White Matter Changes in Corpus Callosum in a Patient with Idiopathic Normal Pressure Hydrocephalus

Efficacy and safety of shunt surgery in patients with idiopathic normal-pressure hydrocephalus: can we predict shunt response by preoperative magnetic resonance imaging (MRI)?

AIM

The aim of this study was to identify preoperative magnetic resonance imaging (MRI) findings that can predict the shunt responsiveness in idiopathic normal-pressure hydrocephalus (iNPH) patients and to investigate postoperative outcome and complications.

MATERIALS AND METHODS

A total of 192 patients with iNPH who underwent shunt at our hospital between 2000 and 2021 were included to investigate complications. Of these, after exclusion, 127 (1-month postoperative follow-up) and 77 (1-year postoperative follow-up) patients were evaluated. The preoperative MRI features (the presence of tightness of the high-convexity subarachnoid space, Sylvian fissure enlargement, Evans' index, and callosal angle) of the shunt-response and nonresponse groups were compared, and a systematic review was conducted to evaluate whether preoperative MRI findings could predict shunt response.

RESULTS

Postoperative complications within one month after surgery were observed in 6.8% (13/192), and the most common complication was hemorrhage. Changes in corpus callosum were observed in 4.2% (8/192). The shunt-response rates were 83.5% (106/127) in the 1-month follow-up group and 70.1% (54/77) in 1-year follow-up group. In the logistic regression analysis, only Evans' index measuring >0.4 had a significant negative relationship with shunt response at 1-month follow-up; however, no significant relationship was observed at 1-year follow-up. According to our systematic review, it is still controversial whether preoperative MRI findings could predict shunt response.

CONCLUSION

Evans' index measure of >0.4 had a significant relationship with the shunt response in the 1-month follow-up group. In systematic reviews, there is ongoing debate about whether preoperative MRI findings can accurately predict responses to shunt surgery. Postoperative corpus callosal change was observed in 4.2% of iNPH patients.

Corpus Callosum Swelling after Resection of Intraventricular Central Neurocytoma

Corpus callosum swelling has been reported to occur after ventriculoperitoneal shunting for long-standing hydrocephalus. This report presents a case of corpus callosum swelling after intraventricular tumor resection. A 34-year-old woman presented with a headache that worsened over 1 month. Magnetic resonance (MR) images revealed a mass lesion in the left lateral ventricle and obstructive hydrocephalus. She underwent subtotal resection with a transcallosal approach. After tumor resection, she had long-lasting status epilepticus followed by consciousness disturbance. T2-weighted MR images obtained 8 hr after the operation showed a hyperintense area in the corpus callosum. The patient then presented with bilateral dilated pupils 14 hr after the operation due to acute hydrocephalus and tension pneumocephalus. An emergent re-craniotomy was performed and a ventricular drain was placed. The patient recovered consciousness 3 days after the operation. However, she experienced progressive corpus callosum swelling 25 days after the operation, which improved since then. Approximately 4 months after the operation, she returned to her usual workplace with no neurocognitive functional decline. Two years later, she was doing well with no radiological abnormal findings except corpus callosum thinning. Thus, corpus callosum swelling can develop not only after shunting for chronic hydrocephalus but also after intraventricular tumor resection. It occurred relatively acutely and there was no decline in intelligence after long-term follow-up. This case suggests that corpus callosum swelling after intraventricular tumor resection is a rare but noteworthy complication that can improve without intervention.