Hypomagnesemia secondary to cerebrospinal fluid losses in a patient with congenital hydrocephalus.

We describe a newborn infant with massive congenital hydrocephalus, presenting with hypomagnesemia secondary to magnesium losses through cerebrospinal fluid (CSF) aspirations. Hypomagnesemia due to CSF losses has not been described in pediatric literature.

Isolated cerebellar edema and obstructive hydrocephalus in a child with cerebral malaria.

An important complication of cerebral malaria is increased intracranial pressure which, when severe, is associated with high mortality or neurologic sequelae. We describe a 7-month-old child with cerebral malaria for whom cerebellar edema and obstructive hydrocephalus were initial radiologic findings. Despite significant hydrocephalus, the child had normal intracranial pressure during the course of the infection, and he recovered with minimal sequelae.

Coccygeal pits.

BACKGROUND: Congenital dermal sinuses represent cutaneous depressions or tracts that are lined by stratified squamous epithelium. They communicate between the surface of the skin and deeper structures and may occur anywhere along the craniospinal axis. These sinuses are thought to result from abnormal separation of the cutaneous and neural ectoderm between the third and fifth week of intrauterine life. They may be often accompanied by other cutaneous stigmata, various dysraphic abnormalities, or intraspinal tumors. In the sacrococcygeal area, cutaneous congenital abnormalities are relatively common. It is estimated that 2% to 4% of children harbor intergluteal dorsal dermal sinuses. These intergluteal sinuses in the perianal region are frequently referred to as pits or dimples. Their cause is considered similar to other congenital dermal sinuses and appears unrelated to acquired pilonidal conditions observed in adults. They may become susceptible to local recurrent infection from trauma or hirsutism. Controversy regarding the evaluation and management of cutaneous defects in the coccygeal region exists. METHODS: Both a literature review and a career review of clinical material were performed. Databases for articles published in English were surveyed for key words relating to coccygeal sinuses using standard computerized search techniques. The medical records of children presenting to our neurosurgical clinic for evaluation of dorsal dermal sinuses were reviewed to identify those with intergluteal sinuses. RESULTS: In the evaluation of reported cases and of our own, we were unable to identify any children with coccygeal sinuses without other cutaneous markers other than hair with findings suggestive of intraspinal communication. CONCLUSIONS: Intergluteal dorsal dermal sinuses are relatively common lesions that frequently come to neurosurgical attention. They do not seem to be associated with significant risk of spinal cord and intraspinal anomalies. Simple intergluteal dorsal dermal sinuses without other cutaneous findings do not require radiographic or surgical evaluation and treatment. If other markers or neurologic symptoms are present, however, radiographic evaluation may be indicated.

Integral and shell-MIP display algorithms in MR and CT three-dimensional models of the brain surface.

BACKGROUND AND PURPOSE: Our purpose was to demonstrate the use of integral and shell maximum intensity projection (shell-MIP) display algorithms in the 3-D CT and MR depiction of cerebral gyral and surface venous anatomy and disorders. These new algorithms are compared against MIP and shaded-surface-display (SSD) algorithms. METHODS: Integral and shell-MIP displays were generated from a specified number of proximal surface voxel layers in a 3-D model. Algorithmic models were compared on nine contrast-enhanced spoiled gradient-recalled acquisition in a steady state (SPGR) MR venograms for brain surface anatomic identification and detail. Seven CT venograms were compared for conspicuity of filling defects. Twelve contrast-enhanced preoperative planning 3-D MR models were rated for neurosurgical utility. RESULTS: A shell-MIP score of 7.00 and an integral score of 6.78 represented the highest mean subjective MR gyral quality (1-10 scale) followed by an SSD score of 3.89 and an MIP score of 1.06. Mean confidence scores for MR central sulcus identification (1-10 scale) were shell-MIP, 7.67; integral, 7.00; SSD, 3.22; and MIP, 1.00. Mean superficial venous quality MR ratings (1-10 scale) were shell-MIP, 8.22; MIP, 7.39; integral, 7.00; and SSD, 3.72. The mean number of cortical veins draining into each side of the superior sagittal sinus on MR was as follows: MIP, 6.19; integral, 6.06; shell-MIP, 5.94; and SSD, 3.81. Mean confidence scores for filling defect identification on CT venograms (1-5 scale) revealed a shell-MIP score of 4.36 and an integral score of 4.29 to be superior to a MIP score of 3.00. In selected cases, 3-D presurgical planning, prior to tumor resection, was clinically useful. CONCLUSION: Integral and shell-MIP are useful 3-D display algorithms for simultaneous display of superficial cerebral veins and gyri on MR images and of thrombosis on CT venograms.

Long-term survival in rhinocerebral mucormycosis. Case report.

Mucormycosis refers to a group of rapidly progressive infections caused by fungi belonging to the order Mucorales. Infection most often develops in individuals with immunological or metabolic compromise, although patients without underlying abnormalities have been affected. Specific clinical manifestations are associated with various predisposing factors. Rhinocerebral mucormycosis is the most common form and most frequently develops in individuals with poorly controlled diabetes mellitus. The extent of anatomical involvement and clinical course are unpredictable, depending on the intrinsic factors of the host. Over the past 20 years the prognosis for patients with rhinocerebral mucormycosis, once considered to be a uniformly fatal disease, has improved. Coordinated medical and surgical treatment, including rapid diagnosis, the advent of systemic antifungal agents, aggressive surgical debridement, and control of the underlying disease process, have been credited with its successful management. The range of survival rates recorded with the regimen of combined therapies is wide because the number of patients reported is limited and anatomical involvement is diverse. Survival with intracerebral abscess is rare. The authors describe the successful management of a patient who developed a bifrontal fungal abscess during treatment for rhinocerebral mucormycosis associated with ketoacidosis and diabetes mellitus. The patient remains without radiographic or clinical evidence of infection more than 2 years after treatment. The authors review the characteristic clinical, radiographic, and pathological features of previously reported infections and emphasize the importance of early detection and aggressive treatment in the management of this frequently fulminant and fatal disease.

