Delayed Cerebrospinal Fluid Cleft Formation Through the Midbrain and Thalamus Following Hemicraniectomy and Cranioplasty for Acute Subdural Hematoma

Abstract

BACKGROUND AND IMPORTANCE Cerebrospinal fluid (CSF) cleft formation through brain parenchyma following nonpenetrating traumatic brain injury (TBI) is a rare phenomenon. Here we present a unique case of delayed CSF cleft formation months after initial injury. CLINICAL PRESENTATION A 41-yr-old male presented after a fall with a right convexity acute subdural hematoma and ipsilateral frontal contusion. He underwent emergent hemicraniectomy with subsequent autologous cranioplasty 2 mo later. At 10-mo follow-up his neurological status had improved. His magnetic resonance imaging (MRI) at that time demonstrated encephalomalacia at the site of his prior contusion and punctate right pontine traumatic shearing injury. The patient re-presented to clinic 13 mo after initial injury with 2 mo of progressively worsening dysarthria, left hand numbness, diplopia, and dysphagia. MRI revealed a new tubular-shaped CSF cleft extending from the fourth ventricle, through the right midbrain and thalamus that was not present on prior MRI. Computed tomography cisternogram confirmed communication with the ventricular system, and there was no clinical evidence for elevated CSF pressure. One month later, the patient's symptoms had not improved, and imaging revealed progression of the CSF cleft. Following placement of a ventriculoperitoneal shunt, progression of the cleft ceased. We postulate that this cleft was a late sequela of traumatic shearing injury. We discuss our efforts to diagnose the etiology of the cleft and the rationale for our management strategy. CONCLUSION To our knowledge, this represents the first reported delayed-onset CSF cleft through the midbrain and thalamus after closed TBI.