Ventricular and dual chamber pacing for treatment of carotid sinus syndrome

Thirty-nine consecutive patients with recurrent syncope and either cardioinhibitory or mixed type carotid sinus syndrome were studied to determine the efficacy of ventricular (VVI) pacing in 16, and dual chamber (DDD/DVI) in 23 patients. Only those patients affected by the isolated vasodepressor form were excluded. Follow-up lasted 12 +/- 5 months. Symptoms were totally eliminated in 67% of patients and ameliorated with persistence of minor symptoms in 33%. All patients underwent an initial 2-month follow-up in the VVI mode. Evaluation of the 19 patients who remained symptomatic and the 20 who became asymptomatic with VVI pacing demonstrated that factors observed prior to pacemaker implant were related to failure of the VVI mode. These included symptomatic pacemaker effect (42% vs 0%), mixed carotid sinus syndrome (95% vs 65%), orthostatic hypotension (47% vs 15%), or ventriculoatrial conduction (68% vs 38%). In the 23 patients with dual chamber pacing, random 2 month comparisons were performed between VVI and DVI/DDD pacing. The dual chamber mode was preferred by 14 patients, none preferred the VVI mode and nine noted no difference. Comparison of the two groups found that the factors linked to DVI/DDD preference were symptomatic pacemaker effect (50% vs 0%), ventriculoatrial conduction (78% vs 44%), or orthostatic hypotension (50% vs 11%). VVI pacing is efficacious in a high proportion of patients affected by cardioinhibitory or mixed carotid sinus syndrome. The identification of causes of VVI pacing failure allows determination of those who will benefit from VVI pacing and those who should have DVI/DDD. VVI pacing is suggested for the cardioinhibitory type with no symptomatic pacemaker effect and for the mixed type with no symptomatic pacemaker effect or orthostatic hypotension or ventriculoatrial conduction. Dual chamber pacing should be used in all other instances.

The effect of early bladder stimulation on spinal shock: a preliminary report

The period of spinal shock which frequently follows spinal cord injury is associated with bladder areflexia and urinary retention. We studied the effect of early bladder electric stimulation on detrusor activity during the spinal shock phase in the dog. The animals had a spinal cord section at T10 vertebra and their bladder management was assigned to one of the three following groups: intermittent catheterization, indwelling catheterization and electric bladder stimulation. The parameters for evaluating each treatment included: blood chemistry, radiographic and urodynamic tests. The salient feature was the early return of detrusor activity in the group of animals treated by early electric stimulation of the bladder.

Assessment of VVI diagnostic pacing mode in patients with cardioinhibitory carotid sinus syndrome

In this study, we used Holter pacemakers in a group of 13 patients affected by severe carotid sinus syndrome in order to evaluate its evolution. All the patients had one to three syncopal episodes and frequent other symptoms such as fainting, dizziness, lightheadedness and pre-syncope interferring with their daily activity so that pacemaker therapy was considered necessary. Patient selection criteria were: presence of the isolated cardioinhibitory type, absence of associated sinus dysfunction and absence of symptomatic VVI pacemaker effect. All the patients received a Micropacer 1 device; among special functions, bradycardia events counter was activated and programmed so that each sequence of three consecutive beats at a cycle length 1.5 sec (i.e., 4.5 sec total interval) could be recognized and stored in its memory. The follow-up lasted 13 +/- 7 months. Brady events occurred in eight out of 13 patients (62%), during this period. Syncope and major symptoms disappeared in all the patients; mild dizziness recurred rarely in two patients and were not linked to brady-events recording. In conclusion, disappearance of severe symptoms observed after pacemaker implant in cardioinhibitory carotid sinus syndrome seems to depend from pacing therapy, in most cases, yet from the benign natural course of the disease in some other cases.

