The State of Essential Tremor

Essential tremor is such an odd disease in many ways. There are over 10 million Americans with essential tremor yet very few people know what it is.

Based on numbers, it is not a rare disease; there are more ET (essential tremor acronym) patients than those with Parkinson’s Disease. Based on awareness, it is extremely rare; the public has no clue what the disease is. We should just change the name to Not Parkinson Tremor.

Last year I wrote two blogs related to movement disorders specialists, Success is in the details and Finding Hope without GPS. I recently saw my movement disorders specialist. This appointment reinforced every reason why I left my old MDS and moved to Dr. Mari. Dr. Zoltan Mari, M.D. is an Associate Professor of Neurology, the Director of the Parkinson’s and Movement Disorder Center and the Director of the National Parkinson Foundation Center of Excellence at the Johns Hopkins University School of Medicine.

After an exam and detailed discussion about my essential tremor symptoms and treatment, Dr. Mari graciously took the time to answer all my questions concerning essential tremor research. And I had a lot of questions. I cannot thank him enough for doing this. I asked Dr. Mari for permission to share what I learned. A couple of quick points here. Every patient should be having conversations with their doctors; asking them questions and getting answers. If your doctor will not take the time to answer questions, you need a new doctor.

Dr. Mari and I discussed Deep Brain Stimulation (DBS) and Focused Ultrasound. DBS has been around for several years. I had questions for him concerning the side effects some patients have reported (slurred speech and cognitive deficients). Dr. Mari told me that many times, those side effects end when the device is removed from the brain. He stated, “While DBS stimulation related adversities/side effects (such as slurred speech) may be reversed by turning the device/stimulation off (same as removing it), not all adversities of DBS implantation are stimulation related.  Some adversities, caused by the surgery itself (i.e. stroke, bleed, infection and their consequences) can be permanent.  It is important to make that distinction.” He was very specific that DBS is a surgery and patients must be aware of those specific risks.

When we spoke of Focused Ultrasound, he explained it to me in a way I understood (no small feat, trust me). I had read several articles and papers on the technique and still could not understand it. Dr. Mari explained that the first step is to have the patient awake and target the area of the brain thought to be involved with a low dose of ultrasound waves. The doctors then see if the patient’s tremor symptoms change at all. If they do, the next step is to repeat the process but with the maximum dosage of ultrasound. Here is the important part; the maximum dosage essentially destroys that area of the brain. It is permanent. There is no undoing what has been done.

Next we discussed Octanoic Acid. Octanoic Acid was in trials as a possible drug to treat essential tremor symptoms.  Dr. Mari suggested reading “Octanoic acid in alcohol-responsive essential tremor: a randomized controlled study.” The paper discusses the “safety and efficacy of an oral, single, low dose of octanoic acid (OA) in subjects with alcohol-responsive essential tremor (ET).” Although the number of patients in the study was described as small in the paper, the patients seemed to have promising results. The current state of Octanoic Acid is trying to find the right delivery method. Octanoic Acid is after all an acid. It is hard on the body’s system. Dr. Mari suggested reading “Treatment of essential tremor with long-chain alcohols: still experimental or ready for prime time?” The paper, authored by Drs. Dietrich Haubenberger, Fatta B. Nahab, Bernhard Voller, and Mark Hallett, states “despite its efficacy and safety, 1-octanol itself does not seem a feasible candidate for further development due to the relatively large volumes to be administered when formulated in capsules for oral administration.” In other words, there is still work to be done before Octanoic Acid can be ready for approval.

The final topic we addressed was the debate on what ET is; is it a single disease or a syndrome? A syndrome is defined as a set of symptoms that are related with a specific disease. As ET patients know, there is variation between patients, not only in severity of symptoms but the symptoms themselves. We all have tremor. But for some it is just the hands, or just the head or both or sometimes involving other body parts. There is no definitive checklist of ET symptoms. Dr. Mari, when asked if ET may be a syndrome and not a single disease, replied, “That is absolutely correct.” He referred me to the article “What is essential tremor?” by Dr. RJ Elble. In it, Dr. Elble states, “the longstanding notion of that essential tremor is a monosymptomatic tremor disorder is being challenged by a growing literature describing associated disturbances of tandem walking, personality, mood, hearing and cognition. There is also epidemiologic, pathologic and genetic evidence that essential tremor is pathophysiologically heterogeneous.” To put in language I can understand, it is not a one-symptom disease. There are also studies showing that the disease causes diverse symptoms. The article is well worth the time and effort to read as it sketches the history of the disease as well as how this diversity of symptoms has impacted research on the cause and medications to treat it. All three articles referenced are available online free.

Dr. Mari’s involvement in ongoing essential tremor research is a huge benefit to his patients. It allows him to give his patient’s the newest information specifically for essential tremor. Essential Tremor cannot be treated like Parkinson’s Disease. Your Movement Disorders Specialist should be up to date on what is happening with your disease. If not, you need to find a new specialist. The Tremor Action Network has a directory to help patients locate movement disorders specialists.

Essential tremor may benefit from several ongoing initiatives in Washington, DC. 21st Century Cures, NIH’s Discovering New Therapeutic Uses for Existing Molecules program, and the Senate’s Advancing Research and Development for Patients all hold promise. Our job as essential tremor patients, family members and advocates is to ensure essential tremor is part of the conversations and not left behind.

Image Source:
Grimaldi G, Manto M. Neurological Tremor: Sensors, Signal Processing and Emerging Applications. Sensors. 2010; 10(2):1399-1422.

Nannette Halliwell
TAN Blog Editor
https://twitter.com/Gatun_CZ