From the Guidelines
Sudden onset numbness on one side of the body requires immediate medical attention as it may indicate a stroke or other serious neurological condition, and calling emergency services right away is crucial. The most common cause is a stroke, which occurs when blood flow to part of the brain is interrupted by a clot (ischemic stroke) or bleeding (hemorrhagic stroke) 1. Other potential causes include transient ischemic attack (TIA or "mini-stroke"), migraine with aura, multiple sclerosis, seizure disorders, or nerve compression.
Key Considerations
- The signs and symptoms of stroke are sudden numbness or weakness of the face, arm, or leg, especially on one side of the body; sudden confusion, trouble speaking or understanding; sudden trouble seeing in one or both eyes; sudden trouble walking, dizziness, loss of balance or coordination; and sudden severe headache with no known cause 1.
- Patients at high risk for stroke, their family members, and BLS providers should learn to recognize the signs and symptoms of stroke and to call EMS as soon as any signs of stroke are present (Class I, LOE C) 1.
- The window of opportunity for effective therapy, such as fibrinolytic therapy, is extremely limited, and early detection of the signs of stroke is critical for limiting neurological injury and improving outcome in selected patients with acute ischemic stroke 1.
Recommended Course of Action
- Call emergency services (911 in the US) immediately if you experience sudden onset numbness on one side of the body, as prompt treatment within the first few hours is critical for preventing permanent damage.
- At the hospital, healthcare providers will likely perform brain imaging (CT or MRI), blood tests, and neurological examinations to determine the cause.
- Treatment depends on the diagnosis but may include clot-dissolving medications like alteplase (tPA) if administered within 3-4.5 hours of symptom onset for ischemic stroke, blood pressure management, anti-seizure medications, or other interventions specific to the underlying condition.
- Remember the acronym FAST to identify stroke symptoms: Face drooping, Arm weakness, Speech difficulties, Time to call emergency services.
Additional Guidance
- Patients experiencing atypical sensory symptoms (such as patchy numbness and/or tingling) are generally considered as less urgent, and may be seen by a healthcare professional with stroke expertise as required (Evidence Level C) 1.
- However, given the potential for serious conditions, it is always best to err on the side of caution and seek immediate medical attention for any sudden onset numbness on one side of the body.
From the Research
Potential Causes of Sudden Onset Numbness
- Sudden onset numbness on one side of the body can be caused by a variety of factors, including transient ischemic attack (TIA) or minor stroke 2, 3
- TIAs are characterized by a temporary disruption in blood flow to the brain, which can cause numbness, weakness, or other neurological symptoms 4, 5
- The numbness can start in one area and migrate to other areas, or it can occur suddenly and affect the entire side of the body 5
Recommended Course of Action
- If you are experiencing sudden onset numbness on one side of the body, it is essential to seek medical attention immediately 2, 3
- A thorough medical evaluation, including imaging tests such as CT or MRI, can help determine the cause of the numbness 2, 3
- Diffusion-weighted MRI is recommended for detecting acute ischemic lesions, which can indicate a high risk of recurrent stroke 2, 3
- Perfusion imaging with perfusion MRI or CT perfusion may also be used to detect ischemic lesions and improve diagnosis 2, 4
Importance of Accurate Diagnosis
- Accurate diagnosis of TIA or minor stroke is crucial for proper management and prevention of future strokes 6
- Non-neurologists, such as general practitioners or emergency physicians, may misdiagnose TIA or minor stroke, highlighting the need for specialist evaluation 6
- A combination of diffusion-weighted MRI and perfusion-weighted MRI can improve the accuracy of TIA diagnosis and help identify patients at high risk of recurrent stroke 5
Characteristics of Numbness
- The numbness can be intermittent or persistent, and its frequency and duration can vary 5
- In some cases, the numbness may be accompanied by other symptoms, such as weakness, tingling, or difficulty with speech or vision 4, 5
- The characteristics of the numbness, including its location, duration, and associated symptoms, can provide valuable information for diagnosis and treatment 5