ANATOMY CASE STUDY 2013 BATCH
Clinical Case (HEAD) 1 A 28-year–old man is treated in the emergency department for a superficial gash on his forehead. The wound is bleeding profusely, but examination reveals no fracture. While the wound is being sutured, he relates that while he was using an electric razor, he remembers becoming dizzy and then waking up on the floor with “blood everywhere”. The physician suspects a hypersensitive cardiac reflex. The patient’s epicranial aponeurosis is penetrated, resulting in severe gaping of the wound. QUESTION: 1. What structures overlay the epicranial aponeurosis? The skin and superficial fascia which contains abundant blood vessels.
2. What are the features of the structures in this region? The structures in this region form into the scalp that is composed of five layers, the first three layers are connected intimately and move as a unit. i. Skin: thin, contains many sweat and sebaceous glands and hair follicles. ii. Superficial fascia: thick, dense, richly vascularized. iii. Aponeurosis (epicranial aponeurosis): the broad, strong, tendinous sheet. iv. Loose areolar tissue: a sponge‐like layer including potential spaces that may distend with fluid as a result of injury or infection. This layer allows free movement of the scalp proper over the underlying calvaria. v. Pericranium: a dense layer of connective tissue, firmly attached but can be stripped fairly easily from the crania of living persons, except where the pericranium is continuous with the fibrous tissue in the cranial sutures.
OR A mnemonic device for remembering the order in which the soft tissues overlie the cranium is SCALP: Skin, Connective tissue, Aponeurosis, Loose connective tissue, and Periosteum. The scalp proper is composed of the outer three layers, of which the connective tissue contains one of the richest cutaneous blood supplies of the body. The occipitofrontal muscle complex inserts into the epicranial aponeurosis, which forms the intermediate tendon of this digastric muscle. This structure, along with the underlying layer of loose connective tissue, accounts for the high degree of mobility of the scalp over the pericranium. If the aponeurosis is lacerated transversely, traction from the muscle bellies will cause considerable gaping of the wound.
Secondary to trauma or infection, blood or pus may accumulate subjacent to the epicranial aponeurosis.
Clinical Case (HEAD) 2 A 65-year-old man complained of inability to shut his right eye, difficulty in moving food around his mouth and weakness on the same side of his mouth with slight numbness on the right cheek. The problem started a few weeks ago following an excisional biopsy of a right facial lump that proved to be a benign parotid tumor. The surgeon was able to verify an area of mild numbness on the right cheek. Upon examining facial muscles, he suspected an injury to facial nerve branches that must have happened during the biopsy. He suggested intensive physiotherapy sessions and regular checkups to monitor the patient's progress. QUESTIONS: (1) How would you explain the patient's numbness on the right cheek? The most likely reason is an injury to the maxillary division of the trigeminal nerve.
(2) Which facial muscles do you think are responsible for the patient's complaints? The main muscles are: orbicularis oculi buccinators orbicularis oris.
(3) How would you test for these muscles? For the orbicularis oculi: ask the patient to shut his eye as tightly as he can. The affected eye is either not closed at all, in which case the eyeball rolls upward to make up for the failure of the lid to descend. For buccinator and orbicularis oris: ask the patient to whistle. If he is unable to do so, ask him to smile or show his upper teeth, the mouth is then drawn to the healthy side. Ask him to inflate his mouth with air and blow out his cheeks. Tap with a finger in turn on each inflated cheek. Air can be made to escape from the mouth more easily on the weak or paralyzed side.
(4) What other functions of the facial nerve need to be checked?
Test sense of taste on the anterior part of the tongue and ask the patient to raise his eyebrows.
Clinical Case (NECK) 3 A 42-year-old Asian women presents to her family practice physician with a bulge in the middle of her neck in front of her trachea. The growth has become bothersome when she swallows and has been noticed by family and friends. An ENT (ear, nose and throat) physician performs a fine-needle biopsy, taking samples from both the right and left sides of the thyroid gland and sends the sample for pathological analysis. The pathology report is returned with a diagnosis of papillary thyroid cancer and the ENT recommends surgical removal of all of the thyroid gland. QUESTIONS: 1. What risk factors does the surgeon warn the patient about before reassuring the woman that he has removed hundreds of cancerous thyroid glands without such complications? The two main arteries supplying the gland are accompanied by nerves that can be damaged during thyroidectomy. The superior thyroid artery is related to the external laryngeal nerve. The inferior thyroid arteries are related to the recurrent laryngeal nerve. Damage to the external laryngeal nerve can result in the inability to tense the vocal folds, producing weakness of the voice; the cricothyroid muscle is unable to contract. Bilateral damage to the recurrent laryngeal nerves may cause the patient to lose speech completely and cause difficulty in breathing. Another possible complication of thyroidectomy is the inadvertent removal of the parathyroid glands, which may cause a severe convulsive disorder known as tetany.
