Although its roots date back over a century, the field of neurotransplantation has been shaped mostly by advances over the past 30 years. Animal models of nigrostriatal disconnection in the 1970s allowed investigators to explore the feasibility of neural grafting. By the end of that decade, functional and behavioral effects had been demonstrated using fetal tissue grafts. In the 1980s, animal experimentation continued, as did clinical trials involving patients with idiopathic Parkinson's disease. Both autologous adrenal medullary tissue and fetal allografts were tested in the clinical setting, with the latter proving to yield superior results. Animal models of striatal cell loss provided the impetus for limited clinical trials in patients with Huntington's disease by the early 1990s, and work with both diseases continues today. Although much has been learned, neural grafting remains experimental. Broader applications are being explored even now, though, as transplant techniques are applied to animal models of dementia, spinal cord injury, cortical injury, and pain. Some very limited human trials have already begun in some of these areas. In this review some of the advances in the field are highlighted.
Robert E. Breeze and Marjorie C. Wang
Case report and review of the literature
Marjorie C. Wang, Ken R. Winston, and Robert E. Breeze
✓ The authors report a case of cerebellar mutism arising from a hemorrhagic midbrain cavernous malformation in a 14-year-old boy. No cerebellar lesion was identified; however, edema of the dorsal midbrain was noted on postoperative magnetic resonance images. Dysarthric speech spontaneously returned and then completely resolved to normal speech. This case provides further evidence for the theory that involvement of the dentatothalamic tracts, and not a cerebellar lesion per se, is the underlying cause of “cerebellar” mutism.
Robert E. Breeze, J. Gordon McComb, Shigeyo Hyman, and Floyd H. Gilles
✓ Clinically, there appears to be a significant reduction in cerebrospinal fluid (CSF) formation during acute ventriculitis — an observation that has not been well documented by experimental studies. To examine this phenomenon, an inoculum of Escherichia coli was injected into the lateral ventricles of New Zealand White rabbits. Approximately 18 hours later, the survivors (64%) underwent a 3-hour ventriculocisternal perfusion of carbon-14-dextran (MW 7 × 104) as a reference marker for CSF formation. On the average, CSF formation in this experimental group was reduced by one-half to two-thirds of normal, confirming the clinical observation. Histologically, the stroma of the choroid plexus was the site of an extensive inflammatory infiltrate. Meningitis, ependymitis, and focal encephalitis completed the picture. Vasculitis was not present in the choroid plexus. The epithelium of the choroid plexus underwent patchy cellular swelling or frank necrosis and destruction.
It is postulated that the changes in the choroid plexus caused by the inflammatory process were responsible for the diminished CSF formation in this acute setting. Reduced choroidal blood flow and/or enterotoxin may play a role in these alterations.
Robert E. Breeze, Peter Nichols, Hervey Segal, and Michael L. J. Apuzzo
✓ A case of an intradural epithelial cyst at the craniovertebral junction is reported in a 37-year-old man. The classification of these rare lesions is discussed.
Marjorie C. Wang, David Rubinstein, Glenn W. Kindt, and Robert E. Breeze
A familial predisposition toward cerebral aneurysms has been previously described in patients with two or more affected family members. In the present study the familial incidence of unruptured intracranial aneurysms was studied in 96 patients with at least one first-degree relative (parent, sibling, or child) in whom a cerebral aneurysm was diagnosed.
All patients were between 20 and 70 years of age and underwent three-dimensional fast–spin echo magnetic resonance imaging. Sixty-one patients (63.5%) were women. The majority of patients (84%) were caucasian and the remainder were Hispanic (13%) or African-American (3%). No patient suffered a medical condition (excluding hypertension and smoking) known to be associated with cerebral aneurysm formation.
In four patients at least one aneurysm was found (two harbored multiple aneurysms). Three of the four patients were women. Two of the patients were siblings. The estimated prevalence in first-degree relatives was 4.2% (95% confidence interval 1.2–10.1). Of note, the mean age in the current study population was 39 years. The authors of recent metaanalyses have suggested that the prevalence of nonfamilial aneurysms is approximately 2%, despite earlier reports in which higher figures were cited.
The authors conclude that first-degree relatives of patients with aneurysms are at higher risk for harboring an intracranial aneurysm.
Steven B. Carr, Greg Imbarrato, Robert E. Breeze, and C. Corbett Wilkinson
The authors present the case of a pediatric patient with Loeys-Dietz syndrome (LDS) who underwent craniotomy for clip ligation of a ruptured intracranial aneurysm. To the authors’ knowledge, this is the youngest reported patient with LDS who has been treated for a ruptured intracranial aneurysm. The patient presented with aneurysmal subarachnoid hemorrhage even though the results of surveillance screening were negative, and the aneurysm arose from the wall of the parent artery away from an arterial branch point. She was treated with open clip ligation and recovered well. The authors review the other reported cases of treated intracranial aneurysms in patients with LDS.