Acute Pain
Acute pain arises from activation of nociceptors for a limited time and is not associated with significant tissue damage (e.g., a pin prick).
Chronic Pain
Chronic pain is prolonged pain lasting for months or longer that arises from tissue injury, inflammation, nerve damage, tumor growth, lesion or occlusion of blood vessels. Chronic or inflammatory pain can sensitize (see "Sensitization" below) the nervous system, evoking chemical, functional, and even structural changes that serve to “prime the pain-processing pump”. Chronic pain, such as lower back pain, rheumatoid and osteoarthritis, and headache (see "Headaches" below) may result from constant inflammatory activity which activates G proteins. In some cases, the pain persists long after the injury heals, but there is no treatment that will eliminate the pain. This chronic pain does not serve a protective function like other types of pain.
Sensitization
One possible explanation for chronic pain is a phenomenon called sensitization. Following continuation and prolong noxious stimulation, nearby silent nociceptive neurons that previously were unresponsive to stimulation, now become responsive. In addition, some of the chemicals produced and released at the injured site also alter the physiological properties of nociceptors. The nociceptors begin to initiate pain signals spontaneously, which cause chronic pain. In addition, weak stimuli, such as a light touch that previously had no effect on these nociceptors, will further activate the nociceptors which result in severe pain signals. This phenomenon is referred to as “peripheral sensitization.” The outcome of peripheral sensitization results in a greater and more persistent barrage of nerve impulses firing in the CNS. The persistent barrage of nerve impulses results in long-term changes in nerve cell activity at the level of the spinal cord and higher centers in the brain. This phenomena is referred to as “central sensitization”. It appears that peripheral and central sensitization persists after the injury apparently has healed. The sensitization of nociceptive neurons after injury results from the release of different chemicals from the damaged area. It is known that substance P and calcitonin gene-related peptides are released from peripheral nerve ending which stimulate most cells to release algesic substances which further potentiates the pain from the injury. In contrast, central sensitization resulting from severe and persistent injury which cause prolonged release of glutamate on nociceptive dorsal horn cells, this constant glutamate release via G protein dependant phosphorylation cascades results in opening of postsynaptic ion channels gated by the NMDA receptors. This phenomenon is also termed "wind up." This activation produces hyperexcitability of the dorsal horn cells and causes "central sensitization." Pain experts now agree that treating chronic pain early and aggressively yields the best results and prevents patients from developing physical and psychological conditions that could worsen the pain.
Fibromyalgia
Fibromyalgia is characterized by widespread chronic pain throughout the body, including fatigue, anxiety and depression. It is now believed that it has a genetic component which tends to run in families.
Headaches
A headache is a poorly understood type of pain that can be either acute or chronic. There are about 300 different types and causes of headaches. The following are some categories of disorders associated with headaches:
- Intracranial structural disease
- Infectious disease
- Cerebrovascular ischemia
- Cerebral vein thrombosis
- Metabolic disease
- Toxic exposures
- Medications
- Extracranial pressure disorders
- Sinusitis
- Vasculitis and collagen vascular disease
- Hemorrhage (parenchymal and subarachnoid)
- Trauma
- Withdrawal syndromes
- Severe hypertension
- Dental, cranial vault, TMJ, and myofascial disorders
- Cervical spine and occipitocervical junction disorders
Summary
Because of the importance of warning signals of dangerous circumstances, several nociception pathways are involved to transmitting these signals and some of them are redundant.
The neospinothalamic tract conducts fast pain (via A delta fibers) and provides information of the exact location of the noxious stimulus, and the multisynaptic paleospinothalamic and archispinothalamic tracts conduct slow pain (via C fibers), a pain which is chronic and poorly localized in nature. (Figure 7.5)
Pain activates many brain areas, which link sensation, perception, emotion, memory and motor reaction. Therefore, many pain clinics target their treatments to block the perception of pain using psychosomatic means of treatments such as biofeedback, hypnosis, physical therapy, electrical stimulation, and acupuncture.