Natural and unnatural history of patients with severe carotid sinus hypersensitivity: a preliminary study

Natural history of patients with symptomatic severe carotid sinus hypersensitivity is not clearly known. In order to evaluate the effectiveness of pacing therapy in these patients we performed a randomized treatment/no-treatment prospective study in 35 patients. They were randomly assigned to two groups: 19 patients received no therapy, 16 patients received a VVI (#11) or DDD (#5) pacemaker implant. During the 8.4 +/- 4.3 month follow-up period patients receiving no therapy had recurrence of syncope in 9 cases (47%) and minor symptoms in 13 (68%); at the 16th month, actuarial curve showed absence of syncope in 36% of patients and of any symptoms in 30%. During the 7.2 +/- 4.1 month follow-up period, the patients receiving the pacemaker implant had no recurrence of syncope, minor symptoms in three (19%); at the 16th month, actuarial curve showed absence of syncope in 100% of patients and of any symptoms in 78%. During follow-up, 12 patients in no-treatment group received a pacemaker implant because of the recurrence of severe symptoms; successively they had a strong reduction of symptoms. In conclusion, this study definitively demonstrates that patients with severe symptomatic carotid sinus hypersensitivity had a high rate of recurrence of spontaneous symptoms and that in these patients cardiac pacing is a useful therapy.

Is DDD superior to VVI pacing in mixed carotid sinus syndrome? An acute and medium-term study

The aim of this study was to evaluate the importance of atrial synchronism for pacing therapy of patients with mixed carotid sinus syndrome. In 23 patients (21 m, two f; mean age 69 +/- 8 years) affected by symptomatic mixed carotid sinus syndrome we performed: (1) Research of ventriculo-atrial conduction, orthostatic hypotension and pacemaker effect; and (2) Carotid sinus massage in the standing position during VVI and DVI temporary pacing. Next, all patients received a permanent DDD pacemaker and entered a 2 month two period single-blind, randomized, cross-over study on DVI/DDD versus VVI mode. During the DVI/DDD period, no syncope occurred in any patients, minor symptoms persisted in 11 (48%) of them; during VVI period syncopes recurred in three patients, symptoms requiring the withdrawal of VVI pacing and premature DVI/DDD reprogramming in eight patients, minor symptoms in 17 (74%). A comparison between 14 patients, who preferred DVI/DDD period (Group A), and the remaining nine patients who noted no preference between DVI/DDD and VVI period (Group B) was performed on the basis of the preimplant evaluation. Group A patients had a greater pacemaker effect (-34 +/- 16 mmHg vs -16 +/- 14 mmHg) and a higher prevalence of symptomatic pacemaker effect (50% vs 0%), of ventriculo-atrial conduction (78% vs 44%) and of orthostatic hypotension (50% vs 11%), while the entity of the systolic pressure fall caused by carotid sinus massage was similar in the two groups either during VVI mode (Group A -51 +/- 16 mmHg vs Group B -56 +/- 27 mmHg) or DVI mode (Group A -38 +/- 17 mmHg vs Group B -45 +/- 17 mmHg).(ABSTRACT TRUNCATED AT 250 WORDS)

Autonomic hyperreflexia, cesarean section and anesthesia. A case report

Autonomic hyperreflexia, a potentially life-threatening condition, can appear during labor, delivery or cesarean section in a woman with a spinal cord injury. A case of autonomic hyperreflexia in a parturient was managed with regional neural blockade.

Effects of botulinum A toxin on detrusor-sphincter dyssynergia in spinal cord injury patients

We evaluated the ability of low doses of botulinum A toxin, an inhibitor of acetylcholine release at the neuromuscular junction, to denervate and relax the spastic rhabdosphincter in 11 men with spinal cord injury and detrusor-sphincter dyssynergia. Toxin concentration, injection volume, percutaneous versus cystoscopic injection of the sphincter and number of injections were evaluated in 3 treatment protocols. All 10 patients evaluated by electromyography after injection showed signs of sphincter denervation. Bulbosphincteric reflexes in the 10 patients evaluated after injection were more difficult to obtain, and they showed a decreased amplitude and normal latency. The urethral pressure profile in the 7 patients in whom it was measured before and after treatment decreased an average of 27 cm. water after toxin injections. Post-void residual urine volume decreased by an average of 146 cc after the toxin injections in 8 patients. In the 8 patients for whom it could be determined toxin effects lasted an average of 50 days. The toxin also decreased autonomic dysreflexia in 5 patients.

