Sub-Arachnoid Hemorrhage

A sub-arachnoid hemorrhage is a type of Stroke in which there is bleeding into the space just outside of the brain itself, i.e., into the sub-arachnoid space.  In all, 80-85% of sub-arachnoid hemorrhages are caused by bleeding from aneurysms, abnormal outswelling in the arteries of the brain.  Between 25% and 50% of patients die from the bleeds and up to two-thirds of the survivors suffer some disability. 

The typical symptoms of a sub-arachnoid hemorrhage are the sudden onset of a headache which is typically described as the worst headache in a person's life.  There is usually a stiff neck as well.  Many patients will also have impaired consciousness or even coma.

If an aneurysm is found on CT scan, an angiogram is done to find any aneurysm.  If an aneurysm is found, it is repaired if possible with a coil which is fed up through the femoral artery in the leg.  If coiling is not possible, the skull is opened surgically and the aneurysm is clipped.  Up to 40% will rebleed.

Sub-Arachnoid Hemorrhage Vasospasm Damage Reduced by Magnesium: Magnesium reverses cerebral vasospasm and reduces infarct volume after experimental subarachnoid hemorrhage (SAH) in rats. In a DB PC study, 283 patients with SAH were started on magnesium sulfate 64 mmol/L/day IV within four days of the bleed until 14 days after the occlusion of the aneurysm.  Magnesium reduced the risk of delayed cerebral ischemia by 34%. After 3 months, the risk reduction for poor outcome was 23%. Magnesium Sulfate in Aneurysmal Subarachnoid Hemorrhage. A Randomized Controlled Trial. van den Bergh WM. Stroke. 2005 Mar 24. Ed: Current treatment uses only nimodipine to reduce the risk of vasospasm. Research suggests that it actually has no effect on vasospasm, but reduces the damage should vasospasm occur. Vasospasm is a common source of additional brain damage after the initial bleed.

Simvastatin Helped Reduce Cerebral Vasospasm: Cerebral vasospasm remains a major source of morbidity after aneurysmal subarachnoid hemorrhage (SAH). In a DB PC study of 39 adults with documented aneurysmal SAH, those randomized within 48 hours of symptom onset to receive either simvastatin (80 mg daily) for 14 days had highest mean middle cerebral artery transcranial Doppler velocities were significantly lower (103 versus 149; P<0.01). In addition, vasospasm was significantly reduced (P<0.05) in the simvastatin-treated group (5 of 19) compared with those who received placebo (12 of 20). Simvastatin Reduces Vasospasm After Aneurysmal Subarachnoid Hemorrhage. Results of a Pilot Randomized Clinical Trial. Lynch JR, et al. Duke University. Stroke. 2005 Jul 28

Pravastin Reduced SAH Mortality Dramatically: In a 14 day DB PC study of 80 aneurysmal SAH patients, those given pravastatin (40 mg) within 72 hours of onset for up to 14 days had the incidences of vasospasm and severe vasospasm reduced by 32% (P=0.006) and 42% (P=0.044) and the duration of severe vasospasm was shortened by 0.8 days (P=0.068). These measurements were maximal on the ipsilateral side of ruptured aneurysms. The duration of impaired autoregulation was shortened bilaterally (P< or =0.01), and the incidence of vasospasm-related DIDs and mortality were decreased by 83% (P<0.001) and 75% (P=0.037). This is the first demonstration of clinical benefits with immediate statin therapy for an acute cerebrovascular disorder. Effects of acute treatment with pravastatin on cerebral vasospasm, autoregulation, and delayed ischemic deficits after aneurysmal subarachnoid hemorrhage: a phase II randomized placebo-controlled trial. Tseng MY, et al. University of Cambridge, United Kingdom. Stroke. 2005 Aug;36(8):1627-32

Animal Research: Melatonin Reduces Vasospasm following experimental Subarachnoid Hemorrhage: Rabbits given 5 mg/kg of melatonin either after the time of a SAH or two hours after an SAH had 33% and 26% constriction vs. 57% constriction of basilr arteries in untreated group. There was also less apoptosis of endothelial cells with melatonin. Aydin MV, et al. Baskent University, Turkey. Neurol Res. 2005 Jan;27(1):77-82. Ed: This combined with 18 animal stroke studies is powerful evidence of benefit.

Peri-Mesencephalic Hemorrhage

One unusually mild type of sub-arachnoid hemorrhage (SAH) is called a peri-mesencephalic hemorrhage.  These make up about 10% of all sub-arachnoid hemorrages.  To receive this diagnosis, blood can only be found in the peri-mesencephalic and pontine cisterns located below the midbrain.  In these cases, no aneurysm is found, no surgery is necessary, up to 100% of patients recover and are able to return to work.  Rebleeds are very rare.  There is some evidence that the blood may have come from a somewhat more primitive venous drainage pattern.  Typically, these patients do not have high blood pressure and are not likely to be smokers, and do not have abnormal blood hematocrits, all risk factors for aneurymal SAH.

Unfortunately, I have not been able to find any study which reports risk factors for peri-mesencephalic hemorrhages (p-SAH).  My interest in the issue comes from the fact that I was studying on MedLine on April 3rd, 2005 at 3:12 p.m., when I suddenly hit by the worst headache in my life coupled with a stiff neck.  It ended up being a peri-mesencephalic hemorrhage. 