- Question 1
- A
- B
- C
- D
- E
Mr. John Thomas experiences visceral pain around the upper left lung. All of the following carry this nociceptive information EXCEPT the:
A. somatic nerves
B. paleospinothalamic tract
C. sympathetic nerves
D. neospinothalamic tract
E. archispinothalamic tract
Mr. John Thomas experiences visceral pain around the upper left lung. All of the following carry this nociceptive information EXCEPT the:
A. somatic nerves This answer is INCORRECT.
B. paleospinothalamic tract
C. sympathetic nerves
D. neospinothalamic tract
E. archispinothalamic tract
Mr. John Thomas experiences visceral pain around the upper left lung. All of the following carry this nociceptive information EXCEPT the:
A. somatic nerves
B. paleospinothalamic tract This answer is INCORRECT.
C. sympathetic nerves
D. neospinothalamic tract
E. archispinothalamic tract
Mr. John Thomas experiences visceral pain around the upper left lung. All of the following carry this nociceptive information EXCEPT the:
A. somatic nerves
B. paleospinothalamic tract
C. sympathetic nerves This answer is INCORRECT.
D. neospinothalamic tract
E. archispinothalamic tract
Mr. John Thomas experiences visceral pain around the upper left lung. All of the following carry this nociceptive information EXCEPT the:
A. somatic nerves
B. paleospinothalamic tract
C. sympathetic nerves
D. neospinothalamic tract This answer is CORRECT!
The neospinothalamic tract carries nociceptive information from the skin only via A delta fibers, while visceral pain is carried via C fibers.
E. archispinothalamic tract
Mr. John Thomas experiences visceral pain around the upper left lung. All of the following carry this nociceptive information EXCEPT the:
A. somatic nerves
B. paleospinothalamic tract
C. sympathetic nerves
D. neospinothalamic tract
E. archispinothalamic tract This answer is INCORRECT.
- Question 2
- A
- B
- C
- D
- E
A surgeon attempting to treat chronic pain from the pelvic region will suggest to make a lesion in the:
A. somatosensory cortex
B. ventroposterior medial thalamus
C. anterior white commissure
D. dorsal column
E. anterior lateral funiculus
A surgeon attempting to treat chronic pain from the pelvic region will suggest to make a lesion in the:
A. somatosensory cortex This answer is INCORRECT.
B. ventroposterior medial thalamus
C. anterior white commissure
D. dorsal column
E. anterior lateral funiculus
A surgeon attempting to treat chronic pain from the pelvic region will suggest to make a lesion in the:
A. somatosensory cortex
B. ventroposterior medial thalamus This answer is INCORRECT.
C. anterior white commissure
D. dorsal column
E. anterior lateral funiculus
A surgeon attempting to treat chronic pain from the pelvic region will suggest to make a lesion in the:
A. somatosensory cortex
B. ventroposterior medial thalamus
C. anterior white commissure This answer is INCORRECT.
D. dorsal column
E. anterior lateral funiculus
A surgeon attempting to treat chronic pain from the pelvic region will suggest to make a lesion in the:
A. somatosensory cortex
B. ventroposterior medial thalamus
C. anterior white commissure
D. dorsal column This answer is INCORRECT.
E. anterior lateral funiculus
A surgeon attempting to treat chronic pain from the pelvic region will suggest to make a lesion in the:
A. somatosensory cortex
B. ventroposterior medial thalamus
C. anterior white commissure
D. dorsal column
E. anterior lateral funiculus This answer is CORRECT!
Anterior lateral corodotomy interrupt the spinothalamic tract carrying the pain sensation.
- Question 3
- A
- B
- C
- D
- E
In Brown-Sequard syndrome:
A. Tactile and pain sensation are lost contralaterally at different levels below the lesion.
B. Thermal sensation is lost in the ipsilateral side above the lesion.
C. Kinesthetic and tectile senses are lost ipsilaterally below the lesion.
D. The withdrawal reflex is lost.
E. Atrophy is developed in the muscles below the lesion.
In Brown-Sequard syndrome:
A. Tactile and pain sensation are lost contralaterally at different levels below the lesion. This answer is INCORRECT.
B. Thermal sensation is lost in the ipsilateral side above the lesion.
C. Kinesthetic and tectile senses are lost ipsilaterally below the lesion.
D. The withdrawal reflex is lost.
E. Atrophy is developed in the muscles below the lesion.
In Brown-Sequard syndrome:
