Pituitary adenoma stroke is a clinical syndrome of headache, visual dysfunction, ocular muscle paralysis and altered state of consciousness and pituitary hormone hypersecretion caused by sudden bleeding or infarction of a pituitary adenoma. The incidence of pituitary adenoma stroke varies, ranging from 1.4% to 16.6% of pituitary tumor patients, mainly due to the inconsistent criteria for classification and diagnosis. With the availability of advanced imaging such as CT and MRI, more and more subclinical pituitary adenoma strokes are being diagnosed without obvious clinical manifestations, so the statistical variation in the incidence of pituitary adenoma stroke is large. Pituitary adenoma stroke is one of the most common neurosurgical emergencies, and if treatment is delayed, the patient’s life may be at risk. The key to clinical management is early diagnosis. In this section, we will analyze the clinical features and effective examination of pituitary adenoma stroke with a case to improve the diagnosis and treatment of pituitary adenoma stroke.
Case recapitulation.
The patient, a male, was admitted to the hospital with one sudden loss of consciousness and limb convulsions. The patient had no previous history of seizures. Physical examination: clear consciousness, poor mental health, sparse beard, 2,5 mm pupils, equal size and roundness, 30 cm of visual acuity in the right eye and 20 cm of visual acuity in the left eye. Visual field examination showed bilateral temporal hemianopsia. Auxiliary examinations: MR showed intra- and supra-saddle soft tissue masses, pituitary stalk was poorly displayed, enhancement scan showed significant enhancement, size about 3, 8×2, 8×2, 8 cm3, with T1 low signal T2 high signal cystic lesions within, concluded as pituitary macroadenoma stroke. Endocrinology: FT3 3, 66 (normal range 2, 3-6, 3) pmol/l; FT4 9, 59 (normal range 10, -24, 5) pmol/l; cortisol 5, 77ug/dl; serum sodium 120 mol/l.
On admission, a diagnosis of pituitary macroadenoma stroke with hyponatremia was made. Considering that the patient’s headache was obvious but vision did not continue to decline and hyponatremia was severe, hydrocortisone was given intravenously and hypertonic saline was supplemented. 3 days later, the patient’s blood sodium rose to 134 mol/l and her spirit improved, so she underwent therapeutic endoscopic transsphenoidal pituitary tumor resection. Intraoperatively, there was a significant increase in intra-saddle tension and a large number of small blood clots interspersed in the tumor tissue with a tough texture. Postoperative pathological findings: pituitary macroadenoma stroke. Postoperative treatment with hydrocortisone and prednisone was continued in sequence. The patient’s visual field improved significantly after surgery, headache disappeared, blood sodium gradually returned to normal, and thyroxine and cortisol levels decreased slightly.
Disease characteristics.
Studies have shown that the tendency of intratumoral hemorrhage in pituitary adenomas is about 5 or 4 times higher than in other central nervous system tumors, but a uniform understanding of the exact cause of hemorrhage has not been reached.