2. Which muscles must be retracted to gain access to the thyroid gland during its removal? a) Platysma b) Sternohyoid mm c) Sternothyroid mm
Clinical case (The upper limb) 1 Following an auto accident, a 23-year-old male was brought to the emergency room for treatment of a fractured right humerus. Although the skin was not broken, there was an obvious deformity caused by an angulated fracture at the mid-shaft. While conducting an examination on the patient’s injured arm, the attending orthopedist noticed that the patient was unable to extend the joints of his wrist and hand. QUESTION: 1. WHAT STRUCTURE COULD BE INJURED IN THE BRACHIAL REGION OF THIS PATIENT THAT WOULD ACCOUNT FOR HIS INABILITY TO EXTEND HIS HAND? LIST THE MUSCLES THAT WOULD BE AFFECTED AND DESCRIBE THE MOVEMENTS THAT WOULD BE DIMINISHED. Inability to extend wrist and hand is due radial nerve damage. The muscles that would be affected： 1) Triceps brachii (long head , medial head , lateral head) –not being able to extend his elbow joint, not being able to extend and adduct his shoulder joint 2) Brachioradialis –not being able to flex elbow joint 3) Extensor carpi radialis longus, extensor carpi radialis brevis, and extensor carpi ulnaris–not being able to extends and abduct wrist 4) Extensor digitorum –not being able to extend wrist and phalanges at joints of carpophalangeal and interphalangeal joints 5) Extensor digiti minimi –not being able to extend joints of fifth digit and wrist 6) Supinator –not being able to supinate forearm and hand 7) Abductor pollicis longus–not being able to abduct joints of thumb and joints of hand 8) Extensor pollicis brevis and extensor pollicis longus–not being able to extend joints of thumb and abduct joints of hand 9) Extensor indicis–not being able to extend the index finger and extend the wrist and midcarpal joints 2. DO YOU THINK THERE MIGHT BE OTHER NEUROLOGICAL DEFECTS? Yes. There might be loss of sensation on the skin of the back of arm, forearm, and radial side of dorsum of hand and radial two and one-half fingers.
Clinical case (The upper limb) 2 Several weeks after surgical dissection of her right axilla for the removal of lymph nodes for staging and treatment of her breast cancer, a 44-year-old woman’s husband noticed that her right scapula protruded abnormally when she pushed against the wall during her stretching exercises. She also had difficulty raising her right arm above her head when combing her hair. During her return visit with her surgeon, she was told that a nerve was accidentally injured during the diagnostic surgical procedure and that this produced her scapular abnormality and inability to raise her arm normally. QUESTIONS TO CONSIDER:
1) WHAT NERVE WAS PROBABLY INJURED?
The long thoracic nerve to the serratus anterior was injured. During surgical axillary dissection, it is normally identified and maintained against the thoracic wall while the lymph nodes are excised. However, the nerve may be accidentally damaged during removal of nodes. 2) WHY DID THIS INJURY CAUSE “WINGING OF HER SCAPULA” AND DIFFICULTY RAISING HER ARM?
Injury to the long thoracic nerve causes paralysis of the serratus anterior, the muscle that keeps the medial border of the scapula in firm apposition with the thoracic wall. The serratus anterior, also powerful, assists the trapezius in rotating the scapula laterally and superiorly when raising the arm over the shoulder. This explains why the person had difficulty combing her hair. 3) IF THESE SCAPULAR ABNORMALITIES WERE OBSERVED IN AN AUTOMOBILE ACCIDENT VICTIM, WHAT FRACTURES MIGHT HAVE CAUSED THE NERVE INJURY?
