{'fraction_non_alphanumeric': 0.013222331047992164, 'fraction_numerical': 0.002448579823702253, 'mean_word_length': 5.742574257425742, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Contralateral cerebellar hemorrhagic infarction after pterional craniotomy: report of five cases and review of the literature.

OBJECTIVE AND IMPORTANCE
Five cases of cerebellar hemorrhagic infarction complicating pterional craniotomy are presented. Recognition of this rare complication may be delayed, with catastrophic consequences, because clinicians are unaware of the possibility. We suggest that the mechanism of this complication is dislocation of the dependent part of the cerebellum and venous obstruction causing hemorrhagic infarction.


CLINICAL PRESENTATION
Five patients undergoing pterional craniotomies for benign conditions (four unruptured aneurysms and one meningioma) developed hemorrhagic infarction of the contralateral cerebellum in the postoperative period. This resulted in obstructive hydrocephalus and brain stem compression. A review of the literature revealed only one previous report of a similar complication in patients with gross coagulopathy. This was not a problem in our patients.


INTERVENTION
The time of onset of symptoms varied from immediately postoperative to 24 hours later. Once the diagnosis was made, the hydrocephalus was drained and the posterior fossa was decompressed.


CONCLUSION
The outcome depended on two variables: 1) the rate of development of hemorrhagic infarction and the associated complications and 2) the amount of time that elapsed before remedial action was taken. Two patients with the first signs of deterioration in the immediate postoperative period had the worst outcome; one died and the other remained severely disabled. In two patients with good neurological recovery, problems were identified and corrected within 4 hours of the first sign of deterioration. Rapid overdrainage of cerebrospinal fluid during supratentorial surgery should be avoided, and the fluid volume should be replaced before closure. Postoperative evaluation of patients whose conditions deteriorate after supratentorial craniotomy should include adequate imaging studies of the posterior fossa.