Mal de Debarquement Syndrome

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Mal de Debarquement Syndrome

• Ashley Bice
• Burnley Dluhosh
• Amanda Howard
• Rebecca Laws

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• What is MdD?
• MdD is a balance disorder which generally
  develops following any type of water travel.
• Can last months to years.
• Symptoms usually include a rocking, swaying or
  bobbing sensation. It can be associated with
  fatigue, impaired cognitive function, and
  difficulty with balance. The sensations can vary
  from mild, during walking or moving, to severe
  and consistent.
• Why is this important?
• The importance of looking at MdD is in the fact
  that there has been very little research done
  surrounding this disorder. A specific mechanism
  has not yet been pin-pointed as the main cause.
  Although it is a fairly rare disorder, the fact
  that there are people experiencing its
  debilitating symptoms shows that it is a topic
  that requires more research.

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Typical Sufferer of MdD

• Female, between ages of 40 and 50 Traveled on a
  seven-day boat cruise
• Symptoms can persist for years after trip

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Relationship to Lecture

• Feed Forward Mechanisms
• An anticipatory mechanism
• When walking or standing gathering sensory input
  from eyes, somatic receptors in feet, vestibular
  apparatus, etc. and adjust voluntary muscles
  accordingly.
• When sufferer gets off boat, plane, etc. after a
  long period of time, the hippocampus remembers
  the previous information from the vestibular
  apparatus, and therefore gives input as if the
  rocking motion is continuing. The brain adjusts
  muscle contractions according to that input,
  instead of reality.

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Previously Theorized Causes of MdD

• Vestibular disorder
• Migraine variant
• Sex hormones, such as estrogen or progesterone
• Genetic

Image //www.tchain.com/otoneurology/images/maste
r-ear.jpg
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• The hippocampus plays an important part in
  storing memory, including spatial memory.
• Both internal and external cues influence
  spatial memory and navigation.
• External cues influence the input from the
  vestibular system to the hippocampus.
• Internal self-motion cues influence the spatial
  firing properties of hippocampus neurons.
• The hippocampus has two types of neurons that
  fire in response to external and internal cues.
• Place cells
• Head direction cells

• Symptoms of MdD may result from a release
• of stored vestibular information from the
• hippocampus.

Image www.alzheimer-adna.com
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• Analogy
• The release of stored vestibular info from the
  hippocampus resulting in the symptoms of MdD can
  be compared to
• Getting a song stuck in your head (earworm)
• Re-living a scary life experience in your dreams

Image www.webware.com
Image www.suckatlife.com
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References Hain, T.C. Mal de Debarquement.
American Hearing Research Foundation (2008).
http//www.american_hearing.ord/disorders/central/
mdd.html Hain, T.C., Hanna, H.A., Rheinberger,
M.A. (1999). Mal de Debarquement. Archives of
Otolaryngology-Head and Neck Surgery, 125,
615-620. Lapsansky, Janice. Major Themes
Concepts in Physiology. March 2, 2008. Mal de
Debarquement. National Organization for Rare
Disorders (2006). http//www.nordonline.org/search
/rdbdetail_abstract.html?disnameMal20de20Debarq
uement Moeller, L., Lempert, T. (2007). Mal de
debarquement psuedo-hallucinations from
vestibular memory? Journal of Neurology, 254,
813-815. Stackman, R.W., Clark, A.S., Tuabe,
J.S. (2002). Hippocampal spatial representations
require vestibular input. Hippocampus, 12,
291-303.