NNS 2015 Program & Abstract Book

stimulation parameters promoted standing with the least amount of

assistance, which was achieved with overall continuous EMG patterns

of the lower limbs’ muscles. Stimulation parameters optimized for one

individual resulted in poor standing and additional need of external

assistance for hip and knee extension in the other participants. During

sitting, little or negligible EMG activity of lower limb muscles was

induced by epidural stimulation showing that weight-bearing related

sensory information was needed to generate sufficient EMG patterns

to effectively support full weight-bearing standing. In general, elec-

trode configurations with cathodes selected in the caudal region of the

array at relatively higher frequencies (25–60 Hz) and near-motor

threshold amplitudes resulted in the more effective EMG patterns for

standing. These results show that human spinal circuitry can generate

motor patterns effective for standing in the absence of functional

supraspinal connections; however the appropriate selection of stimu-

lation parameters is critical.

Keywords: epidural stimulation, standing, spinal cord injury, re-

covery of motor function

AANS03-03

ARE STEM CELLS THE ANSWER?

Allan Levi

University of Miami, Miller School of Medicine/Jackson Memorial

Hospital, Neurological Surgery, Miami, USA

Stem cells have been recog-nized and in-tensively studied for their po-

tential use in restorative appro-aches for traumatic injuries to the spinal

cord. In stem cell-based strategies, the cells have been pro-posed to

replace neu-ronal, astro-cyte, oligo-dendro-cytes loss and also con-tri-

bute to neo-vascularization. This review will dis-cuss some of the pre-

clinical studies supporting the use of stem cells after SCI. The focus will

be on the use of bone marrow stromal cells (BMSCs) / mesenchymal

stem cell as well as neural stem cells for the repair of the spinal cord

injury (SCI). A review of the ex-tent of stem cell tourism for SCI will be

demon-strated. Also some of the pre-liminary data on the use of neural

stem cells for chronic SCI will be dis-cussed.

Keywords: cell-based strategies, BMSCs, spinal cord, SCI

AANS04 Outcomes after Cranial Trauma

AANS04-01

LONG TERM FUNCTIONAL OUTCOMES AFTER HEMI-

CRANIECTOMY FOR TRAUMA

Ann-Christine Duhaime

Massachusetts General Hospital, Harvard Medical School, Pediatric

Neurosurgery, Boston, USA

Hemicraniectomy has gained recent popularity in management of both

pediatric and adult head injury in patients with incipient or established

brain swelling. The exact indications, techniques, and outcomes remain

controversial. While a number of studies have shown improvements in

mortality, morbidity and complications remain significant. This talk will

compare some of the available studies in this area, with particular

emphasis on key differences in populations studied and methodologies

which may underlie differences in conclusions about the utility and

long-term outcomes after hemicraniectomy procedures. Suggested ap-

proaches for decision-making about when and in whom to utilize this

technique will be outlined, as well as research gaps which still need to

be filled for more definitive guidance.

Keywords: Surgery, Decompression, Craniotomy, Outcome

AANS04-02

HOW STRONG IS THE EVIDENCE LINKING TRAUMA AND/

OR TAU TO DEMENTIA

Dan Perl

, Sharon Shively

USUHS, CNRM, Bethesda, USA

One of the most feared long term consequences of traumatic brain

injury (TBI) is the development of dementia. Multiple epidemiologic

studies have shown that experiencing a TBI in early or midlife is as-

sociated with an increased risk of dementia in late life. The best

available data indicate that an episode of moderate to severe TBI in-

creases the subsequent risk for the development of dementia between 2-

and 4-fold. It is less clear whether mild TBI results in increased de-

mentia risk, in part because mild head injuries are often not well

documented and retrospective studies have inherent recall bias. How-

ever, it is well understood that multiple mild TBIs, as experienced by

professional boxers and football players are associated with a high risk

of chronic traumatic encephalopathy (CTE), a type of dementia with

distinctive clinical and pathologic features. The recent recognition of

many cases of CTE among retired professional football and hockey

players has stimulated great interest in this unique condition charac-

terized by the widespread accumulation of the microtubule-associated

protein

tau

, in neurons and astrocytes. In association with the prolonged

and repeated deployments to Iraq and Afghanistan, there has been the

recognition that military personnel also experience high rates of mild

TBIs and may develop a similar syndrome. A recent study has shown an

increased risk of dementia among older Veterans who had previously

experienced TBI (Barnes, DE, et al.

Neurology

83: 312–319, 2014).

Because virtually all epidemiologic studies linking prior episodes of

TBI with late life dementia have lacked postmortem examination, it

remains unclear if this association relates to the subsequent develop-

ment of Alzheimer’s disease, CTE or some other entity. There is clearly

need for detailed neuropathologic evaluations of incident cases of de-

mentia following prior episodes of TBI and the inclusion of postmortem

examination in epidemiologic studies relating dementia with prior TBI.

Keywords: dementia, tau, neuropathology, CTE, Alzheimer’s disease

AANS04-03

PREVALENCE OF VISION PROBLEMS AFTER CONCUS-

SION IN CHILDREN 11–17 YEARS OLD

Christina Master

, Mitchell Scheiman

, Michael Gallaway

, Arlene

Goodman

, Roni Robinson

, Stephen Master

, Matthew Grady

The Children’s Hospital of Philadelphia, Pediatrics/Orthopedic

Surgery, Philadelphia, USA

Pennsylvania College of Optometry at Salus University, Optometry,

Philadelphia, USA

St. Peter’s Sports Medicine Institute, Orthopedics, Somerset, USA

Weill Cornell Medical School, Pathology and Laboratory Medicine,

New York, USA

Vision problems, including binocular vision disorders, accommodative

disorders, such as convergence insufficiency, and eye movement/sac-

cadic disorders have been found after concussion in the adult popula-

tion, both military and civilian. Symptoms are associated with

prolonged visual near work, including eye strain, headaches, blurred/

double vision. There are currently no prospective studies on the prev-

alence of vision problems in adolescents following concussion.

Participants were recruited from the Minds Matter Concussion

Program at The Children’s Hospital of Philadelphia for this pro-

spective, cross-sectional study. Patients with the diagnosis of con-

cussion underwent vision testing, including an assessment of visual

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