Prin X. Amorapanth

Different lateral amygdala outputs mediate reactions and actions elicited by a fear-arousing stimulus.

Fear-arousing stimuli elicit innate reactions and can reinforce acquisition of new responses. We tested whether mechanisms mediating these conditioned stimulus (CS) properties were isomorphic or dissociable within the amygdala. Rats trained on a fear-conditioning task (CS paired with footshock) were then trained on an escape-from-fear task (EFF) in which the CS reinforced a locomotor response terminating the CS. Lateral nucleus (LA) lesions blocked acquisition of both conditioned freezing responses and the CSs reinforcement of a new response in the EFF task. Central nucleus (CE) lesions blocked conditioned freezing but not the EFF, whereas basal nucleus (B) lesions blocked the EFF but not conditioned freezing. Thus, activation of the LA by a CS seems to trigger conditioned reactions via CE and conditioned aversion via B activation, reduction of which reinforces new actions.

Mobile Universal Lexicon Evaluation System (MULES) test: A new measure of rapid picture naming for concussion

OBJECTIVE This study introduces a rapid picture naming test, the Mobile Universal Lexicon Evaluation System (MULES), as a novel, vision-based performance measure for concussion screening. The MULES is a visual-verbal task that includes 54 original photographs of fruits, objects and animals. We piloted MULES in a cohort of volunteers to determine feasibility, ranges of picture naming responses, and the relation of MULES time scores to those of King-Devick (K-D), a rapid number naming test. METHODS A convenience sample (n=20, age 34±10) underwent MULES and K-D (spiral bound, iPad versions). Administration order was randomized; MULES tests were audio-recorded to provide objective data on temporal variability and ranges of picture naming responses. RESULTS Scores for the best of two trials for all tests were 40-50s; average times required to name each MULES picture (0.72±0.14s) was greater than those needed for each K-D number ((spiral: 0.33±0.05s, iPad: 0.36±0.06s, 120 numbers), p<0.0001, paired t-test). MULES scores showed the greatest degree of improvement between trials (9.4±4.8s, p<0.0001 for trials 1 vs. 2), compared to K-D (spiral 1.5±3.3s, iPad 1.8±3.4s). Shorter MULES times demonstrated moderate and significant correlations with shorter iPad but not spiral K-D times (r=0.49, p=0.03). CONCLUSION The MULES test is a rapid picture naming task that may engage more extensive neural systems than more commonly used rapid number naming tasks. Rapid picture naming may require additional processing devoted to color perception, object identification, and categorization. Both tests rely on initiation and sequencing of saccadic eye movements.

Ultrasound Guidance for Technically Challenging Intrathecal Baclofen Pump Refill: Three Cases and Procedure Description.

ABSTRACTIntrathecal baclofen (ITB) therapy is a common treatment used to reduce spasticity due to neurologic disorders and injuries. A variety of factors can increase the difficulty of ITB pump refill. Excess subcutaneous fat overlying the pump, spasticity, suboptimal positioning, pump rotation or inversion, and scar formation over the reservoir fill port can create challenges during pump refill. As a result, multiple unsuccessful attempts at accessing the reservoir fill port can be painful and increase the risk of infection, particularly when repeat skin puncture is required. Blind attempts to refill a pump in challenging cases may also result in subcutaneous injection or pocket fill, resulting in a potentially fatal baclofen withdrawal syndrome. We describe 3 successful ITB pump refills in technically challenging cases when using ultrasound guidance. This represents an innovative approach to using ultrasound guidance to facilitate ITB refill in adults with intractable spasticity. We present these new clinical data with a literature review of potential complications related to inaccurate pump refill procedures and discuss the utility of ultrasound guidance for preventing such adverse events.

Mobile Universal Lexicon Evaluation System (MULES) in MS: Evaluation of a new visual test of rapid picture naming

OBJECTIVE The Mobile Universal Lexicon Evaluation System (MULES) is a test of rapid picture naming that is under investigation for concussion. MULES captures an extensive visual network, including pathways for eye movements, color perception, memory and object recognition. The purpose of this study was to introduce the MULES to visual assessment of patients with MS, and to examine associations with other tests of afferent and efferent visual function. METHODS We administered the MULES in addition to binocular measures of low-contrast letter acuity (LCLA), high-contrast visual acuity (VA) and the King-Devick (K-D) test of rapid number naming in an MS cohort and in a group of disease-free controls. RESULTS Among 24 patients with MS (median age 36 years, range 20-72, 64% female) and 22 disease-free controls (median age 34 years, range 19-59, 57% female), MULES test times were greater (worse) among the patients (60.0 vs. 40.0 s). Accounting for age, MS vs. control status was a predictor of MULES test times (P = .01, logistic regression). Faster testing times were noted among patients with MS who had greater (better) performance on binocular LCLA at 2.5% contrast (P < .001, linear regression, accounting for age), binocular high-contrast VA (P < .001), and K-D testing (P < .001). Both groups demonstrated approximately 10-s improvements in MULES test times between trials 1 and 2 (P < .0001, paired t-tests). CONCLUSION The MULES test, a complex task of rapid picture naming involves an extensive visual network that captures eye movements, color perception and the characterization of objects. Color recognition, a key component of this novel assessment, is early in object processing and requires area V4 and the inferior temporal projections. MULES scores reflect performance of LCLA, a widely-used measure of visual function in MS clinical trials. These results provide evidence that the MULES test can add efficient visual screening to the assessment of patients with MS.

