What are the next steps for a patient with a history of chronic pain, who recently underwent a spinal cord stimulator (SCS) trial and removal, and is now experiencing sharp intermittent electrical impulses in the brain, with progressively increasing frequency and magnitude?

Immediate Neurological Evaluation Required for Post-SCS Removal Neurological Symptoms

This patient requires urgent neurological assessment with brain and spine MRI to rule out serious complications including epidural hematoma, abscess, lead fragment retention, or cerebrospinal fluid leak causing intracranial hypotension. These sharp electrical sensations in the brain following SCS trial removal represent a concerning neurological symptom that demands immediate investigation, not routine follow-up.

Critical Differential Diagnoses to Exclude

Hardware-Related Complications

• Lead migration occurs in 9% of SCS cases 1, and retained lead fragments after removal can cause ongoing electrical sensations or nerve irritation
• Hardware-related complications including lead migration and connection issues occur in 10-29% of cases 2, and incomplete removal may leave conductive material causing aberrant neural signaling
• Obtain immediate spine MRI (non-contrast if any metallic fragments suspected) to visualize the entire lead tract from insertion to removal site 2

Infectious Complications

• Infection rates of 10-29% are reported with SCS 2, and wound dehiscence followed by infection occurs in 14% of cases 1
• Epidural abscess can present with progressive neurological symptoms including paresthesias, pain, and altered sensations that may be perceived as "electrical" 2
• Check inflammatory markers (CBC, ESR, CRP) and obtain contrast-enhanced MRI of spine and brain if infection suspected 2

Cerebrospinal Fluid Complications

• Dural puncture during SCS placement or removal can cause CSF leak 1
• Intracranial hypotension from CSF leak may cause referred head sensations, though typically presents as positional headache rather than electrical impulses
• Brain MRI with gadolinium can identify meningeal enhancement suggestive of CSF leak

Immediate Diagnostic Workup

Neuroimaging Protocol

• Obtain brain MRI without and with contrast to exclude intracranial pathology, meningeal enhancement, or structural abnormalities
• Obtain complete spine MRI covering the entire SCS lead tract (typically cervical-thoracic region based on 1 noting C7-T1 placement for angina, though placement varies by indication)
• Look specifically for epidural fluid collections, retained hardware, or nerve root enhancement 2

Neurological Consultation

• Immediate neurology or neurosurgery evaluation given progressive symptoms with increasing frequency and magnitude
• Document detailed neurological examination including cranial nerves, motor/sensory function, and any autonomic symptoms
• Progressive symptoms following device removal warrant urgent specialist assessment given the potential for serious complications 2

Common Pitfalls to Avoid

Do Not Attribute to "Normal Post-Procedure Sensations"

• While some paresthesias may occur after SCS removal, progressive symptoms with increasing frequency and magnitude are not expected and suggest active pathology
• The description of "electrical impulses in brain" rather than at the implant site is particularly concerning for referred or central nervous system involvement

Do Not Delay Imaging for Symptom Diary

• Unlike chronic pain management where baseline documentation is appropriate 2, 3, acute neurological symptoms after device removal require immediate investigation
• The 7-day trial period with pain diary 3 is for assessing efficacy, not for evaluating post-removal complications

Do Not Assume Psychological Etiology Without Excluding Organic Causes

• While psychological clearance is essential before SCS implantation 2, 3, new neurological symptoms after hardware removal must be presumed organic until proven otherwise
• Complete medical workup before psychiatric referral

Management Based on Findings

If Imaging Reveals Retained Hardware or Hematoma

• Immediate neurosurgical consultation for potential surgical intervention
• Hardware-related complications occur in 10-29% of cases 2 and may require reoperation

If Infection Identified

• Initiate broad-spectrum antibiotics with CNS penetration
• Surgical debridement may be necessary given 14% wound dehiscence with infection rate 1

If No Structural Abnormality Found

• Consider nerve injury or neuropathic pain from lead placement/removal
• Gabapentin or pregabalin should be trialed as first-line neuropathic pain medications 2, 3
• Neurology follow-up for potential central sensitization or other functional neurological disorder only after organic causes excluded

Why Standard SCS Guidelines Don't Apply Here

The provided evidence focuses on patient selection criteria, trial success requirements, and chronic pain management 2, 3, 4, 5, 6, but this patient has an acute complication requiring different management. The American Society of Anesthesiologists guidelines address SCS efficacy and patient selection 1, 2, not post-removal neurological emergencies. This situation demands acute neurological care protocols, not chronic pain management algorithms.