Michael J. Scott

Pial Synangiosis for Moyamoya Syndrome in Children

The authors describe a modification of the encephalo-duro-arterio-synangiosis (EDAS) surgical technique for patients with moyamoya syndrome in which the arachnoid is widely opened over the exposed brain and the donor superficial temporal artery adventitia is sutured directly to the pia with 10-O nylon suture (pial synangiosis). The procedure has been performed in 34 patients over a 10-year period, with follow-up arteriograms 1 year following the procedure demonstrating markedly enhanced middle cerebral artery flow through the surgical site. Operative morbidity has been limited to two postoperative strokes, both in patients who were neurologically unstable preoperatively; and the clinical stability of the operated patients has thus far been excellent.

Surgery, Radiation, and Combination Therapy in the Treatment of Childhood Craniopharyngioma – A 20-Year Experience

The records of 61 children treated for primary craniopharyngioma at the Childrens Hospital in Boston and The Joint Center for Radiation Therapy from 1970 to 1990 were reviewed to determine if any information could be obtained regarding the efficacy of surgery versus radiotherapy or a combination of these modalities for this tumor. A select group of 9 children treated without biopsy by radiation therapy alone were all alive without disease progression at follow-up. Although 9 of the 15 children who underwent surgery alone had tumor recurrence, 7 of the 37 children treated with radiotherapy following surgery have also recurred. Treatment morbidity occurred in all groups, but the 10-year actuarial survival for all patients was 91%. Early postoperative imaging and pre- and posttreatment endocrine and neuropsychologic evaluations need to be carried out in all prospective studies of the treatment of craniopharyngioma in children.

Preparation of α,β-unsubstituted meso-arylbidipyrrins via metal-templated, oxidative coupling of dipyrrins

A three-step, one-pot procedure provides meso-aryl-α,β-unsubstituted bisdipyrrinato nickel complexes; oxidative coupling of these ligands followed by demetallation affords an unprecedented class of meso-aryl-α,β-unsubstituted bidipyrrins.

Advances in Radiation Therapy for Craniopharyngiomas

The overall survival for patients with craniopharyngioma is excellent. However, conventional treatments that include aggressive surgery and standard irradiation have been associated with significant morbidity. Focal radiation treatment with stereotactic radiosurgery has a role in selected cases, but may also be damaging to sensitive normal tissues such as the optic chiasm. Stereotactic radiotherapy (SRT) is a technique that allows for conventionally fractionated radiation under stereotactic guidance. Thus, highly focal and precise radiotherapy is now coupled with fractionation, enabling the treatment of selected tumors with a potentially improved therapeutic index. Dose optimization with SRT for focally discrete tumors should result in equivalent local control and survival compared to patients treated with conventional irradiation. We anticipate a significant decrease in late effects, especially neuropsychological and neuroendocrine sequelae.

Jugular Foraminal Stenosis in Crouzon Syndrome

We describe a 4-year-old boy with Crouzon syndrome, with associated acanthosis nigricans and Chiari-I malformation, who developed increased intracranial pressure necessitating posterior cranial expansion. Postoperatively, an arteriovenous fistula appeared over the mastoid region. Cerebral angiography demonstrated bilateral atresia of the jugular veins and occlusion of the left sigmoid and right transverse sinuses. We propose that increased intracranial venous pressure, secondary to bilateral jugular foraminal stenosis, caused hydrocephaly and venous dilation in the scalp vasculature. The latter set the stage for a traumatic arteriovenous fistula of the scalp, probably resulting from laceration of an adjacent artery and vein. Jugular atresia is a basilar malformation common to achondroplasia and certain eponymous syndromic craniosynostoses. Our patient has a mutation in fibroblast growth factor receptor 3, a different locus in the same gene mutated in achondroplasia.

Seizures in Children with Supratentorial Astroglial Neoplasms

We reviewed the records of 98 consecutive patients, 18 years of age or younger, with pathologically confirmed supratentorial astroglial neoplasms at the Childrens Hospital, Boston, to evaluate the importance of seizures in their presentation and natural history. Tumors were diagnosed using the WHO criteria as pilocytic astrocytomas, astrocytomas, anaplastic astrocytomas, glioblastomas, giant cell glioblastomas, oligoastrocytomas and gangliogliomas. Our results were as follows. (1) Fifty percent of children had seizures as part of their presentation and 30% had seizures as their only presenting phenomenon. (2) The seizures varied in nature, but complex (55%) or simple (28%) partial seizures were by far the most common types, occurring in 77% of cases. (3) Preoperative electroencephalography (EEG) accurately lateralized to the tumor side in 88% of the cases and localized to the correct lobe in 56%. (4) Tumors involving cerebral cortex significantly correlated with seizures at presentation as compared to noncortical locations; 59% of patients with cortical tumors presented with seizures, and only 15% of patients with noncortical tumors experienced seizures. Lesions in the temporal and frontal lobes had the highest incidence of seizures. (5) Patients with gangliogliomas and oligoastrocytomas had the highest incidence of seizures, 88 and 86%, respectively, whereas patients with anaplastic astrocytoma had the lowest incidence, 21%. (6) Histopathologic calcification was associated with seizures at presentation approaching significance (p = 0.06). (7) Seizures at presentation were significantly associated with good prognosis (p = 0.02).

