1505 - Syndrome of the Trephined: A case of fluctuating mental status

Case Diagnosis: Syndrome of the Trephined

Case Description: A 35-year-old healthy male presented with large, traumatic left subdural hemorrhage sustained during mixed martial arts training. He required burr hole subdural evacuation and subsequent left hemicraniectomy. The following weeks at an inpatient rehab facility (IRF), he experienced fluctuating mental status, twice requiring rapid response activation for decreased arousal with subsequent spontaneous improvement in symptoms and stable CT scans of the head. Neurosurgery performed a cranioplasty to treat suspected Syndrome of the Trephined (SoT). After surgery, his fluctuating mental status resolved. The patient returned to the IRF where he made significant functional improvement to supervised and independent levels with activities of daily living and ambulated over 500 feet without an assistive device upon discharge.

Discussions: SoT, also known as sinking skin flap syndrome, is a rare occurrence after decompressive craniectomy described as a constellation of symptoms including headache, motor dysfunction, and cognitive deficits. While the exact mechanism is not fully understood, a hallmark is improvement of symptoms after cranioplasty. One of the most common indications for craniectomy is traumatic brain injury (TBI), which makes it difficult to discern whether the presenting symptoms are secondary to the TBI itself. The timing of SoT onset is variable, with current literature noting a range from days to years after craniectomy. Rapid improvement is seen in most patients post-cranioplasty, with patients continuing to make improvements in neurological function with rehabilitation. It is important for physiatrists to be aware of SoT in the inpatient TBI rehabilitation setting to facilitate timely neurosurgical intervention as needed.

Conclusions: SoT is a rare phenomenon after craniectomy which presents with a variety of symptoms including transient motor and cognitive deficits. Symptoms rapidly improve after cranioplasty. Physiatrists should be aware of SoT in addition to common complications encountered during TBI rehabilitation.