Altered Relationship between Working Memory and Brain Microstructure after Mild Traumatic Brain Injury.

BACKGROUND AND PURPOSE: Working memory impairment is one of the most troubling and persistent symptoms after mild traumatic brain injury (MTBI). Here we investigate how working memory deficits relate to detectable WM microstructural injuries to discover robust biomarkers that allow early identification of patients with MTBI at the highest risk of working memory impairment. MATERIALS AND METHODS: Multi-shell diffusion MR imaging was performed on a 3T scanner with 5 b-values. Diffusion metrics of fractional anisotropy, diffusivity and kurtosis (mean, radial, axial), and WM tract integrity were calculated. Auditory-verbal working memory was assessed using the Wechsler Adult Intelligence Scale, 4th ed, subtests: 1) Digit Span including Forward, Backward, and Sequencing; and 2) Letter-Number Sequencing. We studied 19 patients with MTBI within 4 weeks of injury and 20 healthy controls. Tract-Based Spatial Statistics and ROI analyses were performed to reveal possible correlations between diffusion metrics and working memory performance, with age and sex as covariates. RESULTS: ROI analysis found a significant positive correlation between axial kurtosis and Digit Span Backward in MTBI (Pearson r = 0.69, corrected P = .04), mainly present in the right superior longitudinal fasciculus, which was not observed in healthy controls. Patients with MTBI also appeared to lose the normal associations typically seen in fractional anisotropy and axonal water fraction with Letter-Number Sequencing. Tract-Based Spatial Statistics results also support our findings. CONCLUSIONS: Differences between patients with MTBI and healthy controls with regard to the relationship between microstructure measures and working memory performance may relate to known axonal perturbations occurring after injury.

Constraint-induced motor relearning after stroke: a naturalistic case report.

Constraint-induced movement therapy (CIMT) is a promising approach to promoting recovery of functional arm movement after stroke. However, controlled studies have been limited to persons who sustained strokes at least 1 year before beginning the treatment protocol. This case study documents the neurologic history and motor recovery of a woman whose natural circumstances lend support to the principles of CIMT. The patient sustained a right midpontine vascular infarct and fell simultaneously, fracturing her right humerus. Orthopedic intervention for the fracture mirrored the protocol suggested by proponents of CIMT by immobilizing her right arm. Her significant recovery of left arm use over a 1-year period was more extensive than what would be typically expected after the type of cerebral infarct she incurred. Her case provides the first evidence in the literature that supports the principles of CIMT when it is applied immediately poststroke.

Psychostimulant treatment of stroke and brain injury.

Psychopharmacology is rapidly becoming an adjuvant treatment to traditional rehabilitation strategies for patients with stroke or brain injury because it helps to facilitate recovery in a time-efficient manner. Norepinephrine, dopamine, acetylcholine, and serotonin appear to play important roles in recovery from stroke or brain injury. Animal models have shown that blockade of these neurotransmitters inhibits recovery, whereas recovery is promoted by drugs that promote norepinephrine, dopamine, acetylcholine, and serotonin activity. Preliminary evidence from human trials supports these findings. Further study is needed, but expanded use of pharmacologic agents for stroke and brain-injured patients appears imminent.

Rehabilitation of the geriatric orthopaedic patient.

Older patients who are referred for rehabilitation after undergoing orthopaedic procedures have numerous age-related conditions that may interfere with physical performance and safety. The general rehabilitation goals are to return each patient to the premorbid functional level of mobility and self-care, teach the exercises that are to be performed after hospital discharge, reduce the risk of falls, and ensure that the patient is discharged to a safe environment. Before elective surgery, the elderly orthopaedic patient should be instructed to perform breathing exercises to prevent pulmonary complications and active lower limb exercises to maintain good circulation and joint mobility, and be instructed in functional activities for mobilization in and out of bed. Postoperatively, the interdisciplinary rehabilitation team must facilitate early resumption of active exercises and self-care tasks and discourage prolonged bed rest and dependency on nursing staff and family members. Physical and occupational therapy should be provided to restore mobility and self-care functions. If discharge to home is planned, the home environment should be assessed and modifications recommended to reduce the risk of falls and ensure independent functioning to the extent possible. When the rehabilitation goals have been obtained, the patient should be discharged from the hospital, but additional therapy may be required, either at home or at an outpatient facility.