The carotid sinus syndrome: a frequently overlooked cause of syncope in the elderly

Exaggerated carotid sinus reflexes may account for alterations in consciousness responsible for significant disability and injury in elderly patients. Nonspecificity of symptoms and concomitant medical conditions frequently delay diagnosis and therapy. During a recent 9-year period, 82 patients were identified as having symptomatic carotid sinus hypersensitivity (CSH). Fifty-nine patients described complete syncope, 73 patients had multiple syncopal or near-syncopal episodes, and 40 patients related cervical pressure or motion as provocative events. Electrophysiologic testing demonstrated that 47% had cardioinhibitory CSH, 26% had vasodepressor CSH, and 27% had combined vasodepressor and cardioinhibitory CSH. The mean follow-up period of all patients was 36 months. Surgical therapy included ventricular demand pacemaker implantation in 33 patients and carotid sinus denervation in seven patients. Medical therapy was used in 32 patients, 11 mildly symptomatic patients were not treated, and 3 patients had carotid sinus irradiation. Pacemaker implantation relieved symptoms in 53%; however, 11 patients (33%) had significant postoperative complications. Carotid sinus denervation relieved symptoms in 86%, medical therapy in 54%, and carotid sinus irradiation in 33% of patients. Because of its demonstrated effectiveness in all variants of CSH and negligible perioperative morbidity, carotid sinus denervation should be offered to acceptable operative candidates when the diagnosis of CSH is confirmed.

Transplants of embryonic brainstem containing the locus coeruleus into spinal cord enhance the hindlimb flexion reflex in adult rats

Cell suspensions of embryonic brainstem containing the locus coeruleus were injected intervertebrally into the lumbar spinal cord of adult rats whose descending catecholamine (CA) fibers had been lesioned with intracisternal injection of 6-hydroxydopamine. Up to 1100 CA cells were found 2 and 4 months later, and these cells grew processes which produced histologically detectable reinnervation of the lumbar gray matter on the injected side of the cord. To assess the functional activity of the transplanted CA cells, the force of the hindlimb flexion reflex was measured in acute spinal rats. This reflex has been shown previously to be strongly enhanced by catecholamines. The flexion reflexes were significantly stronger in the transplanted rats than in the controls. Further, the flexion reflexes were significantly reduced by phenoxybenzamine, an alpha-adrenergic blocker, in the transplanted rats while the reflexes of controls were not significantly changed. These results demonstrate that cell suspension transplants of embryonic brainstem containing the locus coeruleus into the adult rat spinal cord survive, grow reinnervating catecholamine processes, and can affect the functional activity of the spinal cord.

Management of a pregnant paraplegic patient in a rehabilitation center

As the population of paraplegic women of child-bearing age increases, the psychiatrist may be more frequently called on to care for pregnant women. Pregnancy in a paraplegic patient can be accompanied by many serious medical problems including autonomic dysreflexia, anemia, decubitus ulcers, urinary tract infections, and premature labor. This is a case report of a successful pregnancy in a spinal cord injured woman who was managed at a rehabilitation center throughout her entire pregnancy, despite developing the multiple complications described above.

Preterm labor in the quadriplegic parturient

The occurrence of preterm labor is not uncommon in the pregnant quadriplegic. Early diagnosis is hampered by the inability of most quadriplegics to sense uterine contractions in the usual way. A patient we recently treated for preterm labor learned to recognize contractions by the associated symptoms of autonomic hyper-reflexia: flushing, headache, and piloerection. Tocolytic therapy was successful and a favorable neonatal outcome occurred. Increased awareness by the physician and the pregnant quadriplegic patient is encouraged so that symptoms of autonomic hyper-reflexia may be recognized as potentially indicative of uterine contractions.

