Atypical presentations of idiopathic intracranial hypertension

Since IJVS induces Intracranial hypertension (IIH) and can affect cranial nerves through styloid or C1 involvement, many folks already know that certain cranial nerves such as Optical nerve, Vagus nerve & Glossopharyngeal nerve can be affected but the effect on the cranial nerves goes way beyond those. I came down with bilateral sensorineural hearing loss (SNHL) 10 years ago as one of the first signs of IJVS but I did not know then. It turns out that roughly ~ 50% of people who suffer from bilateral IJVS get some sort of SNHL. So not only does it affect the usual cranial nerves but IIH can affect Olfactory nerve (smell nerve), Facial nerve, Auditory/Vestibular nerve, Trigeminal nerve to name a few. So if you happen to be wondering all the weird symptoms, this study is good read.

Abstract

Idiopathic intracranial hypertension (IIH) is a disorder of unknown etiology that results in isolated raised intracranial pressure. Classic symptoms and signs of IIH include headache, papilledema, diplopia from sixth nerve palsy and divergence insufficiency, and pulsatile tinnitus. Atypical presentations include: (1) highly asymmetric or even unilateral papilledema, and IIH without papilledema; (2) ocular motor disturbances from third nerve palsy, fourth nerve palsy, internuclear ophthalmoplegia, diffuse ophthalmoplegia, and skew deviation; (3) olfactory dysfunction; (4) trigeminal nerve dysfunction; (5) facial nerve dysfunction; (6) hearing loss and vestibular dysfunction; (7) lower cranial nerve dysfunction including deviated uvula, torticollis, and tongue weakness; (8) spontaneous skull base cerebrospinal fluid leak; and (9) seizures. Although atypical findings should raise a red flag and prompt further investigation for an alternative etiology, clinicians should be familiar with these unusual presentations.

Study Link : Atypical presentations of idiopathic intracranial hypertension - PMC

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Thanks for sharing this, KoolDude. I’ve been wondering if my sensorineural hearing loss could be related to ES/VES. I don’t have it bilaterally, though it is on the side of my longest styloid.

You are welcome, you can have it with unilateral as well or if you have one dominant one that is compressed and a hypoplastic IJV which add up to to bilateral stenosis. One good thing that the study reported is that most of the folks who had the hearing loss improved after normalization of CSF pressure (although I wonder by how much, SNHL is usually permanent in most cases but it is promising to know that some recover)

Hearing loss and vestibular dysfunction

Hearing loss of variable degree is a symptom reported by 30%–85% of patients with IIH.[17,108] Earlier studies of patients with presumed pseudotumor cerebri, including those with IIH mimics such as cerebral venous sinus thrombosis, characterized the hearing loss as sensorineural affecting the lower frequencies (250 and 500 Hz).[17] A recent study of IIH patients (2002 modified Dandy criteria[2]) found asymmetry of the frequencies affected in each ear.[108] Lowering CSF pressure into the normal range led to improved hearing, particularly in the lower frequencies.[17,109]

Hearing loss as a prominent presenting feature of IIH has been reported in five patients [Table 6].[110,111,112,113,114] Four patients presented with bilateral sensorineural hearing loss, and one had unilateral conductive hearing loss.[113] The diagnosis of IIH was questionable in four patients, due to the absence of papilledema or insufficient imaging to exclude venous sinus thrombosis.[110,111,113,114] Hearing improved between one day and six months after normalization of CSF pressure in all five patients.

I also talked about it here a while ago with data from a research on the internet. The unilateral appears to be less than 50% ( ~ 40% or less).

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My understanding from ENTs and neuro-ENTs is that SNHL is permanent, but would be wonderful if gains can be made! Hopefully mine will stop progressing once I have surgery and the IJV compression is relieved.

Thanks for adding the additional information : )

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That is what I was hoping for but mine has progressed to Severe and profound in in the higher frequencies. I am practically deaf anything above 4000 Hz. Hope you do recover some, at least in the lower frequencies.

