Owen B. Evans

MK-801 does not protect against hypoxic-ischemic brain injury in piglets.

Background and Purpose The excitatory amino acid inhibitor MK-801 has been shown in many animals species to protect against hypoxic-ischemic brain injury. We sought to determine whether hypoxic-ischemic injury to the newborn pigs brain could be prevented by the use of MK-801. Methods Hypoxic-ischemic injury to the brain was induced in forty 0-3-day-old piglets. They were randomized to receive either 3 mg/kg MK-801 (MK-801 group, n=20) or vehicle (control group, n=19) prior to insult At time 0, the carotid arteries were ligated and the blood pressure was reduced by one third by hemorrhage. At 15 minutes, inspired oxygen was reduced from 50% to 6%. At 30 minutes, inspired oxygen was changed to 100%, carotid ligatures were released, and the withdrawn blood was reinfused. An additional 14 piglets received 3 mg/kg MK-801 but not hypoxic-ischemic injury (drug-only group), and a final group of 11 piglets were subjected to only a sham operation (sham group). Results Neurological examination scores at 24, 48, and 72 hours showed that MK-801 and drug-only piglets were significantly worse than the controls. Pathological examination of the brains at 72 hours showed significantly greater damage in the brains of the MK-801 and control pigs relative to the sham and drug-only groups. No differences were found between the control and the MK-801 groups. No differences were found between the sham and drug-only groups. Conclusions MK-801, at a dose of 3 mg/kg, causes neurological dysfunction in piglets lasting at least 72 hours, but neither causes brain damage nor ameliorates the effects of hypoxicischemic injury to the brain of the newborn pig.

Treatment of childhood dermatomyositis with high dose intravenous immunoglobulin

Two children with chronic dermatomyositis who were treated with intravenous immunoglobulin (IVIG) for 28 and 12 months, respectively, are reported. Both patients had received prednisone and immunosuppressive agents prior to IVIG treatments and had experienced significant side effects. Strength and functional abilities improved in both patients in a gradual stepwise fashion with IVIG treatment. One patient achieved remission and continues to do well without any immunosuppressive agents; in the other patient, the dose of oral steroids was reduced and other immunosuppressive agents were discontinued. Use of IVIG was associated with headaches, nausea, and vomiting in both patients. IVIG was an useful adjuvant therapy in these 2 children with dermatomyositis without any significant side effects.

Fructose-1,6-bisphosphate, when given immediately before reoxygenation, or before injury, does not ameliorate hypoxic ischemic injury to the central nervous system in the newborn pig.

Background and MethodsWe demonstrated earlier in our laboratories that fructose-1, 6-bisphosphate (FDP) would improve the outcome of hypoxic ischemic injury to the brain in the adult rabbit. Since many human newborns suffer hypoxic injury to the brain, with a secondary ischemic component due to hypoxic cardiac failure, we set out to reproduce similar experiments in newborn piglets. Hypoxic ischemic CNS damage was induced by ligating both carotid arteries and reducing BP to 66% of normal for 30 min; in the last 15 min, FIO2 was reduced to 0.6. Twelve piglets were randomized to receive either 175 mg/kg of FDP in the last 5 min before reoxygenation or the equivalent volume of saline. The other 20 piglets received 75 mg/kg of FDP in the 5 min immediately before carotid ligation, followed by 1.8 mg/kg·min continuous infusion for the 30 min of hypoxia and ischemia or an equivalent volume of saline. ResultsThere were no significant differences in the neurologic exam scores or pathologic exam scores between the FDP and control animals at either dose level. ConclusionIn this animal model, FDP at the doses given was not effective in ameliorating hypoxic ischemic injury to the CNS. (Crit Care Med 1990; 19:75)

