TUTOR GUIDE

University of Sriwijaya

Faculty of medicine

Block 4 2010

SCENARIO 2

TUTOR GUIDE

What systems and organs are involved in Rasunan case ? What is the pathophysiological basis of the pain ?

Learning Objectives of Tutorial 1After completing all of 3 tutorial sessions on the above vignette, the students should be able to:

1. Mention clinical terminologies related to the case.2. Describe anatomy and function of the spine.

3. Explain pathogenesis of any symptoms and signs found in the case.Learning issues

To achieve the above objectives, students should study:

1. The musculo-skeletal system with more focus on:

a. Anatomy and physiology of vertebral column, especially lumbo-sacral and cervical vertebrae.

b. Anatomy and physiology of muscles of the back and lower extremity.c. Embryology, structure and function of intervertebral discs and nucleus pulposus.2. Anatomy and physiology of the spinal nerves especially the lumbar plexus and its branches.

3. Mechanism of muscle spasm and pain, especially radicular pain down the sciatic nerve (sciatica).

4. (in brief) how to make diagnosis (including differential diagnoses) and how to manage Low Back Pain.

CLINICAL CORRELATION

This patient experiences pain radiating down the back of his leg in the distribution served by the sciatic nerve. Hence, the syndrome is referred to as sciatica. The pain is caused by impingement of the nerve roots contributing to the sciatic nerve (L4 through S3). Heavy lifting is often an associated factor, so his past history as a weight lifter may contribute to the etiology of the ailment he is suffering. The pain is worsened by increased intra-abdominal pressure (Valsalva maneuver); thus, coughing and straining often exacerbate the symptoms. The straight leg raising maneuver elicits pain. Because this patient does not have neurological deficits, conservative therapy would include rest, physical therapy, and nonsteroidal anti-inflammatory agents. Most patients improve with this treatment. Lack of improvement, neurological deficits, or history of trauma or malignancy usually necessitates imaging of the spine. MRI is considered to be the most accurate means of examining this region.

THE SEVEN JUMPS

Make sure that students follow the seven jumps approach in the discussion.

In Session 1 of tutorial

After reading the scenario, students should:

1. Clarify all of unknown or poorly understood terminologies and words (phrases or sentences). Let the students identify all the words that they dont understand. Give a hint or direction when they fail to identify the following words : 1. ex-weight-lifter : a person who used to be an athlete in weight lifting. Weight lifting gives a lot of pressure to spine (lumbar vertebrae in particular) and lower extremities, which may contribute to the cause of HNP.2. Lower back pain.3. Radicular pain

4. Tingling sensation.

5. Lumbago.

6. Sciatica.

7. Pain-relieve medication.

8. The pain persists.9. Neurologist.

10. Strength and sensation of lower extremities.

11. Supine position.

12. Neurological examination.

13. severe pain when his right leg is raised.14. MRI examination 15. diagnosis 16. prolapsed of nucleus pulposus2. Identify problems. Problems are anything thats not normal. Clinical problems are presented as symptoms and signs. For the sake of discussion, problems can be divided into :1) Main problem, 2) contributing problems and 3) chief complain. Treating main problem would get rid off all other problems. In most cases, contributing problems are just side-effects of other problems. Chief complaint is problem that make patient visit a doctor. Include also all other clinical facts such as results of physical (clinical) examination and laboratory workups. 1. Pain :Lower back pain called lumbago (chief complaint).

2. Radicular pain (sciatica)3. Tingling sensation.

4. Pain-relieve medication gave no effect (the pain persists).

5. Neurological examination : strength and sensation of lower extremities are normal.

6. severe pain when his right leg is raised.7. MRI examination shows a prolapsed of nucleus pulposus (main problem)3. Analyze the problems. Direction of the analysis is toward 1) looking for relationship between all the problems identified above, 2) Discussion of patho-physiological aspect of the symptoms and signs (see below).4. Make a hypothesis. Hypothesis is actually a brief description of the chief complain and the main problems in this patient. Rasunan, 54 yrs man suffers from lower back pain (lumbago) and sciatica due to a prolapsed nucleus pulposus.

5. List learning issues. Make sure the followings are in the students list. Encourage them to study the learning issues the best they can !!!!!1. Anatomy and physiology of vertebral column, especially lumbo-sacral and cervical vertebrae.

2. Anatomy and physiology of muscles of the back and lower extremity.

3. Embryology, structure and function of intervertebral discs and nucleus pulposus.

4. Anatomy and physiology of the spinal nerves especially the lumbar plexus and its branches.

5. Mechanism of muscle spasm and pain, especially radicular pain down the sciatic nerve (sciatica).

6. (if possible) how to make diagnosis (including differential diagnoses) and how to manage Low Back Pain.

In Session 2

After studying the learning issues, students shoud:

6. Share all information they have studied and make a synthesis.

1. Let the students share what they have studied from the learning issues.2. Review in brief brief about :

i. Features of a typical vertebra and the intervertebral joints.

ii. Components of the spinal nerve from spinal roots to primary rami.

iii. Location where components of the spinal nerve can be compressed.

