Daniel E. Myers

Hypoalgesic effect of caffeine in experimental ischemic muscle contraction pain

It has been theorized that adenosine is a leading candidate for the metabolite responsible for ischemic muscle pain. The purpose of this study was to determine the effect of the non‐selective adenosine receptor antagonist, caffeine, on ischemic skeletal muscle contraction pain. Seven healthy adult volunteers with no history of pain disorders, systemic disease, or habitual caffeine use, were chosen for the two‐session, cross‐over, double‐blind study. Every subject received either 200 mg of caffeine (NoDoz ® , Bristol‐Myers) or identical placebo I hour before each of the two trials. Ischemia of the forearm was achieved by inflation of a blood pressure cuff to 250 mm Hg. Forearm muscle activity was generated by performance of wrist curls using a 5‐gram bar at a rate of 40 cycles per minute. Pain was rated at 15‐second intervals for I minute using a visual analog scale (0 to 10) with verbal descriptors. Significance was determined by univariate and multivariate analyses of variance and covariance including repeated measures. Pain ratings at 15 seconds in the caffeine trial were significantly lower (P<0.02) than those in the placebo trial. This effect continued at 30 seconds (P<0.05). However, by 45 seconds, pain in the caffeine trial was not significantly lower (P= ‐ 0.4) than that in the placebo trial. These results show that high‐dose caffeine exhibits considerable analgesic efficacy in experimental muscle pain, adding support for a role of adenosine in producing ischemic muscle contraction pain.

A Preliminary Report on Hyperbaric Oxygen in the Relief of Migraine Headache

Oxygen inhalation was early advocated as a treatment for migraine headache. It has been theorized that the efficacy of raising blood oxygen levels in vascular headache is mediated by vasoconstriction and metabolic effects. Hyperbaric oxygen can provide a much greater level of blood oxygenation than normobaric oxygen, and in recent studies it has been used in the treatment of cluster headache. The purpose of this study was to compare the effects of hyperbaric oxygen and normobaric oxygen in migraine. Twenty migraineurs were divided randomly into two groups and studied in a hyperbaric chamber during a typical headache attack. Global headache severity was measured by a verbal descriptor scale before and after exposure to oxygen. One group received 100% oxygen at I atmosphere of pressure (normobaric) while the other received 100% oxygen at 2 atmospheres of pressure (hyper‐baric). One of the 10 patients in the normobaric group achieved significant relief of headache symptoms, while 9 of 10 in the hyperbaric group found relief. Based on a chi‐square test, this difference is significant at the P<.005 level. Those patients who did not find significant relief from normobaric oxygen were given hyperbaric oxygen as above. All nine found significant relief. The results suggest that hyperbaric (but not normobaric) oxygen may be useful in the abortive management of migraine headache. Possibilities for the mechanism of this effect, in addition to vasoconstriction, include an increase in the rate of energy‐producing and neurotransmitter‐related metabolic reactions in the brain which require molecular oxygen.

Gravitational effects of the period of high tides and the new moon on lunacy

In this report, the established timing of terrestrial tidal gravity fluxes is examined to assess the role of the full moon per se in modern gravitational lunacy theory. The results show that the principal tidal gravity fluxes are semidiurnal, with lesser diurnal and even smaller fortnightly components. There are no uniquely monthly components that would correspond to the period of the full moon. This means that the gravitational effects of the new moon are equivalent to those of the full moon. Furthermore, the gravitational effects associated with the times of high tide are even greater than those associated with the moon phases. Using the technique of reductio ad absurdum, I suggest that lunacy effects, if indeed there are any, should occur twice each day (high tides) but should be more pronounced during the new moon and full moon (spring tides). On the basis of this analysis, I would recommend that all studies that have compared hospital records with the full moon be redone to coincide with the proper timing as found in this report.

A retrospective study of the effects of edentulism on the severity rating of tardive dyskinesia

Edentulism has been reported to be a risk factor in the development of spontaneous orofacial dyskinesia. This study aimed to determine whether edentulism increases the severity rating of tardive dyskinesia in psychiatric subjects treated with neuroleptic medication. The filed Abnormal Involuntary Movement Scale reports of 84 edentulous and 109 dentate outpatients with schizophrenic or schizoaffective disorder were examined retrospectively. To compare dyskinesia ratings in different body areas with dental status and gender, 2 x 2 multivariate analysis of variance was used. Results show that edentulous subjects had significantly higher dyskinesia ratings in the orofacial categories but not in other body areas. Gender had no influence on dyskinesia ratings. These results indicate that tooth loss may considerably increase the severity of tardive dyskinesia, a finding that suggests a possible role of preventive and prosthetic dentistry in the health care of patients at risk for this condition.

Potential neurogenic and vascular roles of nitric oxide in migraine headache and aura.

It has long been known that nitrate and nitrite medications consistently cause significant headache as a side effect. Classical research has shown that cerebral vasodilation accompanies the use of these medications. More modern studies suggest that these vasodilators exert their action on blood vessels via nitric oxide and its second messenger, cyclic guanosine monophosphate. This paper reviews research studies and theoretical articles which address the concept that nitric oxide plays a major role in the vasodilation associated with the headache phase of migraine with aura. A brief discussion of nitric oxide biochemistry and pharmacology follows.