Publications by authors named "Colachis S"

Traditional gel-based (wet) electrodes for biopotential recordings have several shortcomings that limit their practicality for real-world measurements. Dry electrodes may improve usability, but they often suffer from reduced signal quality. We sought to evaluate the biopotential recording properties of a novel mixed ionic-electronic conductive (MIEC) material for improved performance.

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Context: Despite a high prevalence of neurogenic bladder (NGB) in patients with spinal cord injury (SCI), clinicians are unable to predict long-term bladder outcomes due to variable phenotypes of bladder dysfunction. This study investigates if early bladder events, infections, and spinal cord injury characteristics during rehabilitation admission affect bladder outcomes one year after SCI.

Methods: This retrospective study included patients with SCI admitted to a tertiary rehabilitation center between 1 January 2016 and 1 January 2020.

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Self-initiated behavior is accompanied by the experience of willing our actions. Here, we leverage the unique opportunity to examine the full intentional chain - from will (W) to action (A) to environmental effects (E) - in a tetraplegic person fitted with a primary motor cortex (M1) brain machine interface (BMI) generating hand movements via neuromuscular electrical stimulation (NMES). This combined BMI-NMES approach allowed us to selectively manipulate each element of the intentional chain (W, A, and E) while performing extra-cellular recordings and probing subjective experience.

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For brain-computer interfaces (BCIs) to be viable for long-term daily usage, they must be able to quickly identify and adapt to signal disruptions. Furthermore, the detection and mitigation steps need to occur automatically and without the need for user intervention while also being computationally tractable for the low-power hardware that will be used in a deployed BCI system. Here, we focus on disruptions that are likely to occur during chronic use that cause some recording channels to fail but leave the remaining channels unaffected.

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Motor neurons convey information about motor intent that can be extracted and interpreted to control assistive devices. However, most methods for measuring the firing activity of single neurons rely on implanted microelectrodes. Although intracortical brain-computer interfaces (BCIs) have been shown to be safe and effective, the requirement for surgery poses a barrier to widespread use that can be mitigated by instead using noninvasive interfaces.

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. Brain-computer interfaces (BCIs) that record neural activity using intracortical microelectrode arrays (MEAs) have shown promise for mitigating disability associated with neurological injuries and disorders. While the chronic performance and failure modes of MEAs have been well studied and systematically described in non-human primates, there is far less reported about long-term MEA performance in humans.

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Brain-machine interfaces (BMIs) record and translate neural activity into a control signal for assistive or other devices. Intracortical microelectrode arrays (MEAs) enable high degree-of-freedom BMI control for complex tasks by providing fine-resolution neural recording. However, chronically implanted MEAs are subject to a dynamic environment where transient or systematic disruptions can interfere with neural recording and degrade BMI performance.

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Paralyzed muscles can be reanimated following spinal cord injury (SCI) using a brain-computer interface (BCI) to enhance motor function alone. Importantly, the sense of touch is a key component of motor function. Here, we demonstrate that a human participant with a clinically complete SCI can use a BCI to simultaneously reanimate both motor function and the sense of touch, leveraging residual touch signaling from his own hand.

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We are developing a wearable neural interface based on high-density surface electromyography (HDEMG) for detecting and decoding signals from spared motor units in the forearms of people with tetraplegia after spinal cord injury (SCI). A lightweight, form-fitting garment containing 150 disc electrodes and covering the entire forearm was used to map the myoelectric activity of forearm muscles during a wide range of voluntary tasks of a person with chronic tetraplegia after SCI (C5 motor and C6 sensory American Spinal Injury Association Impairment Scale B spinal cord injury). Despite exhibiting no overt finger motion, myoelectric signals were detectable for attempted movements of individual digits and were highly discriminable.

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Objectives: The aims of the study were to evaluate integration of musculoskeletal ultrasonography education in physical medicine and rehabilitation training programs in 2014-2015, when the American Academy of Physical Medicine & Rehabilitation and Accreditation Council for Graduate Medical Education Residency Review Committee both recognized it as a fundamental component of physiatric practice, to identify common musculoskeletal ultrasonography components of physical medicine and rehabilitation residency curricula, and to identify common barriers to integration.

Design: Survey of 78 Accreditation Council for Graduate Medical Education-accredited physical medicine and rehabilitation residency programs was conducted.

Results: The 2015 survey response rate was more than 50%, and respondents were representative of programs across the United States.

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Objective: To demonstrate naturalistic motor control speed, coordinated grasp, and carryover from trained to novel objects by an individual with tetraplegia using a brain-computer interface (BCI)-controlled neuroprosthetic.

Design: Phase I trial for an intracortical BCI integrated with forearm functional electrical stimulation (FES). Data reported span postimplant days 137 to 1478.

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Individuals with tetraplegia identify restoration of hand function as a critical, unmet need to regain their independence and improve quality of life. Brain-Computer Interface (BCI)-controlled Functional Electrical Stimulation (FES) technology addresses this need by reconnecting the brain with paralyzed limbs to restore function. In this study, we quantified performance of an intuitive, cortically-controlled, transcutaneous FES system on standardized object manipulation tasks from the Grasp and Release Test (GRT).

