Can tingling in the lower legs, arms, and back of a patient who recently discontinued Selective Serotonin Reuptake Inhibitor (SSRI) be a symptom of a brain tumor?

Tingling in Lower Legs After SSRI Discontinuation: Brain Tumor Likelihood

Tingling in the lower legs, arms, and back following recent SSRI discontinuation is far more likely to represent SSRI discontinuation syndrome or peripheral neuropathy than a brain tumor, and does not warrant neuroimaging unless accompanied by specific red flag neurological symptoms. 1

Why Brain Tumors Are Unlikely

Brain tumors causing isolated tingling in the lower extremities would be exceptionally rare and would require specific anatomical involvement:

• Sensory symptoms from brain tumors typically present with multifocal neurological deficits, not isolated peripheral tingling 1
• Leptomeningeal metastases can cause sensorimotor deficits of extremities, but these occur in patients with known cancer and are accompanied by headache, mental changes, gait difficulties, cranial nerve palsies, and radicular pain 1
• Primary brain tumors causing leg paresthesias would require involvement of the sensory cortex or descending pathways, which would produce additional motor deficits, not isolated tingling 2

Red Flag Symptoms That Would Suggest Brain Pathology

You should consider neuroimaging only if the patient develops:

• Morning-predominant headache that improves during the day 3
• Nausea and vomiting, especially worse after lying flat 3
• Mental status changes, personality changes, or cognitive impairment 1, 3
• Cranial nerve palsies (diplopia, visual disturbances, hearing loss) 1
• Gait difficulties or ataxia beyond what tingling alone would cause 1
• Focal motor weakness or true radicular pain 1
• Seizures 1

Most Likely Explanation: SSRI Discontinuation

The temporal relationship to SSRI discontinuation strongly suggests:

• SSRI discontinuation syndrome commonly causes paresthesias (tingling, numbness) in extremities 1
• These symptoms typically involve multiple body regions (legs, arms, back) as described in this case 1
• Peripheral neuropathy from various causes (diabetes, vitamin deficiencies, medication effects) presents with distal symmetric tingling, particularly in the legs 1

Clinical Approach

Evaluate for common causes first:

• Assess for other SSRI discontinuation symptoms: dizziness, flu-like symptoms, insomnia, irritability, sensory disturbances 1
• Screen for metabolic causes: check vitamin B12, folate, thyroid function, hemoglobin A1c 1
• Review medication history: chemotherapy agents (taxanes, platinum-based), other neurotoxic medications 1
• Perform a focused neurological examination: assess for true motor weakness, reflex asymmetry, gait abnormality, cranial nerve deficits 1

Do NOT order brain imaging unless:

• The neurological examination reveals focal deficits beyond sensory symptoms 1
• Red flag symptoms listed above develop 1, 3
• The patient has a known history of cancer 1

Management Recommendation

For isolated tingling after SSRI discontinuation without red flags:

• Reassure the patient that brain tumors do not present this way 1
• Consider restarting the SSRI at a lower dose and tapering more gradually if discontinuation syndrome is suspected 1
• Offer duloxetine for neuropathic symptoms if peripheral neuropathy is confirmed 1
• Recommend physical activity, which has evidence for improving neuropathic symptoms 1

The key clinical pitfall is ordering unnecessary neuroimaging for non-specific sensory symptoms that lack the multifocal, progressive neurological deficits characteristic of brain tumors 1.