The clinical manifestations of pituitary adenoma stroke may vary depending on the degree and extent of necrosis and hemorrhage of the pituitary tumor, but typical clinical symptoms include the following: ① compression symptoms due to tumor enlargement: increased pressure in the saddle, causing severe headache and vomiting; pressure on the optic nerve, optic cross and optic tract, resulting in rapid visual acuity loss and various types of visual field defects; pressure on the cavernous sinus, resulting in articulatory nerve palsy, talocrural nerve, trigeminal nerve and adductor nerve damage; symptoms of cerebral adenoma stroke. The compression of the middle cerebral artery and anterior cerebral artery may cause cerebral ischemic symptoms; the compression of hypothalamus may cause impaired consciousness, uremia or temperature change, and in severe cases, stress ulcers may also occur; ② meningeal irritation signs: tumor contents or blood entering the subarachnoid space may cause fever, cervical ankylosis and other meningeal irritation symptoms; ③ endocrine function changes, intra-tumor hemorrhage aggravates the damage to the residual pituitary tissue. (3) endocrine function changes, intra-tumor hemorrhage aggravates the destruction of residual pituitary tissue, further aggravating the patient’s original anterior hypopituitarism, which may cause pituitary crisis, impaired consciousness and even death in severe cases. The posterior pituitary lobe is also often involved, resulting in transient or permanent uremia. Not all patients with pituitary adenoma hemorrhage have typical clinical symptoms. If the lesion is small and the amount of bleeding is small, there may be no acute neurological and visual field changes as described above, but only clinical manifestations of endocrine function changes. Wang Renzhi et al [1] classified pituitary stroke into four types according to the impact of tumor stroke on surrounding structures and the degree of urgency and severity of the disease. (1) fulminant pituitary adenoma stroke (type I); (2) acute pituitary adenoma stroke (type II); (3) subacute pituitary adenoma stroke (type III); and (4) chronic pituitary adenoma stroke (type IV). Type III and IV pituitary adenoma strokes are called subclinical pituitary adenoma strokes because their clinical manifestations are atypical or absent.
In the acute phase of pituitary stroke, a high-density intra-tumoral hemorrhagic foci can be seen on CT scan, which is easy to identify, but in the subacute phase, they are isointense and difficult to identify. Therefore, MRI scan should be preferred in cases with high suspicion of pituitary stroke. In the acute phase, T1WI shows isosignal or slightly low signal and T2WI shows low signal; in the subacute phase, T1WI shows increasing high signal and T2WI shows low signal, isosignal or high signal; in the chronic phase, T1WI and T2 WI can both show high signal. In addition, MRI can provide a clearer three-dimensional anatomical structure than CT, and it can show the relationship between the tumor and the surrounding normal tissues. Therefore, most scholars believe that MRI is the imaging modality of choice for pituitary tumor stroke [3-5], while CT is preferred in the acute phase, especially in the hyperacute phase.
Treatment.
Treatment for pituitary tumor stroke is aimed at addressing the hypoadrenocorticotropic hormone secretion and the systemic symptoms caused by pituitary tumor stroke on the one hand, and relieving the symptoms of compression of adjacent anatomical structures caused by pituitary tumor stroke on the other hand, including visual acuity, visual field impairment and extraocular muscle paralysis, as well as the impairment of consciousness caused by severe compression. The timing and modality of treatment should be individualized based on the patient’s general condition, neurological symptoms, visual field changes, and endocrine hormone levels.
Pituitary adenoma stroke can cause acute hypopituitarism, so hormone replacement therapy is the basic treatment for pituitary stroke and needs to be applied at any stage of the disease. When a diagnosis of pituitary stroke is confirmed or highly suspected, supraphysiologic doses of adrenal glucocorticoids should be administered immediately. The efficacy of hydrocortisone is well recognized, and the recommended dose is 50 mg/6 h. It not only prevents hyperalgesia due to hemorrhagic necrosis in pituitary tumors and reduces acute edema of the optic nerve and suboptic thalamus, but also enhances the stress capacity of the body and reduces surgical mortality. In addition, strong supportive therapy such as maintaining water and electrolyte balance, close observation of visual field changes and changes in consciousness, and monitoring of hormone levels must be given at the same time.
Currently, most of the scholars advocate the use of transnasal pterygoid approach for the surgical treatment of pituitary adenoma stroke, which is an ideal method for the treatment of pituitary adenoma stroke because of its easy operation, low interference with brain tissue, good exposure of the tumor, easy removal of hematoma and necrotic tissue, satisfactory decompression of the optic nerve, few complications, little damage to residual pituitary tissue, and promotion of post-stroke pituitary function. Especially, with the recent improvement of neuroendoscopic and neuronavigation technology, it has overcome the disadvantage of small field of view and blind area in the nasopalatine approach, making the surgical positioning more accurate, expanding the surgical field of view, and improving the total resection rate of tumor. Only when the tumor is huge, extensively involves the suprasellar and parsellar areas, or invades the frontal and temporal areas, the inferior frontal or pterygoid approach can be adopted to maximize the resection of the tumor, but the incidence of surgical complications is higher.
