Ear Injection of AM-101 May Stop Tinnitus

Phantom ringing of the ears also known as tinnitus is an extremely frustrating condition that afflicts many people. Often triggered by hearing nerve damage, there's no good treatment to fix this condition once it sets in.

Until possibly now... 

AM-101 made by Auris Medical is an experimental drug containing esketamine hydrochloride embedded within a hyaluronic acid gel formulation. It works by blocking the NMDA receptors of the cochlear inner hair cell.

Normally, when there is trauma sustained by the cochlea whether it be loud noise or viral infection, excess amount of a neurotransmitter called glutamate gets release. The problem is that too much glutamate also triggers hearing nerve death due to over-excitation via the NMDA receptor. When these hearing nerves die, it leaves the brain cells responsible for hearing in a permanently switch-on state leading to tinnitus, even if there's no sound present.

AM-101 is hypothesized to block the NMDA receptor from being over-stimulated by the glutamate neurotransmitter thereby preventing hearing nerve death.

But, does it work?

According to one small prospective, double-blind, randomized, placebo-controlled study involving 248 patients, it DOES work to a significant degree.  42% reported their tinnitus was half as quiet as before compared with 14% in the placebo group. After 90 days, 57% of those taking the active gel said their tinnitus was 'much improved' or 'very much improved'.

Of course, the trick is to administer the drug before nerve death has set in after which it would be too late. In the study, only patients with onset of ringing within 3 months were eligible to participate.

Patient also need to realize that the drug is administered by injection through the eardrum and into the middle ear space. This injection technique is commonly used in the treatment of sudden nerve hearing loss where steroids are injected. Watch video of this injection method below.

Unfortunately, AM-101 is not available except under research protocols currently and is undergoing FDA clinical trials. The preliminary results are very promising however.

Reference:
Efficacy and Safety of AM-101 in the Treatment of Acute Inner Ear Tinnitus—A Double-Blind, Randomized, Placebo-Controlled Phase II Study. Otology & Neurotology: April 2014 - Volume 35 - Issue 4 - p 589-597

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Treatment for Vocal Tremor

Vocal tremor is characterized by a rhythmic undulating vocal quality whenever talking, much akin to vibrato that can not be turned off. In the past, it was felt that use of botulinum toxin type A (botox) to treat vocal tremor was not possible nor realistic given the multiple muscle groups involved. This is in contrast to dystonias of the voice (i.e., spasmodic dysphonia) where only one muscle group is involved and is readily and easily treated with botox injections to the affected vocal cord muscle.

However over the past few years, several research papers have been produced that show that botox CAN alleviate (though not eliminate) vocal tremor both objectively and subjectively, though more than one site may need to be injected in order to produce vocal tremor relief. Such muscle sites include thyroarytenoid muscle, ventricularis muscle, lateral cricoarytenoid muscle, interarytenoid muscle, cricothyroid muscle, and strap muscles.

All these muscle sites are easily accessible either via, endoscopic guidance and/or EMG guidance alone. Indeed, physicians who already perform botox injections for spasmodic dysphonia should also be able to inject all the other muscle groups just as easily. [watch video]

Typically, "horizontal" vocal tremor is treated with thyroarytenoid, ventricularis, interarytenoid, and/or lateral cricoarytenoid muscle botox injections.

"Vertical" vocal tremor is treated with strap muscle botox injections.

Dosages are similar to that given to treat spasmodic dysphonia.

SO... for patients suffering from vocal tremor who do not respond well to oral medications (propranolol, primidone), consider botox injections!

Be aware that botox injections to treat vocal tremor may not be covered by insurance.

References:
A new paradigm for the management of essential vocal tremor with botulinum toxin. Laryngoscope. 2013 Apr 1. doi: 10.1002/lary.24073. [Epub ahead of print]

Botulinum toxin type A for treating voice tremor. Arch Neurol. 2004 Sep;61(9):1416-20.

Botulinum toxin for essential tremor of the voice with multiple anatomical sites of tremor: a crossover design study of unilateral versus bilateral injection. Laryngoscope. 2000 Aug;110(8):1366-74.

Tremor laryngeal dystonia: treatment of the lateral cricoarytenoid muscle. Ann Otol Rhinol Laryngol. 2004 May;113(5):349-55.

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Compact EMG System for Targeted Muscle Injections

An EMG system (ElectroMyoGraphy) is a critical piece of equipment when it comes to targeted muscle injections in and around the neck, especially when you cannot see or feel the muscle.