The only treatment I received in the hospital was nimodipine 60 mg every 4 hours for the first week to prevent any damage from arterial spasms should any occur.  None occurred.  I also took melatonin 15-18 mg/day the first week as a precaution, although I did this on my own in view of the very favorable animal research on melatonin preventing brain damage in strokes. 

In any case, the headaches totally disappeared by the 6th day.  I was out of the hospital on the 8th day and out walking on the 9th day.  By the 13th day, my daily walking had increased up to 3 hours with the speed faster than the normal walking pace (normal 120 steps/min vs. 132-144 steps/min for the last two hours).

Perimesencephalic (p-SAH) Often Caused by Abnormal Venous Drainage Pattern: In perimesencephalic nonaneurysmal hemorrhage (PMH), subarachnoid blood accumulates around the midbrain. CT Angiograms of 55 PMH patients and 42 aneurymal SAH patients with a posterior circulation aneurysm were reviewed. Venous drainage was classified into: (1) normal continuous: the basal vein of Rosenthal is continuous with the deep middle cerebral vein and drains mainly to the vein of Galen (VG); (2) normal discontinuous: drainage anterior to uncal veins and posterior to VG; and (3) primitive variant: drainage to other veins than VG. Additionally, we compared in PMH patients the side of the primitive variant and side of the bleeding. A primitive variant was present on one or both hemispheres in 53% of PMH patients with PMH vs. 19% of aSAH patients. In all 16 PMH patients with a unilateral primitive drainage, blood was seen on the side of the primitive drainage; blood was never found mainly on the side with normal drainage. Venous drainage in perimesencephalic hemorrhage. van der Schaaf IC, Velthuis BK, et al, University Medical Centre Utrecht, The Netherlands. Stroke. 2004 Jul;35(7):1614-8.

Repeat of Negative Studies No Value for p-SAH: Repeated catheter angiography remains the most sensitive test to determine the cause of SAH that is not demonstrated on initial angiography, particularly in the subtype of nonperimesencephalic SAH. Newer, noninvasive imaging techniques provide little diagnostic yield. Of 36 patients with p-SAH, 31 repeated angiograms, 23 CT angiography, and 17 MR-Angiograms all found nothing. For other bleeding with negative angiography, 4 of 36 repeat angiograms found aneurysms with other tests found nothing. Subarachnoid hemorrhage without evident cause on initial angiography studies: diagnostic yield of subsequent angiography and other neuroimaging tests. Topcuoglu MA, Ogilvy CS, et al. MGH-Harvard. J Neurosurg. 2003 Jun;98(6):1235-40.

Repeat Angiogram Found Nothing for Peri-Mesencephalic: In a report of 23 patients with negative initial angiograms, 11 found small aneurysm on retesting.  However, for 24 patients with negative initial angiograms but a peri-mesencephalic blood only, none of the repeated angiogram found anything. Medicina (Kaunas). 2002;38(10):976-81.

All Peri-Mesencephalic Returned to Work: All 24 with blood limited to peri-mesencephalic region did well, but 10 with additional blood in ventricles, only eight did excellently and one poorly. J Comput Assist Tomogr. 2001 Sep-Oct;25(5):742-6.

Additional Studies: One of 21 had a rebleed, but 53% retired after the initial bleed. 62% had residual symptoms such as headache or depression. J Neurol Neurosurg Psychiatry. 2000 Jul;69(1):127-30.  CT angiography is best for peri-mesencephalic and angiogram adds very little. Stroke. 2000 Dec;31(12):2976-83. Angiograms can be avoided in cases where CT shows a peri-mesencephalic pattern (95% accurate) and CT antiography is negative for aneurysms. Stroke. 1999 May;30(5):1103-9. MRI's aren't of value in peri-mesencephalic bleeds. Mayo Clinic. Stroke. 1998 Dec;29(12):2514-6. All 14 peri-mesencephalic patients returned to work and only two had frequent headaches with a follow-up of up to 50 months. Fortschr Neurol Psychiatr. 1998 Sep;66(9):387-90. A 2 1/3 year follow-up of 25 PMSAH patients found that they were doing as well as age-matched controls with no reduction in work or quality of life. J Neurol Neurosurg Psychiatry. 1997 Sep;63(3):382-4. 14 PMSAH patients with follow-up up to 4 years found no rebleeds. Zentralbl Neurochir. 1996;57(2):108-12. 33 PMSAH patients all did well. No aneurysms were ever found on follow-up angiograms which authors conclude are not warranted. Neuroradiology. 1996 Jan;38(1):15-9. A 2 1/2 year follow-up of 36 PMSAH found no rebleeds, 11% retired during follow-up, and 22% had headaches. Repeat angiograms said not necessary. Acta Neurochir (Wien). 1995;132(1-3):14-9. Nine PMSAH all did well. Doubts need for repeat angiograms. Australas Radiol. 1993 May;37(2):156-60. Only one of 38 with PMSAH bleeds were found to have an aneurysm. Acta Neurochir (Wien). 1993;124(2-4):79-81. 23 PMSAH followed over 3.5 years. None had rebleeds and repeat angiograms not necessary. Acta Med Port. 1992 Oct;5(9):473-5.

Thomas E. Radecki, M.D., J.D.

modern-psychiatry.com