Overall, 76.9% of patients with PTE had BBB disruption, compared with 33.3% of patients without epilepsy. Increased BBB permeability could be observed months or years following the trauma. In 70% of patients with BBB disruption, the source of abnormal delta band activity could be localized to the area of the BBB disruption.
“The research (together with our animal studies) predicts that patients with prolonged BBB breakdown after brain injury are at greater risk to develop epilepsy,” Dr. Friedman said. “Our results offer new diagnostic tools with potential preventive therapeutic implications,” he noted.
Dr. Friedman and his colleagues are currently conducting a prospective study in which they are closely following patients immediately after head trauma using MRI and EEG. “This study will challenge our hypothesis that prolonged BBB breakdown predicts the development of epileptic seizures,” the researchers said. “We also continue our basic research for better understanding the mechanisms underlying brain dysfunction under BBB breakdown and testing new therapeutic strategies to prevent the development of epilepsy.”
J Neurol Neurosurg Psychiatry. 2008;79(7):774-777.
Change in DBS Parameters May Improve Gait in Advanced Parkinson’s Disease
NEW YORK, July 24 (Reuters Health)—French researchers have reported promising results with subthalamic nucleus deep-brain stimulation (STN-DBS) delivered at 60 Hz and 3.7 volts (rather than 130 Hz at 3 volts) in patients with Parkinson’s disease who develop severe gait disorders.
Dr. David Devos and colleagues at the University of Lille, France, tested various STN-DBS parameters in 13 patients with Parkinson’s disease and severe gait disturbances and frequent freezing episodes. The investigators compared “off stimulation” with STN-DBS at 130 Hz or 60 Hz and at a usual voltage (median 3 volts) or a higher voltage (median 3.7 volts), while maintaining the same energy level.
Dr. Devos and associates reported in the July 8 issue of Neurology that the number of freezing episodes was significantly lower at 60 Hz and higher voltage, and was higher with 130 Hz and higher voltage, than with no stimulation.
“Our results demonstrated ... a negative effect on gait of increasing voltages at a fixed frequency of 130 Hz in Parkinson’s disease patients with severe gait disorders after several years of STN-DBS and ... a positive effect of reduced frequency at equivalent delivered energy levels, with the greatest benefit on freezing episodes appearing in the 60-Hz high voltage/equivalent-energy condition,” the investigators wrote.
The study was accompanied by an editorial by Dr. Michele Tagliati of Mt. Sinai School of Medicine in New York City.
“Believe it or not, we are still trying to learn how DBS works and whether we can use it to better treat Parkinson’s disease symptoms, to avoid complications or to learn more about Parkinson’s disease and the brain in general,” Dr. Tagliati commented in an interview with Reuters Health.
While DBS improves motor symptoms, “there are some symptoms, such as speech and gait difficulties or cognitive deficits, that seem not to respond or even deteriorate in some cases,” Dr. Tagliati explained.
“We try to adjust settings in order to maximize benefits (usually the control of motor symptoms like tremor, rigidity, dyskinesias) and minimize side effects (difficulty with speech, balance, sometimes mood swings and others),” Dr. Tagliati pointed out. “Occasionally we are forced to compromise one function for another (for example, speech for tremor control), but—with a properly placed electrode—that is luckily more the exception than the rule.”
Neurology. 2008;71(2):80-84; 76-77.
Sleep Apnea Increased in Charcot-Marie-Tooth Disease
NEW YORK, July 25 (Reuters Health)—There is a significantly increased prevalence of obstructive sleep apnea in patients with Charcot-Marie-Tooth disease type 1 (CMT1), German researchers reported in the July issue of the Journal of Neurology, Neurosurgery, and Psychiatry.
Dr. R. Dziewas and colleagues at University Hospital of Munster noted that CMT accounts for most diagnosed cases of hereditary motor and sensory neuropathy, and CMT1 is the most common type. Obstructive sleep apnea has been described in a large family with CMT1, they added, and the team sought to find out whether this was also the case in nonrelated patients.
Comparison of 12 such patients with 24 matched controls showed that five patients had an apnea-hypopnea index of greater than 10, compared to only one of the controls, a significant difference.
The team also found that there was a significant correlation between the apnea-hypopnea index value and neurologic disability.
“Pathophysiologically,” the researchers suggested, “one may assume that CMT1-related pharyngeal neuropathy increases the collapsibility of the upper airway, which, in turn, leads to recurring obstructive respiratory events.”
Commenting on the findings, Dr. Michael E. Shy, author of an accompanying editorial, told Reuters Health that given these findings, “the main issue is whether treatment of sleep apnea in CMT patients will improve daytime fatigue and provide increased energy to patients with inherited neuropathies.”