Introduction

The four basic objectives in the clinical investigation of PTCS may be enumerated as follows:

1. To establish the existence of raised CSF pressure

2. To evaluate its severity

3. To exclude other causes of raised CSF pressure, leaving PTCS as a diagnosis of exclusion as it has traditionally been

4. To identify any aetiological factors responsible for the PTCS

To these may be added investigations aimed at clarifying the mechanism of PTCS generally. Of course, these are not an essential component of the clinical investigation of a particular patient, a comment which also applies to some extent to the fourth category above.

The first category includes direct measurement of CSF pressure – either a single measurement by lumbar, cervical, cisternal or ventricular puncture, or continuous monitoring over a period of time from an intracranial or lumbar site – and fluorescein angiography as an ancillary and indirect method. The second category includes continuous CSF pressure monitoring again, as well as, more indirectly, neuro-ophthalmological evaluation, electroencephalography (EEG), and neuro-psychometric assessment. The third category includes analysis of CSF composition, and scanning methods, either CT or MR. The fourth category includes MR venography, DSA and venography, the latter with manometry, and detailed haematological analysis aimed at identifying thrombophilia and/or hypofibrinolysis. Investigations which at this stage are more or less limited to specialist centres are specialized MR techniques aimed at evaluating brain water content or CSF volume and dynamics, radionuclide studies of CSF dynamics, CSF infusion studies to quantitate resistance to CSF absorption, and metabolic or endocrine studies.