Transvesical phenolisation of the pelvic plexuses: a simple technique for the treatment of refractory detrusor instability and hyperreflexia

A simple endoscopic technique for the infiltration of pelvic plexuses with phenol is described. The results suggest that this is a useful technique in the management of detrusor hyperreflexia and for the older patient with detrusor instability when standard conservative measures have failed. It is contraindicated in male patients because of the risk of impotence.

[Association of the carotid sinus syndrome and orthostatic hypotension. Another potential cause of the failure of VVI electrostimulation]

The systolic blood pressure was measured during clinostatism and 15'', 1', 5' after standing in 101 patients with carotid sinus syndrome and in 101 controls matched for age, sex, and prevalence of organic heart disease. In the carotid sinus syndrome group we observed a greater systolic blood pressure reduction from the supine to standing position (20 +/- 19 vs 14 +/- 11 mmHg), a lower orthostatic pressure (111 +/- 23 vs 120 +/- 21 mmHg) and a greater incidence of orthostatic hypotension (defined as a blood pressure reduction greater than or equal to 50 mmHg or greater than or equal to 20 mmHg when orthostatic pressure was lower than 100 mmHg) (35% vs 17%). Twenty-three carotid sinus syndrome patients received a VVI pacemaker for control of their symptoms; after a mean follow-up of 12.2 +/- 7.7 months, unchanged or reduced symptoms persisted in 6 out 9 (67%) patients with previous orthostatic hypotension while only in 1 out of 14 (7%) patients without this feature. In conclusion, orthostatic hypotension is frequently associated with a carotid sinus syndrome and may account for relapses in some patients treated with VVI pacing.

A device for treatment of destrusor hyperreflexia by bio-feedback

Treatment of detrusor hyperreflexia is still a difficult field. Recently bio-feedback has been described as a successful treatment of voiding dysfunction. In this paper we describe a device, which makes it possible for the patients to register any pressure changes in the bladder.

Improvement of cardiovascular autonomic reflexes after amelioration of metabolic control in insulin-dependent diabetic subjects with severe autonomic neuropathy

To evaluate the influence of good metabolic equilibrium on Diabetic Autonomic Neuropathy (DAN), cardiovascular autonomic reflexes were monitored in 9 male insulin-dependent diabetic patients with DAN, treated with Continuous Subcutaneous Insulin Infusion (CSII) by pump: 9 for 10 days, 4 for 1 year and 2 for 20 months. Autonomic neuropathy was assessed evaluating 5 cardiovascular autonomic tests: Valsalva Manoeuvre (VR), Deep Breathing (DB), Lying-to-Standing (L-S), Sustained Handgrip (SHG), and Postural Hypotension (PH). Metabolic control was assessed evaluating the mean daily plasma glucose, glucosuria and glycosylated hemoglobin. Ten days of CSII treatment induced a normalization of glucose balance and a slight but significant improvement in some parasympathetic cardiovascular tests (VR: from 1.09 +/- 0.01 to 1.13 +/- 0.02; P less than 0.05). After 4-8 months of CSII treatment a significant improvement in VR (P less than 0.05); DB (P less than 0.01) and L-S (P less than 0.05) was recorded. The long-term treatment with CSII did not seem to induce a further amelioration in cardiovascular autonomic reflexes. These results show that the slight improvement induced by good metabolic balance in the cardiovascular autonomic response could be related to functional-metabolic rather than structural changes in the nerves.

Reducing occurrences of an asymmetrical tonic neck reflex

A custom-designed foam rubber headpiece was used during lunch with a multiply handicapped child to reduce the occurrences of an asymmetrical tonic neck reflex. After the inappropriate reflex was inhibited, the apparatus was gradually faded out by cutting away sections of the rubber. Ultimately, the headpiece was completely eliminated and the asymmetrical tonic neck reflex maintained a zero level of occurrence during lunch periods. Concomitantly, there was an increase in correct bites of food.

