Analgesia

Analgesia: Excerpt from Professional Guide to Signs & Symptoms (Fifth Edition)

Analgesia, the absence of sensitivity to pain, is an important sign of central nervous system disease, often indicating a specific type and location of spinal cord lesion. It always occurs with loss of temperature sensation (thermoanesthesia) because these sensory nerve impulses travel together in the spinal cord. It can also occur with other sensory deficits—such as paresthesia, loss of proprioception and vibratory sense, and tactile anesthesia—in various disorders involving the peripheral nerves, spinal cord, and brain. However, when accompanied only by thermoanesthesia, analgesia points to an incomplete lesion of the spinal cord.

Analgesia can be classified as partial or total below the level of the lesion and as unilateral or bilateral, depending on the cause and level of the lesion. Its onset may be slow and progressive with a tumor or abrupt with trauma. Transient in many cases, analgesia may resolve spontaneously.

Emergency interventions

History and physical examination

Once you’re satisfied that the patient’s spine and respiratory status are stabilized—or if the analgesia isn’t severe and isn’t accompanied by signs of spinal cord injury—perform a physical examination and baseline neurologic evaluation. First, take the patient’s vital signs and assess his level of consciousness. Then test pupillary, corneal, cough, and gag reflexes to rule out brain stem and cranial nerve involvement. If the patient is conscious, evaluate his speech and ability to swallow.

If possible, observe the patient’s gait and posture and assess his balance and coordination. Evaluate muscle tone and strength in all extremities. Test for other sensory deficits over all dermatomes (individual skin segments innervated by a specific spinal nerve) by applying light tactile stimulation with a tongue depressor or cotton swab. Perform a more thorough check of pain sensitivity, if necessary, using a pin. (See Testing for analgesia, pages 48 and 49.) Also, test temperature sensation over all dermatomes, using two test tubes—one filled with hot water, the other with cold water. In each arm and leg, test vibration sense (using a tuning fork), proprioception, and superficial and deep tendon reflexes (DTRs). Check for increased muscle tone by extending and flexing the patient’s elbows and knees as he tries to relax.

Focus your history taking on the onset of analgesia (sudden or gradual) and on any recent trauma, such as a fall, a sports injury, or an automobile accident. Obtain a complete medical history, noting especially any incidence of cancer in the patient or his family.

Medical causes

Anterior cord syndrome

In anterior cord syndrome, analgesia and thermoanesthesia occur bilaterally below the level of the lesion along with flaccid paralysis and hypoactive DTRs.

Central cord syndrome

In central cord syndrome, analgesia and thermoanesthesia typically occur bilaterally in several dermatomes and may extend in a capelike fashion over the arms, back, and shoulders. Early weakness in the hands progresses to weakness and muscle spasms in the arms and shoulder girdle. Hyperactive DTRs and spastic weakness of the legs may develop. However, if the lesion affects the lumbar spine, hypoactive DTRs and flaccid weakness may persist in the legs.

With brain stem involvement, additional findings include facial analgesia and thermoanesthesia, vertigo, nystagmus, atrophy of the tongue, and dysarthria. The patient may also have anhidrosis, dysphagia, urine retention, decreased intestinal motility, and hyperkeratosis.

Spinal cord hemisection

Contralateral analgesia and thermoanesthesia occur below the level of the lesion. In addition, loss of proprioception, spastic paralysis, and hyperactive deep tendon reflexes develop ipsilaterally. The patient may also experience urine retention with overflow incontinence.

Other causes

Drugs

Analgesia may occur with use of a topical or local anesthetic, although numbness and tingling are more common.

Special considerations

Prepare the patient for spinal X-rays, and maintain spinal alignment and stability during transport to the laboratory.

Focus your care on preventing further injury to the patient because analgesia can mask injury or developing complications. Prevent formation of pressure ulcers through meticulous skin care, massage, use of lamb’s wool pads, and frequent repositioning, especially when significant motor deficits hamper the patient’s movement. Guard against scalding by testing the patient’s bathwater temperature before he bathes; advise him to test it at home using a thermometer or a body part with intact sensation.

Pediatric pointers

Because a child may have difficulty describing analgesia, observe him carefully during the assessment for nonverbal clues to pain, such as facial expressions, crying, and retraction from stimuli. Remember that pain thresholds are high in infants, so your assessment findings may not be reliable. Also, remember to test bathwater carefully for a child who is too young to test it himself.

Pictures

Book Source Details

• Book Title: Professional Guide to Signs & Symptoms (Fifth Edition)
• Author(s): Springhouse
• Year of Publication: 2006
• Copyright Details: Professional Guide to Signs & Symptoms (Fifth Edition), Copyright © 2006 Lippincott Williams & Wilkins.

More About Spinal Cord Tumor

• Back to disease: Spinal Cord Tumor: Introduction
• Next Book Extract About Spinal Cord Tumor: Back pain (Professional Guide to Signs & Symptoms (Fifth Edition))
• More Book Extracts: All Online Books for Spinal Cord Tumor

More Medical Textbooks Online about Spinal Cord Tumor

Review other book chapters online related to Spinal Cord Tumor:

Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.

More About This Book: Title: Professional Guide to Signs & Symptoms (Fifth Edition) Authors: Springhouse Publisher: Lippincott Williams & Wilkins Copyright: 2006 ISBN: 1-58255-510-9

 » Next page: Back pain (Professional Guide to Signs & Symptoms (Fifth Edition))

Rate This Website

What do you think about the features of this website? Take our user survey and have your say:

Website User Survey

Medical Tools & Articles:

Next articles:

• Back pain (Professional Guide to Signs & Symptoms (Fifth Edition))
• Low Back Pain (The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter)
• Low Back Pain (Field Guide to Bedside Diagnosis)
• Scoliosis (Handbook of Diseases)
• Spinal neoplasms (Handbook of Diseases)

Tools & Services:

• Bookmark this page
• Symptom Search
• Symptom Checker
• Medical Dictionary
• Give your feedback

Medical Articles:

• Disease & Treatments Search
• Misdiagnosis Center
• Full list of interesting articles

Forums & Message Boards

• Ask or answer a question at the Boards:
• I cannot get a diagnosis. Please help.
• Tell us your medical story.
• Share your misdiagnosis story.
• What is the best treatment for my condition?
• See all the Boards.

Enter your search terms Submit search form
Search The Web Search wrongdiagnosis.com

Common Health Mistakes

Symptom
Checker

Search Specialists by State and City