Thalamic tumors: clinical presentation.

INTRODUCTION

Thalamic tumors (TTs) account for approximately 1% of all intracranial neoplasms. TTs are seen predominantly in children and young adults. Most childhood neoplasms in this location are of glial lineage, a large proportion being low-grade tumors. The evolution of symptoms before diagnosis is characteristically shorter in children than in adults.

CLINICAL PRESENTATION: Clinical features of TTs reflect the pressure of the mass on the cerebrospinal fluid pathways, the pyramidal tracts, the thalamic nuclei and the optic radiations. In this paper, we review the clinical data of 20 children with TTs seen at our hospital and compare the findings with those in the current literature. An acute presentation is not rare and was encountered in 20% of our patients, although most individuals had a subacute or slow evolution. Symptoms and signs of raised intracranial pressure (65%), motor deficits (40%), and seizures (35%), alone or in combination, were the most frequent manifestations of TTs. Behavioral and mental changes are not uncommon in TTs and were found in 25% of our patients. Involuntary movements (10%) and the classic thalamic syndrome (5%) were quite exceptional. Infants and young children with TTs may present with macrocephaly, psychomotor delay, and failing vision or disorders of ocular movements.