Spinal cord injury (SCI), as with acute stroke, is a dynamic process. In all acute cord syndromes, the full extent of injury may not be apparent initially. Incomplete cord lesions may evolve into more complete lesions. More commonly, the injury level rises 1 or 2 spinal levels during the hours to days after the initial event. A complex cascade of pathophysiologic events related to free radicals, vasogenic edema, and altered blood flow accounts for this clinical deterioration. Normal oxygenation, perfusion, and acid-base balance are required to prevent worsening of the spinal cord injury.
Spinal cord injury can be sustained through different mechanisms, with the following 3 common abnormalities leading to tissue damage:
Destruction from direct trauma
Compression by bone fragments, hematoma, or disk material
Ischemia from damage or impingement on the spinal arteries
Edema could ensue subsequent to any of these types of damage.
Neurogenic shock refers to the hemodynamic triad of hypotension, bradycardia, and peripheral vasodilation resulting from severe autonomic dysfunction and the interruption of sympathetic nervous system control in acute spinal cord injury. Hypothermia is also characteristic. This condition does not usually occur with spinal cord injury below the level of T6 but is more common in injuries above T6, secondary to the disruption of the sympathetic outflow from T1-L2 and to unopposed vagal tone, leading to a decrease in vascular resistance, with the associated vascular dilatation. Neurogenic shock needs to be differentiated from spinal and hypovolemic shock. Hypovolemic shock tends to be associated with tachycardia.
Shock associated with a spinal cord injury involving the lower thoracic cord must be considered hemorrhagic until proven otherwise. In this article, spinal shock is defined as the complete loss of all neurologic function, including reflexes and rectal tone, below a specific level that is associated with autonomic dysfunction. That is, spinal shock is a state of transient physiologic (rather than anatomic) reflex depression of cord function below the level of injury, with associated loss of all sensorimotor functions.
An initial increase in blood pressure due to the release of catecholamines, followed by hypotension, is noted. Flaccid paralysis, including of the bowel and bladder, is observed, and sometimes sustained priapism develops. These symptoms tend to last several hours to days until the reflex arcs below the level of the injury begin to function again (eg, bulbocavernosus reflex, muscle stretch reflex [MSR]).
Spinal cord injuries may be primary or secondary. Primary spinal cord injuries arise from mechanical disruption, transection, or distraction of neural elements. This injury usually occurs with fracture and/or dislocation of the spine. However, primary spinal cord injury may occur in the absence of spinal fracture or dislocation. Penetrating injuries due to bullets or weapons may also cause primary spinal cord injury. More commonly, displaced bony fragments cause penetrating spinal cord and/or segmental spinal nerve injuries.
Extradural pathology may also cause a primary spinal cord injury. Spinal epidural hematomas or abscesses cause acute cord compression and injury. Spinal cord compression from metastatic disease is a common oncologic emergency.
Longitudinal distraction with or without flexion and/or extension of the vertebral column may result in primary spinal cord injury without spinal fracture or dislocation. The spinal cord is tethered more securely than the vertebral column. Longitudinal distraction of the spinal cord with or without flexion and/or extension of the vertebral column may result in spinal cord injury without radiologic abnormality (SCIWORA).
SCIWORA was first coined in 1982 by Pang and Wilberger. Originally, it referred to spinal cord injury without radiographic or computed tomography (CT) scanning evidence of fracture or dislocation. However with the advent of magnetic resonance imaging (MRI), the term has become ambiguous. Findings on MRI such as intervertebral disk rupture, spinal epidural hematoma, cord contusion, and hematomyelia have all been recognized as causing primary or secondary spinal cord injury. SCIWORA should now be more correctly renamed as "spinal cord injury without neuroimaging abnormality" and recognize that its prognosis is actually better than patients with spinal cord injury and radiologic evidence of traumatic injury. [9, 10, 11]
Vascular injury to the spinal cord caused by arterial disruption, arterial thrombosis, or hypoperfusion due to shock are the major causes of secondary spinal cord injury. Anoxic or hypoxic effects compound the extent of spinal cord injury.
One of the goals of the physician is to classify the pattern of the neurologic deficit into one of the cord syndromes. Spinal cord syndromes may be complete or incomplete. In most clinical scenarios, physicians should use a best-fit model to classify the spinal cord injury syndrome.
