TREATMENT OF ARACHNOID CYSTS COMPLICATED BY HEMORRHAGE DUE TO TRAUMATIC BRAIN INJURY Larkin V.I., Larkin I.I., Dolzhenko D.A., Novokshonov A.V.
Omsk State Medical University, Omsk, Russia
Regional Clinical Hospital, Barnaul, Russia,
Kuzbass Clinical Center of Miners’ Health Protection, Leninsk-Kuznetsky, Russia
Intracranial arachnoid cysts (AC) present the quite common event in children. Autopsy studies show that the incidence is 0.1 %, but radiological data shows higher incidence − 0.2-2.6 % [1]. According to the data from Burdenko Neurosurgery Institute, intracranial cysts present about 10 % of all cerebral mass lesions in children [2]. AC are most often located in the middle cranial fossa (34 % of all cysts in adults, and 46 % in children).
AC occur from 7-8th weeks of fetal life. The main location (in descending order) are lateral cerebral fissures, convex, interhemispheric and suprasellar regions, cerebral tentorium region, cerebellopontile region and retrocerebellar region [3].
There are some studies which show higher incidence of AC in Sylvian fissure in men as compared to women (3.9-4.7 : 1), with predominance of left-sided location (2 : 1). Cysts of other locations encounter with similar incidence in men and women. The literature shows some cases of acquired AC [4].
The clinical manifestations of AC depend on its location and degree of mass effect (ME) [5, 6]. Volumetric studies of AC with CT and MRI show that brain volume is almost similar in both semispheres, and additional volume is compensated by brain dislocation and deformation of the adjacent bone [5, 7]. The compensation threshold for extracerebral semispheric masses is ME at the level of 16-20 % with dislocation of mid-line structures up to 8.2 ± 4 mm, for intracerebral − at the level of 22-25 % with dislocation of 18.7 ± 15 mm. The achievement of higher ME of intracerebral masses can be explained by decreasing cerebral component of cranial system according to the theory by Monro-Kelli.
According to Cress M. (2013), the first clinical manifestations are associated with cyst rupture [1].
Brain trauma at the background of compensated course of AC of subthreshold volume causes decompensation and occurrence of intense neurological picture of severe brain injury. In some cases, for example in bleeding into cysts, the clinical picture reminds of the course of acute traumatic hematoma.
CLINICAL CASE 1
A child, age of 13, with complaints of headache and vomiting, was admitted to the neurosurgery unit No. 3. According to information from his parents, he fell from the bicycle (about one hour before admission), he hit his head and lost consciousness. The examination showed severe condition, somnolentia, GCS − 13, signs of mild right-sided hemiparesis with abnormal foot signs, mild anisocoria to the left. The hear circumference was 54 cm. Echocardiography showed dislocation from left to right by 5 mm. MRI showed multiple hematomas: left-sided convexital subdural hematoma (120 × 20 × 70 mm, 87.9 cm3) and subdural hematoma of temporal pole (50 × 30 × 35 mm, 27.4 cm3). The total volumes of hematomas is 115 cm3. The mass effect of hematomas corresponded to severe (8.5 %). According to urgent indications, the child was admitted to the surgery room. Left-sided osteoplastic trepanation was performed. After opening of dura mater, convexital and pole subdural hematomas were removed. Unusual "wateriness" of hematoma with presence of blood clots called attention to itself. In the postsurgical period, the trauma course was favorable. General cerebral syndrome and focal symptoms were regressing. The sutures were removed on 9th day. After completion of treatment, the patient was discharged to home. The neurosurgical follow-up and MRI control were recommended.
MRI control examination showed an arachnoid cyst of the temporal pole (35 × 30 × 20 mm, 9.4 cm3).
The comment. The identification of the arachnoid cyst in the temporal pole one year after trauma supposes the traumatic hemorrhage into the arachnoid cyst at the moment of acute injury. Moderate neurological symptoms and dislocation of endometrial echo (up to 5 mm) with significant volume of hematoma, "wateriness" of hematoma rather indicate the clinical signs of subarachnoid bleeding into extensive convexital arachnoid cyst. Surgical intervention for brain linings positively influenced on its significant regression in the postsurgical period that is confirmed by long term catamnesis more than 10 years.