This scenario is especially true when dealing with spasmodic dysphonia for which targeted botox injections are quite helpful. Given the muscles that need to be injected are contained inside the voicebox and not able to be seen and felt from outside the neck, accurate injection is quite difficult without EMG guidance.

Watch a video of this procedure using a traditional EMG system.

However, such traditional EMG systems are "overkill" in terms of technology and cost when all it is being used for is muscle placement.

It was with great excitement that a compact EMG device has been developed for just such a need when all that is required is needle localization for directed drug delivery.

Check out the MyoGuide made by Intronix Technologies based in Canada. The US supplier is Ambu.

I've been using MyoGuide for a few months now and am quite pleased with its performance. It pretty much does exactly what I want it to do... no more or less. There is both audio and display feedback, though I mainly depend on audio. It runs only on batteries.

For head and neck muscle injections, I find that a volume setting of 8 and vertical sensitivity of 6 works best.

My personal preference is using Ambu Inoject 35mm 27G needle for ADductor spasmodic dysphonia and the Allergan EMG needle for ABductor spasmodic dysphonia.

For those interested in trying out this device, there is a 2 week free trial.

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FDA Approves New Epinephrine Injector That Talks

Sanofi US has introduced a new epinephrine injector (competitor to the more commonly known EpiPen made by Dey Pharma LP) that is equipped with audio and visual cues that helps a patient or care-giver administer epinephrine in cases of a severe allergic reaction (anaphylaxis).

Known as Auvi-Q, it was FDA approved Aug 13, 2012, and should soon become available for purchase by prescription.

Just like EpiPen, Auvi-Q comes in two different dosages of epinephrine... 0.3mg for patients who weigh more than 66 pounds and 0.15mg for those who weigh between 33 and 66 pounds. Each pack contains two devices with active drug plus a non-active training device.

During a life-threatening allergic reaction, Auvi-Q talks the patient or care-giver through each step of the injection process. If more time is needed, it can repeat the instructions step-by-step. The device also comes with written instructions printed on the side. In addition, there are visual cues with an alert light to signal when the injection is complete. Watch video.

Auvi-Q is about the size and shape of a credit card, the thickness of a cell phone and fits comfortably in a pocket or small purse. This size and shape is in contrast to the EpiPen which looks like a fat marker. Being compact and easy to carry should remove one obstacle that could be a reason why as many as two-thirds of patients do not carry their epinephrine injector device.

Like the EpiPen, the device also has an automatic retractable needle mechanism to prevent accidental needle sticks.

Source:
FDA Approves Auvi-Q Voice Activated Epinephrine Injector. EmaxHealth 8/13/12

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Intra-Nasal Trigger Point Injections for Facial Headache

Do you suffer from a stabbing headache in the areas denoted in red? Do these headaches seemingly come out of nowhere one day? Perhaps started after a viral upper respiratory infection?

You may be suffering from a condition known as contact point headache or a type of neuralgia involving one of the nerve plexuses found inside the nose:

• Anterior ethmoid neuralgia (Sluder's neuralgia)
• Sphenopalatine ganglion neuralgia (Pterygopalatine ganglion neuralgia)

This type of headache has often been confused with cluster headache, migraine without aura, sinusitis, or other undefinable pathology especially since CT scans and MRI scans that are obtained often do not reveal any tumor or presence of infection.

In the event of a contact point headache, surgical removal of the offending anatomic abnormality is curative.

However, for neuralgia, trigger point injections may be helpful according to a recent study. Using a 1:1 mixture of 0.5% bupivacaine and Kenalog-40, either the sphenopalatine ganglion or the anterior ethmoid neurovascular bundle or even both are injected. For the sphenopalatine ganglion, the injection is where the middle turbinate inserts into the lateral nasal wall. For anterior ethmoid injection, identify the arch where the middle turbinate inserts superiorly to the lateral nasal wall and inject 5mm above this site.

In a total of 882 nerve blocks in 147 patients, 99.3% had no complications. 2 patients reported visual changes that resolved within 2 days. More importantly, 81.3% claimed improvement in their headache, 17.9% reported no change and 0.79% reported worse pain after the injection.

The typical duration of pain relief was 3-4 weeks. As such, for continued pain relief, the injection needs to be repeated monthly on average.

Reference:
Endoscopic neural blockade for rhinogenic headache and facial pain: 2011 update. Int Forum Allergy Rhinol. 2012 Apr 5. doi: 10.1002/alr.21035. [Epub ahead of print]

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