A complete cord syndrome is characterized clinically as complete loss of motor and sensory function below the level of the traumatic lesion. Incomplete cord syndromes have variable neurologic findings with partial loss of sensory and/or motor function below the level of injury; these include the anterior cord syndrome, the Brown-Squard syndrome, and the central cord syndrome.
Anterior cord syndrome involves a lesion causing variable loss of motor function and pain and/or temperature sensation, with preservation of proprioception.
Brown-Squard syndrome, which is often associated with a hemisection lesion of the cord, involves a relatively greater ipsilateral loss of proprioception and motor function, with contralateral loss of pain and temperature sensation.
Central cord syndrome usually involves a cervical lesion, with greater motor weakness in the upper extremities than in the lower extremities, with sacral sensory sparing. The pattern of motor weakness shows greater distal involvement in the affected extremity than proximal muscle weakness. Sensory loss is variable, and the patient is more likely to lose pain and/or temperature sensation than proprioception and/or vibration. Dysesthesias, especially those in the upper extremities (eg, sensation of burning in the hands or arms), are common.
The conus medullaris syndrome, cauda equina syndrome, and spinal cord concussion are briefly discussed below.
Conus medullaris syndrome is a sacral cord injury, with or without involvement of the lumbar nerve roots. This syndrome is characterized by areflexia in the bladder, bowel, and to a lesser degree, lower limbs, whereas the sacral segments occasionally may show preserved reflexes (eg, bulbocavernosus and micturition reflexes). Motor and sensory loss in the lower limbs is variable.
Cauda equina syndrome involves injury to the lumbosacral nerve roots in the spinal canal and is characterized by an areflexic bowel and/or bladder, with variable motor and sensory loss in the lower limbs. Because this syndrome is a nerve root injury rather than a true spinal cord injury, the affected limbs are areflexic. Cauda equina syndrome is usually caused by a central lumbar disk herniation.
A spinal cord concussion is characterized by a transient neurologic deficit localized to the spinal cord that fully recovers without any apparent structural damage.
More:
Spinal Cord Injuries - emedicine.medscape.com
- Jake Diekman throws BP session for Rangers | MLB.com - MLB.com - August 6th, 2017 [August 6th, 2017]
- Cerebral palsy: Symptoms, diagnosis, treatment - December 5th, 2017 [December 5th, 2017]
- Hypothalamus - the body's thermostat | ASU - Ask A Biologist - December 6th, 2017 [December 6th, 2017]
- When Stroke Affects the Thalamus - Stroke Connection ... - December 28th, 2017 [December 28th, 2017]
- The Endocrine System: Hypothalamus and Pituitary - December 28th, 2017 [December 28th, 2017]
- Hypothalamus - Anatomy, Blood supply and Function | Kenhub - December 28th, 2017 [December 28th, 2017]
- Ulcerative Colitis - Cedars-Sinai - January 6th, 2018 [January 6th, 2018]
- Ulcerative colitis - Treatment - NHS.UK - January 7th, 2018 [January 7th, 2018]
- Business Directory | Uptown Waterloo Business Improvement Area - January 8th, 2018 [January 8th, 2018]
- Will States Continue To Fund Stem Cell Research? : Shots ... - January 28th, 2018 [January 28th, 2018]
- Spinal Cord Injuries - spine.org - February 15th, 2018 [February 15th, 2018]
- Journal of Clinical & Experimental Cardiology - Open Access Journals - April 10th, 2018 [April 10th, 2018]
- Cardiology Treatment - Fortis Healthcare - April 10th, 2018 [April 10th, 2018]
- Biology Junction - April 12th, 2018 [April 12th, 2018]
