PRELIMINARY REPORT UPON A CASE OF UNI- 
LATERAL ATROPHY OF THE CEREBELLUM. 
By O. S. STRONG. 
The following are some observations made upon the ex- 
ternal features of parts of the brain of a child 3 years and 4 
months old. Observations upon the other parts, together with 
the histological findings, accompanied by figures, will be pub- 
lished later. These observations were made in conjunction with 
one of my students, C. E. Doran. 
The clinical data are rather scanty. The child never 
learned to walk nor talk, though it would hum airs to itself. 
It was not deaf. 
The most striking feature of the brain, externally, was the 
almost complete absence of the left hemisphere of the cerebel- 
lum; with the exception noted below no part of the left side © 
of the cerebellum extended more than 2 or 2% cm. to the left 
of the median line. This was true except a small lobe, appar- 
ently in part representing the flocculus, which protruded some 
4cm. to the left of the median line, dorsal to the VIII, IX 
and X nerves. Some transverse cuts made through the cere- 
bellum showed an absence of the left corpus dentatum. The 
inferior vermis was apparently, in part at least, present. All of 
the external surface of the cerebellum appeared normal. 
The. cause of the atrophy was not entirely clear but it 
would seem to be most probably due to some old cyst which 
occupied the space which should have been filled by the left 
cerebellar hemisphere. 
On the ventral aspect, the right olivary body was appar- 
ently entirely absent (cuts made through the medulla have 
shown that a moiety of it is present) ; the left olivary body was 
normal. The’cranial nerves were apparently normal. 
