent memory were mapped by electrical stimulation during neurosurgical treatment of epileptic patients. Stimulation of sites within the left posterior temporo-parietal cortex produced transient dysphasia. Continued stimulation of this cortical region also produced a retrograde type of verbal memory disorder, indicating a failure in the mechanism responsible for retrieval of stored information. In contrast, stimulation of the anterior temporal neocortex did not produce anomia and, instead, resulted in an anterograde memory loss, apparently caused by a defect in the verbal storage mechanism. Comparable stimulation of homologous areas on the right hemisphere did not interfere with object naming or immediate verbal recall.     

Effect of stress induced by electrical stimulation of the hypothalamus on the electrical stability of the heart in rabbits

The influence of stress on cardiac electrical stability (CES) and chaotic dynamics of the electrical activity of the heart was studied in acute and chronic experiments in rabbits. Stress was caused by 2-3 h daily immobilization of the animals with electrical stimulation of emotiogenic centers of the hypothalamus through implanted electrodes. CES was estimated by the thresholds for ventricular arrhythmia: paroxysmal ventricular tachycardia, repeated ventricular extrasystoles and ventricular fibrillation (VF). The results showed: (i) CES in stressed rabbits was decreased significantly compared with controls; (ii) the level of chaos at the onset of VF in stressed rabbits was increased significantly compared with controls; (iii) heart rate of stressed rabbits was significantly greater than in controls; (iv) changes in CES parameters depended on whether stress was acute or chronic; (v) acute stress promoted transition of spontaneously reversible VF into spontaneously irreversible VF. Thus, stress increased the degree of disorganization of heart electrical activity and also decreased its electrical stability. The experiments indicate that stress is a destabilizing factor influencing the reversibility of heart rate disorders. The probability of such reversibility depends on whether stress is acute or chronic: acute stress is more likely to lead to irreversible spontaneous VF.