Stereotactic radiosurgery in pediatric patients.

Although stereotactic radiosurgery has been studied extensively in adults, the data demonstrating its efficacy in children is limited. Medical records were reviewed to identify the indications for and outcomes of patients treated with this modality. Linear accelerator-based radiosurgery was used to treat 11 recurrent brain tumors and one posterior fossa arteriovenous malformation over 3 years. The mean and median age of those treated was 10 and 8 years, respectively (range 1-20 years). Patients received 700 to 3,000 cGy delivered to the 50-90% isodose line in a single fraction. The mean and median follow-up was 15 and 17 months, respectively. Three of the four children with malignant disease died 6 to 9 months after treatment. One patient died of recurrence outside the treatment field. Another child died of complications related to radiation injury, and the third died of disease progression. All children with low-grade tumors remain alive without complications. Six of eight (75%) children exhibit substantial radiographic reductions in tumor size. The child with a vascular malformation has been followed for 26 months, without hemorrhage and with a radiographically proved decrease in size. Our series suggests that radiosurgery has limited usefulness in malignant disease. Therapeutic response is influenced by lesion size and/or location. Stereotactic radiosurgery appears to be effective in children with low-grade intracranial tumors or arteriovenous malformations. Further experience is required to establish the role and long term side effects of radiosurgery in pediatric patients.

Central neurocytoma. Diagnosis and treatment.

Central neurocytoma is a rare intraventricular brain tumor that affects young adults and presents with nonspecific signs and symptoms. This distinct clinicopathological entity has a benign biological behavior with good prognosis following surgical intervention. Two cases of central neurocytoma are presented and the diagnosis and treatment discussed.

Effects of etomidate and hypothermia on cerebral metabolism and blood flow in a canine model of hypoperfusion.

Etomidate is a nonbarbiturate hypnotic agent which, like the barbiturates, decreases the cerebral metabolic rate of oxygen consumption (CMRO2) 35-50%. The present studies assessed whether etomidate decreased CMRO2 through temperature-dependent mechanisms and whether the combination of etomidate and moderate hypothermia (28 degrees C) decreased CMRO2 more than hypothermia alone. Nineteen anesthetized dogs were treated with saline, etomidate (burst-suppressive doses), etomidate with hypothermia, or hypothermia alone. Etomidate did not affect (p > 0.05) the mean arterial pressure (MAP, mm Hg) but modestly lowered the heart rate [HR; 124 +/- 6 to 105 +/- 14, (mean +/- SEM); p < 0.05] whereas hypothermia (without or with etomidate) lowered (p < 0.05) both MAP (141 +/- 4 to 116 +/- 5 and 135 +/- 6 to 81 +/- 7) and HR (135 +/- 14 to 84 +/- 3 and 135 +/- 10 to 69 +/- 5, respectively). Etomidate administration did not result in a change (p > 0.05) in the esophageal, brain parenchymal, or subdural temperature. CMRO2 (ml/100 g/min) decreased (p < 0.05) during etomidate administration (3.2 +/- 0.4 to 1.7 +/- 0.2) and hypothermia (3.5 +/- 0.2 to 1.1 +/- 0.2), but the addition of etomidate to hypothermia did not further reduce CMRO2 in the animals (3.1 +/- 0.5 to 1.3 +/- 0.2) despite decreasing their brain hemispheric electrical activity from 9 +/- 1 Hz to a burst-suppressive state.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of etomidate on cerebral metabolism and blood flow in a canine model for hypoperfusion.

The effects of etomidate, a nonbarbiturate cerebral metabolic depressant, on cerebral metabolism and blood flow were studied in 29 dogs during cerebral hypoperfusion. Three groups of animals were studied during a 45-minute normotensive and a 30-minute hypotensive period: 10 control animals without etomidate, 11 animals receiving a 0.1-mg/kg etomidate bolus followed by an infusion of 0.05 mg/kg/min etomidate (low-dose group), and eight animals receiving doses of etomidate sufficient to suppress electroencephalographic bursts (high-dose group). The mean arterial pressure fell to similar levels (p less than 0.05) during hypotension in all three groups (40 +/- 5, 38 +/- 3, and 27 +/- 6 mm Hg, respectively). The mean cerebral oxygen extraction fraction rose (p less than 0.05) from 0.23 +/- 0.02 to 0.55 +/- 0.08 in the five control animals tested and from 0.33 +/- 0.02 to 0.53 +/- 0.02 in the seven animals tested in the low-dose group, but did not increase (p greater than 0.05) in the four animals tested in the high-dose group (0.24 +/- 0.03 to 0.23 +/- 0.05). Mean cerebral blood flow levels decreased in all groups during hypotension (p less than 0.05): 42 +/- 3 to 21 +/- 4 ml/100 gm/min (52% +/- 12% decrease) in the five animals tested in the control group, 60 +/- 8 to 24 +/- 6 ml/100 gm/min (56% +/- 13% decrease) in the four animals tested in the low-dose group, and 55 +/- 8 to 22 +/- 3 ml/100 gm/min (60% +/- 4% decrease) in the four animals tested in the high-dose group. In summary, the cerebral oxygen extraction fraction increased in the control animals and low-dose recipients during hypotension, suggesting the presence of threatened cerebral tissue. In contrast, the cerebral oxygen extraction did not change during hypotension when high-dose etomidate was administered. It is concluded that high-dose etomidate may preserve the cerebral metabolic state during hypotension in the present model.