William R May

Valley Children's Hospital, Мадера, California, United States

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Publications (4)9.11 Total impact

  • R Shane Tubbs · Marios Loukas · William R May · Aaron A Cohen-Gadol ·
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    ABSTRACT: We report the case of a seemingly rare variation of a branch of the trigeminal nerve. This unusual finding is of practical importance to the neurosurgeon because ablation of this nerve(s) in such a case would require modification of technique. The existence of a bifurcated infraorbital nerve is also relevant for application of local anesthesia to portions of the face innervated by the maxillary nerve. During cadaveric dissection of the face of a male specimen, 2 branches of the infraorbital nerve were identified emanating onto the face. The 2 branches entered separate osseous canals within the orbit to emerge via 2 infraorbital foramina. The unusual variation of the trigeminal nerve branch in the reported case necessitates a change in the way in which the nerve is blocked clinically. A common practice involves blocking the infraorbital nerve as it emerges from the infraorbital foramen. The needle is aimed superiorly, posteriorly, and slightly laterally; however, to provide adequate anesthesia to both branches of the infraorbital nerve, as reported here, a needle can be inserted between the zygomatic arch and the notch of the mandible in the pterygopalatine fossa. After the needle contacts the lateral pterygoid plate, it is withdrawn slightly and angled both superiorly and anteriorly to pass into the pterygopalatine fossa. Although apparently uncommon, such derangement of the infraorbital nerve should be kept in mind by surgeons during surgical procedures in the region for treatment of various disorders including trigeminal neuralgia.
    Neurosurgery 09/2010; 67(3 Suppl Operative):onsE315; discussion onsE315. DOI:10.1227/01.NEU.0000374675.19487.FA · 3.62 Impact Factor
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    ABSTRACT: There is paucity of information regarding the specific anatomy and clinical significance of ossified ligaments near the foramen ovale (e.g., pterygospinous and pterygoalar ligaments). The present study was undertaken to define this anatomy in more detail and to review the literature regarding these anatomic variations. One hundred fifty-four adult human dry skulls were analyzed for the presence of ossified ligaments of pterygospinous (ligament of Civinini) and pterygoalar (ligament of Hyrtl). Measurements were made of these bony structures and observations made of their relationships to the inferior aspect of the foramen ovale and neighboring structures. Two ossifications each (2.6%) of the ligaments of Civinini and Hyrtl were found. One of each of these (1.3%) was completely ossified, thereby resulting in 2 complete foramina (i.e., 1 foramen of Civinini and 1 foramen of Hyrtl). A significant correlation was found between the left and right sides, with either complete or incomplete ossification of these ligaments being found on left sides (75%) (incomplete Civinini on right side and all others on left side). The complete foramen of Civinini was found to have an area of 16.7 mm, and the complete foramen of Hyrtl was found to have an area of 9.42 mm. Such anomalous bony obstructions could interfere with transcutaneous needle placement into the foramen ovale or distort anatomic relationships during approaches to the cranial base.
    Neurosurgery 12/2009; 65(6 Suppl):60-4; discussion 64. DOI:10.1227/01.NEU.0000345952.64041.9C · 3.62 Impact Factor
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    ABSTRACT: Variations within the musculature of the lateral compartment of the leg are uncommon. However, clinicians and radiologists should be aware of anatomical alterations in this region when involved in diagnosis or imaging interpretation. The present report describes a well-developed muscle of the lateral compartment of the leg that inserted distally onto the talus and calcaneus. This muscle could be considered a variation of the so-called peroneus quartus muscle. To the authors' knowledge this muscle variation has not been described as having an attachment onto the talus thus the term 'peroneotalocalcaneus muscle' is proposed.
    Anatomical Science International 01/2009; 83(4):280-2. DOI:10.1111/j.1447-073X.2007.00203.x · 0.83 Impact Factor
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    ABSTRACT: Many authors have included the V2 segment of the trigeminal nerve as a component of the cavernous sinus. However, many authorities have stated that this part of the fifth cranial nerve is not within this intracranial venous sinus. To further elucidate this potentially important relationship, 10 fresh cadaveric heads underwent injection of the cavernous sinus with blue latex or a cresyl-violet solution. Subsequent sectioning in the coronal plane in 1 cm sections from the level of the trigeminal ganglia anteriorly to the level of the superior orbital fissure was made. Observations were then made between the relationships of the cavernous sinus and the V2 nerve. On all 20 sides, the V2 segment of the trigeminal nerve did not have filling of latex or cresyl-violet mixture lateral to it thus implying that this part of the trigeminal nerve is not found within the cavernous sinus. Two sides did demonstrate an emissary vein that traveled with the V2 part of the trigeminal nerve through the foramen rotundum toward the cavernous sinus. Based on our findings, the V2 part of the trigeminal nerve is not found bathed with venous blood within the cavernous sinus. Reports that state the contrary may have confused laterally positioned emissary veins as being part of the cavernous sinus and therefore erroneously concluded that V2 was within this cranial venous sinus. These data may prove useful to neurosurgeons that operate in the region of the cavernous sinus or to radiologists who interpret imaging of this area.
    Surgical and Radiologic Anatomy 03/2008; 30(1):37-40. DOI:10.1007/s00276-007-0280-7 · 1.05 Impact Factor

Publication Stats

32 Citations
9.11 Total Impact Points


  • 2009
    • Valley Children's Hospital
      Мадера, California, United States
  • 2008
    • University of Alabama at Birmingham
      • Department of Cell, Developmental and Integrative Biology (CDIB)
      Birmingham, Alabama, United States