Robin I. Davidson

Intracranial pressure monitors. Epidemiologic study of risk factors and infections

An increase in the number of cases of gram-negative ventriculomeningitis in patients followed with intracranial pressure monitors when compared with patients with craniotomy alone was revealed by routine surveillance data. A study was undertaken at four area institutions to describe the infections, risk factors, and management. Two hundred fifty-five patients with diagnoses of intracerebral hemorrhage (n = 86), closed trauma (n = 66), open trauma (n = 21), tumor (n = 66), and miscellaneous other conditions were compared with their nonmonitored counterparts for type of intracranial pressure monitor used, use of drains, prophylactic antibiotics, and steroids, and remote presence of infection. The presence of intracranial pressure monitor with craniotomy was associated with an 11 percent infection rate whereas craniotomy alone demonstrated a 6 percent rate. Of the intracranial pressure monitors used, the subarachnoid screw was associated with the lowest infection rate (7.5 percent) followed by the subdural cup catheter (14.9 percent) and the ventriculostomy catheter (21.9 percent). Regardless of the monitor used, infection was twice as likely to develop in patients with open trauma or hemorrhage. The use of bacitracin flush solutions for maintenance of lumen patency was more often associated with infections. Use of prophylactic antibiotics did not significantly influence outcome.

Medullomyoblastoma. A histologic, immunohistochemical, and ultrastructural study

The light and electron microscopic features of a medullomyoblastoma arising in the cerebellar vermis of a 3‐year‐old boy are described. Differentiation along both glial and neuronal lines was present in the medulloblastoma component of the tumor. Astroytic differentiation was confirmed by the observation of compact bundles of 8 to 10 nm glial filaments in cellular processes on ultrastructural examination, and by positive immunostaining for glial fibrillary acidic protein (GFAP). Neuroblastic differentiation was suggested by the demonstration of axon‐like processes on silver impregnation, and ultrastructurally by the observation of microtubules, dense‐core and clear vesicles, and rare synapse‐like structures within cytoplasmic processes. The presence of both primitive and well‐differentiated striated muscle fibers in the tumor was confirmed by the demonstration of thick and thin myofilaments and Z bands on electron microscopy, and by positive immunostaining for myoglobin. These findings clearly establish the presence of both neuroectodermal and rhabdomyoblastic components in this neoplasm, and thus set it apart from the pure rhabdomyosarcomas, which may also occur in the cerebellar vermis in children. This case also illustrates the usefulness of electron microscopy and immunohistochemistry in the diagnosis and histogenetic evaluation of primitive or poorly differentiated small cell tumors of the central nervous system.

Glioblastoma of the cerebellum. Computed tomographic and pathologic considerations

Cerebellar glioblastoma is a brain malignancy that is often difficult to distinguish from metastatic disease in the elderly before biopsy. The clinical course and computed tomographic appearance of four patients with multiform glioblastoma of the cerebellum are presented and correlated with other reports in the literature. The appearance of a cerebellar hemispheric lesion with little mass effect is described, and the pathology of the tumor is reviewed.

Intramedullary spinal cord metastasis

Intramedullary spinal cord metastases are rarely the presenting manifestation of a previously undiagnosed neoplasms. We report such a case in which a subacutely progressive motor and sensory spinal cord syndrome was the initial problem. The differential diagnosis and the difficulties in distinguishing intramedullary from extramedullary mass lesions are discussed. The special features of tumors of the lung and their predilection for metastasis to the central nervous system are considered.

Spontaneous hemorrhage in a mixed glioma of the cerebellum: case report.

An 8-year-old boy presented in coma and was found to have a massive posterior fossa hemorrhage on computed tomographic scan. Autopsy disclosed a large cerebellar hematoma within a mixed glioma containing both juvenile pilocytic astrocytoma and oligodendroglioma. It is postulated that the hemorrhage originated from the oligodendroglial component of the tumor.

Intraspinal dislocation of the rib in neurofibromatosis: A case report

Scoliosis is the most common skeletal abnormality in neurofibromatosis, occurring in at least 10% of patients [1, 2]. Spinal MR is commonly used to assess the intraspinal contents prior to surgery for scoliosis.We report a case of neurofibromatosis I with dysplastic scoliosis which demonstrated an extradural mass on MR. Subsequent CT scan showed the presence of dislocation of the adjacent costovertebral articulation, with herniation of the rib head into the spinal canal.

Congenital Choroid Plexus Papilloma of the Fourth Ventricle

A newborn infant with marked hydrocephalus had a large papilloma of the choroid plexus originating in the fourth ventricle and infiltrating the brain stem. The computed tomographic (CT) scan appearance was distinctive, showing vascularity and marked enhancement with contrast medium. Histological confirmation was made from several surgical sites. Total removal of the tumor was not possible. Review of congenital choroid plexus brain tumors reveals the location of this childs tumor in the fourth ventricle to be uncommon. (J Child Neurol 1989;4:127-130).

Neurosyphilis presenting as a focal mass lesion: a case report.

A patient with subacute aphasia and hemiparesis was found to have a low density white matter lesion with mass effect on the computed tomographic (CT) scan. Serological examination and biopsy established the diagnosis of paretic neurosyphilis. This CT appearance has not previously been described in cases of neurosyphilis. Neurosyphilis should be considered as a potentially treatable cause of a cerebral mass lesion.

Gliosarcoma at the site of a surgically treated Actinomyces cerebral abscess.

We describe a man who developed a gliosarcoma at the site of a previously surgically decompressed frontal Actinomyces israelii brain abscess. We review the clinical profile of gliosarcoma and the possible role of the abscess and operation in the induction of this malignancy.

Acute cerebrospinal fluid hydrothorax: a delayed complication of subdural-pleural shunting.

A 31/2-year-old child with a bilateral chronic subdural hematoma due to battering suffered a recurrence on one side. She was treated successfully with a subdural-pleural shunt. Two months later, she returned with severe respiratory embarrassment due to what we think was a cerebrospinal fluid hydrothorax. The maintenance of her earlier neurological recovery was confirmed, and her hydrothorax was cured by removing the shunt. No hydrocephalus ensued.