7. Make a report to be presented on the plenary session. Encourage the students to make a report according to all the previous jumps. Make a nice report and share it to others in plenary session.PROBLEM ANALYSIS OF RASUNAN CASE

The vertebral column is a series of individual bones that are stacked vertically and held together by ligaments and muscles. There are 32 to 34 vertebrae (7 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 3 to 5 coccygeal). The joints between each vertebra provide flexibility, but the vertebrae are held tightly in place by numerous supporting ligaments that provide strength and stability.The main features of a typical vertebra are the tubular body and the posterior arch that surrounds and protects the spinal cord. The arch is composed of pedicles that arise from the vertebral body and lamina that join at the midline. Each vertebra has seven processes: three serve as attachment sites for muscles, and four serve as articular surfaces for adjacent vertebrae. The two transverse processes arise from the arch, where the pedicles and laminae meet.

One spinous process emerges from the middle of the posterior arch. Two types of joints support the articulation of adjacent vertebrae. The flat surfaces of the vertebral bodies join through a secondary cartilaginous joint, or symphysis. The bones themselves are separated by the intervertebral disc,

Major vertebral ligaments.

which has an outer fibrous layer, the anulus fibrosus, that surrounds a soft inner layer, the nucleus pulposus. The disc provides support for the joint but also provides flexibility and a cushion against the weight of the upper body. Secondary support is provided by the four articular processes. These processes also emerge from the posterior arch. Two are directed superiorly and two inferiorly. The superior and inferior processes of adjacent vertebrae join to form a zygapophyseal joint. This synovial joint provides strength with a limited amount of flexibility. The pedicle and superior articular process together form a notch that is complemented by a second notch formed by the pedicle and inferior process. When two vertebrae are in apposition, the superior and inferior notches form the intervertebral foramen. This space is where spinal nerves emerge from the spinal cord to supply peripheral structures. Peripheral nerve fibers arising from the spinal cord as anterior (ventral) roots are primarily motor, whereas the posterior (dorsal) roots are primarily sensory. These roots join to form the spinal nerve. In the cervical spine, the roots travel laterally to leave the vertebral column. The spinal nerve splits to form two mixed-function branches, a small posterior primary ramus and a larger anterior primary ramus. Nerves emerging from lower levels of spinal cord course inferiorly before they exit. This is because the cord itself stops at about vertebral level L1. Therefore the roots must travel nearly straight inferiorly before forming the spinal nerves of the lower lumbar, sacral, and coccygeal regions. As these numerous roots stream inferiorly, they form the cauda equina. The symphysis between vertebral bodies is normally very strong because the intervertebral disc is reinforced by anterior and posterior longitudinal ligaments.

However, in some people, these ligaments weaken, and the intervertebral disc pushes through. If so, the roots may be compressed by the nucleus pulposus through the weakened anulus. The most common result is stimulation of pain fibers in posterior roots. More serious cases may result in paresthesia (area of localized numbness), but rarely is motor function disrupted. Although the actual site of injury is proximal, the brain perceives the information as coming from the region of the body innervated by the compressed root. Thus, with lumbar herniations, the distribution of this type of pain (radicular pain) tends to follow the dermatomes of the lower extremity. These areas progress on the anterior surface from L1 in the inguinal region to L4 at the knee and medial leg and to L5 along the lateral leg. On the posterior surface, S1 is lateral on the thigh and leg, and S2 is medial. S3 through S5 are perianal. Sensory fibers from a given spinal level spread into adjacent dermatomes. Therefore, in order to achieve complete numbness of a single dermatome, three adjacent spinal nerves must be anesthetized.

In this case, the patient experienced pain when, in the supine position, his straightened leg was raised. This sign indicates that slight mechanical stretching of the sciatic nerve is sufficient to enhance the effect of the herniated disc. Dorsiflexion of the foot exacerbates the pain. In some patients, straightening the contralateral leg may also cause pain in the affected leg, thus confirming radiculopathy.

Radiographic imaging can be used to confirm the herniation. Currently, the best modality is MRI because the herniation can be observed directly and MRI is a noninvasive procedure. With the widespread use of MRI, it has become clear that many herniated discs are asymptomatic. An older technique, myelography, is also used on occasion. This technique takes advantage of the fact that the dura mater covers the spinal roots and proximal spinal nerve. Injection of contrast medium into the cerebrospinal fluid (CSF) will infiltrate to the spinal nerves. Therefore, compressed nerve sheaths will not be filled by the dye, and the herniated disc can be observed indirectly.

Rasunan, male, an ex-weight-lifter 54-year complains of lower back pain and radicular pain down the back of his right leg. He states that the pain is worsened by coughing or lifting but relieved by lying down. He also feel that pain after standing or sitting still for an hour or more with a tingling sensation on his right big toe. He mentions that he has been suffering from the pain since 6 months ago after lifting a heavy box during housekeeping activity. He had visited his doctor who told him that he suffered from lumbago and sciatica. The doctor told him that he was not quite sure what causes the pain, but mention some possibilities, and gave him pain-relieve medication. Since the pain persists, he then went to consult a neurologist at RSMH hospital. On examination, the strength and sensation of his lower extremities are normal. During the examination, while the patient is lying in supine position, the patient complains of severe pain when his right leg is raised by the clinician. After a thorough neurological examination the neurologist sent the patient for a MRI examination just to make sure that the diagnosis is correct. MRI confirmed the diagnosis as prolapsed of nucleus pulposus at L5 level.

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