A. Tactile and pain sensation are lost contralaterally at different levels below the lesion.
B. Thermal sensation is lost in the ipsilateral side above the lesion. This answer is INCORRECT.
C. Kinesthetic and tectile senses are lost ipsilaterally below the lesion.
D. The withdrawal reflex is lost.
E. Atrophy is developed in the muscles below the lesion.
In Brown-Sequard syndrome:
A. Tactile and pain sensation are lost contralaterally at different levels below the lesion.
B. Thermal sensation is lost in the ipsilateral side above the lesion.
C. Kinesthetic and tectile senses are lost ipsilaterally below the lesion. This answer is CORRECT!
Thermal and pain sensation are lost contralaterally below the lesion while kinesthetic and tactile senses remain on the ipsilateral side.
D. The withdrawal reflex is lost.
E. Atrophy is developed in the muscles below the lesion.
In Brown-Sequard syndrome:
A. Tactile and pain sensation are lost contralaterally at different levels below the lesion.
B. Thermal sensation is lost in the ipsilateral side above the lesion.
C. Kinesthetic and tectile senses are lost ipsilaterally below the lesion.
D. The withdrawal reflex is lost. This answer is INCORRECT.
E. Atrophy is developed in the muscles below the lesion.
In Brown-Sequard syndrome:
A. Tactile and pain sensation are lost contralaterally at different levels below the lesion.
B. Thermal sensation is lost in the ipsilateral side above the lesion.
C. Kinesthetic and tectile senses are lost ipsilaterally below the lesion.
D. The withdrawal reflex is lost.
E. Atrophy is developed in the muscles below the lesion. This answer is INCORRECT.
- Question 4
- A
- B
- C
- D
- E
Sharp localized pain is transmitted by:
A. archispinothalamic tract
B. Paleospinothalamic tract
C. Neospinothalamic tract
D. Sympathetic nerves
E. Parasympathetic nerves
Sharp localized pain is transmitted by:
A. archispinothalamic tract This answer is INCORRECT.
B. Paleospinothalamic tract
C. Neospinothalamic tract
D. Sympathetic nerves
E. Parasympathetic nerves
Sharp localized pain is transmitted by:
A. archispinothalamic tract
B. Paleospinothalamic tract This answer is INCORRECT.
C. Neospinothalamic tract
D. Sympathetic nerves
E. Parasympathetic nerves
Sharp localized pain is transmitted by:
A. archispinothalamic tract
B. Paleospinothalamic tract
C. Neospinothalamic tract This answer is CORRECT!
Sharp pain is carried by the neospinothalamic tract.
D. Sympathetic nerves
E. Parasympathetic nerves
Sharp localized pain is transmitted by:
A. archispinothalamic tract
B. Paleospinothalamic tract
C. Neospinothalamic tract
D. Sympathetic nerves This answer is INCORRECT.
E. Parasympathetic nerves
Sharp localized pain is transmitted by:
A. archispinothalamic tract
B. Paleospinothalamic tract
C. Neospinothalamic tract
D. Sympathetic nerves
E. Parasympathetic nerves This answer is INCORRECT.
- Question 5
- A
- B
- C
- D
- E
Select the best answer: Pain impulses arising within the abdominal and thoracic cavities may reach the CNS by:
A. somatic nerves innervating
B. sympathetic nerves
C. parasympathetic nerves
D. none of the above
E. all of the above
Select the best answer: Pain impulses arising within the abdominal and thoracic cavities may reach the CNS by:
A. somatic nerves innervating This answer is PARTIALLY correct.
B. sympathetic nerves
C. parasympathetic nerves
D. none of the above
E. all of the above
Select the best answer: Pain impulses arising within the abdominal and thoracic cavities may reach the CNS by:
A. somatic nerves innervating
B. sympathetic nervesThis answer is PARTIALLY correct.
C. parasympathetic nerves
D. none of the above
E. all of the above
Select the best answer: Pain impulses arising within the abdominal and thoracic cavities may reach the CNS by:
A. somatic nerves innervating
B. sympathetic nerves
C. parasympathetic nervesThis answer is PARTIALLY correct.
D. none of the above
E. all of the above
Select the best answer: Pain impulses arising within the abdominal and thoracic cavities may reach the CNS by:
A. somatic nerves innervating
B. sympathetic nerves
C. parasympathetic nerves
D. none of the above This answer is INCORRECT.
E. all of the above
Select the best answer: Pain impulses arising within the abdominal and thoracic cavities may reach the CNS by:
A. somatic nerves innervating
B. sympathetic nerves
C. parasympathetic nerves
D. none of the above
E. all of the above This answer is CORRECT!
All of the above are correct, since visceral pain is carried by them all.
