Cranioplasty for syndrome of the trephined
The therapeutic value of cranioplasty has been proved by various experiments. Increase in cerebrospinal fluid (CSF) and superior sagittal sinus pressure, cerebral expansion, increase in CSF motion after cranioplasty due to an increase in cerebral arterial pulsations and improvement in cerebral blood flow, cerebral metabolism and cerebral vascular reserve capacity have been demonstrated after cranioplasty 1) 2) 3) 4).
A small but significant number of patients appear to improve clinically following cranioplasty. The so-called syndrome of the trephined may be more common than had been previously appreciated 5).
Other syndromes related to the bone defect
For those purists who want to restrict the use of the term “syndrome of the trephined” to nonfocal symptoms, the following syndromes have been proposed.
Sinking skin flap syndrome: neurologic deficit related to the brain immediately underlying the skull defect when the scalp is displaced inward by atmospheric pressure. Deficits may include contralateral hemiparesis (more common in UE than LE due to location of UE motor neurons over the convexity, contralateral visual and somatosensory deficit, speech/language deficit (with dominant hemisphere defects). Not all patients with a sunken flap develop a deficit.
Motor trephine syndrome: limited to contralateral hemiparesis. Mean delay to onset: 5 months.