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Ependymoma of the pituitary fossa

Case report and review of the literature

Karim Mukhida, Sylvia Asa, Fred Gentili and Patrick Shannon

✓The authors describe a case of pituitary fossa ependymoma and discuss its immunohistochemical and ultrastructural characteristics. A 43-year-old man presented with decreased libido and panhypopituitarism. Magnetic resonance imaging demonstrated a well-demarcated enhancing lesion of the pituitary fossa that was completely resected via a trans-sphenoidal approach. Ependymomas rarely occur in the pituitary fossa, and have been reported in this location only three times in humans and once in a horse. This is the first study in which investigators examined the appearance of a pituitary ependymoma by using electron microscopy. Theories of the origin and treatment of these rare tumors are discussed as they relate to other articles on intracranial ependymomas.

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Mark A. MacLean, Karim Mukhida, Jai J. S. Shankar, Matthias H. Schmidt and David B. Clarke

Transorbital penetration accounts for one-quarter of the penetrating head injuries (PHIs) in adults and half of those in children. Injuries that traverse (with complete penetration of) the brainstem are often fatal, with survivors rarely seen in clinical practice. Here, the authors describe the case of a 16-year-old male who suffered and recovered from an accidental transorbital PHI traversing the brainstem—the first case of complete neurological recovery following such injury. Neuroimaging captured the trajectory of the initial injury. A delayed-onset carotid cavernous fistula and the subsequent development of internal carotid artery pseudoaneurysms were managed by endovascular embolization.

The authors also review the relevant literature. Sixteen cases of imaging-confirmed PHI traversing the brainstem have been reported, 14 involving the pons and 12 penetrating via the transorbital route. Management and outcome of PHI are informed by object velocity, material, entry point, trajectory, relationship to neurovascular structures, and the presence of a retained foreign body. Trauma resuscitation is followed by a careful neurological examination and appropriate neuroimaging. Ophthalmological examination is performed if transorbital penetration is suspected, as injuries may be occult; the potential for neurovascular complications highlights the value of angiography. The featured case shows that complete recovery is possible following injury that traverses the brainstem.

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Karim Mukhida, Behnam A. Baghbaderani, Murray Hong, Matthew Lewington, Timothy Phillips, Marcus McLeod, Arindom Sen, Leo A. Behie and Ivar Mendez

Object

Fetal tissue transplantation for Parkinson disease (PD) has demonstrated promising results in experimental and clinical studies. However, the widespread clinical application of this therapeutic approach is limited by a lack of fetal tissue. Human neural precursor cells (HNPCs) are attractive candidates for transplantation because of their long-term proliferation activity. Furthermore, these cells can be reproducibly expanded in a standardized fashion in suspension bioreactors. In this study the authors sought to determine whether the survival, differentiation, and migration of HNPCs after transplantation depended on the region of precursor cell origin, intracerebral site of transplantation, and duration of their expansion.

Methods

Human neural precursor cells were isolated from the telencephalon, brainstem, ventral mesencephalon, and spinal cord of human fetuses 8–10 weeks of gestational age, and their differentiation potential characterized in vitro. After expansion in suspension bioreactors, the HNPCs were transplanted into the striatum and substantia nigra of parkinsonian rats. Histological analyses were performed 7 weeks posttransplantation.

Results

The HNPCs isolated from various regions of the neuraxis demonstrated diverse propensities to differentiate into astrocytes and neurons and could all successfully expand under standardized conditions in suspension bioreactors. At 7 weeks posttransplantation, survival and migration were significantly greater for HNPCs obtained from the more rostral brain regions. The HNPCs differentiated predominantly into astrocytes after transplantation into the striatum or substantia nigra regions, and thus no behavioral improvement was observed.

Conclusions

Understanding the regional differences in HNPC properties is prerequisite to their application for PD cell restoration strategies.