Increased glucose improves recovery of neuronal function after cerebral hypoxia in vitro.

The rat hippocampal slice preparation was used to evaluate the effect of increasing glucose levels in the perfusion medium on the recovery of synaptic function after a standardized hypoxic insult. Slices exposed to low glucose (5 mM) did not recover from a standard hypoxic insult (10 min of 95% N2/5% CO2 atmosphere). Following the same insult, 39% of the control (10 mM glucose) slices recovered their synaptic function, while 93% of the slices provided with high glucose level (20 mM) exhibited recovery of synaptic function. Thus, a dose-dependent effect of glucose on recovery of neuronal function following an intermediate period (10 min) of oxygen deprivation was found. The high-glucose-treated slices could tolerate a severe hypoxic insult of 15 min or even 20 min from which 94% and 81% of them recovered, respectively. Only 21% of the control (10 mM glucose) slices recovered their synaptic activity following 15 min of hypoxia, and none survived 20 min of that insult. The adverse effects of hyperglycemia reported in vivo were not seen in our study. This may be due to the sustained perfusion of the brain slice preparation, which could limit accumulation of lactic acid during hypoxia. However, treatment of slices with lactic acid prior to and during the hypoxic insult did not worsen the outcome. Alternatively, glucose may protect against the damaging effects of oxygen free radicals formed during reoxygenation. Nevertheless, the antihypoxic effect of glucose appears to be a metabolic one, since L-glucose (the non-metabolic analog of D-glucose) was innocuous in this respect.

Localized hypertrophic mononeuropathy involving the tibial nerve.

Localized hypertrophic neuropathy (LHN) is a disorder of unknown cause that presents with progressive, predominantly motor weakness in the distribution of a single nerve, with the histological appearance of the "onion bulb" formation. Because of its rarity, the condition is often ignored in the differential diagnosis of mononeuropathy. We report a case of LHN involving the posterior tibial nerve and review the literature.

Cervical spine fractures with major associated trauma.

A detailed review of 88 consecutive patients placed in skeletal tong traction for cervical fractures by the University of Louisville Neurosurgical Service during a 5-year period from July 1, 1979, through June 30, 1984, was carried out. Of this group, 60% of the patients had a major associated injury consisting of major facial and skull fractures, cerebral contusions or intracerebral blood clots, cardiac or pulmonary contusions, major thoracic injuries including rib fractures and hemo- or pneumothoraces, intra-abdominal injuries, and major extremity fractures. An additional 24% of the patients had minor associated injuries, including facial or scalp lacerations, general body lacerations, or abrasions and cerebral concussions. Only 16% of patients with cervical fractures had no evidence of any other associated injury. Acute cervical spine fractures require prompt assessment and resuscitation by personnel from multiple specialties, usually available only in major trauma centers where experienced personnel capable of handling diverse injuries are always present.

Chemonucleolysis with chymopapain: results in 150 patients.

Chemonucleolysis with chymopapain has been advocated for the treatment of lumbar disc disease. When polled by a mail questionnaire, 150 consecutive patients who had undergone chemonucleolysis reported an overall success rate of only 40% and a failure rate of 60%. However, 57% of the patients were active or had only mild restriction of daily activities. Of those patients employed prior to injection, only 63% had returned to work. Those with workmen's compensation benefits fared considerably worse than those covered by third-party insurance (17% vs. 51% success). These results cast doubt on the long-term benefits of chymopapain in the treatment of lumbar disc disease.