Injuries to the long thoracic nerve and paralysis of the serratus anterior frequently result from weapons (knives, gunshots); however, they may occur during severe automobile accidents, or when a person is run over by a motor vehicle. Scapular fractures and injury to the long thoracic nerve are usually associated with rib fractures. 4) WHAT OTHER NERVES ARE VULNERABLE TO INJURY DURING REMOVAL OF AXILLARY LYMPH NODES?
The thoracodorsal, pectoral, and intercostobrachial nerves are also vulnerable during operations on the inferior part of the axilla. 5) WHAT ABNORMALITIES OF ARM MOVEMENT WOULD LIKELY BE PRESENT AS A RESULT OF THESE NERVE INJURIES?
The thoracodorsal nerve runs inferolaterally along the posterior wall of the axilla and enters the latissimus dorsi at the level of the second and third ribs. A person with paralysis of the latissimus dorsi would have difficulty adducting the arm and rotating it medially. The pectoral nerves supply the pectoralis major and minor. Paralysis of the pectoralis major would seriously affect adduction and weaken medial rotation of the arm.
Clinical case (The upper limb) 3 A 28-year-old dentist consults her physician, complaining that she feels tingling and slight pain in her right hand. The symptoms are localized to her thumb, index, middle and lateral side of her ring finger. The sensations are more intense at night or if she overworks. Recently, she has experienced some weakness in her grasp and finds it more difficult to hold her instruments. Also, movements of her right thumb are not as strong as before. On examination, there is loss of power on certain movements of the thumb. She has impaired appreciation of light touch and pin pricks to the thumb, index, middle and lateral side of her ring finger, but sensation to her palm is not affected. Pressure and tapping over the flexor retinaculum causes tingling. After a complete examination, the patient is diagnosed with carpal tunnel syndrome. Questions to consider:
① WHAT IS THE CARPAL TUNNEL? WHAT IS CONTAINED IN IT?
The carpal tunnel is a canal at the wrist made up of the carpal bones and flexor retinaculum. The tunnel houses the tendon of the flexor pollicis longus in its synovial sheath, the tendons of the flexor digitorum superficialis and profundus in their common synovial sheath and the median nerve. OR The carpel tunnel (or The carpel canal) is the passageway on the palmar side of the wrist that connects the forearm to the middle compartment of the deep plane of the palm. It consist of ::
Bones Connective tissue Several tendons Median nerve
② TWO MUSCLES THAT ARE AFFECTED BY CARPAL TUNNEL SYNDROME ARE THE ABDUCTOR POLLICIS BREVIS AND THE OPPONENS POLLICIS. HOW WOULD YOU TEST THEIR FUNCTION?
The abductor pollicis brevis pulls the thumb away from the palm at a right angle. One way to test this is to lie the forearm on a table, palm up and ask the patient to point their thumb towards the ceiling. At the same time, you can push down on the thumb to give some resistance. The opponens pollicis pulls the thumb across the palm towards the base of the little finger. Ask the patient to do this against resistance.
③ WHAT CAUSES THE SYMPTOMS OF CARPAL TUNNEL SYNDROME? Carpal tunnel syndrome is caused by a compression of the median nerve. This can be due to the inflammation of the common flexor tendon sheath after strain and overexertion. Fluid retention, as seen in pregnancy and hormonal imbalances, can also cause compression of the nerve. Patients often feel an increase in symptoms at night due to venous stasis. Venous stasis contributes to the compression of the nerve. ④ WHAT STRUCTURES MIGHT BE ENDANGERED BY SURGERY AND NEED TO BE AVOIDED? Surgery can decompress the median nerve. Structures superficial to the flexor retinaculum, however, can be endangered. This includes the superficial palmar vascular arch formed by the superficial branch of the ulnar artery and superficial branch of the radial artery, the palmar cutaneous branches of the median and ulnar nerves and the recurrent motor branch of the median nerve.
Clinical Case 4 An 8-year-old boy returns to the pediatric clinic because he has a “pain in his butt� and walks with a limp. He just visited the clinic a few days ago for a normal summer checkup and an update on his vaccinations. When the physician asks how this happened, the boy says that the pain started when the nurse gave him his booster shot in his left buttock. When he walks, he drops his right hip as he places all the weight on his left leg and swings his right leg forward. When lying prone on the examination table while both legs flex normally with equal strength, and he can extend his thigh at the hip well, but there is flaccidity of his muscles just under the iliac crest only on the left side. QUESTION: 1. Which structures were most likely damaged by the booster shot that the boy received a couple of days ago? o
The nurse might have injected to Sciatic nerve.
o
INTRAGLUTEAL INJECTION. Some people restrict the area of the buttock to the most prominent part, which may be dangerous because the sciatic nerve lies deep to this area.
