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Show Atypical Oculomotor Paresis To the Editor: I re.1d with interest the .1rticle entitled, Atypic.ll Ocull)ll1otor l'.Hesis in the IOl/m.ll (Vl)lull1C' 2, Number I), .1I1d I re.ld with elju.ll interC'st your editllri.11 Cllll1n1l'nt reg.Hding this p.1per. I h.lvC' enc!l)sed h)r YOU .1 nll)dest effort of mine studying the third ne~'e nucleus in C.1tS. In this .1I1imal, it .lppe.1rs th.1t the fibers l)f the superior rectus subnucleus l)f l)Ill' side p.1ssed th rough the fellow subnucleus l)f the l)tlwr side. The result of this is th.lt und.1ter.11 destruction of the superior rectus . ubnucleus wl)uld result in bdateral paralysis of the superior rectus muscles. This follows from the destruction of the cell bodies of the one side and the .1'\l)nS passing thwugh the subnucleus but originating in the other side. I think if this information IS true for m.ln, it bears on cases 4 and 5 in the article. Don C Bienfang, M.D. Boston. Massachusetts Response to Atypical Oculomotor Paresis To the Editor: We appreciate Dr. Bienfang's letter concerning our paper, I and we are aware of his work.2 Although there are distinct differences between the oculomotor nucleus of the cat and the primate, we believe his findings can be used to support our clinical hypothesis. Dr. Bienfang has demonstrated that the presumed crossing fibers of the superior rectus muscle cross the midline in the dorsoventral center of the caudal end of the third nerve nucleus in the location of the 5'uperior rectus, inferior oblique, and levator palpebrae superioris subnuclei. It is our contention that the lesion in these December 1982 individuals is rostral to the region of the crossing fibers (see Figure 3 of our paper), and in this area one can SC'C' an ipsilateral inferior rectus paresis associated with a contralateral superior rectus paresis on the basis of a small nuclear lesion, especially if the lesion involves the dorsal aspect of the nucleus. Second, we would like to take this opportunity to address Dr. Smith's editorial' concerning the differentiation between an isolated muscle paresis and a skew deviation. It is our understanding that by definition, a skew deviation is a vertical deviation that cannot be isolated to the dysfunction of a single muscle. In addition, although skew deviation can be laterally or even vertically incomitant, we do not believe (by definition) these patients demonstrate a primary and secondary deviation as did each of the patients reported in our paper. It is our contention that to label these deviations as skew is inappropriate by definition. Be that as it may, the importance of the observations and the report in our minds is that use is made of the known microanatomy to invoke an explanation of clinical findings (and to provoke discussion). Ronald M. Burde, MD. Walter Warren, M.D. Terence G. Klingele, MD. Gill Roper-Hall, D.B.O.(T.) St. Louis, Missouri References 1. Warren, W., Burde, R.M, Klingele, T.G., and RoperHall, G.: Atypical oculomotor paresis. I Clin. Neuroophth. J/mol. 2: 13-18, IQ82. 2. Bienfang, D.C.: Crossing a'\ons in the third nerve nucleus iIJI'f'st. Opth.l/mol. 14: Q27-Q30, 1Q75. 3. Smith, J.L: Editori.ll comment: The "nucle.H third" question. /. Clin Neuro-t'phtha/mol. 2: 01-03, IQ82. 281 |