Sentinel Headache: Subarachnoid Hemorrhage

A 25 year old male college student presents to the ER with complaint of sudden severe headache with an episode of vomiting. On exam he looks uncomfortable but is neurologically normal, that is, he is awake, oriented fully, moving arms and legs without weakness or neglect. Pupils are 3 mm and reactive. A head CT is ordered:

Sudden, severe headache

Sudden, severe headache

The verbal report is “normal,” and he is discharged home.

One week later the same patient arrives at the ER by ambulance, non arousable, with decerebrate (extensor) posturing to deep pain stimulus, no verbalizations, and non reactive pupils measuring 5 mm. A CT scan is again ordered:

Devastating subarachnoid hemorrhage

Devastating subarachnoid hemorrhage

This devastating subarachnoid hemorrhage was preceded a week earlier by a tiny bleed in the region of the left posterior cerebral artery, a hemorrhage so small in fact that is was not identified on the radiologist’s formal reading. The patient experienced a sentinel headache that heralded the aneurysm rupture that took his life a week later. In the case of a suspected subarachnoid hemorrhage with a negative head CT, consider lumbar puncture to look for RBCs or xanthochromia in the CSF.  


Cranial fossae: Anterior, middle and posterior

How would you describe the location of this mass?Describe the location

a. Cerebellar

b. Infratentorial

c. Posterior fossa

d. Suboccipital

Answer: All of the above.

All these terms refer to the same space. The cerebellum resides in the posterior cranial fossa, in a location that is infratentorial or suboccipital.

Please note the “occipital” and “suboccipital” are NOT synonymous. (“Occipital” refers to the occipital lobe which is a part of the cerebrum and is supratentorial.)

The term “fossa” refers to a “scooped out” space, like the palm of your cupped hand. There are three fossa of the skull base: anterior, middle and posterior.

Cranial fossae

The anterior fossa (green) is where the frontal lobe is located.

The middle fossa (purple) is where the temporal lobe is located.

The posterior fossa (orange) is where the cerebellum is located.

The mass presented above is a tumor of the posterior fossa, that is, in an infratentorial location. It abuts the cerebellum. Surgical resection may be achieved through a suboccipital craniectomy.

Pituitary Adenoma

Pituitary Adenoma

Tumors at the pituitary are classified by SIZE and by SECRETIONS. They are treated with medication, surgery, or active surveillance.


A MICROadenoma is less than 1 cm and is often an incidental finding on an MRI of the brain done for other reasons, like workup of a headache. Unless it is secreting active hormone, a small adenoma is asymptomatic and will not cause visual disturbance or headache.

A MACROadenoma is larger than 1 cm and often presents with visual field cut due to compression of the optic chiasm. This produces tunnel vision, with a loss of peripheral vision called bitemporal hemianopsia.Pituitary macroadenoma. MRI T1 with contrast


Pituitary tumors are also classified by secretions.

A “non-functioning” adenoma does not secrete active hormone. It may actually suppress the production of normal hormones, with TSH, LH, and FSH being most vulnerable. Paradoxically it can result in *mild* elevation of PRL to about 20-100. It is often discovered by visual field loss caused by compression of the optic chiasm causing bitemporal hemianopsia.

Functioning” pituitary adenomas secrete active hormone. These tumors may secrete any hormone, but PRL, GH, and ACTH are by far the most common.

A PRL secreting tumor mimics the postpartum state in females, with amenorrhea and galactorrhea.  In males it’s even worse: impotence and poor libido! A prolactinoma can be quite large on initial presentation, and the serum PRL may measure in the several hundreds. Fortunately, these are nicely responsive to dopaminergic drugs like bromocriptine and cabergoline, shrinking the tumor dramatically within a few weeks.

A GH secreting tumor causes acromegaly in adults and giantism in children. Acromegaly in adults can occur insidiously, barely noticed by the patient and close family. On questioning the patient may admit enlarged hands and feet such that rings and shoes have been resized. Other stigmata include an enlarged brow, protruding jaw, or enlargement of the cartilaginous nose. One patient noticed that he could floss easier as his teeth separated due to elongation of the jaw! Surgery is needed to remove this tumor.

An ACTH secreting adenoma causes Cushing’s disease, named for Harvey Cushing, the father of neurosurgery. ACTH production in the pituitary stimulates production of cortisol in the adrenal gland. This produces clinical hallmarks of Cushing’s: moon face, buffalo hump, abdominal obesity with striae, wasting of arms and legs, and easy bruising. This, too, is a surgical condition.


Non-functioning MICROadenomas: No intervention needed, just periodic MRIs to check for growth, and periodic labs to check endocrine function.

Non-functioning MACROadenoma: Check endocrine labs, especially thyroid and sex hormones which can be diminished in the presence of a tumor. Check visual fields for bitemporal hemianopsia. Transphenoidal adenomectomy surgery can remarkably restore visual fields.

Prolactinoma: Pro-dopamine drugs like bromocriptine or cabergoline shrink the tumor dramatically and help with symptoms in males and females.

GH or ACTH secreting tumors usually need surgical resection to correct the harmful effects of these excess hormones.

Glioblastoma: Growth rate

Glioblastoma: How fast do they grow?

A 57 year old female presented with new onset seizure. An MRI was obtained showing a lesion in the right frontal/parietal region. You can see there is some mass effect, slight effacement of the ventricle, and a whiff of enhancement. Needle biopsy returned astrocytoma, WHO Grade 3.Astrocytoma WHO Grade 3

Surgical resection was recommended, but the patient chose instead to pursue external beam radiation and oral chemotherapy in the form of temozolomide.

Unfortunately, she now presents three months later with confusion, agitation, and left arm weakness. An MRI is again obtained. The tumor shows marked growth and different signal characteristics. You see that the mass is inhomogeneously enhancing, with marked mass effect, surrounding edema, ventricular effacement, and minimal midline shift.

Glioblastoma, WHO Grade 4

At this time the patient requests craniotomy for surgical debulking. The final pathologic diagnosis is Glioblastoma, WHO Grade 4.

This shows how rapidly a glioma can grow and transform to a higher grade, in this case just three months.