Spontaneous intracranial hypotension with pituitary adenoma

Abstract

Spontaneous intracranial hypotension (SIH) is an unusual syndrome that is characterised by positional headache, neck rigidity, nausea and vomiting. The characteristic magnetic resonance imaging (MRI) findings are diffuse smooth pachymeningeal thickening and enhancement, downward displacement of posterior fossa structures and pituitary gland enlargement. An unusual case of SIH with pituitary macro-adenoma and subsequent subdural haemorrhage is presented, and its clinical picture, MRI findings and possible pathophysiological mechanism are discussed. [PUBLICATION ABSTRACT]

J Headache Pain (2006) 7:4750

DOI 10.1007/s10194-006-0269-3BRIEF REPORTAhmet K. Firat

Hakki M. Karakas

Zeynep Y. Firat

Bayram Kahraman

Glnur ErdemSpontaneous intracranial hypotension with

pituitary adenomaReceived: 5 December 2005

Accepted in revised form: 12 January 2006

Published online: 20 February 2006A.K. Firat () H.M. KarakasB. Kahraman G. Erdem

Department of Radiology,

Inonu University Medical Faculty

Turgut Ozal Medical Center,

Malatya, Turkey

e-mail: [email protected]

Tel.: [phone]/5704

Fax : [phone] Z.Y. Firat Department of Otorhinolaryngeology,

Inonu University Medical Faculty

Turgut Ozal Medical Center,

Malatya, TurkeyAbstract Spontaneous intracranial

hypotension (SIH) is an unusual

syndrome that is characterised by

positional headache, neck rigidity,

nausea and vomiting. The characteristic magnetic resonance imaging

(MRI) findings are diffuse smooth

pachymeningeal thickening and

enhancement, downward displacement of posterior fossa structures

and pituitary gland enlargement. An

unusual case of SIH with pituitary

macro-adenoma and subsequent

subdural haemorrhage is presented,

and its clinical picture, MRI findings and possible pathophysiological mechanism are discussed.Keywords Spontaneous intracranial

hypotension Pituitary adenoma

Pachymeningeal thickening

Subdural haemorrhageIntroductionAcquired intracranial hypotension is more frequent than

spontaneous ones and they are usually due to a lumbar

puncture, spinal anaesthesia and neurosurgical operations. Spontaneous intracranial hypotension (SIH) was

first described by Schaltenbrand in 1938 [1]. SIH is a rare

phenomenon characterised by postural headache, neck

pain, nausea/vomiting and findings of cranial neuropathies. Although it was already a well known clinical

entity, the diagnostic value of imaging was better valued

after magnetic resonance imaging (MRI) became widely

available. The characteristic MRI findings are diffuse

intracranial pachymeningeal thickening and enhancement, downward displacement of posterior fossa structures and pituitary gland enlargement. However, SIH

associated with pituitary adenoma has not been previously reported. In this paper, a SIH case with pituitary adenoma and associated subsequent subdural haemorrhage is

presented.Case reportA 41-year-old woman was presented to our hospital

with a one-year history of severe headache,48a b cFig. 1 a Axial T1-weighted MRI. The dura matter over cerebral convexities is isointense to cerebral cortex (arrow). b Coronal FLAIR

image. The dura matter is relatively hyperintense (arrows). c Post-gadolinium axial T1-weighted image. Diffuse smooth dural thickening

with enhancement and bilateral frontal subdural collections (arrows)Fig. 2 Post-gadolinium coronal T1-weighted image: pituitary

macro-adenoma (arrow) and accompanying adenohypophyseal

deviationnausea/vomiting and acoustic impairment. Whereas her

headache had not responded to analgesics, it improved

in the supine position. On neurological examination,

neck rigidity, cranial nerve palsy and neurological

deficits were absent. Her body temperature was 37.6C

and no sign of infection was noted. History of trauma or

surgery that might initiate cerebrospinal fluid (CSF)

leakage was not present.On the cranial MRI performed in 1.5 T scanner, a diffuse smooth dural thickening of 3 mm was noted. Dural

membranes were isointense to brain parenchyma on T1-

weighted, and relatively hyperintense on T2 and fluidattenuated inversion recovery (FLAIR) images. Intense

dural enhancement and bilateral frontal subdural collections were also observed (Fig. 1). Cerebellar tonsils were

situated normally, whereas pons was flattened, basal cisterns were narrowed and iter was descended on sagital

images. Pituitary gland was asymmetrically larger and its

maximum height was measured to be 10 mm in the midsagittal plane. Prominent cavernous sinuses were also

observed.A spinal MRI was acquired to investigate the possible

site of CSF leakage. No evidence of Tarlovs cyst, dural

tear or arachnoid diverticula was noted. As the pituitary

gland was asymmetrically enlarged, a dynamic pituitary

gland MRI was performed. On the left side, a pituitary

macro-adenoma measuring 14x15x19 mm was observed.

The mass was deviating the normal adenohypophysis to

right side and indenting the left lateral side of the sellar

floor (Fig. 2). Pituitary laboratory tests including T3, T4,

TSH, FSH, LH, prolactin, progesterone and oestradiol

were within normal ranges.We recommended lumbar puncture and myelography

for CSF pressure measurement and analysis, and also to

demonstrate the site of CSF leakage. Some of the physicians opposed lumbar puncture as it might exacerbate

the symptoms. They recommended a conservative treatment protocol including bed rest and oral hydration.