- Managing Right Ventricular Failure in PAH: An Algorithmic ... - April 14th, 2018 [April 14th, 2018]
- Ticagrelor vs Clopidogrel After Fibrinolytic Therapy in ... - April 22nd, 2018 [April 22nd, 2018]
- Cardiovascular Pharmacotherapeutics: William H. Frishman ... - May 13th, 2018 [May 13th, 2018]
- 13 Super Foods Good for Eczema - Top Eczema Treatments - May 15th, 2018 [May 15th, 2018]
- Diagnosis & Treatment of Parkinson's - ParkinsonsDisease.net - May 30th, 2018 [May 30th, 2018]
- Arizona Heart Rhythm Center - June 10th, 2018 [June 10th, 2018]
- Ayurvedic Medicines for Ulcerative Colitis | Natural ... - June 21st, 2018 [June 21st, 2018]
- Weinstein Cardiovascular Development and Regeneration Meeting - June 30th, 2018 [June 30th, 2018]
- Ulcerative Colitis Information Centre - July 31st, 2018 [July 31st, 2018]
- Sudden Death in Dogs - Pet Health Network | Pet Health ... - August 7th, 2018 [August 7th, 2018]
- Coronary Heart Disease - Ischaemic heart disease - British ... - August 21st, 2018 [August 21st, 2018]
- Cardiac Rehabilitation: Overview, History and Definition ... - August 25th, 2018 [August 25th, 2018]
- Difference between Cardiac Arrest and Respiratory Arrest ... - August 25th, 2018 [August 25th, 2018]
- ECM for Pericardial Closure - Aziyo - August 25th, 2018 [August 25th, 2018]
- Adult Mental Health | Georgia Department of Behavioral Health ... - September 6th, 2018 [September 6th, 2018]
- Mental Health | ECLKC - September 6th, 2018 [September 6th, 2018]
- Mental Health - The Church of Jesus Christ of Latter-day Saints - September 6th, 2018 [September 6th, 2018]
- Center for Vascular Biology - Home | UConn Health - September 22nd, 2018 [September 22nd, 2018]
- # Diabetes Stem Cell Research Diabetes Care Measures - September 30th, 2018 [September 30th, 2018]
- Cardiac Rhythm Disturbances | The Patient Guide to Heart ... - November 2nd, 2018 [November 2nd, 2018]
- Arrhythmia | Cleveland Clinic - November 2nd, 2018 [November 2nd, 2018]
- Hyperbaric Oxygen Therapy for Wound Healing | Johns ... - November 13th, 2018 [November 13th, 2018]
- NIMH Home - November 24th, 2018 [November 24th, 2018]
- What is an interventional cardiologist? | Heart Surgeries ... - November 26th, 2018 [November 26th, 2018]
- Molecular Cardiology Research Institute Boston | Tufts ... - November 29th, 2018 [November 29th, 2018]
- Lower vascular plant | botany | Britannica.com - December 7th, 2018 [December 7th, 2018]
- Welcome to the ABG Tutorial Welcome to Hansen - December 12th, 2018 [December 12th, 2018]
- Cardiac catheterization - Wikipedia - December 12th, 2018 [December 12th, 2018]
- Stem Cell Research & Therapy | Home page - December 22nd, 2018 [December 22nd, 2018]
- Journal of Stem Cell Research and Therapy- Open Access ... - December 22nd, 2018 [December 22nd, 2018]
- Stem-cell therapy - Wikipedia - December 22nd, 2018 [December 22nd, 2018]
- Cardiology and Interventional Cardiology - December 23rd, 2018 [December 23rd, 2018]
- Rhode Island Interventional Cardiology | Cardiovascular ... - December 23rd, 2018 [December 23rd, 2018]
- Interventional Cardiology Certification Policies | ABIM.org - December 23rd, 2018 [December 23rd, 2018]
- Interventional Cardiology - Boston Scientific - December 23rd, 2018 [December 23rd, 2018]
- 9 Benefits of Human Growth Hormone (Along with Side ... - December 27th, 2018 [December 27th, 2018]
- Growth hormone deficiency - Wikipedia - December 27th, 2018 [December 27th, 2018]
- Dr. Lorrie Kirshenbaum, Cardiac Gene Biology | St ... - January 28th, 2019 [January 28th, 2019]
- Cardiomyopathy - CardioSmart - February 8th, 2019 [February 8th, 2019]
- Centenary Institute | Medical Research, Life Saving Research - February 24th, 2019 [February 24th, 2019]
