osmotic demyelination syndrome ( ods ) including central pontine myelinolysis ( cpm ) and extrapontine myelinolysis ( epm ) following overly rapid correction of hyponatremia has been well recognized515 ) .
although ods occurring after transsphenoidal resection of pituitary adenoma has been reported occasionally111618 ) , to our knowledge , few preoperative epm cases with pituitary adenoma have been reported14 ) .
unfortunately , the outcomes of patients with ods are often disappointing with high rate of mortality and irreversible neurological deficits5 ) . here
, we report a case of preoperative epm with nonfunctional pituitary macroadenoma who made a great clinical recovery after supportive therapy and transsphenoidal adenoma resection .
a 38-year - old man was admitted to our hospital in december 2012 because of nausea , malaise , altered mental status , behavioral disturbances , dysarthria and dysphagia .
the patient had been well until 2 months before admission , when nausea and malaise developed .
his wife also reported that the patient had two episodes of transient loss of consciousness .
he was sent to the emergency department of an outside hospital . at presentation , the patient had no sign of dehydration like poor skin turgor , orthostasis or decreased urine output , nor sign of volume overload including peripheral edema , ascites or elevated jugular vein pressure .
serum sodium of 102 mmol / l , potassium of 3.9 mmol / l and phosphate of 1.08
mmol / l were reported . the complete blood count and the remainder of metabolic panel including
intravenous hypertonic saline was given with an average correction rate of 8 mmol/24 h. despite slow rate of correction , neurologic symptoms including restlessness and irritability developed . in the following days , the patient developed apathy , confusion and obtundation , followed by dysarthria , dysphagia , paraparesis , behavioral disturbances and disorientation .
endocrine studies revealed a serum cortisol concentration ( 8 : 00 a.m. ) of 62.4 nmol / l ( normal , 138635 nmol / l ) , plasma adrenocorticotrophin ( acth ) of 1.03 pmol / l ( normal , 2.217.6 pmol / l ) .
miu / l ) ; serum free thyroxine ( ft4 ) was 6.91 pmol / l ( normal , 11.522.7 pmol / l ) , and serum total thyroxine ( t4 ) was 43.0 nmol / l ( normal , 65155
cranial magnetic resonance imaging ( mri ) was performed and a pituitary macroadenoma ( fig .
one week before admission , mri was repeated and epm was detected at bilateral basal ganglion and thalamus ( fig .
the patient was referred to our hospital because of persistent neurologic deficits . on physical exam , he was unresponsive to verbal or pain stimuli .
hormone studies showed normal atch , cortisol , tsh , t4 , and ft4 , decreased growth hormone and insulin - like growth factor 1 , normal prolactin , decreased gonadotrophin ( follicle - stimulating hormone and luteinizing hormone ) , estrogen and testosterone .
the patient had several episodes of restlessness and agitation with shouting and fighting lasting 10 minutes every day .
the decision of surgery was made then based on the improved general state of the patient and the intent to remove the underlying cause of hypopituitarism and hyponatremia .
pathologically , the mass was confirmed to be nonfunctional adenoma by hematoxylin and eosin ( h&e ) staining and immunohistochemical examination .
pseudorosette patterns were found on h&e staining and nuclear division was less than one per 10 high power field .
the tumor cells were scattered positive for p53 and ki-67 . and ki-67 index was < 1% .
the immunostainings for acth , fsh , lh , prl , tsh and gh were negative .
recent hormone studies showed normal level of acth , cortisol , tsh , ft4 and t4 .
the patient was able to resume his work as a bank accountant three months after the surgery .
the latest follow - up mri was obtained 7 months postoperatively , and these images showed demyelination at bilateral basal ganglions and thalamus resolved and pituitary adenoma resected ( fig .
among various etiologies of hyponatremia , endocrine disorders , including adrenal insufficiency and hypothyroidism , are uncommon causes which may be overlooked1712 ) .
while hyponatremia can be caused by hypopituitarism , severe hyponatremia occurring as the presenting manifestation of pituitary adenoma is rare8 ) . at the onset of hyponatremia ,
given the endocrine abnormality and histology - confirmed pituitary adenoma , we propose that secondary adrenal insufficiency and hypothyroidism resulting from hypopituitarism was the underlying cause of his hyponatremia .
however , demyelination can occur even with this correction rate ( as in our case ) , especially in those with other ods risk factors5 ) .
except for the rate of correction , serum sodium concentration at presentation and the duration of the hyponatremia are also important risk factors . on presentation ,
our patient had been symptomatic for 2 months and the serum sodium level was as low as 102
therefore , patients with more than one risk factors for ods may still be at risk for development ods at " normal " rates of correction and may require slower rates . if ods does develop despite the steps taken to avoid overly rapid correction , effective management is rare .
although reintroduction of hyponatremia , plasmapheresis and corticosteroids has been used , most evidence comes from animal models and data in humans are limited to case reports2513 ) .
a more recent review of 32 german patients with ods showed a much better outcome with only 30% having irreversible and incapacitating neurological deficits9 ) .
this review suggests that patients with ods can survive if the nonspecific secondary complications of transient illnesses such as aspiration pneumonia , deep venous thrombosis , and pulmonary embolism can be avoided .
some patients with ods can recover function after prolonged periods of severe neurologic impairment59 ) .
as in our case , the patient had developed progressive neurologic symptoms for two months on admission to our hospital .
the patient was able to resume the job as a banking account after surgery , indicating complete recovery from neurologic and cognitive deficits .
therefore , supportive therapy should be continued for at least six to eight weeks before concluding that the deficits are irreversible .
surgery is the ultimate effective treatment for nonfunctioning adenoma , which not only removes the underlying cause of hypopituitarism , but also reverses or prevents vision impairment . according to a systemic review and meta - analysis evaluating the outcome of surgical treatment for nonfunctioning pituitary adenomas , pituitary hypofunction
improved in as many as 30 percent after surgery10 ) . while for patients with epm , appropriate surgical timing of adenoma resection is of great importance .
neurologic deficits of preoperative epm such as decreased level of consciousness , paraparesis , dysarthria and dysphagia , posed great challenge to the transsphenoidal operation of pituitary adenoma .
risk of complications such as aspiration , respiratory failure , and deep vein thrombosis is much higher than patients without neurologic deficits49 ) . to minimize the risk of surgery and to remove the underlying cause of hyponatremia
, we selectively arrange the operation after dysphagia and dysarthria resolved , and the patient became ambulant and able to obey simple commands .
we report a case of preoperative epm with nonfunctional pituitary macroadenoma who made a great clinical recovery after supportive therapy and transsphenoidal adenoma resection .
more cases are required to clarify the prognosis of ods and identify the factors associated with better outcome .
 few preoperative extrapontine myelinolysis ( epm ) cases with pituitary adenoma have been reported . 
 no such case had long follow - up to see the outcome of epm . 
 we reported a 38-year - old man complaining of nausea , malaise and transient loss of consciousness who was found to have severe hyponatremia . 
 neurologic deficits including altered mental status , behavioral disturbances , dysarthria and dysphagia developed despite slow correction of hyponatremia . 
 endocrine and imaging studies revealed hypopituitarism , nonfunctional pituitary macroadenoma and extrapontine myelinolysis . 
 transsphenoidal surgery was performed after three weeks of supportive therapy , when neurological symptoms improved significantly . 
 the patient recovered function completely 3 months after surgery . 
 our case indicates that outcome of epm can be good even with prolonged periods of severe neurologic impairment . 