Chiari & Post Decompression Tinnitus?

December 1st, 2010 - Tinnitus or "ringing in the ears" is a common adult disorder. People with tinnitus have described it as hissing, roaring, whistling, chirping or clicking. According to the American Speech-Hearing-Language Association its prevalence in adults based on a review of several studies is between 10 to 15% and up to 30% of all adults will experience tinnitus at some point in their life. Tinnitus is a subjective complaint that cannot readily be confirmed by an objective test and can have many causes. People with tinnitus have varying responses to it. Some can successfully tune it out or ignore it. Others have great difficulty with it. Many find it difficult to fall asleep and some people become depressed and fatigued as a result.

Before I talk about post decompression tinnitus let me say a few words about tinnitus in Chiari patients prior to surgery. Chiari patients often present with tinnitus. Milhorat et al.1, reported that 140 out of 364 or 38% of the Chiari patients they studied complained of tinnitus. In another large study by Mueller and Oro2, 56% presented with tinnitus. These incidence figures are significantly higher than in the overall adult population. For some patients presenting with tinnitus, the cause may have nothing to do with Chiari. In others, their tinnitus may very definitely be related to Chiari. The association between Chiari and tinnitus is not understood. Chiari patients presenting with tinnitus who struggle with it should be evaluated by a specialist to determine is the cause is unrelated to Chiari and can be treated. Chiari patients presenting with tinnitus should also understand that decompression surgery may or may not result in the resolution of their tinnitus.

Interestingly, some Chiari patients who do not present with tinnitus develop chronic tinnitus following decompression surgery. The incidence of chronic post decompression tinnitus is unknown. I can tell readers however from personal experience that it is real. I did not have tinnitus before surgery but the first thing I noticed upon waking up from surgery was the intense ringing in my ears particularly the right ear. It was so loud that I was concerned that something seriously went wrong with the surgery. The intensity decreased in a couple of weeks to a more moderate level but has persisted ever since (11 years). I became accustomed to it without much problem. It can be particularly annoying when the surrounding environment is relatively quite as is the case when trying to fall asleep. Over the years, I have encountered a large number of Chiari patients who were left with tinnitus following surgery who like myself did not have tinnitus prior to surgery.

Apparently, either some type of surgical trauma or some change in intracranial pressure as a result of decompression is the cause but what exactly is unknown. I never sought any treatment for it because, one, I'm pretty good at tuning it out and, two, I figure if the cause was surgical trauma/damage or a change in intracranial pressure nothing can be done about it. Nevertheless, I have remained curious. And since it may be presumptuous of me to think it cannot be treated, I decided to finally investigate it.

My investigation is not yet complete but my early findings are interesting. As I so often do for topics I write about in this column, I start by searching the medical literature. My first search was to check if tinnitus had been specifically reported as a consequence of hindbrain decompression. As I suspected, it had not. I then broadened my search to look for tinnitus following head/neck surgery or injury. Nothing of relevance emerged with respect to surgery which somewhat surprised me however with respect to injury several hits were obtained were tinnitus following whiplash or head/neck injury was reported. It may be possible that the trauma or damage as a result of whiplash or head/neck injury resembles that which occurs during decompression surgery. Perhaps some nerve is compressed or pinched or stretched. Perhaps blood vessels that nourish a nerve are damaged. With that in mind, I examined whiplash and head/neck injury papers were tinnitus was reported.

In reviewing these papers, it was important to keep in mind that tinnitus like pain is very subjective and some people may report such symptoms following a whiplash injury in order to fraudulently make insurance claims or sue another party for compensation. Indeed, in reading these papers, it was apparent that this was a key point of interest on the part of the authors/investigators. However, without getting into the details here, I concluded that while some cases of whiplash induced tinnitus are fraudulent many, if not most, are legitimate.

Another problem with the papers is that most are not specific to tinnitus. Head/neck injury victims have many other symptoms such as headache, vertigo, vision problems, poor concentration, etc. Tinnitus is usually lumped in with the other symptoms and complaints so for example when the authors report that they had some success with a particular treatment, you cannot always tell what specific symptoms were alleviated.

Three important pieces of information were important to me, what is the reported incidence of tinnitus due to whiplash or head/neck injury, were any objective diagnostic tests used and were any specific anatomical sites of damage identified as the cause, and what treatments were applied and were any effective.