Autonomic hyperreflexia: a mortal danger for spinal cord-damaged women in labor

Reproductive care of women with spinal cord damage demands knowledge of such women's reproductive potential and the specific complications to which these women are prone during pregnancy and childbirth, especially autonomic hyperreflexia. Fertility in cord-damaged women of reproductive age is generally undiminished as are libido, ability to have intercourse, and ability to bear children. Frequent complications of cord-damaged pregnant women include urinary tract infection, anemia, pressure sores, sepsis, unattended birth, and autonomic hyperreflexia. Autonomic hyperreflexia or autonomic dysreflexia occurs during labor in up to two thirds of women with cord lesions above T-6. Autonomic hyperreflexia results from noxious stimuli including distention of the bladder, cervix, or rectum, which evokes mass triggering of sympathetic and parasympathetic afferents that are uninhibited by supraspinal centers below the cord lesion. Autonomic hyperreflexia manifests itself with sudden onset of marked hypertension and headache during uterine contractions, as well as bradycardia or tachycardia, various cardiac dysrhythmias, and marked diaphoresis with piloerection and flushing above the level of the cord lesion. We describe the second reported occurrence of intraventricular hemorrhage due to autonomic hyperreflexia during labor and detail recommendations for anticipating and mitigating this potentially lethal complication of parturition in cord-damaged women. Pregnancy and parturition are best carried out with informed cooperation of the patient and of obstetric, cord rehabilitation, anesthetic, and nursing personnel.

The contribution of reflex inhibition to arthrogenous muscle weakness

‘Arthrogenous muscle weakness’ is weakness of muscles acting about an injured or inflamed joint. The weakness may be due to loss of muscle or to inability to activate the muscle (Fig. 1). Weakness of the thigh muscles, and of the quadriceps in particular, is a common and important consequence of knee trauma, surgery or arthritis. Muscle weakness contributes significantly to disability and probably also renders the joint vulnerable to further damage (Fig. 1). This review starts with a brief discussion of the contribution of atrophy to weakness. It concentrates, however, on inhibition of quadriceps activation and suggests some therapeutic implications. It does not deal with the reduced oxidative capacity and increased fatiguability of disused muscle since, although important, these have not been part of our programme of work.

[Effect of long-term cryotherapy on the Hoffmann reflex]

Investigations about Hoffmann reflex of M. triceps surae on both extremities were carried out on 10 young volunteers before and after cryoapplication of ten minutes on the left leg. Determination of H/M ratio indicates the influence of cold application on muscle tonus, which was decreased on the treated side without any influence on the contralateral. The results support the view that muscle relaxation depends on decrease of muscle temperature.

Treatment of an overactive gag reflex: two cases

Two cases are presented in which avoidance of dental work was caused by an overactive gag reflex rather than fear. Subjects were able to demonstrate increased control of gagging in the laboratory, and to complete a series of dental visits immediately after treatment and again at 6 or 12 month follow-up. Assessment and treatment strategies which were developed with these subjects are described.

The influence of electrostimulation on hexobarbital induced loss of righting reflex in rats

Electrostimulation (ES) of slow (SF, 10 Hz) or fast (FF, 500 Hz) frequency decreases the sleeping time of rats anaesthetized by administration of acute doses of hexobarbital. When ES is applied via the ears, both SF and FF are equally efficient in reducing the loss of righting reflex (LRR), whereas if ES is applied peripherally via the paws, only FF decreases the acute narcosis time. Applied cranially, either continuous stimulation or administration of intermittent current (5 minutes on and off) were equally effective in reducing narcosis. A decreased period of 30 minutes' continuous stimulation will reduce sleeping time only if administered immediately after LRR. When restrained animals received ES for periods of up to 3 hours prior to administration of the barbiturate, the sleeping time of the stimulated and sham treated animals were not significantly different.

