Hemispherectomy for intractable unihemispheric epilepsy etiology vs outcome.

BACKGROUND: Surgical removal of one hemisphere has been performed for several decades to treat intractable unihemispheric epilepsy. A prior case series focused on the outcomes after 58 surgeries at Johns Hopkins Hospital in 1997. This series, and an additional 53 cases, were reviewed to bring the outcomes up to date. METHODS: Charts of the 111 patients undergoing hemidecortications at the Pediatric Epilepsy Center from 1975 to 2001 were reviewed and families were contacted. Three children died in the immediate perioperative period and three were lost to follow-up immediately after surgery. Follow-up ranged from 3 months to 22 years. RESULTS: Two children died several years later due to intractable seizures. Overall, 65% are seizure-free, 21% have occasional, non-handicapping seizures, and 14% have troublesome seizures. Eighty percent are on one anticonvulsant or none and 89% are able to walk without assistance. Etiology strongly predicted seizure outcome. Patients with migrational disorders are less likely to be seizure-free than all other etiologies (predominantly Rasmussen and congenital vascular injuries) combined (51% vs 71%, p = 0.05). CONCLUSIONS: Hemidecortication continues to be a beneficial procedure in reducing seizure frequency in cases of unilateral cortical epilepsy. Fewer children with migrational disorders are seizure-free.

The postoperative course and management of 106 hemidecortications.

RATIONALE: The excellent long-term outcome for most children undergoing hemispherectomy is well documented. However, the condition of these children in the immediate postoperative period is poorly described. The purpose of this study was to evaluate the short-term issues surrounding hemispherectomy and their management in a series of patients from our institution. METHODS: 106 hemispherectomies were performed at our institution from 1975 to 2001 (102 hemidecortications). Medical records were retrospectively examined for information regarding immediate postoperative problems and care. RESULTS: Three children died in the immediate perioperative period, while 3 others had significant postoperative morbidity. 82% of these children had postoperative fevers (temperature >38.5 degrees C). Of these children, 62% had lumbar punctures. Ten cases had positive CSF growth, of which 6 cases were felt to have actual meningitis. Patients with CSF growth had a significantly longer prior duration of steroid therapy and higher maximum temperature peaks. CSF pleocytosis and an ill clinical appearance neared significance for prediction of CSF growth. Shunting was performed in 19% of all children and was associated with CSF growth. CONCLUSIONS: Postoperative fevers are common after hemidecortication, but meningitis is not. Children with CSF growth tended to appear more ill and have higher temperature spikes and CSF pleocytosis. Shunting was related to CSF growth.

The ketogenic diet: a 3- to 6-year follow-up of 150 children enrolled prospectively.

OBJECTIVE: To document the long-term outcome of the 83 children with difficult-to-control seizures who were enrolled prospectively in a study of the efficacy of the ketogenic diet and who had remained on the diet for 1 year. METHODS: A total of 150 consecutive children were entered prospectively into a study of the ketogenic diet's efficacy and tolerability. Three to 6 years after diet initiation, all 150 families were sent a survey inquiring about their child's current health status, seizure frequency, and current anticonvulsant medications. They were asked about their experience with the diet and reasons for discontinuation. Several telephone attempts were made to contact those who did not respond to the written questionnaire. Responses were entered in an Access database and analyzed. RESULTS: In 1999, 3 to 6 years after initiating the diet, 107 of 150 families responded to a questionnaire. Thirty-five additional families were interviewed by telephone, 4 were lost to follow-up, and 4 children had died, unrelated to the diet. Of the original 150 patient cohort, 20 (13%) were seizure-free and an additional 21 (14%) had a 90% to 99% decrease in their seizures. Twenty-nine were free of medications, and 28 were on only 1 medication; 15 remained on the diet. There were no known cardiac complications. CONCLUSION: Three to 6 years after initiation, the ketogenic diet had proven to be effective in the control of difficult-to-control seizures in children. The diet often allows decrease or discontinuation of medication. It is more effective than many of the newer anticonvulsants and is well-tolerated when it is effective.

Risk factors for urolithiasis in children on the ketogenic diet.

Kidney stones have been associated with use of the ketogenic diet in children with refractory seizure disorders. We performed a case-control study examining risk factors for the development of stones on the ketogenic diet, and prospectively followed children initiating the ketogenic diet to evaluate the incidence of urolithiasis. Clinical characteristics of 18 children presenting with stones (8 uric acid stones, 6 mixed calcium/uric acid stones, 1 calcium oxalate/phosphate stone, 3 stones not evaluated) were compared with characteristics of non-stone-forming children initiating the ketogenic diet at Johns Hopkins since July 1996. Since July 1996, 112 children initiating the ketogenic diet have been followed for development of stones. Follow-up times on the diet range from 2 months to 2.5 years. Of 112 children, 6 have developed stones (3 uric acid, 3 mixed calcium/uric acid stones) (0.8 children developing stones/ 100 patient-months at risk). Comparisons of children presenting with stones on the ketogenic diet with characteristics of the entire cohort initiating the ketogenic diet suggest younger age at diet initiation and hypercalciuria are risk factors for the development of stones. Prospective evaluation of children initiating the ketogenic diet revealed that almost 40% of patients had elevated fasting urine calcium: creatinine ratios at baseline; this increased to 75% after 6 months on the diet. Median urine pH was 5.5 at diet initiation, and remained at 6.0 thereafter. In a subset of patients tested, urinary citrate excretion fell from a mean of 252 mg/24 h pre diet initiation to 52 mg/24 h while on the diet. Uric acid excretion remained normal. Patients maintained on the ketogenic diet often have evidence of hypercalciuria, acid urine, and low urinary citrate excretion. In conjunction with low fluid intake, these patients are at high risk for both uric acid and calcium stone formation.