Figure 1
MRI of the child with multiple subarachnoid hematomas (a, b) and arachnoid polus cyst in MRI control after one year (c)
CLINICAL CASE 2
A patient, age of 49 (director of an enterprise) addressed to the neurosurgery unit of the regional clinical hospital. He had complaints of headache, speech disturbance, motor dysfunction after a non-serious head injury with short term unconsciousness in the workplace (he hit his head on a support beam). At the moment of examination, his condition was satisfactory, consciousness was clear, GCS − 14, macrocephaly (head circumference − 60 cm). His face was symmetrical. Pupils were identical. There was horizontal nystagmus. Reflexes were without differences in sides. Romberg's position was shaky. Some elements of motor aphasia were noted.
MRI showed a multi-compartment (combination of convexital and intracerebral components with agenesia of a hemisphere) gigantic AC of the left hemisphere (131 × 40 × 106 mm, 290 mm3). The mass effect of the cyst was 19.3 %.
The examination of eye ground identified venous extension and a choked disk to the left. The patient was admitted with clinical signs of mild TBI and decompensation of hypertension and dislocation syndrome at the background of gigantic AC. During follow-up and conservative management, the patient's condition improved, and speech disorders disappeared. The patient refused from offered surgical management of the brain cyst. Catamnesis is unknown.
Figure 2
MRI of the patient A., age of 49, with gigantic arachnoid cyst
DISCUSSION
According to various authors, diagnosis of AC is commonly made before accident. Not more than in 6 % of cases, the first clinical manifestations appeared as result of cyst rupture. The risk factors of rupture are head injury (sometimes, mild one), vascular abnormality and coagulopathy [1, 4]. Some additional risk factors of rupture are AC size > 5 cm. However, the literature does not include any studies which show the direct correlation between cyst size and the risk of its rupture. A spontaneous AC rupture has been described in some cases [1, 8].
Some researchers note that general cerebral symptoms usually dominate over focal symptoms in spontaneous ruptures [7].
There is not any uniform opinion about relationship between head injury and AC rupture. From one side, some clinical cases of serious head injuries as result of road traffic accidents, falling from height and sport injuries have been described [7]. However, in some cases, a rupture occurs due to a relatively mild head injury, but it is accompanied by rough clinical manifestations with high volume of hematoma. According to А.В. Kulkarni (2013), many injuries were quite trivial, and the causes of bleeding were not statistically significant [7]. However, there are some unsolved questions of estimation of severity of such injury.
The literature does not demonstrate any uniform opinion on treatment strategies. Conservative therapy and surgical techniques have been offered [9]. The main part of authors believe that draining through trephine opening is the method of choice [10]. In case of spontaneous hematoma, some authors recommend craniotomy and cystectomy [11, 12].
Some authors believe that it is possible to perform cyst cisternostomy for spontaneous rupture.
In our case (the clinical case 1), AC diagnosis was not confirmed before surgery, but the neurosurgeons selected the treatment strategy for severe brain trauma. The confirmed diagnosis in the second case allowed using only conservative methods.
Some cases of a combination of chronic subdural hematoma and AC without injuries to linings have been described. The authors believe that fenestration and resection of the cyst wall is not obligatory if the clinical manifestations of AC were absent previously [11, 12, 13].
CONCLUSION
1. Bleeding into a cyst at the background of TBI is a rare pathology. We met with two cases (1.6 %) over 15 years of follow-up.
2. It is necessary to note that patients with AC, especially > 5 cm in diameter, present the risk group of spontaneous ruptures and bleedings. Children need for dynamic follow-up. Parents should be warned about possible complication. Combat sports are contraindicated for children.
3. Currently, there is no uniform treatment strategy for ruptures or bleedings into AC. Each case requires for individual approach to treatment.
4. There is a difficulty in estimation of a severity degree of TBI in such cases (determination of mild TBI in presence of dislocation syndrome and in absence of rough neurological disorders).
Information on financing and conflict of interests
The study was conducted without sponsorship. The authors declare the absence of any clear or potential conflicts of interests relating to publication of this article.