Neurology India Medknow Publications on behalf of the Neurological Society of India ISSN: 0028-3886 EISSN: 1998-4022 Vol. 58, Num. 4, 2010, pp. 654-658

Neurology India, Vol. 58, No. 4, July-August, 2010, pp. 654-658

Case Report

Acute spontaneous subdural hematoma of arterial origin: A report of four cases and review of literature

Chhiber SarbjitSingh, Singh JP

Department of Neurosurgery, SKIMS, Soura, Srinagar, J&K - 190 017

Correspondence Address:Department of Neurosurgery, SKIMS, Soura, Srinager, J&K - 190 017, sarabjitchhiber@gmail.com

Date of Acceptance: 10-Jun-2010

Code Number: ni10173

PMID: 20739817

DOI: 10.4103/0028-3886.68698

Abstract

Keywords: Acute spontaneous subdural hematoma, arterial origin, cortical artery rupture, perisylvian region

Introduction

Acute subdural haematoma is a neurological emergency and is often associated with disruption of superficial cerebral or cortical veins secondary to head trauma. Spontaneous subdural hematomas, however, are uncommon and is limited to case reports and small series. ^{[1],[2],[3],[4],[5],[6],[7],[8],[9],[10],[11],[12],[13],[14]} The etiological spectrum includes: arteriovenous malformation (AVM), ^[15] cocaine abuse, ^[16] dural metastasis, ^[17] coagulopathy, ^[11],[18] falx meningioma, ^[19] moyamoya disease, ^[11] and aneurysm rupture. ^{[5],[20],[21],[22]} Munro ^[23] was the first to describe a patient with subdural hematoma without history of head trauma. Acute spontaneous subdural hematoma (ASSDH) is a separate clinical entity with no apparent cause where the source of bleeding is almost invariably a branch of the middle cerebral artery (MCA) in the vicinity of the sylvian fissure. ^[11] The clinical characteristics of this entity were first described in 1971 by Tallalla and Mckissock and they referred to this clinical entity as a syndrome of "acute spontaneous subdural haematoma". ^[12] Tokoro et al. ^[1] termed it acute spontaneous subdural hematoma (ASSDH) of arterial origin and proposed the following diagnostic criteria: (a) no history of head trauma, (b) no damage to the underlying cortex, (c) no aneurysm or AVM around the affected artery, and (d) identification of hemorrhage as arterial at operation. Invariably, the site of the bleed has been identified near the sylvian fissure, affecting one of the cortical branches of the MCA. ^{[1],[3],[4],[8],[9]} We report four patients with ASSDH) who fulfilled the criteria proposed Tokoro et al.[1]

Case Report

Of the four patients seen during the period 2002-2006, two were male and two female and the age range was 24-59 years (mean: 44.25). The clinical features are summarized in [Table - 1]. Three patients developed sudden onset headache associated with vomiting and two of them lapsed into coma. The fourth patient was irritable at the time of admission and became unconscious following generalized seizures. None of the patients had history of any bleeding disorder or recent head trauma. In all the patients the provisional diagnosis was stroke. Three of the patients had a history of hypertension (pregnancy-induced hypertension in one of the female). Both the males had history of diabetes mellitus. None of the patients had history of alcohol abuse. Computed tomography (CT) scan of head showed ASDH centered aroung the sylvian fissure with significant midline shift [Figure - 1]a-d in all the four patients. In view of emergent situation, angiography was not done.

Operation was performed within 12 hours of onset of symptoms in one patient who presented directly to our hospital. Surgery was delayed beyond 24 hours in other three patients who were initially seen at other facility. All patients underwent large fronto-temporo-parietal craniotomy around the sylvian fissure and the source of bleeding was identified as a small cortical artery located near the sylvian fissure. Of the four patients, one patient who presented with bilaterally fixed dilated pupils and poor Glasgow Coma Scale (GCS) score (E1V1M2) died, whereas the others made remarkable recovery,and are back to their normal routines.

Discussion

Spontaneous ASDH of arterial origin is relatively unrecognized entity. Diagnosis is based on the the criteria proposed by Tokoro et al. ^[1] Only 38 such cases have been reported in English literature up to September 2009 [Table - 2]a and b. ASDH is usually associated in the majority of cases with disruption of superficial cerebral or cortical vessels secondary to head trauma, and sometimes it is a result of extension from an intracerebral hemorrhage from ruptured intracranial aneurysms, AVMs, hypertensive intracerebral hematoma, neoplasms, coagulopathy, cerebral amyloid angiopathy, and AIDS. ^[11] ASSDH of arterial origin usually results from a ruptured cortical artery that is situated within 3 cm of the sylvian fissure. ^[4] All our patients had a perisylvian bleeding cortical artery, though in one patient the clot was seen at the site of rupture.

