bilateral spectrum
   Also known as bilateral scotoma. The term bilateral spectrum comes from the Latin words bi (two), latus (side), and spectrum (image, apparition). It is used to denote a relatively rare fortification spectrum (i.e. a * scintillating sco-toma), occurring in the context of a *migraine aura, whose development is exactly synchronized in the two hemifields. As a result, the bilateral spectrum may present in the form of a single central or pericentral spectrum. Various types of bilateral spectra (including the * rainbow spectrum) were described in 1904 by the British neurologist Sir William Richard Gowers (18451915). Bilateral negative scotomata (i.e. regions of loss of vision) occasionally develop into transient * blindness. In those rare cases where the tactile cortex is affected as well, a total loss of body-sense (i.e. *acenesthesia) may be experienced. As the involvement of both hemifields in fortification spectra is extremely rare, and cannot be explained with recourse to current hypotheses involving the mediation ofthese phenomena in a single cerebral hemisphere, the British neurologist Oliver Wolf Sacks (b. 1933) notes that "The existence of such scotomata poses very difficult problems to those who postulate a local, unilateral process as the basis of migraine auras."
   References
   Gowers, W.R. (1904). Subjective sensations of sight and sound: Abiotrophy, and other lectures. Philadelphia, PA: P. Blakiston's Son & Co.
   Sacks, O. (1992). Migraine. Revised and expanded. New York, NY: Vintage Books.

Dictionary of Hallucinations. . 2010.

Look at other dictionaries:

  • bilateral scotoma —    see bilateral spectrum …   Dictionary of Hallucinations

  • Spectrum (functional analysis) — In functional analysis, the concept of the spectrum of a bounded operator is a generalisation of the concept of eigenvalues for matrices. Specifically, a complex number λ is said to be in the spectrum of a bounded linear operator T if… …   Wikipedia

  • rainbow spectrum —    The term rainbow spectrum comes from the Latin noun spectrum, which means image, representation, shadow. It is used to denote a relatively rare * fortification spectrum (i.e. a * scintillating scotoma) which may occur in the context of a *… …   Dictionary of Hallucinations

  • Military spectrum management — Every military force has a goal to ensure and have permanent access to radio frequencies to meet its vital military tasks. This is based on strategies, doctrines and different policies that military forces adhere to. The nature of high mobility… …   Wikipedia

  • fortification spectrum —    Also known as fortification figure, fortification of Vauban, geometrical spectrum, herringbone, flittering scotoma, Norman arch, scintillating scotoma, telehopsia, and teichopsia. The introduction of the term fortification spectrum is commonly …   Dictionary of Hallucinations

  • Aretaeus of Cappadocia — (c. 150 AD)    A classical physician of the pneumatic school who has been credited with making an early conceptual distinction between illusions and hallucinations. Thus Aretaeus s work would seem to have foreshadowed the distinction between… …   Dictionary of Hallucinations

  • acenesthesia —    Also known as acoenesthesiopathy, general elementary somatopsychosis, and asomatognosia. The term acenesthesia comes from the Greek words a (not), koinos (communal), and aisthanesthai (to notice, to perceive). It translates loosely as not… …   Dictionary of Hallucinations

  • Mexico — /mek si koh /, n. 1. a republic in S North America. 97,563,374; 761,530 sq. mi. (1,972,363 sq. km). Cap.: Mexico City. 2. a state in central Mexico. 6,245,000; 8268 sq. mi. (21,415 sq. km). Cap.: Toluca. 3. Gulf of, Mexican, Golfo de México /gawl …   Universalium

  • Electronic amplifier — A practical amplifier circuit An electronic amplifier is a device for increasing the power of a signal. It does this by taking energy from a power supply and controlling the output to match the input signal shape but with a larger amplitude. In… …   Wikipedia

  • syndrome — The aggregate of symptoms and signs associated with any morbid process, and constituting together the picture of the disease. SEE ALSO: disease. [G. s., a running together, tumultuous concourse; (in med.) a concurrence of symptoms, fr. syn,… …   Medical dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”