Brain tumor with ipsilateral cerebral hemiatrophy in children.

A series of six cases of cerebral tumor with ipsilateral cerebral hemiatrophy, including four cases admitted at our institute, were studied. Various common clinical features were noted in these six cases. The mechanism whereby ipsilateral hemiatrophy of the cerebrum arises from brain tumor has been discussed on the basis of symptomatologic and clinicopathologic findings noted in these 6 cases. 1) The onset of the disease was between 8 and 14 years of age with a mean of 11 years and 8 months; thus all the 6 patients being juvenile. 2) Presenting symptoms developed from 1 year and 2 months to 4 years before admission, with an average of 2 years and 1 month. The clinical course was therefore relatively chronic in every case. 3) Presenting symptoms were: decline of school work, hemiparesis and loss of consciousness. These symptoms were all progressive throughout the course. The principal symptoms were hemiparesis, hemihypoesthesia, character and emotional changes, deterioration of mental faculties and behavioral abnormalities. No sign or symptom of significant increase of intracranial pressure were observed in any case. 4) Ipsilateral cerebral hemiatrophy on the tumor side was evidenced by carotid angiography and by pneumoencephalography. 5) The common site of tumor in this series was the thalamus and its surrounding areas. 6) The tumor was invariably a pinealoma which seemed to be ectopic in every case. 7) The obtained histopathological findings suggest that the ipsilateral cerebral hemiatrophy was due to thinning of the cerebral cortex with degeneration and disappearance of ganglion cells, demyelination in the subcortex and destruction of axons. Our speculated mechanism of ipsilateral cerebral hemiatrophy due to thalamic tumor is that thalamic tumor causes the degeneration and disappearance of thalamic ganglion cells and nerve fibers, consequently occurring secondary Waller's degeneration of afferent and projecting fibers from the thalamus as well as retrograde degeneration of efferent fibers, thus resulting in an extensive atrophy of the cerebral cortex and subcortical tissue.