The new Mobile Universal Lexicon Evaluation System (MULES): A test of rapid picture naming for concussion sized for the sidelines

OBJECTIVE Measures of rapid automatized naming (RAN) have been used for over 50 years to capture vision-based aspects of cognition. The Mobile Universal Lexicon Evaluation System (MULES) is a test of rapid picture naming under investigation for detection of concussion and other neurological disorders. MULES was designed as a series of 54 grouped color photographs (fruits, random objects, animals) that integrates saccades, color perception and contextual object identification. Recent changes to the MULES test have been made to improve ease of use on the athletic sidelines. Originally an 11 × 17-inch single-sided paper, the test has been reduced to a laminated 8.5 × 11-inch double-sided version. We identified performance changes associated with transition to the new, MULES, now sized for the sidelines, and examined MULES on the sideline for sports-related concussion. METHODS We administered the new laminated MULES to a group of adult office volunteers as well as youth and collegiate athletes during pre-season baseline testing. Athletes with concussion underwent sideline testing after injury. Time scores for the new laminated MULES were compared to those for the larger version (big MULES). RESULTS Among 501 athletes and office volunteers (age 16 ± 7 years, range 6-59, 29% female), average test times at baseline were 44.4 ± 14.4 s for the new laminated MULES (n = 196) and 46.5 ± 16.3 s for big MULES (n = 248). Both versions were completed by 57 participants, with excellent agreement (p < 0.001, linear regression, accounting for age). Age was a predictor of test times for both MULES versions, with longer times noted for younger participants (p < 0.001). Among 6 athletes with concussion thus far during the fall sports season (median age 15 years, range 11-21) all showed worsening of MULES scores from pre-season baseline (median 4.0 s, range 2.1-16.4). CONCLUSION The MULES test has been converted to an 11 × 8.5-inch laminated version, with excellent agreement between versions across age groups. Feasibly administered at pre-season and in an office setting, the MULES test shows preliminary evidence of capacity to identify athletes with sports-related concussion.

The effect of linguistic background on rapid number naming: implications for native versus non-native English speakers on sideline-focused concussion assessments

ABSTRACT Objective: To determine if native English speakers (NES) perform differently compared to non-native English speakers (NNES) on a sideline-focused rapid number naming task. A secondary aim was to characterize objective differences in eye movement behaviour between cohorts. Background: The King-Devick (KD) test is a rapid number-naming task in which numbers are read from left-to-right. This performance measure adds vision-based assessment to sideline concussion testing. Reading strategies differ by language. Concussion may also impact language and attention. Both factors may affect test performance. Methods: Twenty-seven healthy NNES and healthy NES performed a computerized KD test under high-resolution video-oculography. NNES also performed a Bilingual Dominance Scale (BDS) questionnaire to weight linguistic preferences (i.e., reliance on non-English language(s)). Results: Inter-saccadic intervals were significantly longer in NNES (346.3 ± 78.3 ms vs. 286.1 ± 49.7 ms, p = 0.001), as were KD test times (54.4 ± 15.1 s vs. 43.8 ± 8.6 s, p = 0.002). Higher BDS scores, reflecting higher native language dominance, were associated with longer inter-saccadic intervals in NNES. Conclusion: These findings have direct implications for the assessment of athlete performance on vision-based and other verbal sideline concussion tests; these results are particularly important given the international scope of sport. Pre-season baseline scores are essential to evaluation in the event of concussion, and performance of sideline tests in the athlete’s native language should be considered to optimize both baseline and post-injury test accuracy.