The ketogenic diet: seizure control correlates better with serum beta-hydroxybutyrate than with urine ketones.

The objective of this study was to determine the relationship between beta-hydroxybutyrate levels and seizure control in children on the ketogenic diet. Seventy-four children on the ketogenic diet presenting for routine follow-up visits had blood levels of beta-hydroxybutyrate correlated with their seizure control. Forty-two children admitted for initiation of the ketogenic diet had urine ketones measured by dipstick and correlated with simultaneous blood levels of beta-hydroxybutyrate. Blood beta-hydroxybutyrate levels statistically correlated with seizure control (P = .003). Children with blood beta-hydroxybutyrate levels greater than 4 mmol/L were significantly more likely to have a decrease in seizure frequency than those with levels less than 4 mmol/L. Urine ketones of 4+ (160 mmol/L) were found on dipstick when blood beta-hydroxybutyrate levels exceeded 2 mmol/L. Seizure control correlates with blood beta-hydroxybutyrate levels and is more likely when blood beta-hydroxybutyrate levels are greater than 4 mmo/L. The traditional measurement of urine ketones by dipsticks in children on the ketogenic diet provides a less than optimal assessment of the degree of blood ketosis. Three to four plus (80-160 mmol/L) urine ketones are necessary, but not necessarily sufficient, to achieve optimal seizure control in children on the ketogenic diet. At present, however, urine ketones are the only readily available inexpensive approach to ketone assessment.

Medication cost reduction in children on the ketogenic diet: data from a prospective study.

In a prospective study of the efficacy of the ketogenic diet in children with severe, refractory epilepsy, data were collected on medication changes over 1 year. Cost reductions in medications were calculated over the first year and estimated for a second year. Fifty-seven percent of the children stayed on the diet for 1 year, and 74% of these children had their number of medications reduced. Forty-eight percent of children who stayed on the diet were on no medications at 12 months follow-up. Daily medication costs were reduced by nearly 70%.

The efficacy of the ketogenic diet-1998: a prospective evaluation of intervention in 150 children.

OBJECTIVE: The ketogenic diet is a high-fat, low-protein, low-carbohydrate diet developed in the 1920s for the treatment of children with difficult to control seizures. Despite advances in both the pharmacotherapy and the surgery of epilepsy, many children continue to have difficult-to-control seizures. This prospective study sought to determine the ketogenic diet's effectiveness and tolerability in children refractory to today's medications. METHODS: One hundred fifty consecutive children, ages 1 to 16 years, virtually all of whom continued to have more than two seizures per week despite adequate therapy with at least two anticonvulsant medications, were prospectively enrolled in this study, treated with the ketogenic diet, and followed for a minimum of 1 year. Seizure frequency was tabulated from patients' daily seizure calendars and seizure reduction calculated as percentage of baseline frequency. Adverse events and reasons for diet discontinuation were recorded. RESULTS: The children (mean age, 5.3 years), averaged 410 seizures per month before the diet, despite an exposure to a mean of 6.2 antiepileptic medications. Three months after diet initiation, 83% of those starting remained on the diet and 34% had >90% decrease in seizures. At 6 months, 71% still remained on the diet and 32% had a >90% decrease in seizures. At 1 year, 55% remained on the diet and 27% had a >90% decrease in seizure frequency. Most of those discontinuing the diet did so because it was either insufficiently effective or too restrictive. Seven percent stopped because of intercurrent illness. CONCLUSIONS: The ketogenic diet should be considered as alternative therapy for children with difficult-to-control seizures. It is more effective than many of the new anticonvulsant medications and is well tolerated by children and families when it is effective.

Polysomnography after adenotonsillectomy in mild pediatric obstructive sleep apnea.

OBJECTIVES: a) To determine the need for intensive monitoring on the first operative night of surgery in children undergoing adenotonsillectomy for mild obstructive sleep apnea; b) to examine the effect of narcotics on postoperative obstructive sleep apnea. DESIGN: Randomized, prospective study. SETTING: University hospital. PATIENTS: Children, ranging in age between 1 and 18 yrs, presented to the Pediatric Otolaryngology Clinic for adenotonsillectomy for mild obstructive sleep apnea defined as from one to 15 obstructive apnea events per hour on preoperative polysomnogram. INTERVENTIONS: Patients were assigned to receive either a narcotic- or a halothane-based anesthetic for adenotonsillectomy. A postoperative polysomnogram was performed in the pediatric intensive care unit on the first operative night. MEASUREMENTS AND MAIN RESULTS: Eighteen patients were recruited, 15 of whom met inclusion criteria: nine patients received a halothane-based anesthetic and six patients received a fentanyl-based anesthetic. When the data were analyzed by pooling both groups, the differences between pre- and postoperative sleep studies demonstrated a reduction in the number of obstructive events and less severe oxygen desaturations on the operative night. Total sleep time between the two sleep studies decreased from 371 +/- 13 to 304 +/- 14 mins. The number of obstructive apnea events/hr decreased as well. The lowest oxygen saturation measured during rapid eye movement sleep was 78 +/- 5% preoperatively and 92 +/- 1% postoperatively. CONCLUSIONS: Our data suggest that children without underlying medical conditions, neuromotor diseases, or carniofacial abnormalities, 1 to 18 yrs of age, who suffer from mild obstructive sleep apnea, have improvements documented by polysomnography on the night of surgery following adenotonsillectomy and do not necessarily need to be monitored intensively. These findings were not significantly affected by the choice of intraoperative anesthetic.