What is the appropriate management for a patient presenting with signs of intracranial pathology, such as severe headache, confusion, seizures, or focal neurological deficits?

Management of Signs of Intracranial Pathology

For patients presenting with signs of intracranial pathology such as severe headache, confusion, seizures, or focal neurological deficits, obtain an emergent noncontrast CT head as the first-line imaging test to rapidly identify life-threatening conditions including hemorrhage, mass effect, or hydrocephalus. 1

Initial Imaging Approach

Noncontrast CT Head - First-Line Test

• Perform emergent noncontrast CT head for patients with any of the following high-risk features: severe headache, persistent altered mental status, focal neurological deficits, seizures, anticoagulant use, history of malignancy, fever suggesting CNS infection, or signs of elevated intracranial pressure 1

• CT is the optimal initial test because it can be performed rapidly in all patients, is less susceptible to motion artifact than MRI, and effectively detects acute hemorrhage, mass effect, hydrocephalus, and large territorial infarctions 1

• Risk factors warranting CT imaging include: history of trauma or falls, hypertension, anticoagulant use, headache with nausea/vomiting, older age (>60 years), impaired consciousness, neurologic deficit, and history of malignancy 1

• Yield of acute findings on CT ranges from 2% to 45% depending on patient selection, with 7.4% showing acute changes in patients with altered mental status and no focal deficits 1

When to Add Contrast-Enhanced CT

• Consider contrast-enhanced CT if intracranial infection (abscess, empyema), tumor, or inflammatory pathology is suspected based on clinical presentation 1

• Common practice is to perform noncontrast CT first as a screening test, followed by contrast-enhanced CT or MRI if the noncontrast study is unrevealing but clinical suspicion remains high 1

MRI as Second-Line or Complementary Imaging

Indications for MRI

• Obtain MRI brain when initial CT is unrevealing but clinical suspicion for intracranial pathology remains high, particularly for detecting ischemia, encephalitis, subtle subarachnoid hemorrhage, or small cortical infarcts 1

• MRI has superior sensitivity for detecting acute ischemic stroke (70% of strokes presenting with altered mental status were missed on initial evaluation), small ischemic lesions, demyelinating disease, and subtle neurological pathologies 1, 2

• MRI is complementary to abnormal CT findings for further evaluation of suspected intracranial mass lesions, infection, nonspecific edema, ischemia, and cases of intracranial hemorrhage when an underlying lesion is suspected 1

MRI Protocol Selection

• Start with MRI brain without IV contrast as the initial MRI study for most patients with focal neurological deficits 2

• Add contrast (gadolinium) if demyelinating disease, infection, tumor, or inflammatory conditions are suspected 1, 2

• Include MRA (magnetic resonance angiography) of the head and neck to evaluate for vascular abnormalities in patients with transient or persistent neurological symptoms 2

Specific Clinical Scenarios

Seizure Patients

• Obtain emergent CT head for seizure patients with any of the following: persistent altered mental status, focal neurological deficits, headache, vomiting, age >60 years, short-term memory deficits, physical evidence of trauma above the clavicle, or GCS score <15 1, 3

• For first-time seizures, CT should be performed emergently when serious structural lesion is suspected (new focal deficits, persistent altered mental status, fever, recent trauma, persistent headache, history of cancer, anticoagulation, or known HIV) 1

• Consider urgent CT (either in ED or scheduled as part of disposition) for patients >40 years or those with partial-onset seizures 1

Patients with Known Intracranial Pathology

• Obtain noncontrast CT head emergently for patients with known intracranial process (mass, recent hemorrhage, recent infarct, CNS infection) who develop acute or progressively worsening mental status changes 1

• CT effectively detects complications including progressive mass effect, increasing edema, hydrocephalus, new or enlarging intracranial hemorrhage, and progressive ischemia 1

• Add contrast-enhanced CT or MRI if clinical concern exists for progression of intracranial infection, tumor, or inflammatory conditions 1

Head Trauma with Altered Mental Status

• CT head is mandatory for patients with mild traumatic brain injury (GCS 13-15) who have any of the following: headache, vomiting, age >60 years, drug or alcohol intoxication, deficits in short-term memory, physical evidence of trauma above the clavicle, or seizure 1

• Absence of all seven predictors (headache, vomiting, age >60, intoxication, short-term memory deficit, trauma above clavicle, seizure) has a negative predictive value of 100% for intracranial lesions 1

• Anticoagulant use is an absolute indication for CT brain scanning even with minor head trauma 3

Critical Pitfalls to Avoid

• Do not rely solely on CT for patients with transient neurological symptoms or persistent deficits after initial negative CT, as small ischemic lesions and subtle pathology may be missed 1, 2

• Do not delay imaging in patients with persistent altered mental status not explained by metabolic causes or intoxication, as 70% of missed stroke diagnoses presented with altered mental status 1

• Avoid reflexive stroke treatment in seizure patients with Todd's paralysis (transient hemiparesis), as the risk of thrombolytic-related hemorrhage far outweighs any potential benefit 4

• Do not discharge patients with negative CT if they have persistent symptoms or high-risk features without considering MRI or close observation with serial neurological examinations 4

Management of Elevated Intracranial Pressure

• Administer mannitol 0.25 to 2 g/kg body weight as a 15% to 25% solution over 30 to 60 minutes for reduction of intracranial pressure and brain mass in adults 5

• Pediatric dosing is 1 to 2 g/kg body weight or 30 to 60 g/m² body surface area over 30 to 60 minutes 5

• Monitor for complications including renal failure (especially with pre-existing renal disease or concomitant nephrotoxic drugs), fluid and electrolyte imbalances, and CNS toxicity 5

• Discontinue mannitol if renal, cardiac, or pulmonary status worsens, or if CNS toxicity develops 5