Traumatic brain injury results in altered physiologic, but not subjective responses to emotional stimuli

ABSTRACT Background: While the cognitive sequelae of traumatic brain injury (TBI) are well known, emotional impairments after TBI are suboptimally characterized. Lack of awareness of emotional difficulties can make self-report unreliable. However, individuals with TBI demonstrate involuntary changes in heart rate variability which may enable objective quantification of emotional dysfunction. Methods: Sixteen subjects with chronic TBI and 10 age-matched controls were tested on an emotional function battery during which they watched a series of film clips normed to elicit specific positively and negatively valenced emotions: amusement, sexual amusement, sadness, fear and disgust. Subjective responses to the emotional stimuli were also obtained. Additionally, surface electrodes measured cardiac and respiratory signals to compute heart rate variability (HRV), from which measures of parasympathetic activity, the respiratory frequency area (RFA) and sympathetic activity, the low frequency area (LFA), of the HRV frequency spectrum were derived. The Neurobehavioral Rating Scale-Revised (NRS-R) and the King-Devick (KD) test were administered to assess neurobehavioral dysfunction. Results: The two groups showed no differences in subjective ratings of emotional intensity. Subjects with TBI showed significantly decreased sympathetic activity when viewing amusing stimuli and significantly increased sympathetic activity when viewing sad stimuli compared to controls. Most of the subjects did not show agitation, anxiety, depression, blunted affect, emotional withdrawal, decreased motivation or mental fatiguability on the NRS-R. However, 13/16 subjects with TBI demonstrated attention difficulty on the NRS-R which was positively correlated with the increased sympathetic activity during sad stimuli. Both attention difficulty and abnormal autonomic responses to sad stimuli were correlated with the timing on the KD test, which reflected difficulty with visual attention shifting. Conclusions: The HRV spectrum may be useful to identify subclinical emotional dysfunction in individuals with TBI. Attention difficulites, specifically impairment in visual attention shifting, may contribute to abnormal reactivity to sad stimuli that may be detected and potentially treated to improve emotional function.

Poster 300: Acute Onset of Psychotic Symptoms Following Abrupt Discontinuation of Hormone Replacement Therapy in a Trangendered Woman with Traumatic Brain Injury: A Case Report

Disclosures: Yu Chiu: I Have No Relevant Financial Relationships To Disclose Case/Program Description: We present the case of a 35-year-old transgendered woman undergoing acute rehabilitation for traumatic brain injury and associated orthopedic polytrauma who experienced the onset of acute psychotic symptoms during her rehabilitation course. In the course of her evaluation and treatment, it was determined that her acute behavioral dysregulation and mood disorder were likely due to the abrupt discontinuation of hormone replacement therapy (HRT). Setting: Level I Trauma Center, Acute Inpatient Rehabilitation Center. Results: The patient displayed multiple episodes of behavioral and mood disturbance that were marked by the presence of psychotic symptoms. Discussion: To our knowledge, this represents the first documented case of acute onset of psychotic symptoms due to acute discontinuation of HRT (in this case, estrogen) in a transgendered woman with TBI. Due to insurance qualifications and restrictions regarding the off-label use of HRT, especially for Cross-Sex Hormone Treatment (CHT), HRT is not generally approved in the acute inpatient rehabilitation setting. However, hypo-estrogenic states have been shown to be associated with occurrence of psychotic disorders in women, termed estrogen withdrawal associated psychosis (EWAP). Furthermore, given the known neuroprotectant effects of estrogens in animal models of TBI, it may be reasonable to continue HRT in transgendered patients. Conclusions: Serious adverse events may occur with abrupt discontinuation of HRT in transgendered patients, leading to the development of psychotic symptoms. Optimal management of mood and behavioral disturbances is a major goal of TBI rehabilitation due to implications for patient and caregiver health, but is challenging due to the sheer multitude of possible etiologies. As the use of CHT in transgendered women is likely to continue to increase in the future with increasing awareness and access, rehabilitation physicians should be aware of the risk of the development of psychotic symptoms with the abrupt discontinuation of CHT. Level of Evidence: Level V

Central Poststroke Pain Syndrome

Pain is a common complication in the poststroke population. Central poststroke pain syndrome (CPSP) is a type of central neuropathic pain characterized by dysesthesia and allodynia on the side contralateral to the stroke. The quality is most commonly burning or aching, though it may also be described as lacerating or pricking. The time course is variable and can be episodic or continuous. In order to accurately diagnose CPSP, the physician must eliminate other peripheral causes of pain, ranging from musculoskeletal to rheumatologic to peripheral neuropathic (diabetes especially), and must make sure that the site of cerebral lesion is consistent with the distribution of suspected CPSP. This chapter provides a brief overview of the diagnosis and treatment of central poststroke pain syndrome.

Indications for/Interpretation of Electrodiagnostic Testing

Electrodiagnostic testing is an extension of the physical exam and is dynamic, assessing the real-time function of nerves and muscles. Standard electrodiagnostic testing includes nerve conduction studies and electromyography. These studies are sensitive in the diagnosis of peripheral nervous system disease. This chapter provides an overview of electrodiagnostic testing.