- Cardiovascular Medicine | Department of Medicine - March 29th, 2019 [March 29th, 2019]
- Rapid Test Market 2019 with Recent Trends, Revenue, Demand and Top Manufactures- Bureau Veritas, SGS SA, Intertek Group plc, Eurofins Scientific -... - October 11th, 2019 [October 11th, 2019]
- Medical Imaging Equipment Market Research Report 2019: Global Industry Analysis, Business Development, Size, Share, Trends, Future Growth, Forecast To... - October 11th, 2019 [October 11th, 2019]
- Analysis on the Global DNA Read, Write & Edit Market, 2017-2019 and Forecast to 2024 - Yahoo Finance - October 11th, 2019 [October 11th, 2019]
- Cardiac Surgery Instruments Market is Expected to Tread a Steady Growth Trajectory by Clocking a CAGR of 5.9% from 2017 to 2022 - Health News Office - October 24th, 2019 [October 24th, 2019]
- PEDIATRIC MEDICAL DEVICES MARKET IS PROJECTED TO EXPAND AT A CAGR OF 8.0% FROM 2018 TO 2026 - Health News Office - November 1st, 2019 [November 1st, 2019]
- myTAIHEART Test Provides Evidence for Injury from Biopsy of Heart Transplant Recipients Cardiology2.0 - Cardiology2.0 - November 1st, 2019 [November 1st, 2019]
- Mental health and your heart - British Heart Foundation - November 19th, 2019 [November 19th, 2019]
- BUZZ-U.S. STOCKS ON THE MOVE-Cango, Gulfport Energy, Abiomed, Standard Diversified, Wanda Sports, Eidos - Nasdaq - November 19th, 2019 [November 19th, 2019]
- Cost Analysis of COPD Exacerbations and Cardiovascular Events in SUMMIT - AJMC.com Managed Markets Network - November 19th, 2019 [November 19th, 2019]
- Hundreds walk to defeat ALS in Ancient City - St. Augustine Record - November 22nd, 2019 [November 22nd, 2019]
- Living with Lung Cancer: The Silver Linings - Curetoday.com - November 22nd, 2019 [November 22nd, 2019]
- Building the human spinal cord atlas - SynBioBeta - November 22nd, 2019 [November 22nd, 2019]
- The Week That Wasn't: Keto and the Flu, Human Cyborg, Duvet Disease - Medscape - November 22nd, 2019 [November 22nd, 2019]
- ALS advance offers hope for those diagnosed with deadly disease - WRAL.com - November 22nd, 2019 [November 22nd, 2019]
- ALS Stem Cell Therapy Developer Seeks Amendment to its AstroRx Trial - ALS News Today - November 22nd, 2019 [November 22nd, 2019]
- Former Boston Globe writer, current NHL executive Snow diagnosed with ALS | College Hockey - USCHO - December 23rd, 2019 [December 23rd, 2019]
- AB Science announces the publication of new results in the peer-reviewed journal Glia that further support masitinib's potential mode of action in ALS... - December 23rd, 2019 [December 23rd, 2019]
- Christmas in the City thrills homeless families, takes on poignancy with founders ALS diagnosis - The Boston Globe - December 23rd, 2019 [December 23rd, 2019]
- Amylyx Pharmaceuticals Announces AMX0035 Demonstrated Statistically Significant Treatment Benefit for People with ALS in the CENTAUR Trial - Business... - December 23rd, 2019 [December 23rd, 2019]
- RADICAVA (edaravone) - December 23rd, 2019 [December 23rd, 2019]
- List of Amyotrophic Lateral Sclerosis Medications (5 Compared ... - December 23rd, 2019 [December 23rd, 2019]
- Neuropore Completes Phase 1 Clinical Trial in Healthy Volunteers with NPT520-34, a Therapeutic Candidate Aimed at Treating Parkinson's Disease and... - January 14th, 2020 [January 14th, 2020]
- Comprehensive Analysis on Prostacyclin Market based on types and application - Technology Magazine - January 18th, 2020 [January 18th, 2020]
- N.J. karate legend who inspired thousands loses battle with ALS - NJ.com - January 18th, 2020 [January 18th, 2020]
- Denali Therapeutics Announces Broad Pipeline Progress Including Positive Results From Its LRRK2 Program for Parkinson's Disease - Associated Press - January 18th, 2020 [January 18th, 2020]