1.
DERMATOME:
Vertex of skull
PARESTHESIAS:
None
Correct Answer
A. C1
Explanation
The correct answer is C1. C1 is the first cervical dermatome, which is located at the vertex of the skull. Dermatomes are specific areas of the skin that are innervated by a single spinal nerve. In this case, C1 innervates the area at the top of the head, known as the vertex. Paresthesias refer to abnormal sensations like tingling or numbness, and in this case, there are no reported paresthesias associated with C1.
2.
DERMATOME:
Temple, Forehead, Occiput
PARESTHESIAS:
None
Correct Answer
B. C2
Explanation
The correct answer is C2. The distribution of symptoms in the given question suggests involvement of the second cervical dermatome. The symptoms mentioned, such as temple, forehead, and occiput, are all areas innervated by the second cervical nerve. Additionally, the absence of paresthesias further supports the involvement of the C2 dermatome, as paresthesias would typically be present if there was nerve dysfunction in this area.
3.
DERMATOME:
Entire neck
Posterior cheek
Temporal area
Prolongation forward under mandible
PARESTHESIAS:
Cheek
Side of neck
Correct Answer
B. C3
Explanation
The correct answer is C3. The explanation for this answer is that the C3 dermatome covers the entire neck, which matches the description given in the first part of the question. Additionally, the C3 dermatome also includes the posterior cheek and temporal area, which aligns with the second part of the question. The other options (C2, C4, and C1) do not cover the entire neck or include the specified areas, making them incorrect choices.
4.
DERMATOME:
Shoulder area
Clavicular area
Upper Scapular area
PARESTHESIAS:
Horizontal band along clavicle and upper scapula
Correct Answer
B. C4
Explanation
The correct answer is C4. Paresthesias refer to abnormal sensations such as tingling or numbness. The given options represent different dermatomes, which are specific areas of the skin that are innervated by different spinal nerves. The horizontal band along the clavicle and upper scapula corresponds to the C4 dermatome. Therefore, the correct answer is C4.
5.
DERMATOME:
Deltoid area
Anterior aspect of entire arm to base of thumb
PARESTHESIAS:
None
Correct Answer
C. C5
Explanation
The correct answer is C5 because the dermatome of C5 covers the anterior aspect of the entire arm to the base of the thumb. Since there are no paresthesias reported, it suggests that there is no abnormal sensation or tingling in this area, further supporting the answer of C5.
6.
DERMATOME:
Anterior arm
Radial side of hand to thumb and index fingers
PARESTHESIAS:
Thumb and index finger
Correct Answer
B. C6
Explanation
The correct answer is C6 because the symptoms described in the question, paresthesias in the thumb and index finger, are associated with nerve impingement at the C6 level. The C6 dermatome covers the radial side of the hand to the thumb and index fingers, which matches the distribution of symptoms mentioned.
7.
DERMATOME:
Lateral arm and forearm to index, long, and ring fingers
PARESTHESIAS:
Index, long, and ring fingers
Correct Answer
B. C7
Explanation
The correct answer is C7. C7 refers to the seventh cervical nerve root, which innervates the lateral arm and forearm as well as the index, long, and ring fingers. Paresthesias, or abnormal sensations like tingling or numbness, are specifically experienced in the index, long, and ring fingers. Therefore, C7 is the most appropriate answer that matches the description given.
8.
DERMATOME:
Medial arm and forearm to index, long, and ring fingers
PARESTHESIAS:
Little finger alone or with two adjacent fingers, NOT ring or long fingers, alone or together
Correct Answer
C. C8
Explanation
The correct answer is C8. C8 refers to the eighth cervical nerve root, which innervates the medial arm and forearm as well as the index, long, and ring fingers. Paresthesias, which are abnormal sensations like tingling or numbness, are commonly experienced in the little finger alone or with two adjacent fingers, but not in the ring or long fingers alone or together. Therefore, the symptoms described in the question are consistent with C8 nerve root involvement.
9.
DERMATOME:
Medial side of forearm to base of little finger
PARESTHESIAS:
None
Correct Answer
B. T1
Explanation
The correct answer is T1. The question is asking for the dermatome that corresponds to the medial side of the forearm to the base of the little finger. The dermatome that covers this area is T1. Paresthesias, which refer to abnormal sensations such as tingling or numbness, are not mentioned in the given information.
10.
