Differential Diagnosis for Right Upper Extremity Weakness after Fall
Single Most Likely Diagnosis
- Radial nerve injury or fracture: A fall can directly injure the radial nerve or cause a fracture that compresses or damages the nerve, leading to weakness in the right upper extremity. The radial nerve controls extension of the wrist and fingers, so damage to this nerve could result in an inability to extend these parts, manifesting as weakness.
Other Likely Diagnoses
- Brachial plexus injury: The brachial plexus is a network of nerves that originates in the spinal cord and controls muscle movements and sensation in the shoulder, elbow, wrist, and hand. A fall can cause a brachial plexus injury, leading to weakness or paralysis of the affected arm.
- Humerus fracture: A fracture of the humerus (upper arm bone) can cause weakness in the right upper extremity, especially if the fracture affects the nerve supply to the muscles of the arm.
- Shoulder dislocation or separation: A fall can cause a shoulder dislocation or separation, which may lead to weakness in the affected arm due to pain, instability, or nerve injury.
Do Not Miss Diagnoses
- Spinal cord injury: Although less common, a fall can cause a spinal cord injury, which may result in weakness or paralysis of one or more limbs, including the right upper extremity. This diagnosis is critical to identify promptly due to its potential for long-term disability.
- Stroke or transient ischemic attack (TIA): While a fall might not be the direct cause of a stroke or TIA, the incident could be a consequence of a stroke, with the weakness being a presenting symptom. It's crucial to consider vascular events, especially in patients with risk factors.
- Cervical spine fracture or instability: A fall can cause a fracture or instability in the cervical spine, potentially leading to spinal cord compression or injury, which could manifest as weakness in the right upper extremity.
Rare Diagnoses
- Peripheral nerve tumors or cysts: Pre-existing conditions like nerve tumors or cysts could potentially be irritated or damaged during a fall, leading to nerve compression and subsequent weakness.
- Infection or abscess: Although rare, an infection or abscess affecting the nerves or muscles of the upper extremity could cause weakness, especially if the fall somehow introduced bacteria into the tissue or exacerbated an existing condition.
- Neuromuscular disorders: Certain neuromuscular disorders, such as muscular dystrophy or myasthenia gravis, could be unmasked or worsened by the physical stress of a fall, leading to noticeable weakness in the right upper extremity.