Recurrent perimesencephalic nonaneurysmal subarachnoid hemorrhage within a short period of time: A case report

BACKGROUND Spontaneous subarachnoid hemorrhage(SAH)is primarily caused by a ruptured intracranial aneurysm.Perimesencephalic nonaneurysmal SAH(PNSAH)accounts for approximately 5%of all spontaneous SAH.PNSAH displays favorable prognosis.The risk of hemorrhage recurrence is low.We report a case of PNSAH recurrence,occurring within a short time after the initial episode in a patient not receiving antithrombotic or antiplatelet drugs.CASE SUMMARY A 66-year-old male,without any history of recent trauma or antithrombotic/antiplatelet medication,suffered two similar episodes of sudden onset of severe headache,nausea,and vomiting.A plain head computed tomography(CT)scan showed subarachnoid blood confined to the anterior part of the brainstem.Platelet count and coagulation function were normal.PNSAH was diagnosed by repeated head CT,magnetic resonance imaging,and cerebral angiography,none of which revealed the source of SAH.The patient was discharged without focal neurological deficits.At 6-mo follow-up,the patient had experienced no sudden onset of severe headache and presented favorable clinical outcome.Studies have reported a few patients with recurrent PNSAH,originating frequently from venous hemorrhage and conventionally associated with venous abnormalities.PNSAH recurs within a short time following the initial onset of symptoms,although the possibility of re-hemorrhage is extremely rare.CONCLUSION PNSAH recurrence should arouse vigilance;however,the definite source of idiopathic SAH in this case report deserves further attention.

A minor perimesencephalic subarachnoid hemorrhage on CT changes

Despite the increasing number of reports of patients with perimesencephalic subarachnoid hemorrhage (PMSAH), a minor or atypical PMSAH on CT changes has not been reported. We present the first described case of a minor subarachnoid hemorrhage located in the right perimesencephalic cistern on CT 4 h after headache onset. Twenty-six hours after headache on-set, another CT of the head showed that blood dis-persion. On the third day in hospital, examination of cerebrospinal fluid revealed xanthochromia. Minor PMSAH is rare type of SAH, and can been missed if there is a delay in CT imaging of the head. Any pa-tient with a suspected minor PMSAH or equivocal results on CT should undergo routine lumbar punc-ture.

The prospective study of the relationship between perimesencephalic cistern of CT scanning and the outcome of the patients with acute craniocerebral injury

Objective: To explore prospectively the relationship between the state of perimesencephalic cistern and the degree of deformation of the midbrain on CT scanning and the outcome of the patients with acute craniocerebral injury.Methods: The CT scan features including the states of perimesencephalic cisterns, the deformations of the midbrain and the ratios of the occipitofrontal diameter and the transverse diameter of the midbrain of 132 cases were measured. The GOS of the patients 3 months after trauma were regarded as outcome.Results: The rate of unfavorable outcome ( dead, vegetative status, severe disability ) was significantly correlated with perimesencephalic cistern narrower than 1mm (P < 0.05), especially narrower than 0.5 mm (P < 0.005), deformed midbrain (P< 0.005) or abnormal ratio ( < 0.9 or >.1) of the occipitofrontal diameter and transverse diameter of the midbrain (P < 0.01). But the patient's perimesencephalic cistern wider than 1mm and the patients without deformed midbrain got favorable outcome (moderate disability/good recovery).Conclusions: The state of the compressedperimesencephalic cistern ( < 1 mm) and the deformation of the midbrain may significantly indicate unfavorable outcome of the patients with acute craniocerebral injury.