There are still controversies about whether to adopt conservative or surgical treatment for pituitary tumor stroke, the indications for surgical treatment and the timing of surgery. Some scholars advocate surgery for decompression as soon as possible, and believe that patients who undergo decompression surgery within one week after the onset of stroke have a better recovery of visual impairment and pituitary dysfunction. Some scholars believe that even if the surgery is postponed, the neuro-optical impairment can be recovered. On the contrary, some scholars advocate conservative medical treatment, especially for patients with mild neuro-optical signs, and the same satisfactory prognosis has been obtained with conservative treatment. Summarizing the literature, most researchers believe that the main factors affecting the recovery of visual function after acute pituitary stroke are the duration of visual impairment, the severity of visual impairment and the alteration of the optic disc, and therefore early transsphenoidal decompression surgery has positive significance for the recovery of visual acuity and the preservation of pituitary endocrine function. Therefore, it is now generally accepted that for patients with progressive visual impairment or with a deepening degree of consciousness impairment, if there is no contraindication to surgery, surgery should be performed promptly after the diagnosis is clear, and it is recommended that the surgery be performed within one week. For patients with mild and stable symptoms, or those with more pronounced symptoms but with obvious signs of improvement in a short period of time, conservative treatment can be used, but the patient’s condition must be closely monitored, including changes in visual acuity, changes in water and electrolytes, and monitoring of endocrine function, and if there is deterioration, surgical decompression should be performed immediately. It is generally believed that pituitary tumors with necrosis after stroke have poor response to radiotherapy and are potentially dangerous after radiotherapy because of the increased possibility of bleeding due to rupture of the fragile blood vessels of the tumor, so most scholars advocate that direct radiotherapy after acute pituitary stroke is contraindicated. However, radiotherapy can be administered to residual or recurrent tumors after surgical decompression of acute pituitary stroke.
Important points.
1. The classification criteria for pituitary adenoma stroke are inconsistent, resulting in large statistical differences in its incidence.
The typical clinical symptoms include compression of the enlarged tumor and further aggravation of the existing anterior pituitary hypoplasia, which may lead to pituitary crisis, impaired consciousness and even death in severe cases.
3. MRI is the first choice of imaging for pituitary tumor stroke, but CT is more intuitive in the acute stage.
4. Hydrocortisone replacement therapy is the basic treatment for pituitary stroke and should be used at any stage of the disease.
5. The preferred surgical approach for pituitary adenoma stroke is intra-saddle decompression via a transsphenoidal approach.
6. The application of neuroendoscopic and neuronavigation techniques has improved the rate of total tumor resection in patients with pituitary adenoma stroke.
Blind spots.
1, Patients with manifestations such as headache and vision loss should be highly alert to the possibility of pituitary adenoma stroke if they have recently developed symptoms such as severe headache and rapid vision loss.
2. Patients with sudden onset of severe hypopituitarism, hyponatremia, or even seizures should be careful to exclude pituitary tumor stroke.
3. CT and/or MRI examinations suggest pituitary tumor, but density and/or signal inhomogeneity and the presence of fluid plane within the tumor are the more characteristic changes of pituitary macroadenoma cystic hemorrhage.
4. In patients without obvious intracranial pressure increase, preoperative lumbar puncture placement and intraoperative release of cerebrospinal fluid in patients with pituitary tumor stroke can avoid premature collapse of the saddle septum and facilitate total resection of the tumor.
Clinical proverbs.
Pituitary tumor stroke is one of the common neurosurgical emergencies. If treatment is delayed, the patient will have a life-threatening condition. For patients with progressive visual impairment or a deepening degree of consciousness, if there is no contraindication to surgery, surgery should be performed promptly after the diagnosis is clear. For patients with mild symptoms, conservative treatment can be adopted, but the patient’s condition must be closely monitored, and if it deteriorates, surgical decompression should be performed immediately.