Tetraplegia, also known as quadriplegia, is defined as the dysfunction or loss of motor and/or sensory function in the cervical area of the spinal cord. A loss of sensory function can present as an impairment or complete inability to sense light touch, pressure, heat, pinprick/pain, and proprioception. Secondarily, because of their depressed functioning and immobility, tetraplegics are often more vulnerable to pressure sores, osteoporosis and fractures, frozen joints, spasticity, respiratory complications, infections, autonomic dysreflexia, deep vein thrombosis, and cardiovascular disease.
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|Trauma
|Motor vehicle accident, falls, violence, recreational activity For example, an injury at the C6 nerve root level will affect the function of the triceps (elbow extension) but the biceps (elbow flexion) will be spared; in this case, an injury at the C6 root level affects all function at that level and below whereas the C5 nerve root, which controls the biceps, is spared since it is above the C6 level in the spinal column. When classifying an individual's level of function, there are numerous functional assessment tools that may be used in a clinical setting and it is often up to the clinician's discretion as to which tools are used. A comprehensive list of these tools may be found on the ShirleyRyan AbilityLab website.
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|+Key Muscle Groups and Sensory Points After a comprehensive neurologic exam testing segments of the body corresponding to spinal nerve roots, the examiner will determine the patient's motor level and sensory level (e.g. motor level C6, sensory level C7). These levels are unique for the patient's left and right side. This level is assigned based on the lowest (closest to the patient's feet) intact motor and sensory level. After this assignment, a neurological level of injury (NLI) is determined. The NLI is the lowest segment with intact sensory and motor function provided there is normal sensory and motor function above this segment.
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! colspan = 3 | American Spinal Injury Association Impairment Scale
Prognosis
alt=Christopher Reeve speaking at MIT, 2003|thumb|Christopher Reeve speaking at MIT, 2003
Delayed diagnosis of cervical spine injury has grave consequences for the victim. About one in 20 cervical fractures are missed and about two-thirds of these patients have further spinal-cord damage as a result. About 30% of cases of delayed diagnosis of cervical spine injury develop permanent neurological deficits. In high-level cervical injuries, total paralysis from the neck can result. High-level tetraplegics (C4 and higher) will likely need constant care and assistance in activities of daily living (ADLs), such as getting dressed, eating, and bowel/bladder care. Individuals with C5 injuries retain some function in their biceps, deltoids, and other muscles; they typically can perform many ADLs including feeding, bathing, and grooming but require total assistance with bowel/bladder care. The C6 level adds function in the extensor carpi radialis, longus, and other muscles allowing for wrist extension, scapular abduction, and wrist flexion; typically, these patients have modified independent feeding and grooming with adaptive equipment, independent with dressing, can use both a manual and power wheelchair but require assistance with some activities of daily living. The C7 level is where function is retained in the triceps allowing for arm extension; C7 is considered the key level at which most activities can be performed independently with a wheelchair and assistive devices; activities include feeding, grooming, dressing, light meal preparation, and transfers on level surfaces.
Epidemiology
There are an estimated 17,700 spinal cord injuries each year in the United States; the total number of people affected by spinal cord injuries is estimated to be approximately 290,000 people.
The estimated lifetime costs for a 25-year-old in 2018 is $3.6 million when affected by low tetraplegia and $4.9 million when affected by high tetraplegia.
"Tetraplegia", meaning the paralysis of four limbs, may be confused with "tetraparesis", meaning the weakness of four limbs. In medicine, it is important to not use these terms when making a diagnosis. When diagnosing and classifying spinal cord injuries, the ASIA classification is used to distinguish between weakness vs. no weakness, and to classify neurologically complete vs. incomplete lesions. Use of "tetraparesis" is discouraged as it inaccurately describes an incomplete lesion and incorrectly implies tetraplegia applies only to cases of complete lesions.
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