The authors report the case of a 30-year-old woman who was a long-term intranasal cocaine abuser and who presented with transient ischemic attacks and multiple cerebral infarctions that were associated with moyamoya syndrome. The authors suggest that, because of its sympathomimetic effects, chronic cocaine use may promote intracranial arterial stenosis, distal ischemia, and subsequent formation of moyamoya-like vessels. The patient has remained clinically stable with no new episodes of stroke 6 years after undergoing “pial synangiosis” (modified encephaloduroarteriosynangiosis) to revascularize both hemispheres. Cocaine abuse may lead to moyamoya syndrome and may represent a chronic effect on the cerebral vasculature.
Marc S. Schwartz and R. Michael Scott
Gwen Schwartz and Michael G. Fehlings
Object. Persistent activation of voltage-sensitive Na+ channels is associated with cellular toxicity and may contribute to the degeneration of neural tissue following traumatic brain and spinal cord injury (SCI). Pharmacological blockade of these channels can attenuate secondary pathophysiology and reduce functional deficits acutely.
Methods. To determine the therapeutic effects of Na+ channel blockers on long-term tissue sparing and functional neurological recovery after traumatic SCI, the authors injected Wistar rats intraperitoneally with riluzole (5 mg/kg), phenytoin (30 mg/kg), CNS5546A, a novel Na+ channel blocker (15 mg/kg), or vehicle (2-HPβCD; 5 mg/kg) 15 minutes after induction of compressive SCI at C7—T1.
Functional neurological recovery of coordinated hindlimb function and strength, assessed 1 week postinjury and weekly thereafter for 6 weeks, was significantly enhanced in animals treated with riluzole compared with the other treatment groups. Seven weeks postinjury the preservation of residual tissue and integrity of descending axons were determined with digital morphometrical and fluorescent histochemical analysis. All three Na+ channel blockers significantly enhanced residual tissue area at the injury epicenter compared with control. Riluzole significantly reduced tissue loss in rostrocaudal regions surrounding the epicenter, with overall sparing of gray matter and selective sparing of white matter. Also, counts of red nuclei neurons retrogradely labeled with fluorogold introduced caudal to the injury site were significantly increased in the riluzole group.
Conclusions. Systemic Na+ channel blockers, in particular riluzole, can confer significant neuroprotection after in vivo SCI and result in behavioral recovery and sparing of both gray and white matter.
Michael L. Schwartz, Charles H. Tator and Harold J. Hoffman
✓ At 2, 10, and 60 min after intravenous injection of tritiated hydrocortisone into tumor-bearing mice, samples of brain and tumor were taken for autoradiography. Within 2 min of injection, large amounts of the steroid had left the bloodstream and had penetrated normal brain. By 60 min virtually all the drug had left the brain. The most radioactive structure was the choroid plexus. Within the normal and edematous brain, hydrocortisone was not found in cells alone but was spread randomly throughout the tissue. Edematous brain adjacent to implanted tumor contained much more steroid than normal brain. This difference was maximal at 10 min after injection. Edematous white matter adjacent to tumor was usually as radioactive as tumor. In the ependymoblastoma at 2 min after injection, neoplastic cells and interstitial tissue adjacent to blood vessels contained much hydrocortisone. At 10 min the drug was uniformly spread through the tumor tissue and by 60 min was largely gone. The uptake of the drug by the edematous brain suggests a direct local action. The high choroid plexus concentration may indicate a direct action there, perhaps to reduce cerebrospinal fluid production.
Charles H. Tator and Michael L. Schwartz
Jonathan P. S. Knisely, Rohan Ramakrishna and Theodore H. Schwartz
Michael A. Horgan, Jennifer C. Kernan, Johnny B. Delashaw, Marc S. Schwartz and Todd Kuether
Michael Hoa, Doniel Drazin, George Hanna, Marc S. Schwartz and Gregory P. Lekovic
With the increasing prevalence and decreasing cost of MRI scans, incidental discovery of vestibular schwannoma (VS) has become more common. Scarce literature exists regarding management of the tumors in those patients with incidentally discovered VSs, and clear guidelines for management do not exist. In this review, the authors examine the available literature for insights into management of incidentally diagnosed VS and provide an algorithm for their management.
Andrei I. Holodny, Theodore H. Schwartz, Martin Ollenschleger, Wen-Ching Liu and Michael Schulder
Michael L. Schwartz, Alan R. Hudson, Geoffrey R. Fernie, Ken Hayashi and Allan A. Coleclough
✓ It is known that boxers suffer a characteristic cumulative brain injury from repeated blows to the head that correlates well with the number of bouts fought. Much less is known about full-contact karate (kickboxing), which is relatively new. In full-contact karate, punches and kicks are actually landed, rather than being focused to culminate just short of an opponent, as practiced in traditional karate. Although a combatant can win on points, the surest means of victory is a knockout. Consequently, fighters strive to land blows to the head.
To investigate the relative force of kicks and punches, a dummy head was mounted 175 cm above the floor (to simulate a 50th-percentile man standing erect) and 125 cm above the floor (to simulate the man in a crouched position) on a universal joint permitting motion about three axes. The mechanism was contrived to provide constant rotational stiffness, and springs provided constant restorative moments about the three axes. The texture of soft tissue was simulated by a mask of visco-elastic foamed materials. Fourteen karate experts punched and kicked the dummy. Accelerometer measurements in the 90- to 120-G range indicated that safety-chops (hand protectors) and safety-kicks (foot padding) did not reduce acceleration of the dummy. Ten-ounce boxing gloves mitigated peak acceleration to some extent. Kicks and punches produced accelerations in the same range.
Violent acceleration of the head by any means produces injury. The authors conclude that, if full-contact karate is widely practiced, cases of kickboxer's encephalopathy will soon be reported.
Donald T. Stuss, Malcolm A. Binns, Fiona G. Carruth, Brian Levine, Clare E. Brandys, Richard J. Moulton, William G. Snow and Michael L. Schwartz
Object. The goal of this study was to characterize more fully the cognitive changes that occur during the period of acute recovery after traumatic brain injury (TBI).
Methods. The pattern of performance recovery on attention and memory tests was compared with the results of the Galveston Orientation and Amnesia Test (GOAT). Tests of memory and attention were administered serially to a hospitalized group of patients with TBI of varying severity. The tests differed in their level of complexity and/or requirement for more effortful or strategic processing. The authors found a regular pattern to recovery. As expected, ability to perform on simpler tests was recovered before performance on more effortful ones. The ability to recall three words freely after a 24-hour delay (the operational definition in this study of return to continuous memory) was recovered last, later than normal performance on the GOAT. Ability to perform simple attentional tasks was recovered before the less demanding memory task (recognition); ability to perform more complex attentional tasks was recovered before the free recall of three words after a 24-hour delay. This recovery of attention before memory was most notable and distinct in the group with mild TBI.
Conclusions. The period of recovery after TBI, which is currently termed posttraumatic amnesia, appears to be primarily a confusional state and should be labeled as such. The authors propose a new definition for this acute recovery period and argue that the term posttraumatic confusional state should be used, because it more appropriately and completely characterizes the early period of recovery after TBI.