I"m curious as to whether SNHL in addition to being caused by nerve compression progresses because the sensory hairs in the ear begin to die once nerve stimulation declines or ceases. I ask this because in Meniere’s Disease, hearing loss has been reported to come from the die off of those sensory hairs. There is currently an MD drug trial going which is in it’s third phase. The drug has been shown to help those sensory hairs regrow & thus restore hearing to at least some degree. It seems that hearing loss in general must have something to do w/ those sensory hairs, & if that’s the case, & the medication is approved it might be helpful for all hearing loss, not just MD. The drug is currently called SPE 1005. It may get a more glamorous name down the road.

About SPI-1005

SPI-1005 is an investigational new drug that contains ebselen, a new chemical entity. Ebselen is a selenorganic compound that mimics and induces glutathione peroxidase (GPx) activity, and is effective in reducing neuroinflammation across the central and peripheral nervous system. GPx activity is critical to several cell types and tissues in the inner ear, retina, prefrontal cortex of brain, lung, and kidney, and is often reduced during exposures to environmental insults or aging. Loss of GPx activity has been shown to result in sensorineural hearing loss in multiple animal models. SPI-1005 is being developed for several neurotologic indications including noise-induced hearing loss and two types of ototoxicity (hearing loss, tinnitus, dizziness, or vertigo) caused by aminoglycoside antibiotics (such as tobramycin or amikacin) or platinum-based chemotherapy (such as cisplatin or carboplatin). To date, no significant drug-drug interactions have been observed across multiple study populations including bipolar mania and treatment resistant depression.

About Sound Pharmaceuticals

A privately held biotechnology company is testing SPI-1005 under four other active Investigational New Drug Applications involving several neurotologic indications including aminoglycoside-induced ototoxicity co-funded by the CF Foundation and COVID-19 inpatients co-funded by the NIH. The leadership team consists of Jonathan Kil, MD, Co-Founder and CEO, Jacqueline Nguyen, MBA, VP Clinical Operations, John Sullivan, MBA, CFO, and G. Michael Wall, PhD, VP Pharmaceutical Development. Details of the SPI-1005 clinical trials can be viewed online at www.clinicaltrials.gov or by visiting www.soundpharma.com.

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Thanks @Isaiah_40_31 for sharing this. This is good news and yes, if it is proven to help restore hearing , it will benefit many people who currently have to rely on hearing aids or cochlear implants only to gain some hearing back. you are right, sensory hair cells are what is responsible of converting sound waves into electrical waves in the cochlear and transmit them via auditory nerve. The problem is the ones that sense higher sound frequencies die off first (for various reasons) and hence the loss of hearing higher frequencies. That is why hearing aids are used to amplify (make it loud) the higher sound frequencies so that they can be heard. This is the work around of losing the higher frequency sensing hair cells so if they find a mechanism to regrow or regenerate the hair cells, that is a game changer ( I like regenerative medicine but it is still in its infancy).

It is still not fully known/understood the mechanism behind how IIH induces hearing loss but it is taught to stem from transmitted CSF pressure to inner ear organs according to this study and many I have read. In the case of IJVS, there is the added venous congestion which can also affect inner ear circulation and drainage.

Different mechanisms have been proposed to explain otological symptoms in IIH. Transmitted pressure into the inner ear from the subarachnoid space via the vestibular aqueduct or from increased perilymphatic pressure via the cochlear aqueduct has both been proposed.[114,116,117] Alterations in perilymphatic and endolymphatic pressures by raised ICP, akin to endolymphatic hydrops, has also been speculated.[109

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I am truly sorry for your hearing loss & that of others from IIH, @KoolDude. I am hopeful the SPI-1005 will prove to be an effective medication for hearing restoration. The jury will be out for some years regarding whether or not there are side-effects from long-term use. There’s also the question of whether or not one can stop taking it once hearing is restored.

I expect many people will be willing to take their chances if the drug trials prove successful. Speaking from experience, not being able to hear fully is something we adapt to but sure makes life a bit more challenging & in some ways less enjoyable.

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