What is the diagnosis and treatment approach for paresthesia?

Paresthesia: Diagnosis and Treatment

Paresthesia requires a systematic diagnostic approach based on onset timing, distribution pattern, and associated symptoms to differentiate between central versus peripheral nervous system etiologies, with treatment directed at the underlying cause.

Diagnostic Framework

Initial Assessment Priority

Document the rate of symptom onset immediately, as this determines the diagnostic pathway and urgency of intervention. 1

• Acute onset (within hours to days): Consider vascular causes (stroke, spinal cord ischemia), inflammatory conditions (Guillain-Barré syndrome), or cerebral venous thrombosis 2, 1
• Subacute progression (days to weeks): Suspect inflammatory neuropathies, infectious processes, or metabolic disturbances 3
• Gradual onset (weeks to months): Evaluate for compressive lesions, neoplastic processes, or degenerative conditions 1, 3

Critical Red Flags Requiring Urgent Evaluation

Immediately escalate care if paresthesia presents with any of the following features: 4

• Rapidly progressive symptoms over days
• Asymmetric or multifocal distribution
• Proximal involvement (not just distal extremities)
• Associated motor weakness or paralysis
• Severe dysautonomia (blood pressure instability, bowel/bladder dysfunction)
• Bilateral lower extremity involvement suggesting spinal cord pathology 1

Anatomic Localization

Determine whether paresthesia originates from central or peripheral nervous system pathology: 3

Central causes (brain or spinal cord):

• Ischemic events (stroke, spinal cord ischemia following aortic surgery with 2-6% incidence) 1
• Structural compression from tumors or disc herniation 3
• Inflammatory conditions (multiple sclerosis, transverse myelitis) 3
• Cerebral venous thrombosis affecting the sagittal sinus can cause bilateral motor signs 1

Peripheral causes (nerve roots, plexus, or individual nerves):

• Entrapment neuropathies (carpal tunnel syndrome is the most common cause of acroparesthesia) 4
• Metabolic disturbances (diabetes causing distal symmetric polyneuropathy) 4
• Nutritional deficiencies (vitamin B12 deficiency) 4
• Monoclonal gammopathy of undetermined significance 4
• Guillain-Barré syndrome variants (distal paresthesias preceding weakness, with decreased/absent reflexes) 2

Diagnostic Testing Algorithm

Laboratory Evaluation

For suspected vascular or inflammatory causes, obtain: 1

• Complete blood count
• Comprehensive metabolic panel
• Prothrombin time and activated partial thromboplastin time
• Screening for prothrombotic conditions if cerebral venous thrombosis suspected

For suspected inflammatory or infectious causes: 1

• CSF examination, particularly when Guillain-Barré syndrome variants are considered 2

Imaging Studies

Obtain imaging based on localization: 3

• MRI for suspected central nervous system pathology or spinal cord compression
• Ultrasound for peripheral nerve entrapment showing nerve enlargement, hypoechogenic appearance, and intraneural vascularity 4
• CT or panoramic radiography for dental-related paresthesia 5

Neurophysiological Testing

Consider electrophysiological studies: 1

• Somatosensory or motor evoked potentials to detect spinal cord ischemia (Class IIb recommendation)
• Nerve conduction studies for peripheral neuropathy confirmation 4

Treatment Approach by Etiology

Spinal Cord Ischemia (Post-Aortic Surgery)

For patients at high risk during thoracic aortic repair: 1

• Cerebrospinal fluid drainage is the primary protective strategy (Class I recommendation)
• Maintain spinal cord perfusion pressure through proximal aortic pressure optimization and distal aortic perfusion (Class IIa recommendation)
• Apply moderate systemic hypothermia during open repairs (Class IIa recommendation)
• Continue CSF drainage for >40 hours postoperatively to reduce paraparesis incidence
• Avoid postoperative hypotension aggressively

Prognosis: Two-thirds of patients with paraparesis following thoracic aortic surgery will recover, and approximately half with complete paraplegia will regain walking ability 1

Guillain-Barré Syndrome

For patients presenting with distal paresthesias followed by ascending weakness and areflexia: 2

• Initiate treatment with either intravenous immunoglobulin (0.4 g/kg daily for 5 days) or plasma exchange (200-250 ml/kg for 5 sessions)
• Monitor for dysautonomia and respiratory compromise
• Provide supportive care including pain management (pain is frequently reported) 1

Peripheral Nerve Entrapment

For carpal tunnel syndrome and other entrapment neuropathies: 4

• Ultrasound-guided steroid injection for initial management
• Surgical decompression (ultrasound-guided carpal tunnel release) for refractory cases
• Address underlying causes such as space-occupying lesions or anatomical variations identified on ultrasound

Metabolic and Nutritional Causes

For diabetic polyneuropathy or vitamin B12 deficiency: 4

• Optimize glycemic control for diabetic neuropathy
• Vitamin B12 supplementation for confirmed deficiency
• Screen for and treat monoclonal gammopathy of undetermined significance

Neuropathic Pain Component

When paresthesia includes burning, stinging, or aching qualities: 2

• Consider oral neuromodulators (pregabalin, gabapentin, duloxetine, amitriptyline, nortriptyline, or low-dose naltrexone)
• Allow 3-4 months at therapeutic dose to assess pain reduction
• For peripheral neuropathic pain, consider topical nerve regenerative therapies like autologous serum tears (in ocular contexts)

Spinal Cord Compression

For tumor-related or mass lesion compression: 1

• Surgical decompression is the primary intervention
• Combined surgery and radiotherapy for malignant spinal cord compression shows superior outcomes compared to radiotherapy alone

Common Pitfalls to Avoid

Do not dismiss acute bilateral lower extremity paresthesia as benign peripheral neuropathy - this pattern suggests spinal cord pathology requiring urgent imaging 1

Do not attribute all distal symmetric paresthesia to diabetes without excluding other causes including vitamin B12 deficiency, monoclonal gammopathy, or Fabry's disease 4

Do not delay CSF examination when inflammatory causes are suspected - early diagnosis of Guillain-Barré syndrome is critical for optimal outcomes 2, 1

Do not overlook Bell's palsy in facial paresthesia - ipsilateral periauricular pain is a common presenting symptom, and treatment with oral steroids within 72 hours improves outcomes in patients ≥16 years old 2