What are the likely diagnoses (including non‑serous etiologies) and recommended next steps for a patient presenting with new left‑sided pounding headaches, pain with head movement, persistent ocular pressure, tinnitus, brief falls, progressive balance disturbance, and a known left‑sided brain hypodensity?

Cerebral Venous Thrombosis (CVT) is the Most Likely Diagnosis

Given the constellation of new left-sided pounding headache, pain with head movement, persistent ocular pressure, tinnitus, falls, progressive balance disturbance, and a known left-sided brain hypodensity, cerebral venous thrombosis (CVT) is the primary diagnosis that must be urgently excluded. This presentation matches the classic features of CVT with both increased intracranial pressure symptoms (headache, ocular pressure, tinnitus) and focal neurological dysfunction (balance disturbance, falls) 1.

Critical Diagnostic Features Supporting CVT

The patient's symptom complex aligns precisely with CVT pathophysiology:

• Progressive headache with pain on head movement - CVT typically presents with diffuse headache that progresses over days to weeks, present in nearly 90% of CVT cases 1
• Ocular pressure and tinnitus - These indicate increased intracranial pressure from impaired venous drainage 1
• Falls and progressive balance disturbance - Suggest focal brain injury from venous ischemia/infarction, particularly concerning given the known brain hypodensity 1
• Left-sided localization - The known left-sided brain hypodensity may represent venous infarction or hemorrhage 1

Critical distinction: CVT can present with bilateral involvement despite unilateral symptoms, and focal seizures occur in 40% of patients 1. The progressive nature over days to weeks is typical, with median delay from symptom onset to diagnosis being 7 days 1.

Alternative Diagnoses to Consider

Idiopathic Intracranial Hypertension (IIH)

This remains a differential diagnosis given:

• Headache with ocular pressure
• Tinnitus (pulsatile tinnitus is characteristic) 2
• However, IIH typically lacks focal neurological signs like balance disturbance and falls, making it less likely 2

Vestibular Migraine

Consider but less likely because:

• Requires ≥5 episodes of vestibular symptoms lasting 5 minutes to 72 hours 3
• The progressive nature and persistent ocular pressure argue against episodic vestibular migraine
• Falls and balance disturbance in vestibular migraine are episodic, not progressive 4

Posterior Circulation Stroke

Must be excluded given:

• Balance disturbance and falls
• However, onset is typically more sudden than the progressive course described 4
• The known hypodensity requires urgent vascular imaging

Mass Lesion/Tumor

Given the known brain hypodensity:

• Progressive headache worse with head movement
• Balance disturbance
• However, the acute ocular pressure and tinnitus favor a vascular/pressure etiology 2

Immediate Next Steps

1. Urgent Neuroimaging (Within Hours)

MRI brain with MR venography (MRV) is the diagnostic study of choice 1:

• MRI will characterize the known left-sided hypodensity
• MRV will evaluate for venous sinus thrombosis
• Look for bilateral thalamic involvement or bihemispheric injury suggesting deep venous system involvement 1
• If MRI unavailable, CT head with CT venography is acceptable 1

2. Ophthalmologic Examination

Urgent fundoscopy to assess for papilledema 1:

• Papilledema indicates increased intracranial pressure
• Also evaluate intraocular pressure given persistent ocular pressure symptoms 5
• Sixth nerve palsy may be present 1

3. Laboratory Studies

• D-dimer (high sensitivity for CVT exclusion, though methodological limitations exist) 1
• Complete blood count, coagulation studies
• Thrombophilia workup if CVT confirmed 1

4. Neurological Examination Focus

Document specifically:

• Focal motor deficits (hemiparesis is most common in CVT) 1
• Cranial nerve examination (sixth nerve palsy, visual fields)
• Gait and coordination testing
• Mental status changes 1

Red Flags Present in This Case

Multiple red flags mandate urgent evaluation 6, 7, 8, 9:

• Progressive headache - suggests intracranial space-occupying lesion or increased pressure 6
• Headache aggravated by head movement - suggests intracranial hypertension 6
• Focal neurological symptoms (balance disturbance, falls) - suggests secondary headache 6, 4
• Known brain hypodensity - requires urgent characterization 2

Treatment Considerations Pending Diagnosis

If CVT is confirmed, anticoagulation is the primary treatment despite presence of hemorrhage 1. However, do not initiate treatment until diagnosis is confirmed with imaging.

For symptom management while awaiting imaging:

• Avoid opioids and barbiturates 6, 10
• Simple analgesia (acetaminophen) may be used cautiously
• Maintain adequate hydration
• Avoid medications that could mask neurological deterioration

Common Pitfalls to Avoid

1. Delaying imaging due to "typical migraine" features - The progressive nature, focal signs, and known brain lesion mandate urgent imaging 1, 8, 9

2. Assuming unilateral symptoms exclude bilateral pathology - CVT frequently causes bilateral brain involvement despite lateralized symptoms 1

3. Missing the diagnosis due to subacute presentation - 56% of CVT cases present subacutely over >48 hours to 30 days, with median 7-day delay to diagnosis 1

4. Attributing all symptoms to the known hypodensity - The hypodensity itself requires urgent characterization and may represent venous infarction 1