With respect to incidence, investigators in Lithuania3 who studied 210 whiplash patients found less than 1% reporting any kind of symptom. Here is there unedited conclusion. " Unlike whiplash claimants in many Western societies, Lithuanian accident victims do not appear to report the chronic symptoms of temporomandibular disorders despite their acute whiplash injuries." (Let me just say that it is reports like this that make it so difficult to compare the quality of health care between countries that have adopted socialized medicine and the United States.)

In another paper published by Rowlands et al4 of the Royal Throat, Nose and Ear Hospital in London, 109 patients with low grade whiplash were followed for 149 days after their accidents. None reported tinnitus. However, unlike the patients in the previously reported paper, the whiplash severity in this patient population was low.

Trantor and Graham5 from the ENT Department of Brighton and Sussex Hospital in the UK report that 10% of patients who suffer whiplash develop symptoms such as tinnitus, vertigo and deafness.

Similarly, Claussen and Claussen6 of the Neurological Research Center in Bad Kissingen, Germany, found that 15 to 20% of the 197,731 whiplash cases reported in 1992 developed late whiplash injury syndrome with complaints such as headache, vertigo, instability, nausea, tinnitus, hearing loss, etc.

Segal and co-investigators7 at Tel Aviv University in Israel, conducted a retrospective chart review of 83 patients who experienced blunt neck trauma (not whiplash) and found that 46 or 55.4% complained of tinnitu

Finally, a retrospective study conducted at the Oregon Health and Science University Tinnitus Clinic8 of 2400 tinnitus patients found that 297 or 12.3% reported that their chronic tinnitus started as a result of head or neck injury.

Looking at these references together it appears safe to conclude that trauma to the craniocervical area can result in tinnitus, unless of course you get in an accident in Lithuania.

Moving on to the question of diagnostic tests to identify specific injury sites and potential effective treatment, one paper published by Johansson9 in Sweden evaluated the use of functional MRI. Functional MRI is a special neuro-imaging technique that measures the change in blood flow related to neural activity. The study was limited to three severely injured patients who had been extensively examined without any findings of structure leasons by other tests. The technique identified lesions in the craniocervical region which were confirmed upon surgery. Further, it was reported that the medical condition of the three patients significantly improved as a result of the stabilizing surgery. While functional MRI may possess the potential to identify the site of damage in post decompression Chiari patients with tinnitus it is not a practical approach in part because it is difficult to justify additional surgery in the absence of more serious complaints. It also expensive and time consuming and from an insurance and reimbursement point of view difficult to employ beyond patients with more serious problems.

Does a more practical treatment potentially exist for this type of apparent neurological damage? One group which explored this question from Speising Orthopedic Hospital in Vienna, Austria10, treated 23 whiplash patients with adjuvent laser acupuncture . Unfortunately, no statistically significant advantage of the laser acupuncture treatment was found in the incidence of chronic recurrent problems such as myofascial pain, headaches, vertigo and tinnitus.

My exploratory literature review was interesting in terms of the range. Injury ranged from low grade whiplash to severe head/neck blunt truama. The incidence of post injury tinnitus ranged from 0 to over 50 percent. Diagnostic techniques ranged from subjective questionairres to functional MRI neuro-imaging. Treatment ranged from acupuncture to stabilizing neck surgery. It seems reasonable to hypothesize that decompression surgery can result in tinnitus probably by causing some sort of neurological truama in the craniocervical junction. Identifying the site of damage is not readily done and even if accomplished an effective treatment approach with acceptable safety risk is not at all apparent

As time permits, I hope to look into this problem more. I hate to leave any readers struggling with severe level post decompression tinnitus without hope. I request any readers with this condition who may have found an effective treatment to email me.

1Neurosurgery, 1999 May;44(5):1005-1017
J. Am. Acad. Nurse Pract., 2004 March;16(3):134-138
Oral Surg Oral Med Oral Pathol Oral Radiol Endod., 1999 Jun;87(6):653-7
J Laryngol Otal., 2009 Feb;123(2):182-5
J Forensic Leg Med., 2009 Feb;16(2):53-5
Acta Otolaryngol Suppl., 1995;520 Pt 1:53-6
Otol Neurotol., 2003 Sep;24(5):734-7
Laryngoscope, 2003 May;113(5):821-7
Pain Res Manag., 2006 Autumn;11(3):197-9
Wein Klin Wochenschr., 2006 Mar;118(3-4):95-9

Ed. Note: The opinions expressed above are solely those of the author. They do not represent the opinions of the editor, publisher, or this publication. Mr. D'Alonzo is not a medical doctor and does not give medical advice. Anyone with a medical problem is strongly encouraged to seek professional medical care.