DERMATOME:
Medial side of upper arm to medial elbow
Pectoral and midscapular areas
PARESTHESIAS:
None
Correct Answer
C. T2
Explanation
The correct answer is T2. The given information states that the dermatome extends from the medial side of the upper arm to the medial elbow, as well as covering the pectoral and midscapular areas. The absence of paresthesias suggests that the T2 dermatome is not affected, indicating that the correct answer is T2.
11.
DERMATOMES:
Upper thorax
PARESTHESIAS:
None
Correct Answer
A. T3-T6
Explanation
The correct answer is T3-T6. Dermatomes are specific areas of skin supplied by specific spinal nerves. In this case, the upper thorax is supplied by the spinal nerves T3-T6. Paresthesias refer to abnormal sensations such as tingling or numbness. Since there are no paresthesias mentioned, it indicates that the sensory function in the dermatomes T3-T6 is normal.
12.
DERMATOMES:
Costal margin
PARESTHESIAS:
None
Correct Answer
B. T5-T7
Explanation
The correct answer is T5-T7. Dermatomes are specific areas of the skin that are innervated by a single spinal nerve. T5-T7 refers to the dermatomes that cover the area around the mid-chest and upper abdomen. Paresthesias, which are abnormal sensations such as tingling or numbness, are not reported in this dermatome region.
13.
DERMATOMES:
Abdomen and lumbar region
PARESTHESIAS:
None
Correct Answer
A. T8-T12
Explanation
The correct answer is T8-T12. Dermatomes refer to specific areas of skin that are innervated by a single spinal nerve. In this case, the abdomen and lumbar region are innervated by the thoracic spinal nerves T8-T12. Paresthesias, which are abnormal sensations like tingling or numbness, are not reported in this dermatome region.
14.
DERMATOME:
Back, over trochanter and groin
PARESTHESIAS:
Groin; after holding posture which causes pain
Correct Answer
A. L1
Explanation
The correct answer is L1. This is because the symptoms described, which include paresthesias in the groin after holding a painful posture, are consistent with nerve impingement at the level of the L1 dermatome. The L1 dermatome covers the back, over the trochanter, and the groin, which aligns with the mentioned symptoms.
15.
DERMATOME:
Back, front of thigh to knee
PARESTHESIAS:
Occasionally anterior thigh
Correct Answer
B. L2
Explanation
The correct answer is L2. L2 is the level of the spinal cord responsible for innervating the front of the thigh to the knee. Paresthesias, which are abnormal sensations like tingling or numbness, occasionally occur in the anterior thigh.
16.
DERMATOME:
Back
Upper buttock
Anterior thigh and knee
Medial lower leg
PARESTHESIAS:
Medial knee
Anterior lower leg
Correct Answer
B. L3
Explanation
The correct answer is L3. The dermatome for L3 includes the anterior thigh and knee, while the paresthesias associated with L3 are felt in the medial knee. Therefore, L3 is the most appropriate answer as it matches both the dermatome and the paresthesias described.
17.
DERMATOME:
Medial buttock
Lateral thigh
Medial leg
Dorsum of foot
Big toe
PARESTHESIAS:
Medial aspect of calf and ankle
Correct Answer
B. L4
Explanation
The correct answer is L4. The distribution of paresthesias in the medial aspect of the calf and ankle corresponds to the L4 dermatome. Dermatomes are specific areas of skin that are innervated by a single spinal nerve. In this case, the paresthesias are occurring in the L4 dermatome, indicating a potential issue with the L4 spinal nerve or its corresponding nerve roots.
18.
DERMATOME:
Buttock
Posterior and lateral thigh
Lateral aspect of leg
Dorsum of foot
Medial half of sole
First, second, and third toes
PARESTHESIAS:
Lateral aspect of leg
Medial three toes
Correct Answer
B. L5
Explanation
The correct answer is L5. L5 dermatome includes the lateral aspect of the leg and the medial three toes. Paresthesias in the L5 dermatome would present as abnormal sensations such as tingling or numbness in these areas.
19.
DERMATOME:
Buttock
Thigh
Posterior leg
PARESTHESIAS:
Lateral two toes
Lateral foot
Lateral leg to knee
Plantar aspect of foot
Correct Answer
B. S1
Explanation
The given answer, S1, is the correct answer because the symptoms described in the PARESTHESIAS section match the dermatome distribution of S1. The symptoms include paresthesias in the lateral foot and leg to the knee, which correspond to the sensory innervation of the S1 dermatome. Therefore, S1 is the most likely nerve root involved in this case.
20.
