131 patients with epilepsy and phenytoin exposure.
The majority of the patients were severely retarded, with 83% having an intelligence quotient of less than 35.
No controls were employed.
The authors thought that cerebellar atrophy as diagnosed with pneumoencephalography
correlated with a history of phenytoin intoxication and serum phenytoin levels.
As in the previously mentioned study, the issue of possible preexistent congenital cerebellar pathology is not addressed.
At most, one could only conclude that phenytoin may play a role with respect to cerebellar atrophy in brain-damaged individuals.
In the only investigation that we know of in which modern neuroimaging techniques were used, Ballenger compared the computed to patients with seizures with those of a control group and failed to demonstrate cerebellar atrophy within the seizure group; 84% of the seizure group had had significant phenytoin exposure.
Details of the epilepsy group are not available. Furthermore, mild cerebellar atrophy may have been missed on computed tomographic scans....