Brain abscess and generalized seizure caused by halo pin intracranial penetration: case report and review of the literature

The objective of our study is to report a rare complication of halo pin insertion associated with an epileptic seizure and brain abscess, and to discuss the diagnostic and therapeutic approach to its management. The treatment of unstable cervical spine injuries with a halo vest is an established procedure. Complications of pin penetration such as brain abscess and seizure are rare, and need to be urgently treated. Intracranial abscess and seizure associated with the use of the halo device is an unusual complication, and only a few cases have been reported in the literature. A 21-year-old male had a halo vest placed for the management of an odontoid type II fracture, which he sustained from a motor vehicle accident. Ten weeks after halo ring placement he complained of headaches which relieved by analgesics. After 2 weeks he was admitted at the emergency unit in an unconscious condition after a generalized tonic-clonic seizure. The halo pins were displaced during the seizure and were removed at his admission. No drainage was noted from the pin sites, and a Philadelphia cervical collar was applied. A brain CT and MRI revealed intracranial penetration of both posterior pins and a brain abscess in the right parietal lobe. Computed tomography of the cervical spine revealed stable fusion of the odontoid fracture. Cultures from the pin sites were negative; however, intravenous wide spectrum antibiotic treatment was administered to the patient immediately for 4 weeks followed by oral antibiotics for additional 2 weeks. Anti-epileptic medication was also started at his admission. The patient was discharged from the hospital in 6 weeks without symptoms, continuing anti-epileptic medication. On the follow-up visits he had fully recovered without any neurologic sequelae. In conclusion, complications of halo pin penetration are rare which need immediate intervention. Any neurologic or infectious, local or generalized, symptom need to be investigated urgently with available imaging techniques and treated promptly. Pin over-tightening may cause bone penetration and possible deep cranial infection with serious complications

Lack of Physiological Depth Patterns in Conspecifics of Endemic Antarctic Brown Algae: A Trade-Off between UV Stress Tolerance and Shade Adaptation?

A striking characteristic of endemic Antarctic brown algae is their broad vertical distribution. This feature is largely determined by the shade adaptation in order to cope with the seasonal variation in light availability. However, during spring-summer months, when light penetrates deep in the water column these organisms have to withstand high levels of solar radiation, including UV. In the present study we examine the light use characteristics in parallel to a potential for UV tolerance (measured as content of phenolic compounds, antioxidant activity and maximum quantum yield of fluorescence) in conspecific populations of four Antarctic brown algae (Ascoseira mirabilis, Desmarestia menziesii, D. anceps and Himantothallus grandifolius) distributed over a depth gradient between 5 and 30 m. The main results indicated that a) photosynthetic efficiency was uniform along the depth gradient in all the studied species, and b) short-term (6 h) exposure to UV radiation revealed a high tolerance measured as chlorophyll fluorescence, phlorotannin content and antioxidant capacity. Multivariate analysis of similarity indicated that light requirements for photosynthesis, soluble phlorotannins and antioxidant capacity are the variables determining the responses along the depth gradient in all the studied species. The suite of physiological responses of algae with a shallower distribution (A. mirabilis and D. menziesii) differed from those with deeper vertical range (D. anceps and H. grandifolius). These patterns are consistent with the underwater light penetration that defines two zones: 0-15 m, with influence of UV radiation (1% of UV-B and UV-A at 9 m and 15 m respectively) and a zone below 15 m marked by PAR incidence (1% up to 30 m). These results support the prediction that algae show a UV stress tolerance capacity along a broad depth range according to their marked shade adaptation. The high contents of phlorotannins and antioxidant potential appear to be strongly responsible for the lack of clear depth patterns in light demand characteristics and UV tolerance

Tight Glycemic Control

Intensive insulin therapy consists in insulin protocols targeting euglycemia (blood glucose 80-110 mg/dL). After initial enthusiasm for the positive results of the Leuven trials, concerns were raised about the incidence of hypoglycemia and extra-mortality in both surgical and medical patients. Despite a clear physiologic rationale for glucose control in critically ill patients, the best target level of glycemia, particularly for previously non-diabetic patients, is still debated. Aiming at glycemic stability may be more beneficial. Concomitant administration of insulin and nutrition is necessary and may exert positive effects on metabolism of critically ill patients, though further studies are necessary to confirm these findings. Dynamic protocols and automated insulin infusion may help to achieve a more stable and safer glycemic control