IIH is more common in young, obese women characterised by raised intracranial pressure in the absence of alternative causes (intracranial lesion or ventricular dilatation) with normal CSF composition. On examination, neurological findings are often normal except papilloedema and sixth cranial nerve palsy. Furthermore, lumbar puncture and brain scan are pivotal investigations to make our diagnosis3.
In our case, a middle-aged, standard stature lady with hypertension who presented a 2-week history of progressive cough, slurred speech and depression without other neurological symptoms, was surprisingly showed the empty sella (Fig. 1A), buckling and dilatation4 of the optic nerve sheaths (Fig. 1B) and sigmoid sinus stenosis5 (Fig. 1C)6 in the meantime by MRI. Although thus image symptoms above are common in IIH, however all of the representative changes occurred on one patient at the same time are extremely rare7. Interestingly, brain hernia embedded sigmoid sinus ditch was even been observed in our case (Fig. 1D, E, F), which hasn't been reported in IIH patients ever before.
This lady presented bulbar paralysis as the first symptom instead of classic symptoms such as headache, nausea and vomiting. Combined with the MRI results, we considered that it was due to the cerebrospinal fluid pulsation in the empty sella (Fig. 1A) to from the medulla oblongata to dura mater with surrounding structure of oppression and epidural expansion. The rise in venous sinus pressure resulting from sigmoid sinus stenosis (Fig. 1C) is increasingly regarded as a relevant factor in the pathogenesis of ICP. Nevertheless, several studies8,9 of which results indicate that venous sinus stenoses are a consequence of the pathological process of IIH rather than a cause of the disease10. Then however, although MRI showed the buckling and dilatation of the optic nerve sheaths (Fig. 1B), this lady didn't show visual symptoms or pulsatile tinnitus2 in her course of disease. Which cause might due to the degree of dilatation of the optic nerve sheaths hasn't reach the pathogenic state, therefore vision loss cannot be ruled out in the future. In addition, brain hernia embedded sigmoid sinus ditch (Fig. 1D, E, F) was more likely to occur under the increased intracerebral pressure, which enhanced the extent of to the sigmoid sinus stenosis. The performance explained the clinical manifestation of frontotemporal dementia (FTD) of the patient to a certain degree.
Our patient was timely treated with mannitol and other assistant medicine to decrease intracranial pressure, meanwhile, adalat was used to reduce blood pressure. During this time, lumbar puncture was performed to provide temporary and sometimes permanent relief from the symptoms. Amazingly, she had significantly improved with a reduction of her bulbar paralysis and depression after 15-day of treatment. Further 1 months of treatment had resolved her majority of bulbar paralysis and she is now under follow-up in our outpatient. Moreover, MRI is necessary to be reviewed to confirm the curative effect in the future. In our case, the patient showed well reaction to combination of mannitol and LP therapy, in addition, carbonic anhydrase inhibitors, octreotide, surgical/interventional treatments may be tried in this condition11.
In general, a systematic and comprehensive examination and investigation should be taken on patient of IIH, especially in who develop no classic symptoms such as headache, nausea, vomiting and so on. Although there's no visual symptoms initially of the patient, however, investigation should be taken more thoroughly to prevent long-term visual problems. Based on our present case and previously documented cases to date, we expect to provide our diagnostic and therapeutic strategy for the benefit clinical outcomes to meeting this group patients of IIH.