DERMATOME:
Buttock
Thigh
Posterior leg
PARESTHESIAS:
Lateral leg, knee, and heel
Correct Answer
B. S2
Explanation
The correct answer is S2. The question is asking for the dermatome associated with paresthesias in the lateral leg, knee, and heel. Dermatomes are specific areas of skin that are innervated by specific spinal nerves. In this case, paresthesias in the lateral leg, knee, and heel are associated with the S2 dermatome.
21.
DERMATOME:
Groin
Medial thigh to knee
PARESTHESIAS:
None
Correct Answer
C. S3
Explanation
The correct answer is S3. The question is asking for the dermatome that corresponds to the groin area. Dermatomes are specific areas of skin that are innervated by a single spinal nerve. The S3 dermatome covers the area of the medial thigh to the knee, which includes the groin region. Paresthesias refers to abnormal sensations like tingling or numbness. The statement "None" indicates that there are no abnormal sensations reported in the S3 dermatome.
22.
DERMATOME:
Perineum
Genitals
Lower sacrum
PARESTHESIAS:
Saddle area
Gentials
Anus
Impotence
Massive posterior herniation
Correct Answer
D. S4
Explanation
The correct answer is S4. The S4 dermatome refers to the area of the skin innervated by the fourth sacral nerve. Paresthesias, or abnormal sensations, in the saddle area, genitals, and anus are commonly associated with S4 dermatome involvement. Impotence and massive posterior herniation are not specific to the S4 dermatome.
23.
Myotome/Muscle Weakness:
NONE
Correct Answer
A. C1, L1, S3
Explanation
This answer suggests that the myotome/muscle weakness is present in the C1, L1, and S3 regions. The myotome refers to a group of muscles that are innervated by a specific spinal nerve root. In this case, the weakness is observed in the muscles innervated by the C1, L1, and S3 nerve roots. The specific muscles affected in these regions are not mentioned, but it can be inferred that weakness is present in these areas.
24.
Myotome/Muscle Weakness:
Longus Colli, SCM, rectus capitis
Correct Answer
A. C2
Explanation
The correct answer is C2. C2 is the correct answer because the muscles mentioned in the question (Longus Colli, SCM, rectus capitis) are innervated by the C2 spinal nerve. Each spinal nerve innervates specific muscles, and in this case, the muscles mentioned receive their motor innervation from the C2 spinal nerve. Therefore, if there is weakness in these muscles, it suggests a problem with the C2 nerve root.
25.
Myotome/Muscle Weakness:
Trapezius, Splenius Capitis
Correct Answer
A. C2
Explanation
The correct answer is C2. The trapezius and splenius capitis muscles are innervated by the C2 spinal nerve. Therefore, weakness in these muscles would suggest a problem at the C2 level.
26.
Myotome/Muscle Weakness:
Trapezius, Levator Scapulae
Correct Answer
A. C4
Explanation
The muscles mentioned in the question, Trapezius and Levator Scapulae, are innervated by the C4 spinal nerve. This means that the motor signals for these muscles originate from the C4 level of the spinal cord. If there is any dysfunction or injury at the C4 level, it can lead to weakness or paralysis of these muscles, resulting in myotome/muscle weakness. Therefore, the correct answer is C4.
27.
Myotome/Muscle Weakness:
Supraspinatus, infraspinatus, deltoid, biceps
Correct Answer
B. C5
Explanation
The muscles listed (supraspinatus, infraspinatus, deltoid, biceps) are all innervated by the C5 nerve root. This means that if there is weakness or dysfunction in these muscles, it is likely due to an issue with the C5 nerve.
28.
Myotome/Muscle Weakness:
Biceps, supinator, wirst extensors
Correct Answer
A. C6
Explanation
The correct answer is C6. The muscles mentioned, including the biceps, supinator, and wrist extensors, are innervated by the C6 nerve root. Each nerve root corresponds to a specific level of the spinal cord, and damage or compression at the C6 level can result in weakness or paralysis of these muscles. This can lead to difficulty in flexing the elbow, rotating the forearm, and extending the wrist.
29.
Myotome/Muscle Weakness:
Triceps, wrist flexors (rarely, wrist extensors)
Correct Answer
A. C7
Explanation
This answer refers to the specific level of spinal nerve involvement in a condition called myotome/muscle weakness. The C7 spinal nerve is responsible for innervating the triceps muscle and the wrist flexors. In some cases, the wrist extensors may also be affected, although this is less common. The other options (C8, T1, and C6) do not correspond to the specific muscles mentioned in the question.
30.