- Question 6
- A
- B
At the level of the ventral trigeminothalamic tract, pain fibers are generally crossed or uncrossed?
A. Crossed
B. Uncrossed
At the level of the ventral trigeminothalamic tract, pain fibers are generally crossed or uncrossed?
A. Crossed This answer is CORRECT!
At the ventral trigeminothalamic tract, the fibers are already crossed and ascend to the thalamus.
B. Uncrossed
At the level of the ventral trigeminothalamic tract, pain fibers are generally crossed or uncrossed?
A. Crossed
B. Uncrossed This answer is INCORRECT.
- Question 7
- A
- B
- C
- D
- E
Cell bodies of first order pelvic visceral pain fibers are found in:
A. dorsal root ganglion
B. mesentric ganglion
C. superior cervical ganglia
D. inferior cervical ganglion
E. middle cervical ganglion
Cell bodies of first order pelvic visceral pain fibers are found in:
A. dorsal root ganglion This answer is CORRECT!
The cell bodies of the entire somatosensory system are located in the dorsal root ganglion.
B. mesentric ganglion
C. superior cervical ganglia
D. inferior cervical ganglion
E. middle cervical ganglion
Cell bodies of first order pelvic visceral pain fibers are found in:
A. dorsal root ganglion
B. mesentric ganglion This answer is INCORRECT.
C. superior cervical ganglia
D. inferior cervical ganglion
E. middle cervical ganglion
Cell bodies of first order pelvic visceral pain fibers are found in:
A. dorsal root ganglion
B. mesentric ganglion
C. superior cervical ganglia This answer is INCORRECT.
D. inferior cervical ganglion
E. middle cervical ganglion
Cell bodies of first order pelvic visceral pain fibers are found in:
A. dorsal root ganglion
B. mesentric ganglion
C. superior cervical ganglia
D. inferior cervical ganglion This answer is INCORRECT.
E. middle cervical ganglion
Cell bodies of first order pelvic visceral pain fibers are found in:
A. dorsal root ganglion
B. mesentric ganglion
C. superior cervical ganglia
D. inferior cervical ganglion
E. middle cervical ganglion This answer is INCORRECT.
- Question 8
- A
- B
- C
- D
- E
The following pathway is sectioned in a chordotomy for the treatment of pain:
A. Lateral spinothalamic tract
B. Ipsilateral dorsal column
C. Corticospinal tract
D. Spinocerebellar pathway
E. Spino-olivary tract
The following pathway is sectioned in a chordotomy for the treatment of pain:
A. Lateral spinothalamic tract This answer is CORRECT!
From the above nerve fibers, only the lateral spinothalamic tract carries pain sensation, and sections of these fibers will prevent pain information from getting to the brain.
B. Ipsilateral dorsal column
C. Corticospinal tract
D. Spinocerebellar pathway
E. Spino-olivary tract
The following pathway is sectioned in a chordotomy for the treatment of pain:
A. Lateral spinothalamic tract
B. Ipsilateral dorsal column This answer is INCORRECT.
C. Corticospinal tract
D. Spinocerebellar pathway
E. Spino-olivary tract
The following pathway is sectioned in a chordotomy for the treatment of pain:
A. Lateral spinothalamic tract
B. Ipsilateral dorsal column
C. Corticospinal tract This answer is INCORRECT.
D. Spinocerebellar pathway
E. Spino-olivary tract
The following pathway is sectioned in a chordotomy for the treatment of pain:
A. Lateral spinothalamic tract
B. Ipsilateral dorsal column
C. Corticospinal tract
D. Spinocerebellar pathway This answer is INCORRECT.
E. Spino-olivary tract
The following pathway is sectioned in a chordotomy for the treatment of pain:
A. Lateral spinothalamic tract
B. Ipsilateral dorsal column
C. Corticospinal tract
D. Spinocerebellar pathway
E. Spino-olivary tract This answer is INCORRECT.
