Epilepsy and respiratory chain defects in children with mitochondrial encephalopathies.

OBJECTIVE: The purpose of this study was to determine the relationship between epilepsy and respiratory chain defects in children with mitochondrial encephalopathies (ME). STUDY DESIGN: We conducted a retrospective review of the medical records of children referred for evaluation of an ME. Only patients assigned a definite diagnosis of ME using modified Walker criteria and with a respiratory chain defect were included. Clinical data pertaining to the ME and epilepsy type were collected. Mitochondria were isolated by subcellular fractionation from a vastus lateralis muscle biopsy and studies were performed using polarographic and spectroscopic techniques for the quantitative determination of NADH and cytochrome components of the respiratory chain. RESULTS: A total of 38 children with ME were identified. Seizures were present in 61%. Sixteen of 23 children with epilepsy (70%) had refractory epilepsy associated with a progressive encephalopathy. Children with epilepsy had a significantly higher incidence of complex I defects than children without epilepsy (p<0.01). Complex III and IV defects were significantly higher in patients without epilepsy (p<0.01 and p<0.05, respectively) than in those with epilepsy. CONCLUSIONS: Epilepsy is an important component of ME. The higher incidence of complex I defects in patients with epilepsy suggests a possible relationship between mitochondrial oxidative stress dysfunction and epileptogenic process.

Outcome of children with primary intramedullary spinal cord tumors.

The influence of clinical and treatment factors on the outcome of children with primary intramedullary spinal cord tumors (PST) was evaluated by reviewing the records of 26 children diagnosed during the 15-year period 1970-1984. Five-year survival was 39%, but 5-year event-free survival (EFS) was only 14%. Eighteen-month EFS was 53% (9/17) among children with low-grade astrocytoma. 100% (2/2) with ependymoma, and 0 of 7 with anaplastic astrocytoma or ganglioglioma. There was no significant difference in the 18-month EFS by location of tumor, duration of symptoms, or extent of surgical removal. Five of 9 children with locally recurrent PST had a second operation, and 4 were alive a median of 56 months later. PST disseminated to the leptomeninges or the III ventricle in 5 children: 2 at diagnosis, 2 as the first sign of disease relapse, and 1 after local recurrence. Given the poor outcome of our children, different methods of treatment for children with tumors in this location should be evaluated.

Iron deficiency in children: the relationship between pretreatment laboratory tests and subsequent hemoglobin response to iron therapy.

The goal of detecting iron deficiency in children is to identify those whose Hb concentration will rise in response to treatment with iron. In a controlled treatment trial conducted among Eskimo children, we examined the effectiveness of various measures of iron nutrition in predicting a response to iron therapy (greater than 1.0 g/dl rise in Hb). A response was seen in 43%, and an additional 26% had an intermediate response (0.5 to 1.0 g/dl rise). When individual Hb values were expressed as SD scores of the Hb distribution of a reference population, a marked skew toward low scores was seen before treatment. After treatment, the distribution became more Gaussian, indicating that iron deficiency had been the major cause of anemia. Serum ferritin, transferrin saturation, and free erythrocyte protoporphyrin levels moved toward normal with treatment, however, none of the tests used was very effective in distinguishing individuals who would have a response t Hb from those who would not (sensitivities: 63 to 42%, specificities: 45 to 61%). Laboratory measures of iron nutrition were far more helpful in depicting the iron status of the population than they were in distinguishing iron-responsive from nonresponsive individuals.

Primary hepatocellular carcinoma in Alaskan natives, 1969-1979.

The records of 20 Alaskan Native patients with primary hepatocellular carcinoma (PHC) diagnosed in the 11-year period 1969-1979 were reviewed. The annual incidence of PHC was found to be high among Alaskan Native males and especially high among Alaskan Eskimo males (7.6 and 11.2 per 100,000 respectively) in comparison to Greenland and Canadian Eskimos and US white males. Familial and geographic clustering of PHC patients was noted in areas known to be hyperendemic for hepatitis B virus (HBV) infection. A bimodal age distribution among PHC patients occurred with peaks at 15-25 years and 40-65 years. A high prevalence of hepatitis B surface antigen (HBsAg) in serum of patients in the younger age group suggests that HBV infection might be a factor associated with the development of PHC in young Eskimos. PHC in Alaskan Natives is apparently not closely associated with alcoholic cirrhosis.

Hepatitis B testing in the families and villages of five young eskimos with primary hepatocellular carcinoma.

A 15-year-old female Eskimo and a 22-year-old male Eskimo from a southwestern Alaskan village (population 540) were diagnosed as having primary hepatocellular carcinoma (PHC) in December, 1977. The fathers of both patients also died of PHC. Three additional cases of PHC affecting young Alaskan Eskimos had been diagnosed since 1972, all from neighboring villages. Four of the five young patients were positive for hepatitis B surface antigen (HBsAg), and the family members of three patients were all positive for HBsAg or antibody to this antigen (anti-HBs). The other two families had no members positive for HBsAg. The prevalence of HBsAg in the villages of these patients ranged from 0--5%, and the prevalence of anti-HBs ranged from 3--25%. This part of Alaska has a high rate of infection with hepatitis B virus and an increased incidence of PHC. However, other Alaskan villages of similar ethnic background have considerably higher rates of hepatitis B infection than the four villages described and to date they have no PHC. This suggests that genetic and/or environmental factors in addition to hepatitis B infection may have a role in the etiology of PHC in Alaska.