Clinical Case 5 A 65-year-old woman was submitted to cardiac catheterization in order to measure the pressures in the chambers of her heart. A catheter was inserted in her right femoral vein in the femoral triangle and floated through the iliac veins and the inferior vena cava to the right heart, where diagnostic procedures were performed without incident. She began to complain of a painful throbbing in her right groin 4 hours after completion of the procedure. Over the course of the next hour, the pain worsened and she began to experience numbness and tingling in her right anteromedial thigh and leg. On examination, her right leg felt cool and a mass was observed in the right groin. No distal pulses could be felt in the leg. She was immediately taken up to surgery for exploration of the groin region. QUESTIONS TO CONSIDER: 1. Given what you know about the anatomy of the inguinal region and the anteromedial thigh, what are the risks associated with catheterization in the groin region? The risks of catheterization include damage to the femoral artery or vein leading to an internal hemorrhage, injury to the FEMORAL NERVE, needle introduction into the peritoneal cavity, & formation of an arteriovenous fistula. 2. What do you think caused the mass in the patient's groin?
The mass in the patient's groin was due to the formation of a hematoma. The hematoma could result from failure of the wound in the femoral vein to close, or more likely, due to a laceration of the femoral artery that occurred at some point during the procedure. 3. How would you explain the numbness and absence of distal pulses? The numbness and lack of distal pulses are most likely due to the compression of the neurovascular structures of the FEMORAL TRIANGLE (femoral a., v., and n.) by the hematoma.
Clinical Case 6 A 24-year-old football player was taken to the emergency room after receiving a blow to the left leg that resulted in severe pain and inability to stand up. The attending physician was able to locate a very painful area just below the knee and suspected a fracture to the fibula. He ordered a plain AP and lateral x-ray of the leg and knee. A clear spiral fracture in the left fibular neck and a cracked tibial shaft were shown on the x-ray. The patient was given analgesics, and a thorough neurological examination was done. No signs of nerve injury were detected. A plaster cast was applied, and the patient was discharged. QUESTIONS TO CONSIDER: 1. Which nerve is most likely to be injured in such incidents? THE COMMON PERONEAL NERVE (COMMON FIBULAR NERVE.) 2. What would the doctor look for to confirm nerve injury?
There is loss of eversion and dorsiflexion of the foot. Foot-drop is the usual result of this injury, but this cannot be confirmed very early after the accident or when the patient is still having pain on walking. Tendon reflexes will be weak or absent. There is loss of sensation on the anterolateral aspect of the leg and the dorsum of the foot.
3. Which of the two injured leg bones was the primary factor in the patient's inability to walk & why? The tibia, since it is the principal weight-bearing bone of the leg.
Clinical cases (Thorax). 1 A 28-year-old woman comes into the emergency department exhibiting dyspnea and mild cyanosis, but no signs of trauma. Her chest x-ray is shown below. The most obvious abnormal finding in the inspiratory posteroanterior (PA) chest x-ray of this patient (performed in the anatomic position) is a left pneumothorax (collapsed lung) as indicated by the dark appearance of the left lung and the shifting of the heart to the right.
