RESUMEN
Bowhunter's syndrome, also known as rotational occlusion of the vertebral artery, involves posterior circulation ischemia resulting from dynamic compromise of the dominant vertebral artery. This case highlights the importance of provocative digital subtraction angiography in making the diagnosis. A 41-year-old man presented for outpatient neurological evaluation for "lightheadedness" of several years' duration provoked by leftward head rotation. The only abnormality identified on initial magnetic resonance angiography was atresia of the nondominant left vertebral artery. Conventional digital subtraction angiography (DSA) followed by provocative DSA revealed development of a dynamic stenosis of the right vertebral artery involving the extraforaminal segment just superior to the C1 vertebra. Noncontrast computed tomography of the cervical spine confirmed ossification of the posterior right atlanto-occipital membrane leading to a near complete bony arcuate foramen. Following neurosurgical decompression, the patient demonstrated complete resolution of all neurologic symptoms. Bowhunter's syndrome is a unique clinical entity that must be considered in the evaluation of patients with symptoms of posterior circulation ischemia. Provocative DSA remains the preferred modality for definitive diagnosis.
RESUMEN
Presented is a patient with papillary tumor of the pineal region (PTPR), an uncommon and recently recognized neoplasm. As its name implies, PTPR does not arise from the pineal gland itself. The cell of origin is thought to be the specialized ependymocytes of the subcommissural organ. Primary tumors of the pineal region include pineal parenchymal neoplasms, germ cell neoplasms, and tumors arising from adjacent structures, including meningiomas, astrocytomas, and ependymomas. Like other masses in this location, PTPR often leads to obstructive hydrocephalus. Due to the relative paucity of reported cases of PTPR, its natural history is unknown.