What is the most likely cause of paresthesia in a patient with neck extension-induced hand tingling and sensory deficit over the radial thumb?

Differential Diagnosis for Paresthesia in a 74-year-old Woman

The patient presents with a 3-month history of tingling in her hand when she extends her neck, along with tender points over the spinous processes of C4-C6 and an area of sensory deficit over the radial aspect of the thumb. Based on these symptoms, the following differential diagnoses are considered:

• Single most likely diagnosis

  • E. spondylosis at the C5-C6 intervertebral space: This is the most likely cause due to the patient's age and the nature of her symptoms. Spondylosis, or cervical spondylosis, is a common condition in older adults characterized by wear and tear on the discs and joints in the neck. The symptoms of tingling in the hand, especially when extending the neck, and the specific area of sensory deficit over the radial aspect of the thumb, can be associated with compression or irritation of the C6 nerve root, which is commonly affected at the C5-C6 level.

• Other Likely diagnoses

  • C. herniation of the C4 cervical disk: Although less likely than spondylosis at C5-C6 given the specific symptoms, a herniated disk at the C4 level could potentially cause similar symptoms if it compresses or irritates the C5 nerve root, which could result in sensory deficits in the arm and hand.
  • B. bulging disk at the C7 intervertebral space: A bulging disk at C7 could cause symptoms by compressing the C7 nerve root, but the sensory deficit pattern described (over the radial aspect of the thumb) is less typical for C7 radiculopathy, which more commonly affects the middle finger.

• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)

  • None of the provided options directly fit into the "do not miss" category as they are primarily related to mechanical or degenerative issues rather than life-threatening conditions. However, it's crucial to consider other potential causes of neck and arm symptoms that could be more serious, such as:
    • Vertebral artery dissection or other vascular issues
    • Infections (e.g., osteomyelitis, discitis)
    • Tumors (metastatic or primary)

• Rare diagnoses

  • A. acute torticollis: This condition involves a sudden onset of neck muscle spasm, leading to an abnormal posture of the head and neck. While it could potentially cause discomfort and limited range of motion, it is less likely to cause the specific pattern of sensory deficit described.
  • D. spondylolisthesis: This condition involves the forward displacement of a vertebra, which could potentially cause nerve compression. However, it is less common in the cervical spine and might not directly explain the patient's specific symptoms without additional information on the degree of slippage and the presence of nerve root compression.