Nonrhinologic headache in a tertiary rhinology practice.

OBJECTIVE: Our goal was to determine the etiology of headache in patients who were referred for sinus evaluation but were found to have no evidence of rhinosinusitis on computed tomography (CT) of the sinuses and on endoscopic examination. METHODS: Data were collected prospectively from 100 patients with headache but with normal sinus CT and endoscopic examination. Headache and 20-Item Sino-Nasal Outcomes Test (SNOT-20) scores of patients with the chief complaint of headache and who requested further neurologic evaluation (group I) were compared with the scores of patients who did not list headache as a significant symptom (group II) and with the scores of patients without headache (group III). RESULTS: The most common neurologic diagnosis for group I patients (n = 36) was migraine headaches (58%). These patients also had higher mean SNOT-20 scores (24 +/- 3.3) compared to group II patients with mild headache (14.6 +/- 2.3) or group III patients without headache (12.4 +/- 2.1). CONCLUSION: Migraine was the most common type of headache in patients with normal sinus CT treated for presumed rhinosinusitis as the cause of the headache. Patients with headache as their chief complaint that required further neurologic evaluation had overall higher SNOT-20 scores than nonheadache patients, indicating greater disability of their overall quality of life index.     

Distraction effects on muscle: Leg lengthening studied in rabbits

We investigaed changes in the anterior tibial muscle during lengthening of the lower leg in rabbits. In 37 rabbits, an osteotomy of the right middle tibia was performed and was fixed by a unilateral external fixator. The rabbits were randomized into 6 groups. In groups 1, 2, and 3 the tibiae were distracted 0.5 mm/day. In groups 1 and 2, the rabbits were killed after 14 and 28 days of distraction, respectively, and in group 3 after 28 days of distraction, followed by 14 days of rest. Groups 1a, 2a, and 3a served as controls. They were treated similarly as groups 1, 2, and 3, but no distracton was performed. Proliferating cell nuclei were labeled with 5-bromo-2-deoxyuridine and were identified by immunohistochemical staining. The weight of the muscle was measured. During bone lengthening the muscle showed signs of growth, as indicated by increasing weight and number of proliferating cell nuclei. This was observed only during lengthening and it ceased when the lengthening was stopped.     

Interaction of thiamine deficiency and voluntary alcohol consumption disrupts rat corpus callosum ultrastructure.

The relative roles of alcohol and thiamine deficiency in causing brain damage remain controversial in alcoholics without the Wernicke-Korsakoff syndrome. Experimental control over alcohol consumption and diet are impossible in humans but can be accomplished in animal models. This experiment was designed to differentiate the separate and combined effects on the macro- and ultrastructure of the corpus callosum of thiamine deficiency and voluntary alcohol consumption. Adult male alcohol-preferring (P) rats (9 chronically alcohol-exposed and 9 water controls) received a thiamine-deficient diet for 2 weeks. There were four groups: five rats previously exposed to alcohol were treated with pyrithiamine (a thiamine phosphorylation inhibitor); five rats never exposed to alcohol were treated with pyrithiamine; four alcohol-exposed rats were treated with thiamine; and four rats never exposed to alcohol were treated with thiamine. On day 14, thiamine was restored in all 18 rats; 2 weeks later the 10 pyrithiamine-treated rats received intraperitoneal thiamine. The rats were perfused 61 days post-pyrithiamine treatment at age 598 days. Brains were dissected and weight and volumes were calculated. Sagittal sections were stained to measure white matter structures. The corpus callosum was examined using transmission electron microscopy to determine density of myelinated fibers, fiber diameter, and myelin thickness. The corpus callosum in the alcohol/pyrithiamine group was significantly thinner, had greater fiber density, higher percentage of small fibers, and myelin thinning than in the alcohol/thiamine and water/thiamine groups. Several measures showed a graded effect, where the alcohol/pyrithiamine group had greater pathology than the water/pyrithiamine group, which had greater pathology than the two thiamine-replete groups. Across all 16 rats, thinner myelin sheaths correlated with higher percentage of small fibers. Myelin thickness and axon diameter together accounted for 71% of the variance associated with percentage of small fibers. Significant abnormalities in the alcohol/pyrithiamine group and lack of abnormality in the alcohol-exposed/thiamine-replete group indicate that thiamine deficiency caused white matter damage. The graded abnormalities across the dually to singly treated animals support a compounding effect of alcohol exposure and thiamine depletion, and indicate the potential for interaction between alcohol and thiamine deficiency in human alcohol-related brain damage.     

Emergence of disinhibition-induced synchrony in the CA3 region of the guinea pig hippocampus in vitro

Suppressing inhibition mediated by GABA_A receptors induces rhythmic bursts of synchronous firing in the CA3 region of the hippocampus. Extracellular and intracellular records were made from guinea pig hippocampal slices to examine the emergence of this synchrony. We found that application of GABA_A receptor antagonists initiated a sequence of changes in the activity of the CA3 neuronal population. First, the frequency of firing detected in multiunit records increased. Then, firing began to oscillate with increases followed by decreases in firing that occurred at intervals of 0.5–2 s. The coherence of the rhythmic activity at a single site increased with time, and discharges at distant sites in the CA3 region became correlated. Fluctuations in firing were associated with extracellular field potentials. Finally, epileptiform events associated with large field potentials began to recur at intervals of 5–10 s. The onset of fully synchronous events was sudden and correlated with a large increase in the amplitude of the field potential. Thus the CA3 population can express states of partial population synchrony preceding the onset of epileptiform discharges. A similar activity was induced and maintained by applying low doses of GABA_A receptor antagonists. Intracellular records suggest that inhibitory signalling mediated by GABA_B receptors contributes to the emergence of this activity. States of partial synchrony in the CA3 region exposed to GABA_A receptor antagonists therefore depend on alternating periods of firing, presumably dependent on excitatory synaptic mechanisms, and silence, mediated in part by the activation of GABA_B receptors.     

Arthroscopy and microfracture technique in the treatment of osteochondritis dissecans of the humeral capitellum: report of three adolescent gymnasts

The aim of this paper is to report on three cases of symptomatic osteochondritis dissecans of the humeral capitellum in adolescent gymnasts, two females and one male. In all the cases arthroscopic surgery was performed. During arthroscopy, loose osteochondral fragments were removed, the defect was debrided and microfractures were performed. All the three patients regained the full range of motion of the affected elbow, and returned to the high-level gymnastics within a period of 5 months. At 12 months follow-up, all the three patients remained symptomless and were participating in high-level gymnastics. A combination of arthroscopy and the microfracture technique is a reliable method with excellent short-term results in the treatment of the osteochondritis dissecans of the elbow.     

Rates of intestinal absorption of molybdenum in humans.

The intestinal absorption of molybdenum in healthy human volunteers has been measured by simultaneous oral and intravenous administration of the stable isotopes 95Mo and 96Mo, and the results were analysed using the convolution integral technique. The results showed that molybdenum ingested in liquid form was rapidly and totally absorbed into the circulation under ordinary intake regimes. The rates and extent of absorption were lower for composite meals, and also for increasing levels of administration. This information can be helpful in the application of the new ICRP model of the human alimentary tract.