Myotome/Muscle Weakness:
Ulnar deviators, thumb extensors, thumb adductors (rarely, triceps)
Correct Answer
A. C8
Explanation
The correct answer is C8. The ulnar deviators, thumb extensors, thumb adductors, and rarely the triceps muscles are innervated by the C8 nerve root. Damage or compression of the C8 nerve root can result in weakness or paralysis of these muscles, leading to a loss of function in ulnar deviation, thumb extension, thumb adduction, and triceps extension.
31.
Myotome/Muscle Weakness:
Articular and dural signs and root pain are common. Root signs (cutaneous analgesia) are rare and have such indefinite area that they have little localizing value. Weakness is not detectable.
Correct Answer
B. T3-T12
32.
Myotome/Muscle Weakness:
Psoas, Hip adductors
Correct Answer
B. L2
Explanation
The correct answer is L2. The psoas and hip adductors are innervated by the L2 spinal nerve. This means that if there is damage or dysfunction at the L2 level, it can result in weakness or impaired function of these muscles. This can manifest as difficulty with hip flexion, hip adduction, and possibly walking or standing. Therefore, L2 is the correct answer for the myotome/muscle weakness associated with the psoas and hip adductors.
33.
Myotome/Muscle Weakness:
Psoas, quadriceps, thigh atrophy
Correct Answer
B. L3
Explanation
The correct answer is L3. The muscles mentioned, including the psoas, quadriceps, and thigh, are innervated by the L3 nerve root. Damage or compression of the L3 nerve root can lead to weakness or atrophy in these muscles.
34.
Myotome/Muscle Weakness:
Tibialis anterior, extensor hallucis
Correct Answer
C. L4
Explanation
The correct answer is L4. The tibialis anterior and extensor hallucis muscles are innervated by the L4 nerve root. Therefore, weakness in these muscles suggests a problem with the L4 nerve root.
35.
Myotome/Muscle Weakness:
Extensor hallucis, peroneals, gluteus medius, dorsiflexors, hamstring and calf atrophy
Correct Answer
C. L5
Explanation
The given answer, L5, refers to the fifth lumbar spinal nerve. The symptoms described, including weakness in the extensor hallucis, peroneals, gluteus medius, dorsiflexors, hamstring, and calf muscles, are consistent with a nerve root compression or injury at the L5 level. This can result in weakness and atrophy of the muscles innervated by the L5 nerve, leading to difficulty with foot and ankle movements, as well as hip stability.
36.
Myotome/Muscle Weakness:
Calf and hamstring, wasting of gluteals, peroneals, plantar flexors
Correct Answer
B. S1
Explanation
The given answer, S1, is the correct answer because the symptoms described in the question are consistent with a nerve root compression at the S1 level. This compression can result in weakness and wasting of the calf and hamstring muscles, as well as the gluteals, peroneals, and plantar flexors. Therefore, S1 is the most appropriate answer based on the provided information.
37.
Myotome/Muscle Weakness:
Calf and hamstring, wasting of gluteals, plantar flexors
Correct Answer
B. S2
Explanation
The correct answer is S2. The S2 nerve root innervates the calf and hamstring muscles, as well as the gluteal muscles and plantar flexors. Damage or compression of the S2 nerve root can result in weakness or wasting of these muscles.
38.
Myotome/Muscle Weakness:
Bladder, rectum
Correct Answer
A. S4
Explanation
The correct answer is S4 because the S4 spinal nerve is responsible for innervating the bladder and rectum. Damage or weakness in this myotome can result in impaired control or function of these organs.
39.
In regards to T1 and T2 myotomes/muscle weakness:
Disc lesions at upper two thoracic levels do not appear to give rise to root weakness. Weakness of intrinsic muscles of the hand is due to other pathology (e.g: thoracic outlet pressure, neoplasm of lung, and ulnar nerve lesion). Dural and nerve root stress has T1 elbow flexion with arm horizontal. T1 and T2 scapulae forward and backward on chest wall. Neck flexion at any thoracic level.
Correct Answer
A. True
Explanation
The explanation for the correct answer is that disc lesions at the upper two thoracic levels do not cause root weakness. Weakness in the intrinsic muscles of the hand is typically caused by other factors such as thoracic outlet pressure, lung neoplasms, or ulnar nerve lesions. The stress on the dural and nerve roots affects T1 elbow flexion with the arm horizontal, as well as the movement of the scapulae forward and backward on the chest wall. Neck flexion can occur at any thoracic level. Therefore, the statement is true.