Pseudo Chiari type I malformation secondary to cerebrospinal fluid leakage.

Cerebrospinal fluid (CSF) leakage may occur spontaneously, iatrogenically or from spinal trauma. Postural headache is the cardinal symptom; dizziness, diminished hearing, nausea and vomiting are additional symptoms. In neurological examinations cranial nerve palsies may be found. Due to low CSF pressure neuroimaging studies may reveal dural enhancement and vertical displacement of the brain. We describe a patient with the history of an uncomplicated lumbar discectomy at the level L4-5 and the typical clinical symptoms of intracranial hypotension. MRI of the craniocervical junction showed typical features of a Chiari type-I malformation. After neurosurgical ligation of a CSF leak at L4-5 caused by lumbar disc surgery, the patient was free of orthostatic headache. A repeated MRI showed a striking reduction of the previous downward displacement of the cerebellar tonsils and pons.