Lethal neonatal autosomal recessive axonal sensorimotor polyneuropathy

Peripheral neuropathy is an uncommon cause of generalized hypotonia and weakness in infancy. It occurs as a part of the clinical syndrome in some neurodegenerative disorders of infancy, but seldom causes respiratory failure or swallowing difficulties. We report a lethal autosomal recessive axonal polyneuropathy with neonatal onset in a large kindred from Northern Mississippi. One patient was studied in detail at our medical center and the information on 12 other affected infants in this large family were gathered from medical records and by interviewing the family members. Patients were symptomatic for the polyneuropathy before birth and died in the first year of life from respiratory complications. Thirteen babies were affected by this clinical phenotype in four generations of this family with a high frequency of consanguinity. Affected babies were of both sexes and were born to healthy consanguineous parents. The clinical phenotype of polyneuropathy in our index patient and other affected babies in this family was similar, and represents a unique form of hereditary neonatal polyneuropathy.

Fructose-1,6-Diphosphate, when Given Five Minutes after Injury, Does Not Ameliorate Hypoxic Ischemic Injury to the Central Nervous System in the Newborn Pig

Hypoxic ischemic injury to the brain was induced in 12 0- to 3-day-old piglets. At time 0, the carotid arteries were ligated, and the blood pressure was reduced by one third by hemorrhage. At 15 min, inspired FIO2 was reduced from 50 to 6%. After 10 min of flat EEG, the FIO2 was changes to 100%, the carotid ligations were released, and the withdrawn blood was reinfused. Five minutes after reoxygenation, the piglets were randomly assigned to either receive 350 mg of fructose-1,6-diphosphate over 5 min, followed by 6 mg/kg/min for the ensuing 50 min, or an equivalent volume of normal saline. 3 days after the experiment, the animals received a neurologic examination by a blinded observer, were then sacrificed, and the brains examined by a blinded observer. There were no significant differences in the degree of damage between the two groups.

Fat embolism syndrome in a child with muscular dystrophy

Fat embolism syndrome is a relatively common complication of orthopedic trauma. Once thought to be rare in children, it probably occurs with a similar frequency as in adults, but is often subclinical. Clinically apparent fat embolism syndrome may exhibit neurologic, pulmonary, and cutaneous manifestations. It often resolves without sequelae if it is recognized promptly and supportive treatment is provided. We present a pediatric case of fat embolism syndrome and review the literature on its diagnosis and management in children.

Intervertebral disc calcification in children

Calcification of cervical intervertebral discs in children is due to an uncommon, but distinct, disease of unknown etiology. Signs and symptoms of nerve root or spinal cord compression are unusual and acute symptoms are followed by a benign course and spontaneous recovery. We describe a 5-year-old patient with symptomatic cervical disc calcification and discuss the relevant clinical and radiographic features.

Bilateral Mental Nerve Neuropathy in an Adolescent During Sickle Cell Crises

Mental nerve neuropathy causes the “numb chin” syndrome and is usually associated with mandibular bone injury or disease in adults. It has been reported in adults during sickle cell crises. We describe a 15-year-old boy who developed bilateral mental nerve neuropathies during a sickle cell crisis. This case is unusual because of the simultaneous bilateral involvement and because of the age.

Metabolic disorders causing childhood ataxia.

Ataxia is a common neurologic finding in many disease processes of the nervous system, and has classically been associated with numerous metabolic disorders. An error of metabolism should be considered when the ataxia is either intermittent or progressive. Acute exacerbation or worsening after high protein ingestion, concurrent febrile illness, or other physical stress is also suggestive. A positive family history can be an important diagnostic clue. Progressive molecular and biochemical techniques are revolutionizing this area of medicine, and there has been rapid advancement in understanding of the disease processes.

Vogt-Koyanagi-Harada Syndrome in a 4-Year-Old Child

Vogt-Koyanagi-Harada syndrome is an acquired illness with ocular, cutaneous, and/or neurologic features. A 4-year-old child who acutely developed visual disturbances and headache and was found to have serous retinal detachments and aseptic meningitis is presented. Improvement was rapid with corticosteroid therapy. This is the youngest reported patient with Vogt-Koyanagi-Harada syndrome.