Question: What structure is the one indicated by the arrow? THE ARCH OF AORTA
Clinical cases (Thorax). 2 A mammogram of a woman, age 48, reveals macrocalcification within the right upper, lateral quadrant of the breast, indicating the need for a biopsy. The surgeon closely examines the nipple for indications of ductal carcinoma. A surgery for the biopsy, a locator needle is inserted into the region of the macrocalcification and the position confirmed by mammography. The surgeon incises the skin and dissects a block of tissue. The pathology report indicates ductal carcinoma with microinvasion necessitating surgery. The woman undergoes a complete mastectomy, including removing several axilary lymph nodes. The lymph nodes are all negative for evidence of metastasis. However, the patient is found to have winging of the scapula when her flexed arm is pressed against a fixed object. Question: Which nerve is injured that is indicated by the symptom? LONG THORACIC NERVE which supplies the serratus anterior
Clinical case (The abdomen) 1 : A full-term 8 lb baby boy was delivered vaginally to a 36-year-old mother. At delivery he had a large scrotum. The delivering obstetrician (OB) palpated the enlarged scrotum and determined that both testicles were present. When the OB pressed gently on the newborn’s abdomen the scrotum swelled even more. QUESTION: WHAT CONGENITAL CONDITION DID THE OB NOTE IN THE CHART? CONGENITAL HYDROCELE
Clinical case (The abdomen) 2 : A 65-year-old man presents with jaundice of 2 to 3 weeks duration, fatigue and increasing epigastric pain. He has no history of peptic ulcers and says the pain does not relate to eating in
anyway. His epigastric pain is midline and he reports recent back pain. He has pale stools, dark urine, and elevated urinary and serum conjugated bilirubin. Helical CT reveals a suspicious mass in the head of the pancreas adjacent to the descending duodenum. The gallbladder is significantly enlarged. QUESTION: WHAT IS THE LIKELY CAUSE OF THE ELEVATED BILIRUBIN? Tumor in the head of the pancreas compresses the common bile duct , resulting in blockadge of the normal bile recycling circuit. This blockade prevents excretion of bilirubin. The accumulation of bilirubin in various tissues, including the skin, causes jaundice.
Clinical case (The abdomen) 3 : A 78-year-old man is brought to the emergency department by his wife. The man is doubled over with sudden onset of lower abdominal pain after eating dinner at an “all-you-can-eat” buffet. The man’s abdomen is distended, with vague lower left abdominal pain and he states that he cannot pass any gas. Bowel sounds are extensive in the upper abdomen, but are lacking in the left lower abdomen. The on-call GI fellow is asked to bring a sigmoidoscope. QUESTION: WHAT CONDITION DOES THIS PATIENT HAVE AND HOW MIGHT A SIGMOIDSCOPE HELP ?
Sigmoid volvulus; the diverticulum may actually be used to help straighten the sigmoid colon if it has twisted on itself.
Clinical case (The back and the vertebral region)1 :: A 25-year-old woman is brought to the emergency department by her roommate because she has a fever of 39℃, stiff neck, and the “worst headache of her life”. The fundus of her eyes shows no evidence of papilledema. In addition to collecting blood to be sent to the lab for evidence of sepsis, the attending doctor recommends a spinal tap to obtain CSF for evidence of infection. QUESTIONS: 1. WHERE ALONG THE VERTEBRAL COLUMN IS A NEEDLE INSERTED FOR A LUMBAR PUNCTURE? WHICH LANDMARK CAN YOU USE TO FIND THIS LEVEL?
The spinal cord usually ends at the inferior border of L1 or the superior border of L2. Therefore, inserting the needle between L3 and L4 or L4 and L5 is relatively safe. This level corresponds to the lumbar cistern. The line connecting the top of the two iliac crests, the supracrestal line, passes through the spinous process of the L4 vertebra
2. DURING A LUMBAR PUNCTURE, THE SYRINGE NEEDLE IS INSERTED IN THE MIDLINE AND WITHIN THE MEDIAN PLANE. WHY? WHAT STRUCTURES, LIGAMENTS AND OTHERS, DOES THE NEEDLE TRAVERSE BEFORE ENTERING THE LUMBAR CISTERN? At the level of the lumbar cistern the nerve roots are suspended in CSF and therefore float away from the pressure of the needle. However, as the nerve roots exiting the vertebral canal at this level approach their fixed dural sleeves laterally, they are unable to move freely. Hence it is necessary to remain in the median plane in order to avoid damage to the nerve roots. The needle must pass through the following body layers in order to reach the lumbar cistern : skin, fat, supraspinous ligament, interspinous ligament, between or through the ligamenta flava, epidural fat and veins, dura, subdural space, and arachnoid.
3. WHAT POSITION IS THE PATIENT PLACED IN DURING THIS PROCEDURE? JUSTIFY THIS ANATOMICALLY. The patient is asked to flex his or her back as much as possible during a lumbar puncture, either sitting up or lying on their side in the fetal position. This increases the space between the spinous processes.