11 whydid I choose to write about Vega, the blue star of Constellation Lyra? Because of the association of ideas between the cavum of Verga developing at the junction of the fornix and the corpus callosum and the name of David's lyra or psalterium given by anatomists to this region when the fibers of the hippocampal commissurelie separated but parallel underneath the splenium of the corpus callosum. Although not mentioned as such in the literature, I believe that a cavum Vergae and a psalterium are coexisting anatomical varients."

Denis Melanson, M.D. NEURO-IMAGE Dl

Walter Dandy noted that: "the cavum septi pellucidi is frequently present when the cavum Vergae is absent and Verga's cavity may be present when the cavum septi pellucidi is absent". THE CONSTELLATION LYRA

It seems that the cavum septi THE ALPHA STAR pellucidi is always present, albeit smaller, when the cavum Vergae is present. The opposite is not true, not- withstanding Dandy's opinion, and many others with him. A cavity in a long septum pellucidum creates a looser hippocampal commissure, and the ega is the fifth brightest star in the crossing fibers appear as strings, for v sky. The name VEGA is derived which the name PSALTERIUM. from the arabic A1 Nasr a1 Waki, the The music of the LYRE, in Greek Another cavity may exist in the same he septum pellucidum is a thin vertical swooping eagle, the falling eagle. Pliny's legends, casts such a spell that Orpheus region, the cavum veli interpositi; title, usually translated "the harp star", T partition, consisting of two laminae, whereas Verga's cavum communicate charmed every living creature with it. is a reference to the legendary 7-stringed sometimes separated by a narrow interval, with the lateral ventricular system, the lyre of Hermes, later the property of termed the "cavum septi pellucidi". velum's cavum communicates with the To observers in the Earth's Northern Orpheus, but associated also with a When the septum extends more posteriorly, local subarachnoid cistern. However, it Hemisphere, VEGA reigns as the leader veritable galaxy of gods and heroes in- the cavity lies in between the crura of the fornix has a similar effect on the crura of the of the "stars of a summer night" and cluding Apollo, Mercury, King Arthur, in front of the splenium. The hippocampal fornix than Verga'cavum, although dominates the heavens from its position the Biblical David and the Greek poet commissure is thus stretched and assumes the assuming a different shape (Fig.2). It also virtually at the zenith in the evening Arion. This is the lyre whose strings "give shape of a PSALTERIUM or LYRA (Fig. 1). creates a looser fornical commissure, a hours of August. music audible to holy ears". Longfellow, It has been named "cavum Verga" from PSALTERIUM, a LYRA. in his "Occultation of Orion", speaks of Andre Verga, an Italian anatomist, assistant The presence of a long cavity in the the heavenly lyre: VEGA is approximately 27 light to the chair of anatomy in Pavia. He wrote a septum pellucidum (cavum Verga)- and years distant and has an actual lumi- brief note (1851) on Ferrario's report of such a I loose hippocampal commissure may not nosity of about 58 times that of the Sun, cavum, on the observation of which he claims Figure 1 be irrelevant, as some psychiatric while her mass is about that of three priority: "dell Bpparato ventricolare del setto disorders (schizophrenia) have been solar masses. During the courses of the lucido e della volta a tre pilastri". recently reported to exist with such an slowly changing orientation of the Gazz.Med.Lomb., no 7, July 7,1851 anatomical varient (Gustav Degreef, "... with its celestial keys, Earth's axis in space (the Precession of AJNR: 13, May / June 1992). the Equinoxes) VEGA was the Pole Star Its chords of air, its frets some 12,000 years ago and will occupy of fire, the position again about the year 12,000 While writing on the blue star AD. It is towards a spot in the general VEGA, within its immense lyra- The Samian's great direction of VEGA that the Sun-and the shape constellation, I have dreamed Aeolian lyre, entire Solar System-moves in the depths of space at a velocity of 12 miles per of the immensity around us and all Rising through all its second. This position is known as the the knowledge it must conceal, sevenfold bars, Apex of the Sun's Way, or simply the unattainable by human nature. I "Solar Apex". Some idea of the vastness have also dreamed that our "lyra", From earth unto the fixed of space may be gained from the fact that it would take the Sun over 450,000 years our psalterium, our hippocampal stars...I1 to reach VEGA at this speed, even if it harp could be able to "give music were moving directly toward it. audible to holy ears". Figure 2 AGE

his is the history of an 87 year old lady who was- well Because of her age and the extensiveness of the cerebral T until approximately one year before her admission to .lesion, it was decided there would be no intervention. hospital. Since thahme, she had become gradually de- The images shown are quite eloquent: it is indeed a large mented, especially disoriented to time and place, dysphasic at glial tumour with a mixture of densities, truly bifrontal times with incoherence of words. She was thought to have de- .through the genu of the corpus callosum. Its features are mentia of the Alzheimer type. not that of a recent growth,- such as glioblastoma;- indeed, The day of her admission to hospital, she had suddenly the presence of calcifications suggests a chronic growth, .collapsed and become irresponsive: she was incontinent of more benign at the beginning, which is now undergoing urine but there were no seizures. anaplastic changes.

Figure 2: Figure 1: CT with CT plain contrast shows the shows the calcified enhancing portion of parts of the the hunour tumour

Computed tomography revealed a large enhancing Could this lesion have been the cause of the dementia? Likely .neoplasm with calcifications, anterior callosal and bifrontal, .so. There is no way to know for sure, there was no histology and a second enhancing nodule in the left temporal lobe. of the tumour, as the decision not to treat is often taken by the family in this age group. While in hospital, she remained mute, not recognising her .family and refusing any food.

Editor: Denis Melanson, M.D. Published by: Neurikon Produced by: ~ditionet Graphisme dlAvant-garde Nos remerciements ii ceux qui ont contribu6 P la parution du bulletin Neuro-image durant la demi5re annee. Our thanks to everyone who contributed to the production of Neuro-image over the past year.