What is the differential diagnosis for a 58-year-old male with a history of severe head trauma, presenting with sharp pain radiating from the left temple to the left eye, frequent urination, and recent cessation of creatine supplements, who takes Wellbutrin (bupropion) and an antibiotic for psoriasis, and works construction outdoors in winter?

Differential Diagnosis and Clinical Assessment

This patient most likely experienced a post-traumatic headache variant (possibly cluster-type or migraine-type) triggered by environmental stress and metabolic factors, with the spontaneous resolution after eating and rest suggesting a benign, self-limited episode rather than an acute neurovascular emergency. 1

SOAP Note with OPQRST

Subjective

Onset: 9-10 AM, acute onset of sharp pain 1

Provocation/Palliation:

• Improved 45 minutes after eating and resting 1
• Recent cessation of creatine supplement (5 days prior) 2
• Environmental exposure (outdoor construction work in winter) 1

Quality: Sharp pain radiating from left temple to left eye 1, 3

Region/Radiation: Left temple → left eye (unilateral distribution) 1, 3

Severity: Initially 9-10/10 based on vital sign response (BP 160/100, PR 81) 4

Time/Temporal Pattern:

• Duration: Approximately 45 minutes until significant improvement 1
• Serial vitals showing stabilizing trend over 20 minutes 4

Associated Symptoms:

• "Heavier recognition of breathing" (possible autonomic symptom) 3
• Frequent urination (recent onset) 1
• Patient states "does not feel like himself" 4

Objective

Vital Signs Trend:

• Initial: BP 160/100, PR 81 4
• 10 minutes: BP 140/90, PR 70 4
• 20 minutes: BP 122/82, PR 61 4

Medications:

• Wellbutrin (bupropion) - known to lower seizure threshold and can affect headache patterns 1
• Antibiotic for psoriasis (likely methotrexate or similar) 1

Recent Changes:

• Stopped creatine supplement 5 days ago 2
• Frequent urination (new symptom) 1

Assessment

Primary Differential Diagnoses:

1. Post-traumatic headache with migraine features (MOST LIKELY): History of severe head trauma with unilateral sharp pain, autonomic features, and improvement with rest/food intake strongly suggests this diagnosis 4, 1. The International Headache Society defines post-traumatic headache as beginning within 2 weeks of closed head injury, but chronic post-traumatic headaches can persist and be triggered by various factors 4.

2. Cluster-type headache variant: The strictly unilateral pain from temple to eye with "heavier breathing recognition" (possible autonomic symptom) fits cluster headache patterns 3, 5. However, the 45-minute duration is at the upper limit (cluster typically 15-180 minutes), and the rapid improvement with food/rest is atypical 3.

3. Hypertensive urgency with secondary headache: Initial BP 160/100 with sharp headache could represent hypertensive episode 4. The rapid normalization of BP correlates with symptom improvement 4.

4. Metabolic/environmental trigger: Creatine withdrawal, cold exposure, dehydration (outdoor construction in winter), and possible hypoglycemia (improved after eating) may have triggered headache in patient with previous head trauma 1, 2.

Critical Red Flags to EXCLUDE:

1. Intracranial aneurysm with thrombosis/enlargement: History of severe head trauma increases risk; dramatic worsening of headache characteristics can indicate aneurysmal enlargement 6. However, spontaneous resolution argues against this.

2. Vertebral artery dissection: Unilateral pain with autonomic features (Horner's-like symptoms) can indicate vertebral artery pathology 7. The patient's construction work and potential neck trauma are risk factors 4.

3. Increased intracranial pressure: Previous severe head trauma history raises concern, but improvement with rest and lack of progressive worsening makes this less likely 4, 1.

Plan

Immediate Physical Assessment Tests:

Neurological Examination:

• Cranial nerve testing (especially CN II, III, IV, VI for visual fields, pupil symmetry, extraocular movements) to assess for Horner's syndrome or other focal deficits 8
• Motor and sensory examination bilaterally to detect asymmetry 8
• Cerebellar testing (finger-to-nose, heel-to-shin, gait if safe) 8
• Neck examination for cervical strain, range of motion, and vertebral artery tenderness 4
• Fundoscopic examination for papilledema (increased ICP) 4, 1

Cardiovascular Assessment:

• Orthostatic vital signs to assess for dehydration/volume depletion 1
• Repeat BP in both arms to rule out dissection 4

Head/Neck Examination:

• Temporal artery palpation for tenderness (though age 58 makes giant cell arteritis less likely) 1, 8
• Scalp tenderness assessment 1
• Neck stiffness/meningismus testing 8

Diagnostic Testing Required:

Immediate (if any red flags present):

• Non-contrast CT head if any focal neurological deficits, altered consciousness, or concern for acute hemorrhage 4, 8
• CT angiography (CTA) of head and neck given history of severe head trauma with focal neurological deficit not fully explained, to rule out vertebral artery dissection or aneurysm 4, 6

Urgent (within 24-48 hours if symptoms recur or worsen):

• MRI brain without and with contrast is preferred for subacute presentation with history of severe head trauma 4. Include susceptibility-weighted imaging (SWI) or gradient echo (GRE) sequences to identify hemosiderin deposition from prior trauma 4
• MRA head and neck if CTA not performed and vascular pathology suspected 4, 7

Laboratory Studies:

• Basic metabolic panel to assess for electrolyte abnormalities and renal function (given frequent urination) 1
• Glucose to rule out hypoglycemia as trigger 1
• Urinalysis to evaluate frequent urination (rule out diabetes, UTI) 1
• Creatine kinase (CK) levels given recent creatine cessation 2
• ESR/CRP if any concern for temporal arteritis despite age <60 1, 8

Disposition and Follow-up:

If patient remains asymptomatic with normal neurological exam:

• Discharge with strict return precautions for recurrent headache, focal neurological symptoms, altered consciousness, or persistent vomiting 1, 8
• Outpatient neurology referral within 2-4 weeks for evaluation of post-traumatic headache and consideration of preventive therapy 1
• Headache diary to document frequency, duration, triggers, and associated symptoms 1

If any red flags or abnormal neurological findings:

• Emergency admission for urgent neuroimaging and neurology/neurosurgery consultation 1, 8

Symptomatic Management:

• NSAIDs (ibuprofen 400-800 mg or naproxen 500-550 mg) for mild-to-moderate recurrent headaches 4, 1
• Avoid opioid analgesics due to risk of medication-overuse headache and dependency 4, 1
• Hydration and electrolyte repletion given outdoor work in winter 1
• Resume creatine supplement if no contraindications, as abrupt cessation may have contributed 2

Critical Pitfalls to Avoid:

• Do not dismiss this as simple migraine without imaging given history of severe head trauma and new-onset unilateral pain pattern 4, 6
• Do not miss vertebral artery dissection in patient with neck trauma risk (construction work) and unilateral pain with autonomic features 4, 7
• Do not overlook medication interactions between Wellbutrin and other agents that may lower seizure threshold or affect headache patterns 1
• Do not attribute all symptoms to benign causes when dramatic changes in headache characteristics can indicate aneurysmal enlargement 6
• Repeat imaging is mandatory if headache significantly worsens or changes character 6