Effect of high haematocrit on alertness

Patients with high-normal or above-normal haematocrit were found to have impaired alertness when compared with a control group matched for age and occupation. On retesting the controls had improved alertness scores attributable to a practice effect; but the patients, when retested after reduction of haematocrit by venesection, had improved significantly more than the controls. Improvement in alertness correlated very well with the increase in cerebral blood flow which followed venesection. Levels of venous haematocrit that are generally accepted as normal may not necessarily be optimum.

Incontinence of urine due to instability of micturition reflexes: Part I. Detrusor reflex instability

Micturition reflex instability may result from malfunction of the detrusor reflex or instability of the pudendal nucleus which innervates the pelvic floor muscles and external sphincter. Detrusor instability is the result of sacral micturition reflex center (SMRC) hyperexcitability. This may be caused by underinhibition or overfacilitation of the SMRC, and there are both central and peripheral causes of each. Detrusor hypertrophy may invoke chronic overactivity of the detrusodetrusor facilitative reflex causing SMRC overfacilitation. Similarly, distal urethral stricture and/or chronic urethritis causing chronic overactivity of the urethrodetrusor facilitative reflex is a common cause of SMRC overfacilitation. Pathologic relaxation and weakness of the striated muscles of the pelvic floor and perineum resulting in underactivity of the perineodetrusor inhibitory reflex, is a common cause of SMRC underinhibition. In adult women these factors often coexist. Each may predispose to stress-induced detrusor instability and are often seen in association with, or are confused with, true stress incontinence. The distinguishing characteristics of detrusor hypertonicity and detrusor hyperreflexia are reviewed, and the various mechanisms of pseudostress incontinence and of urgency incontinence are discussed in detail.

Autonomic hyper-reflexia modulated by percutaneous epidural neurostimulation: a preliminary report

Our clinical experience in the management of five paraplegic or quadriplegic patients with subjective complaints and objective findings of autonomic hyper-reflexia is presented. These five patients had epidural neurostimulation systems implanted percutaneously to regulate intractable spasticity. During a follow-up period varying from 2 months to almost 2 years, four of the five patients experienced no episodes of autonomic dysfunction with the use of a low frequency, low voltage, square wave pulse output. From their responses and from recent neurophysiological evidence, the potential benefit of percutaneous epidural neurostimulation in the modulation of autonomic hyper-reflexia without antihypertensive medication is suggested. Further follow-up of these patients and additional clinical research should be performed to confirm our initial clinical impressions.

The polystyrene vacuum wheelchair cushion

A polystyrene bead vacuum wheelchair cushion has been tried with several patients with abnormal postural reflex activity. Excess spasticity can be reduced by this means and sitting comfort enhanced.

Autonomic hyperreflexia. A serious complication of radiological procedures in patients with cervical or upper thoracic spinal cord lesions

Autonomic hyperreflexia is a reflex response to visceral distension which occurs only in patients with spinal cord lesions above T6. The marked hypertension, which is an integral part of this reflex, may lead to severe morbidity, or even death. The mechanism whereby interruption of the sympathetic outflow from the spinal cord results in autonomic hyperreflexia is described, as well as the clinical signs and symptoms associated with this condition. The value of autonomic hyperreflexia as a clinical indicator of complications in patients with spinal cord lesions is stressed. The diagnosis and treatment of autonomic hyperreflexia which has occurred as a complication of radiological procedures are discussed.

The tonic ambulatory foot response. A clinical and electromyographic study

Three cases with "pyramidal" symptoms in which standing and/or walking evoked a tonic flexion of the toes and sole of the affected foot, have been studied from the clinical and electrophysiological standpoint. The phenomenon, for which the definition of tonic ambulatory foot respone (TAFR) is proposed, appeared to be triggered by cutaneous stimuli travelling along fibres lying in the range of nociceptive afferents, and to depend on a background of complex sensorimotor patterns of standing posture and/or stepping movements against resistance. The relationship of TAFR to other flexor foot responses described in the literature is discussed.