Differential Diagnosis for Wrist Weakness and Drop
- Single most likely diagnosis
- Radial Nerve Palsy: This condition is the most likely cause of wrist drop due to its direct involvement with the muscles responsible for wrist extension. The radial nerve controls the extensor muscles of the wrist, and damage to this nerve can lead to an inability to extend the wrist, resulting in a drop.
- Other Likely diagnoses
- Cervical Radiculopathy (C7): Compression or injury to the C7 nerve root can affect the muscles of the wrist and hand, leading to weakness and potentially wrist drop.
- Peripheral Neuropathy: Certain types of peripheral neuropathy can affect the nerves that control wrist movement, leading to weakness and drop.
- Muscular Dystrophy: Some forms of muscular dystrophy can lead to progressive muscle weakness, including the muscles of the wrist, resulting in wrist drop.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Acute Compartment Syndrome: This is a medical emergency that can cause nerve and muscle damage if not promptly treated. It can lead to wrist weakness and drop among other symptoms.
- Tumor or Cyst Compressing the Radial Nerve: A tumor or cyst compressing the radial nerve can cause wrist drop and needs to be identified and treated to prevent further nerve damage.
- Stroke or Cerebral Vasculitis: Although less common, a stroke or cerebral vasculitis affecting the motor areas of the brain can lead to wrist weakness and drop.
- Rare diagnoses
- Lead Poisoning: Lead poisoning can cause peripheral neuropathy, which may result in wrist drop among other neurological symptoms.
- Saturday Night Palsy: A condition caused by prolonged compression of the radial nerve, often due to sleeping with an arm over a chair or other object, leading to temporary wrist drop.
- Charcot-Marie-Tooth Disease: A group of inherited disorders that affect the peripheral nerves, potentially leading to muscle weakness and atrophy, including wrist drop.