Management of Patients with Decreased Consciousness, Lateralization Signs, and Fever with Cough

Priorities in Diagnostic Approach

The American College of Radiology recommends that neuroimaging should be performed immediately before lumbar puncture if there are focal deficits, decreased consciousness, or suspicion of increased intracranial pressure, with relevant abnormal results in about 11% of cases 1
Neuroimaging, specifically CT head without contrast, must be done immediately before lumbar puncture due to the presence of focal deficits and decreased consciousness, which may indicate increased intracranial pressure or mass lesions 1, 2
MRI of the brain with contrast should be performed within 48 hours if CT is negative but clinical suspicion remains high, especially to detect cerebral abscesses showing diffusion restriction and ring enhancement 2

The combination of fever, decreased consciousness, and focal neurological signs may indicate bacterial meningoencephalitis or cerebral abscess, which requires immediate therapy to prevent high mortality 1, 2
Meningoencephalitis bacterial - The combination of fever, decreased consciousness, and focal neurological signs, although the classic triad (fever, neck stiffness, decreased consciousness) appears in less than 50% of cases 1, 3
Encephalitis (including HSV) - Changes in mental status that occur earlier in the course of the disease are more common in encephalitis than in meningitis 1

Antibiotics should be given immediately, even before neuroimaging or lumbar puncture is completed, because delay significantly increases mortality 2
The recommended empirical antibiotic regimen includes Ceftriaxone 2g IV every 12 hours for coverage of Streptococcus pneumoniae, Streptococcus viridans, and other respiratory pathogens 2
Vancomycin 15-20 mg/kg IV every 8-12 hours should be added for coverage of resistant S. pneumoniae and Staphylococcus aureus 2
Acyclovir should be added for presumptive HSV encephalitis because encephalitis cannot be ruled out 1

Evaluation of airway and oxygenation - supplemental oxygen should be given if saturation is less than 92% or there is respiratory distress 2
Consider intubation if the Glasgow Coma Score is less than 8 or the patient cannot protect their airway 2
Aggressive IV crystalloid fluid resuscitation to correct hypotension and tachycardia, normalize heart rate, blood pressure, capillary refill, urine output, and mental status 2

At least 3 sets of blood cultures should be drawn before antibiotics if possible, but therapy should not be delayed more than a few minutes 2
Leukocyte count - leukocytosis is an important diagnostic clue for meningitis 3

Urgent neurosurgical consultation is required if a cerebral abscess is confirmed, especially if the diameter is greater than 2.5cm, there is significant mass effect, or there is progressive neurological deterioration despite antibiotic treatment 2
Monitoring of intracranial pressure should be considered if there is diffuse cerebral edema, hydrocephalus, or impending herniation 2

The patient should be admitted to the ICU immediately because of decreased consciousness indicating encephalitis, meningitis, or cerebral abscess, risk of progressive neurological deterioration, and the need for close monitoring of intracranial pressure and neurological status 2, 4

Do not wait for the classic triad of meningitis (fever, neck stiffness, decreased consciousness) because it appears in less than 50% of cases 1, 3
Do not delay antibiotics while waiting for lumbar puncture or neuroimaging, as this significantly increases mortality 2
Do not underestimate the severity of the condition based on initial vital signs, as patients with sepsis and neurological compromise can deteriorate rapidly 2

CSF obtained after neuroimaging should be sent for cell count, protein, glucose, Gram stain, bacterial culture, HSV PCR, and additional viral studies to comprehensively assess for bacterial meningitis and HSV encephalitis. [5][6]

The classic triad of fever, neck stiffness, and altered consciousness is present in less than 50 % of adult bacterial meningitis cases, indicating that reliance on the full triad will miss many patients. 5
The absence of neck stiffness or any component of the classic triad does not exclude bacterial meningitis; clinicians should proceed with diagnostic work‑up and empiric therapy when suspicion is high. 5

Kernig’s and Brudzinski’s signs have very low sensitivity (≈ 9 % in adults) and should not be used to rule out meningitis. 5

Early mental‑status changes are more common in HSV encephalitis than in bacterial meningitis, helping to differentiate the two conditions. 6
Altered behavior, confusion, and speech disturbances are characteristic clinical manifestations of HSV encephalitis. 6
Fever in HSV encephalitis may be low‑grade rather than high, which can contrast with the typically higher fevers seen in bacterial meningitis. 6