Clinical features

In the non-trauma patient, there may or may not be a clear history of novel headache, vomiting, and visual disturbance suggestive of papilloedema (blurring of vision, obscuration) or a sixth cranial nerve palsy (lateral diplopia). The absence of papilloedema does not exclude raised ICP in patients with acute or chronic problems: disc swelling was found in only 4% of head-injured patients, 50% of whom had raised ICP on monitoring.8 Even in the twenty-first century, it is regrettable that a clear history of raised ICP may be misinterpreted until the final denouement of disturbance of consciousness and pupillary abnormality or apnoea presents. Some patients have learnt to control their intracranial hypertension by hyperventilating, only to be dismissed as hysterics. Only slowly has the danger of lumbar puncture in the differential diagnosis of neurological patients been appreciated by the non-expert. Many of the later signs of raised ICP are the result of herniation: monitoring should detect raised ICP at an earlier stage and hence treatment should be started before irreversible damage occurs.

Extracraniain cerebrain arteries

Intracraniain cerebrain arteries Arterioles

Productionn of CSFn

Capillaries andn smaii veinsn Bridgingn ein

Cv Reabsorption n)| of CSFn

Rcsf

Sagittain sinus

Extracraniain cerebrain arteries

Intracraniain cerebrain arteries Arterioles

Capillaries andn smaii veinsn Bridgingn ein

Sagittain sinus

Productionn of CSFn

Cv Reabsorption n)| of CSFn

Rcsf

Cerebrospinain fiuid space

Cerebrospinain fiuid space a

Figure 7.8 Hydrodynamic model of cerebral blood flow (CBF) and CSF circulation with the electrically equivalent circuit (for details, see Ursino25).

Pa = internal carotid artery blood pressure; Pv = cerebral venous pressure; Pss = sagittal sinus blood pressure; ICP = intracranial pressure; If = CSF formation rate; CVR = resistance of cerebral arterial bed; Rb = resistance of bridging veins; RCSF = resistance to CSF reabsorption; Ca = compliance of cerebral arterial bed; Cv = compliance of cerebral venous bed; Ci = compliance of lumbar CSF compartment

a ss

Figure 7.8 Hydrodynamic model of cerebral blood flow (CBF) and CSF circulation with the electrically equivalent circuit (for details, see Ursino25).

Pa = internal carotid artery blood pressure; Pv = cerebral venous pressure; Pss = sagittal sinus blood pressure; ICP = intracranial pressure; If = CSF formation rate; CVR = resistance of cerebral arterial bed; Rb = resistance of bridging veins; RCSF = resistance to CSF reabsorption; Ca = compliance of cerebral arterial bed; Cv = compliance of cerebral venous bed; Ci = compliance of lumbar CSF compartment

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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