Differential Diagnosis for Abrupt Onset Numbness and Tingling to Front of Upper Leg

• Single Most Likely Diagnosis
  • Meralgia Paresthetica: This condition is characterized by numbness, tingling, and burning pain in the outer part of the thigh due to compression of the lateral femoral cutaneous nerve. The abrupt onset and specific location of symptoms make this a highly plausible diagnosis.
• Other Likely Diagnoses
  • Lumbar Radiculopathy (L2-L3): Nerve root compression or irritation at the lumbar spine can cause numbness and tingling in the front of the upper leg. The symptoms can have an abrupt onset if caused by a sudden disc herniation or other acute processes.
  • Femoral Neuropathy: Damage or compression of the femoral nerve can lead to numbness, tingling, and sometimes weakness in the front of the thigh. This could be due to various causes, including trauma, compression, or systemic diseases.
• Do Not Miss Diagnoses
  • Diabetic Amyotrophy: Although less common, this condition can present with abrupt onset of pain, weakness, and numbness in the thigh, typically in patients with diabetes. Missing this diagnosis could lead to delayed treatment and significant morbidity.
  • Spinal Cord Infarction or Compression: Though rare, conditions affecting the spinal cord, such as infarction or compression by a tumor, can present with sudden onset of neurological deficits, including numbness and tingling. These conditions are medical emergencies.
• Rare Diagnoses
  • Vasculitis (e.g., Giant Cell Arteritis, Polyarteritis Nodosa): Certain types of vasculitis can affect nerves and present with neurological symptoms, including numbness and tingling. These conditions are rare but can be serious if not treated promptly.
  • Nutritional Deficiencies (e.g., Vitamin B12 Deficiency): Deficiencies in certain vitamins, particularly B12, can cause neurological symptoms, including numbness and tingling. While less common, these deficiencies can be easily treated if identified.