Joseph M. Waltz

Chronic cerebellar stimulation in cerebral palsy

Data are presented for the first 50 patients with cerebral palsy who underwent chronic cerebellar stimulation for symptom alleviation. We observed significant shorter and longer term improvement in spasticity as well as athetosis, speech, and functional status. Continuing increments in improvement were noted as a function of time on stimulation. In many instances, psychometric test scores and behavior also were improved. There was one death in this series. There were no neurologic complications due to cerebellar stimulation. The results of this study warrant the judicious use of cerebellar stimulation for symptomatic and functional relief in cerebral palsy.

The Effect of Chronic Stimulation of Cerebellar Cortex on Epilepsy in Man

The purpose of this report is to summarize our observations of the effects of chronic stimulation of the cerebellar cortex in 7 patients with intractable epilepsy and one patient totally incapacitated by generalized intention myoclonus. These 8 patients represent part of a series of 28 cases in whom we have attempted to utilize the inhibitory function of cerebellar cortex to achieve a therapeutic modification of motor behavior. The remaining 20 patients were incapacitated by various types of spasticity and/or rigidity. Preliminary results in this latter group have been reported separately (Cooper, Crighel, & Amin, 1973).

Effects of cryogenic thalamic lesions on the somesthetic evoked response in man

Abstract The effects of cryogenic lesions of certain thalamic nuclei (mainly VL, VPL and VPM) were determined during surgery on the somesthetic evoked response recorded from the cerebral cortex with epidural and scalp electrodes. A total of 102 dyskinesic patients undergoing cryothalamectomy (without premedication) as a means of relieving incapacitating motor symptoms were used for this study. Somesthetic responses were elicited with electrical stimulation of the contralateral median nerve at the wrist at 1, 2, and 3 x sensory threshold. The evoked responses were algebraically summated using conventional computer techniques. Selective lesions of nucleus VL in nineteen cases did not significantly after the evoked responses recorded in the first 125 msec after the stimulus. Lesions of nucleus VL and a portion of VPL which produced transient paresthesias during freezing, did not significantly depress most components of the evoked response in thirteen cases. However, some of the early components were slightly reduced. Massive lesions of VPL encroaching on VPM and possibly CM produced obvious paresthesias of the hand and reduced all components of the evoked response in fifteen cases. It is suggested that the major components of the somesthetic evoked response within 125 msec following stimulation, are primarily mediated through nucleus VP of the thalamus. The contribution of CM, if any, to the passage of some of the later components is uncertain. In some patients discrepancies between the amplitude of the somesthetic evoked potential and subjective complaints of paresthesias were noted. However, in patients with severe paresthesias involving the contralateral hand and wrist, the somesthetic evoked response to stimulation of the median nerve at the wrist was statistically significantly reduced.

Cervical spondylosis and dyskinesias

THE ROLE OF TRAUMA, occupational and sporadic, in the production of cervical spondylosis has been alluded to in past studies of this disease entity.l-3 While in the older age groups the importance of this factor may b e disputed, in patients below 50 it seems to have definite significance. By involving the cervical spine in repetitive abnormal movements, the dyskinesias-choreoathetosis, dystonia, and spasmodic torticollis-should give rise to an earlier and higher incidence of spondylosis. This has not been extensively studied. We became interested in this problem through one of our patients, a 38-year-old man with choreoathetosis. In addition, he had severe cervical spondylosis, with progressive neurological disability. Root and cord encroachment had caused bilateral flaccid weakness of the upper extremities with spastic lower extremities. Subsequently, w e reviewed X-rays of the cervical spine in twenty cases of dyskinesia. These suggested a causal relationship between the movement disorder and the development of cervical spondylosis.

SIMULTANEOUS RECORDINGS OF SCALP AND EPIDURAL SOMATOSENSORY-EVOKED RESPONSES IN MAN.

The calvarium and scalp markedly attenuate the amplitude, but do not alter the latency or frequency, of somatosensory responses evoked by electrical stimulation of the contralateral median nerve in man. With scalp electrodes no significant potentials are obtained that are not also present in the epidural recordings when proper averaging techniques are used. The somatosensory-evoked response recorded with scalp electrodes in man appears to be the result of brain activity.

