Radionuclide cisternography: A prudent investigation in diagnosing spontaneous intracranial hypotension
A 31-year-old male presented to us with the chief complaints of headache and diplopia. The symptoms presented 15 days back when he suddenly developed occipital headache with neck stiffness followed by multiple episodes of vomiting occurring in the next 24 h. The pain was relieved within 15 min of lying down and recurred after 15 min of upright posture. This was followed by complaints of tinnitus and hyperacusis. A day later he also developed diplopia on looking to the left side. There was no history of fever, limb weakness, associated ear or nasal discharge, any trauma or prior lumbar puncture.\nA lumbar puncture revealed low CSF opening pressure and on analysis, normal sugar, high protein content of 200 mg/dl with 10 cells (all lymphocytes) was seen. No organisms were seen on microscopy and culture was negative. A Magnetic resonance imaging (MRI) brain with gadolinium contrast was performed, which showed diffuse pachymeningeal enhancement []. SIH was suspected and the patient was referred to the Department of Nuclear Medicine for radionuclide cisternography (RNC).\nAfter explaining the procedure, a written consent was obtained from the patient and 10 mCi of 99m Technetium Diethylenetriaminepenta acetic acid was injected via a lumbar puncture into the sub-arachnoid space. Serial images were obtained (Philips Precedence 16 single-photon computed emission tomography — computed tomography [SPECT-CT]) in anterior, posterior, and lateral views with the patient in supine position at 1 h, 2 h, 4 h and 24 h. Gradual ascent of tracer was seen along the spinal axis. There was early visualization of the kidneys and bladder on the 1 h delayed image []. Subtle extra-dural tracer accumulation of radiotracer was noted in the region of upper thoracic spine on the right side in the 2 h anterior and posterior delayed images []. Inadequate ascent of tracer over the higher cerebral convexities was noted in the 24 h delayed image [].\nPatient started recovering with bed-rest and good hydration, and was discharged after full recovery with conservative management.