Walsh & Hoyt: Tumors Involving the Thalamus

Many tumors that involve the thalamus do so by extension from the brain stem, the third ventricle, or the pineal gland. Other tumors, especially primary gliomas, originate within the thalamus. ""Pure"" thalamic tumors account for up to 5% of intracranial tumors in adults and 10% in children. Such tumors are usually neuroglial in origin, but angiomas and germinomas may also occur in this region. The initial symptoms in patients with primary thalamic tumors are most often those related to increased ICP, including headache, papilledema, nausea, vomiting, and abducens nerve paresis. Hemiparesis and hemiplegia are common signs of thalamic tumors, occurring in up to 53% of patients. This probably results from tumor extension or compression of the neighboring internal capsule or basal ganglia.