Free and conjugated dopamine in human ventricular fluid

Free dopamine and an acid hydrolyzable conjugate of dopamine were measured in human ventricular fluid specimens with a radioenzymatic assay and by high performance liquid chromatography (HPLC) with electrochemical detection. Only trace amounts of free norepinephrine and dopamine were detected in ventricular fluid from patients with movement disorders. When the ventricular fluid was hydrolyzed by heating in HClO4 by lyophilization in dilute HClO4, however, a substantial amount of free dopamine was released. Values for free plus conjugated dopamine in ventricular fluid from patients who had never taken L-DOPA ranged from 139 to 340 pg/ml when determined by HPLC and from 223 to 428 pg/ml when measured radioenzymatically. The correlation coefficient for values obtained by the two methods in the same sample of CSF was 0.94 (P less than 0.001). Patients who had been treated with L-DOPA had higher levels of conjugated dopamine in their ventricular CSF which correlated inversely with the time between the last dose of L-DOPA and withdrawal of the ventricular fluid. Additionally, one patient with acute cerebral trauma had elevated levels of free norepinephrine and both free and conjugated dopamine in his ventricular fluid. Conjugation may be an important inactivation pathway for released dopamine in man.

Spinal Cord Stimulation: A Quarter Century of Development and Investigation

The past two and a half decades have seen the development of a spinal cord stimulator from the early 2-electrode fixed system to the present multielectrode computerized systems. During these 25 years, spinal cord stimulation has been studied in the treatment of motor disorders. The effectiveness was studied in 1,336 cases, including cerebral palsy (456), dystonia (173), torticollis (90), multiple sclerosis (130), spinocerebellar degeneration (71), spinal cord injury (303) and posttraumatic brain injury (113). It has become increasingly evident that the maximum therapeutic effect is achieved by virtue of the applied field variables of the spinal cord level stimulated, the field configuration, its polarity, and the frequency of the stimulation. These observations have led to investigational corollaries of the therapeutic specificity of the applied field, the neurophysiologic mechanisms of these fields and the underlying abnormal neurophysiologic substrate, which may indeed be secondary to abnormalities in the nerve impulse itself.

Vasoactive intestinal peptide in cerebrospinal fluid

Immunoreactive vasoactive intestinal peptide (VIP) was measured in lumbar and ventricular cerebrospinal fluid (CSF) from patients with various neurological disorders and in 2 hour aliquots of cisternal fluid removed continuously from rhesus monkeys. Although most of the VIP in concentrated pools of human ventricular fluid and of monkey cisternal fluid co-eluted with synthetic porcine VIP28 on a column of Sephadex G-25 superfine, there was evidence that smaller immunoreactive fragments were also present. A circadian pattern of CSF VIP concentration was observed in 2 of the 3 monkeys studied, with highest levels occurring at night and lowest during the day. Ventricular fluid VIP levels were highest in hydrocephalic children and lowest in patients with multiple sclerosis or epilepsy, while VIP was not detectable in ventricular fluid from patients in coma following a severe head injury. There were no significant differences in VIP concentrations in CSF from patients with dystonia. Parkinsons disease, or Alzheimers disease, suggesting that VIP containing neurons are not affected in these disorders. Lumbar fluid VIP levels were low in patients undergoing aneurysm surgery. Since VIP is a potent vasodilator, these findings may have important implications in relation to the development of vasospasm following subarachnoid hemorrhage.

Multi-Lead Spinal Cord Stimulation for Control of Motor Disorders

This report presents observations in 160 patients undergoing chronic spinal cord stimulation for various disorders of the motor system and compares the results obtained using older conventional two-electrode bipolar stimulation with a newly developed four-electrode multiple level system. Improvement was noted in 84% of the 75 patients with cerebral palsy, 67% of the 42 patients with dystonia, 62% of the 21 patients with torticollis and 73% of the 22 patients with post-traumatic neurologic loss. Significant improvements were noted when comparing the two-electrode system with the new multiple level electrode. Marked to moderately improved patients increased from 57 to 84% in cerebral palsy, from 44 to 82% in dystonia, from 53 to 75% in torticollis and from 53 to 80% in dystonia, from 53 to 75% in torticollis and from 53 to 80% in posttraumatic neurologic conditions. There was a corresponding marked drop in unimproved patients in each condition.

Spinal Cord Stimulation and Motor Disorders

Spinal cord stimulation has been investigated by us during the past 10 years in the treatment of various disorders of the motor system. The effectiveness was studied in 735 cases, including cerebral palsy (212), dystonia (129), torticollis (66), spinal cord injury (169), and degenerative diseases (159). Our resuits indicate that in properly selected patients, stimulating the spinal neural axis is therapeutically effective in the majority of the cases treated. Our data demonstrate that the level stimulated, the pattern and the polarity of the applied field, and the frequency of the stimulation are critical to achieve a satisfactory therapeutic result and must be individualized in each patient.