Table of Contents

Intracranial Pressure Monitoring Techniques

Intracranial Pressure Monitoring Techniques

🧠 Invasive Techniques (Gold Standard)

Intraventricular Catheter (EVD – External Ventricular Drain)

Location: Lateral ventricle
Advantages:
- Gold standard – measures true ICP
- Allows cerebrospinal fluid (CSF) drainage
- Can be recalibrated and zeroed
Disadvantages:
- Requires anatomical precision
- Risk of infection and hemorrhage

Intraparenchymal Monitor (e.g., Codman, Camino)

Location: Frontal white matter (brain parenchyma)
Advantages:
- Easier and faster to place than EVD
- Lower infection rate
Disadvantages:
- Cannot drain CSF
- Cannot be recalibrated – may drift over time

Subdural / Epidural Sensors

Location: Subdural or epidural space
Advantages:
- Less invasive
Disadvantages:
- Less accurate
- Rarely used today

Subarachnoid Bolt

Location: Subarachnoid space
Advantages:
- Moderate accuracy
Disadvantages:
- Cannot drain CSF

🩺 Non-Invasive Techniques (Adjuncts or Experimental)

Transcranial Doppler Ultrasonography (TCD)

Measures cerebral blood flow velocity and pulsatility index
Indirect correlation with ICP

Optic Nerve Sheath Diameter (ONSD) via Ultrasound

Detects optic nerve sheath dilation due to raised ICP
Rapid bedside screening tool

MRI / CT-Based Morphometrics

Measures ventricular size and brain shifts
Not continuous monitoring

Tympanic Membrane Displacement

Measures displacement due to CSF pressure transmission to cochlea
Experimental

📊 Comparative Table

Parameter	Intraventricular	Intraparenchymal	Non-Invasive
Accuracy	High	High	Low–Medium
CSF drainage	Yes	No	No
Infection risk	High	Moderate	None
Recalibration possible	Yes	No	No
ICU use	Yes	Yes	Rare/Adjunct only