The patient was operated by me several times for persisting hydrocephalus with persistent headache and blurred vision for what the last time low pressure VPS was inserted 14-September-2015. The patient the first days improved but later got signs of low pressure with headache and bilateral tinnitus and feeling that the head is empty and having strange feeling when changing position of the head.

On examination: the patient neurologically free.

The patient was sent for new investigations and MRI of the brain and CT-scan of the brain done 22-September-2015 and repeated several times showing wide subarachnoid spaces with shrinking of the hemispheres with bilateral hygromas. The last one done 15-January-2016 showing the same picture. Considering that the condition is not acceptable, it was decided to replace the shunt to medium pressure type.

Immediately before surgery, CT-scan brain done showing left sided convexital subdural hematoma. The old incision was refreshed and the reservoir was removed and medium pressure adult type was replaced. Routine closure of the wound. In the most dependent part of the left subdural hematoma, burr hole was created and evacuation of the hematoma was achieved and subdural drain was left for 36 hours. Routine closure of the wounds.

Smooth postoperative recovery.

Low pressure VPS in adults rarely needed and could cause subdural hematoma.

This case confirm this speculation, that the hematoma progressed in the contralateral side. The ipsilateral side was protected by the shunt and the other side was more vulnerable to such event.