Three months later, she presented with the same symptoms without significant change. On the MRI,

meningeal enhancement and thickening were not modified. At the six-month examination, her symptoms were

improved but had not totally disappeared. However on

MRI, the meningeal enhancement and thickening were

increased compared to previous images, and surprisingly a subsequent subacute subdural haemorrhage was

noted (Fig. 3). As the patient refused to undergo further

investigation and blood patch therapy, she was under

our control without significant complaint except

improving headache.49Fig. 3 Six-month follow-up. Pre- (a) and

post-gadolinium (b) axial T1-weighted

MRI revealed interval elevated thickening

of dura (arrow) compared to previous MRI

and subsequent subdural haemorrhage

(arrowheads)abDiscussionClinical features of SIH are usually pathognomonic.

Postural headache unresponsive to analgesics is the main

characteristic symptom. It is aggravated in the upright

position and decreased in the recumbent position. Valsalva

manoeuvre and head shaking may also aggravate the

headache [2]. Nausea/vomiting, tinnitus, vertigo, photophobia, visual field defects, neck traction and cranial

nerve palsies are among the other clinical features [2, 3].CSF pressure evaluation is a reliable method for the

diagnosis of SIH and the pressure is usually less than 56

cm H2O [4, 5]. CSF analysis can be normal or it may

reveal increased protein and white cell count [24, 6, 7].

It is not recommended anymore, as it may exacerbate the

headache [6]. The presented case had features of abovementioned clinical and imaging findings; however it was

especially remarkable for subsequent subdural haemorrhage. Although a conservative approach is advised in the

relevant literature, lumbar puncture for CSF pressure

measurement, radioisotope cisternography and CT myelography might be considered in long-acting or persistent

disease.The cardinal MRI finding of SIH is the continuous

smooth thickening and diffuse intense enhancement of

dura matter [3, 8]. Subdural collections, prominent cavernous sinus and increased pituitary gland height may also

be seen [7]. The flattening of the pons, ventricles and

basal cisterns, representing the downward displacement of

the brain and brainstem, can be observed. These findings

may be subtle when the patient is examined in the supine

position, and they may therefore easily be missed [8]. As

a late manifestation, descent of cerebellar tonsils may be

noted [2]. On spinal MRI, meningeal diverticula or dural

tears may be observed [2]. Diffuse dural enhancement of

the spinal canal was also described [3]. In the presented

case, with the exception of dural tear, meningeal divertucula and spinal dural enhancement, the classical neuroradiological findings were observed.Diffuse dural enhancement and prominent cavernous

sinus represent the venous congestion that occurs to compensate the intracranial volume loss in accordance with

the Monroe-Kellie doctrine [9].Transient pituitary gland enlargement is a rare but

interesting MRI finding in SIH. In such cases an upward

bowing of the diaphragma sella, and an increase in pituitary height in the mid-sagittal plane may be observed [3,10]. These findings are transient and they disappear on

subsequent follow-ups. They are also thought to be caused

by venous engorgement, however the mechanism is not

very clear [3]. The presence of pituitary adenoma, if not

coincidental, may change the above-mentioned hypothesis

explaining the pituitary enlargement. In that situation, one

might speculate that a disease with short duration with

proper treatment may have transient causes; whereas a

chronic course may end up with over-stimulation, causing

a nonfunctioning pituitary adenoma. This over-stimulation may be due to altered neural regulation and feedback

control of the hypothalamic-pituitary axis.Our patient also exhibited the above-mentioned MRI

findings: upward bowing of the diaphragma sella and

increase in pituitary height in the mid-sagittal plane. In

addition to those, she also had a pituitary macro-adenoma.

That association had not been reported before and it was

thought to be either coincidental or related. Still, this association reminded us of the utility of a dedicated pituitary

MRI in this disease, as an underlying pituitary pathology

may be masked by the pituitary changes. The appropriate

time for scheduling is probably the follow-up period, after

resolution of pituitary enlargement.We observed persistent meningeal thickening and

enhancement in the subsequent MRI examinations of the

presented case. According to us, this finding pointed out50the ineffectiveness of the treatment protocol and the need

for further evaluation and therapy. The appearance of subdural haemorrhage at the follow-up supported our proposal. In this situation, the risk of clinical exacerbation due to

lumbar puncture and blood patching should be accepted in

order to avoid mortality and morbidity due to subdural

haemorrhage. The meningeal thickening can be used as an

additional and independent prognostic factor in SIH.In conclusion, the availability of MRI has greatly

influenced the diagnosis of SIH. Although the diagnosis

is usually based on clinical and laboratory investigations, imaging is necessary for the differentiation of SIH

from other life-threatening intracranial pathologies and

also for grading of disease. However, the imaging features of SIH may be misleading because of their similarity to the features of other disease, such as hypertrophic

pachymeningitis, granuloumatous and malignant dural

involvement, and pituitary pathologies. Therefore, the

clinician should be aware of the necessity of further

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