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Background: Exposure to musculoskeletal ultrasound (MSUS) is now a mandatory component of physical medicine and rehabilitation (PM&R) residency training. However, reports on the extent of the implementation and efficacy of MSUS education are lacking in the literature.

Objective: To determine the extent to which PM&R residencies are implementing MSUS education.

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Context: To describe a case of a 44-year-old man with complete C4 tetraplegia who developed transient cortical blindness in the subacute setting following episodes of autonomic dysreflexia.

Findings: Transient cortical blindness the day after surgery for appendicitis that had resulted in severe autonomic dysreflexia (AD) requiring aggressive blood pressure management. Imaging showed no evidence of acute stroke, but did show vasospasm in the occipital lobes.

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Spastic hypertonia is a common sequelae after a cerebrovascular accident (CVA) and is a component of an upper motoneuron lesion. Management of spastic hypertonia may involve the use of centrally acting agents, peripheral blockade, and ablative therapies. We report a case of spastic hypertonia leading to severe trismus after CVA that was successfully treated with botulinum toxin type A.

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Objective: To determine cost-effectiveness of surveillance with duplex ultrasound for thromboembolic disease in individuals with acute traumatic spinal cord injury at admission to rehabilitation.

Design: In this retrospective sequential case series study, individuals with traumatic spinal cord injury admitted to our rehabilitation facility between July 1, 1988, and December 31, 1998, were identified. Cost at our institution for treatment of thromboembolic disease was tabulated in 2001-2002 dollar amounts.

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Objective: To determine the prevalence of deep vein thrombosis (DVT) by surveillance duplex ultrasound in the traumatic spinal cord injury (SCI) population on admission to rehabilitation.

Design: Retrospective sequential case series.

Setting: Midwest regional, university-based, Commission on Accreditation of Rehabilitation Facilities-accredited acute rehabilitation center.

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Abrupt withdrawal from intrathecal baclofen (ITB) can result in severe rebound spasticity, confusion, and seizures. It has been recently recognized that abrupt withdrawal from ITB may, in rare cases, result in life-threatening rhabdomyolysis, hyperthermia, autonomic disturbances, and sepsis-like presentations. Early recognition of the most severe forms of the withdrawal syndrome is essential for effective intervention.

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Neuroleptic malignant syndrome is a rare disorder that manifests with hyperthermia, muscle rigidity and autonomic instability. Presented is a case series of individuals with traumatic brain injury and agitation who, when treated with neuroleptics, developed neuroleptic malignant syndrome. Although the incidence of this syndrome is rare, it is associated with significant morbidity and mortality.

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We report an unusual case of aerophagia after traumatic spinal cord injury (SCI), which shows the profound effects of abdominal distension on respiratory ability in such individuals. In this case, abdominal distension resulting from aerophagia reduced the effectiveness of phrenic nerve pacing on diaphragm function necessitating greater use of positive-pressure ventilatory (PPV) support. Reduction of postprandial gastric air and abdominal distension with insertion of a percutaneous endoscopic gastrostomy tube ameliorated the condition and allowed for more effective phrenic nerve pacing and greater PPV-free breathing.

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Individuals with traumatic upper thoracic and cervical spinal cord injuries are at increased risk for the development of both thermoregulatory dysfunction and autonomic dysreflexia. It is unclear, however, what effect reflex autonomic sympathetic outflow has on thermoregulatory dysfunction during episodes of autonomic dysreflexia. The following case of an individual with C5 tetraplegia and both thermoregulatory dysfunction and autonomic dysreflexia illustrates the profound effects that the autonomic nervous system may have on body temperature in individuals at risk for this complication.

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Study Design: Case report of autonomic dysreflexia presenting with transient aphasia in a subject with C4 tetraplegia.

Objectives: To report a rare case of autonomic dysreflexia.

Setting: Rehabilitation Service, The Ohio State University, USA.

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There appears to be a high incidence of fever after brain injury. The most common cause for fever is infection. The incidence of fever occurring as a result of hypothalamic thermoregulatory dysfunction after brain injury is less clear.

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Autonomic hyperreflexia is a condition which may occur in individuals with spinal cord injuries above the splanchnic sympathetic outflow. Noxious stimuli can produce profound alterations in sympathetic pilomotor, sudomotor, and vasomotor activity, as well as disturbances in cardiac rhythm. A case of autonomic hyperreflexia in a patient with C6 tetraplegia with recurrent ventricular fibrillation and cardiac arrest illustrates the profound effects of massive paroxysmal sympathetic activity associated with this condition.

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Traumatic spinal cord injuries occurring after cardiac arrest are rare. In such cases, injury to the cervical cord may result from the intubation of a patient during resuscitation. We report a very unusual case where cardiac arrest occurring during cardiac rehabilitation resulted in an unexpected traumatic cervical spinal cord injury.

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