Effect of Surgical Repair on the Neurourologic Function in Infants with Lipomeningocele

Eighteen children under the age of 1 year underwent surgery for lipomeningocele at our institution between 1983 and 1991. All the patients had neurologic exams and urodynamic studies (UDS) including a cystometrogram and electromyography of the external urethral sphincter pre- and postoperatively. The surgical procedure performed included an untethering of the spinal cord, laser debulking of the lipoma and placement of a dural graft. All the infants presented with a lesion on their back. Two of 10 infants with a normal neurological exam had abnormal UDS preoperatively. Early surgery normalized abnormal preoperative UDS in 5 of 6 (83%) infants with abnormal UDS. Moreover, 3 of 8 (38%) infants with an abnormal neurological exam preoperatively improved after surgery and none worsened. These observations suggest that abnormal urinary tract function in infants with lipomeningocele may be reversible with early prophylactic surgery.

Spontaneous Rapid Resolution of an Epidural Hematoma Associated with an Overlying Skull Fracture and Subgaleal Hematoma in a 17-Month-Old Child

Acute traumatic epidural hematomas (EDH) constitute one of the most critical emergencies in neurosurgical management. The rapid spontaneous resolution (<24 h) of EDH is an extremely rare phenomenon. A 17-month-old patient fell from a height of 1.5 m and presented with a 8-mm temporal EDH, an overlying linear skull fracture, and a subgaleal hematoma without evidence of intraparenchymal injury or edema. The patient complained only of mild headache, harbored no neurological deficits, and was, therefore, managed conservatively in the intensive care unit with provision to proceed to surgical decompression in the event of neurological change. A repeat CT study 18 h later revealed near-complete resolution of the EDH with a coincident increase in the volume and spread of the subgaleal hematoma. This is the fourth reported case of rapid spontaneously resolving EDH and the youngest one to date. All 4 cases have coincided with an overlying linear skull fracture. We propose that unlike classical EDH, rapidly resolving EDH in the absence of elevated intracranial pressure (ICP) originates from elevated interstitial pressure in the subgaleal compartment transiently decompressing into the epidural space through a skull fracture and resolving as the pressure in the subgaleal compartment decreases below ICP.

C3-symmetric tripodal thio/diglycolamide-based ligands for trivalent f-element separations

Abstract Three new C 3‐symmetric ligands bearing diglycolamide and thiodiglycolamide units on a triphenoxymethane platform have been synthesized and evaluated as trivalent f‐element extractants from nitric acid media. Liquid‐liquid extraction studies of eleven different lanthanides from 1 M nitric acid into dichloromethane revealed a strong influence of the amidic substituents on the extraction efficiency. A comparison of the 1H NMR spectrum of the Lu(III) complex formed with the tris‐DGA ligand and the organic solution after the extraction experiment confirms that all three arms bind the metal during the extraction experiment and form a C 3‐symmetric complex. The newly synthesized lipophilic di‐n‐butyl tris‐diglycolamide was found to be a significantly weaker extractant in comparison to the di‐isopropyl analogs. The distance separating the metal binding groups from the triphenoxymethane platform had little influence on the selectivity or binding efficiency of the ligands. Experiments with the tris‐thiodiglycolamide derivative highlighted the importance of the etheric oxygens for metal binding.

Extended Structures Built on a Triphenoxymethane Platform − C3-Symmetric, Conformational Mimics of Calix[n]arenes

A series of C3-symmetric tris(3,5-dialkyl-2-hydroxyphenyl)methanes (alkyl = tert-butyl, methyl, tert-pentyl) have been synthesized in high yield from their respective phenols and fully characterized, including single crystal X-ray structures for two examples. The di-tert-butyl-substituted compound, 1a, has been derivatized to a tris-acid chloride, 4, which was treated with a variety of amines (dimethylamine, benzylamine, glycine, and alanine) from which the corresponding tris-amides 5−8 were formed. The absolute geometry and conformation of the dimethylamine, glycine, and alanine derived systems were determined by X-ray analyses, and in all cases, the three phenolate arms point up with respect to the central methine. Alkali metal binding studies (Li, Na, K, Rb, and Cs) were carried out for the dimethylamine, benzylamine, and glycine compounds 5−7, and these compounds were found to have some selectivity for potassium cations. NMR studies demonstrate that C3 symmetry is retained in all the compounds and the stoichiometry for lithium ion complexation is 1:1, whereas two ligands are needed to complex sodium cations. Crystal structures of the dimethylamine derivative with lithium picrate and the benzylamine and glycine derivatives with sodium tetraphenylborate were also determined.