Case Studies
Case 8: A young lady with a bad headache
A 22-year-old woman gives a two week history of headache with occasional loss of vision lasting a few seconds on standing or straining. On examination she has a body mass index of 33, bilateral papilloedema and no neurological deficits. Her CT scan of her head is normal. She goes on to have a lumbar puncture which shows an opening pressure of 42 cm H2O, 3 white cells, no red cells, a protein of .3 g/l and a glucose of 3.2 mmol/l.
Your Answer:
Correct answer: The CSF in terms of its constituents is normal, although one clearly needs to make sure that her serum glucose is taken such that the CSF is still approximately half that of the serum. The most striking abnormality in this lady is the markedly raised opening pressure as this should be less than 20 cm H2O.
Your Answer:
Correct answer: The most likely diagnoses in a lady of this age, with a normal brain scan and this body mass index along with papilloedema and raised opening pressure, is either benign intracranial hypertension or raised pressure due to a sagittal sinus thrombosis.
Your Answer:
Correct answer: In order to exclude a major venous sinus thrombosis or obstruction as a cause of her symptoms she requires imaging of her venous sinuses which is typically done using magnetic resonance venography (MRV). One can go on to do formal angiography if the MRV is equivocal.
Your Answer:
Correct answer: The phenomena that she is describing is visual obscuration. This is as a result of the transient rises in her CSF pressure which is greater than her arterial blood pressure giving her transient ischaemia of the optic nerve head. If this were to continue then there is a real risk that she will infarct her optic nerve head and she will become blind.
Your Answer:
Correct answer: This depends on the aetiological cause. If she has a sagittal sinus thrombosis, she needs investigation to make sure she doesn’t have some underlying coagulopathy and treatment with anticoagulants, typically warfarin, for six months. If she has normal sagittal sinuses and the diagnosis is benign intracranial hypertension, then, whilst the condition is benign, it can lead to irreversible visual loss and blindness for the reasons given above. Typically the management involves losing weight and the use of acetazolamide as a way of reducing the production of CSF. If this fails to improve the situation more radical approaches are possible including shunting to reduce the CSF pressure. This is typically done with a lumboperitoneal shunt.
Your Answer:
Correct answer: The common causes of papilloedema are raised intracranial pressure. This is typically due to mass lesions but can be due to raised pressure as a consequence of benign intracranial hypertension as well as sagittal sinus thrombosis. It is also seen with malignant hypertension and a range of other rare causes. However when present, the BP needs to be checked and urgent imaging organized. Only if these are normal should a lumbar puncture be undertaken.