Vestibular Disorders: Many Varied Causes, and link to CMT

I don’t log onto facebook that often, and when I do it’s often to see if anyone has any new info on the VHT special 6 ultra guitar amp, but as I sprinted on down the virtual corridor I noticed this message posted on some wall or other.

A link to an article on Vestibular Disorders website, Understanding vertigo, and what to do if you have it.

It’s a short article which was originally posted in the Washington Times, and is written by Dr. Tim Hain.

Dr. Hain has a website with possibly the most comprehensive information on vestibular disorders anywhere on the net. He has an impressive CV which includes neurology, otoneurology, otolaryngology and many other disciplines of medicine and science.

Dizziness And Balance Website

I know it’s not specifically to do with HNPP, but Vertigo is something that I have to endure, and have done so for the past 33 years (and possibly more). In my case it’s an inner ear disease of some kind, which has knocked out my vestibular sense and much of my hearing. Both ears are affected, left greater than right. The cause is probably a mix of disease of peripheral end organ, cochlea and vestibular labyrinth, and disease of the auditory and vestibular nerves.

 

Although there are only tenuous links between HNPP and vestibular nerve involvement, which is very much disputed by some neurologists (not all), there is the problem with balance which is often noted in cases of hereditary sensory motor neuropathy. This is often attrributed to poor proprioception, ie the spatial sense of where the body, or in the case of CMT and HNPP, where the feet are. It is often assumed that the feet are the main cause of proprioceptive loss in CMT / HNPP, but there are many other important proprioceptive areas in the body. The neck, lower back and spine as well as arms. If the neuropathy affects these then balance and potentially dizziness can become a problem.

Further info on Vestibular Disorders and Causes at VEDA, including info on proprioception

Whether or not HNPP or CMT can affect the vestibular sense, is frequently ignored as it is often assumed that the main issue is proprioception. A few studies looking into this have recently been instigated by CMT specialists in the last few years. So that’s a good step forward.

A quick search now reveals that one study has indeed been completed and published, (link in title)

Vestibular impairment in patients with Charcot-Marie-tooth disease.

PMID: 23658384 [PubMed – indexed for MEDLINE]

1. Neurology. 2013 Jun 4;80(23):2099-105. doi: 10.1212/WNL.0b013e318295d72a. Epub
2013 May 8.

Vestibular impairment in patients with Charcot-Marie-tooth disease.

Poretti A(1), Palla A, Tarnutzer AA, Petersen JA, Weber KP, Straumann D, Jung HH.

Author information:
(1)Departments of Neurology, University Hospital Zurich, Switzerland.

OBJECTIVE: This case-control study aimed to determine whether the imbalance in
Charcot-Marie-tooth (CMT) disease is caused only by reduced proprioceptive input
or whether the involvement of the vestibular nerve is an additional factor.
METHODS: Fifteen patients with CMT disease (aged 48 ± 17 years; 8 women)
underwent cervical vestibular-evoked myogenic potentials, which reflect
otolith-spinal reflex function, and quantitative horizontal search-coil
head-impulse testing, which assesses the high-acceleration vestibulo-ocular
reflex of the semicircular canals.
RESULTS: Relative to healthy age-matched control subjects, cervical
vestibular-evoked myogenic potentials were found to be impaired in 75% of
patients (average p13 latency: 23.0 ± 2.7 milliseconds, p = 0.01; average n23
latency: 29.0 ± 1.8 milliseconds, p = 0.01) and the quantitative head-impulse
test in 60% of patients (average gain ± 1 SD: 0.67 ± 0.24, p < 0.001). All
patients with head-impulse test impairment also showed cervical vestibular-evoked
myogenic potential abnormalities, while the reverse was not true.
CONCLUSIONS: We conclude that the neuropathic process in patients with CMT
disease frequently involves the vestibular nerve and that cervical
vestibular-evoked myogenic potentials may be more sensitive than quantitative
head-impulse testing for detecting vestibular involvement, in particular at an
early disease stage.

 

 

 

No mention of HNPP, but I think results would be similar for some, but there might be greater variation due to HNPP’s episodic and environmentally influenced nature.

 

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