Probable imaging diagnosis
Case 293
【Progress】
She returned to local clinic with a written reply making an imaging diagnosis of intracranial hypotension.
【Discussion】
Cerebrospinal fluid (CSF) hypovolemia is a disease typically with orthopedic headache which sometimes combines with neck pain, nausea, vomiting, dizziness, tinnitus, hard to hear and diplopia. CSF hypovolemia occurs a middle-aged (approximately 40ies) woman most (1, 2). Because brain exists in the situation like floating in CSF, the symptoms are induced by central nerve system descent inferiorly. The incidence is reported rare, 1/20000 (1). However, as this disease is becoming to be well-known, the real incidence of CSF hypovolemia is thought to rise. CSF hypovolemia emerges in various conditions and then, coverages intracranial hypotension, CSF leakage and spontaneous CSF hypovolemia (2, 3).
Intracranial hypotension is characteristic of severe orthopedic headache, CSF pressure less than 6 cm H2O or less (2). Brain non-enhanced MRI shows descent of cerebellum tonsil and swollen pituitary gland (4-6). Gd-enhanced MRI shows meningeal vasodilatation, indicating thick or marked dura or meninge enhancement. Swollen spinal gland indicates dilatation of pituitary portal circulation (4-7).
CSF leakage can occur by sport injury, traffic accident and lumbar anesthesia. Brain non-enhanced MRI or Gd-enhanced MRI might not show typical findings of meningeal vasodilation. Instead, RI cisternography or MRI myelography is useful to detect the site of CSF leakage (2, 4-7).
Spontaneous CSF hypovolemia indicates no typical image characteristics with persistent orthopedic headache. It is thought to occur with disorder of CSF production or CSF absorption.
As treatment, in case of cranial hypotension or spontaneous hypovolemia, rest lying bed as possible and water ingestion of 1 to 2 litter /day more than usual is recommended (1, 2). In CSF leakage, intradural blood patch with autologous whole blood injection is reported to be effective to occlude the site of leakage (1-3).
In our case, a forty-year-old female perceived unusual headache for approximately one month with no episodes of trauma and iatrogenic intervention, indicative of typical age and typical symptom on intracranial hypotension, non-enhanced MRI showed inferior descent of cerebellar tonsil, swollen pituitary gland and venous distension sign. Gd-enhanced MRI showed a characteristic of marked dura enhancement, indicative of meningeal vasodilatation. She was scheduled to be rest at lying bed for while with much water ingestion.
【Summary】
We presented a forty-year-old female who experienced unusual headache for a month and presented to our hospital for being a diagnosis of probable intracranial hypotension by a local clinic. Brain MRI depicted inferior descent of cerebellar tonsil, swollen pituitary gland, venous dilatation sign and marked enhancement of dura indicative of intracranial hypotension.
It is borne in mind that CSF hypovolemia coverages intracranial hypotension, CSF leakage and spontaneous CSH hypovolemia. Intracranial hypotension occurs in middle-aged woman most whose typical MRI findings are inferior descent of cerebellum tonsil, swollen inferior hypophysis and venous distension sign and marked dura enhancement, indicative of meningeal vasodilatation.
【References】
1.Chung SJ, et al. Syndrome of cerebral spinal fluid hypovolemia: clinical and imaging features and outcome. Neurology 2000;55:1321-1327
2.Miyazawa K, et al. CSF hypovolemia Vs intracranial hypotension in ′spontaneous intracranial hypotension syndrome. Neurology. 2003;60:941–947.
3.Kong DS, et al. Clinical features and long- term results of spontaneous intracranial hypotension. Neurosurgery. 2005;57:91–6.
4.Spelle L, et al. Neuroimaging features of spontaneous intracranial hypotension. Neuroradiology. 2001;43:622–7.
5.Farb RI, et al. The venous distesion sign: a diagnostic sign of intracranial hypotension at MR imaging of the brain. AJNR Am J Neuroradiol. 2007;28:1489–93.
6.Pannulo SC, et al . MRI changes in intracranial hypotension. Neurology. 1993;43:919–26.
7.Mokri B, et al. Syndrome of orthostatic headaches and diffuse pachymeningeal gadolinium enhancement. Mayo Clin Proc. 1997;72:400–13.
2023.3.10