Several possible mechanisms have been proposed for ASSDH formation. Vance, ^[24] in his autopsy series found small twigs connecting to the dura mater that branched perpendicularly from the cortical arteries. These twigs were torn by the shearing forces causing ASSDH. Drake et al[25] found adhesions between the dura mater and cortical arteries, which led to laceration of the adherent arterial wall following trivial trauma. The points of rupture were always located at branch points of MCA. According to Talalla, ^[12] prior head injury forms subdural clots, which results in adhesions. The involved artery is lacerated due to frictional forces and bleeding occurs. McDermott ^[13] described the presence of a rete mirabile connecting a cortical artery and the dura mater and found that disruption of this connection by trauma caused ASDH. Though we could see a lacerated cortical artery in all the four patients, we could not demonstrate any of the mechanisms described above.

The source of bleeding was confirmed by angiography and/or at operation and in all the cases reported, invariably, a ruptured cortical artery at or near the sylvian fissure was found. Yasui et al. ^[9] demonstrated extravasation of contrast from a cortical branch of the MCA on angiography in three of their four patients, the fourth patient showed extravasation from one of the branches of posterior cerebral artery (PCA) and the contralateral anterior cerebral artery (ACA). This is the only reported case with a bleeding source other than a perisylvian artery. Matsuyama et al. ^[4] studied points of rupture of cortical arteries at surgery in 19 patients, out of which only four met the criteria laid down by Tokoro et al. ^[1] The authors found that all ruptured arteries were in the distribution of MCA and the bleeding points were within 3 cm of sylvian fissure. In all our patients, the source of bleeding was a perisylvian artery on the temporal side. The reason for this predilection is not known.

ASSDH is more commonly reported in the elderly males, ^{[1],[2],[3],[14]} however it has been reported in a teenager. ^[26] The mean age of our patients was 44 years. About 40% of patients with ASSDH have associated hypertension and alcohol abuse. The arteriosclerotic vessels in hypertensive patients may interface and bind to dura mater thus may predispose to rupture. ^[4] Patients with ASSDH have a progressive deterioration over hours or days. ^[12],[25] One of the explanation for this couse has been attributed to the persistent tiny opening of the ruptured cortical artery resulting in gradual expansion of the clot and subsequent sealing of the opening by the clot. ^[25] Tokoro et al. ^[1] attributed this to the phenomenon of re-rupture, where the initial minor hemorrhage is followed by a major arterial rupture. Probably this phenomenon of re-rupture may explain the course observed in our four patients. CT scan confirms the diagnosis and it is prudent to perform angiography only if the patient′s condition permits the slight delay of angiogram ^[5] and also when the aneurysmal bleed is suspected. Preoperative CT angiography can be an option, but without delaying surgery. ^[20] Postoperative angiogram is complementary in the absence of identification of a cortical arterial bleed or other source of bleeding.

The reported mortality in ASSDH varies between 50% and 90%, ^[11] and in our series there was one death (25%). The possible factors for higher mortality are delay in diagnosis, arterial origin of the bleed. Significant factors associated with good outcome include early surgical evacuation, higher preoperative GCS scores, normal pupil reactivity, and young age. ^[5] A high index of suspicion is necessary as this rare entity can be a great mimic of stroke. Since the arterial bleed needs to be controlled, a wide craniotomy over the sylvian fissure has been the recommendation. ^{[1],[2],[3],[4],[5],[8],[9],[11],[20]} There are reports of spontaneous resolution of symptoms without emergency craniotomy. ^[11],[26] Microsuturing of the lacerated arterial wall instead of sacrificing the artery was suggested by Matsuyma et al., ^[4] whereas Pritz, in his comments on article by Koc et al. ^[3] suggested that biopsy of the artery may reveal the cause for the bleed. Strict adherence to the diagnostic criteria of ASSDH ^[1] is very much essential and coagulopathy-associated ASSDH should also be excluded as it is associated with high mortality. ^[11] In patients with ASSDH managed conservatively, angiographic evidence of cortical vessel extravasation can be considered as evidence of bleed from cortical vessel.

References

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