Location, sidedness, and sex distribution of intracranial arachnoid cysts in a population-based sample

Electroconvulsive Therapy With Brain Cyst: A Simulation Study

INTRODUCTION

Electroconvulsive therapy (ECT) is effective in treating severe depression and other neuropsychiatric disorders, but how the presence of an anatomical anomaly affects the electrical pathways between the electrodes remains unclear. We investigate the difference in electric field (E-field) distribution during ECT in the brain of a patient with an arachnoid cyst relative to hypothetical condition where the cyst was not present.

METHODS

Magnetic resonance imaging scans of the head of a patient with a large left frontal cyst were segmented to construct a finite element model to study the E-field distribution during ECT. Five electrode configurations were investigated: right unilateral, left unilateral, bifrontal, and bitemporal and left anterior right temporal. The E-field distributions for all montages were compared with a hypothetical condition where brain tissue and electrical conductivity from the right frontal region was mirrored across the longitudinal fissure into the cyst.

RESULTS

Differences in mean E-field and 90th percentile E-fields were mainly observed in brain regions closest to the cyst including the left inferior frontal gyrus and left middle frontal gyrus. This trend was most pronounced in montages where the electrodes were closest to the cyst such as left unilateral and bitemporal.

CONCLUSION

The presence of a highly conductive cyst close to the ECT electrode tended to attract current into the cyst region, altering current pathways, with potential implications for therapeutic efficacy and safety. Placing electrodes farther away from the cyst is likely to minimize any effects on the E-field distribution and potentially clinical outcomes.

Endoscopic Trans-Aqueductal Procedures for Juxta 4th Ventricular and Posterior Fossa Arachnoid Cyst using Flexible/Video Neuroendoscope: A Novel Approach

Objective Fourth ventricular and juxta fourth ventricular arachnoid cysts (ACs) are rare clinical entities. Conventionally, ACs are managed with either micro-surgical excision or cerebrospinal fluid (CSF) diversionary procedures such as a shunt. Effective treatment modality still remains controversial. Advances in neuroendoscopy have helped in the effective management of this benign condition in a minimally invasive method. Description of a subset of patients with fourth ventricular and juxta fourth ventricular ACs and hydrocephalus who underwent transaqueductal cysto-ventriculostomy with a flexible neuroendoscope was the objective of this study.

Methods This study included the data of patients with fourth ventricular and juxta fourth ventricular ACs and hydrocephalus operated between 2008 and 2019. Of 350 intraventricular neuroendoscopic procedures done during the last 11 years, 8 had obstructive hydrocephalus due to fourth ventricular and juxta ventricular arachnoid cyst. Endoscopic transaqueductal cystoventriculostomy and transaqueductal shunt placement was done in all using a flexible neuro-endoscope.

Results Patients were aged 20 days to 15 months; in the neonate, the diagnosis was established during routine antenatal screening. Surgical procedure was done using a flexible neuro-endoscope. All improved symptomatically, radiologically and are on regular follow-up to date. One patient had postoperative meningitis, which gradually improved with antimicrobial therapy. None required alternative form of treatment such as shunt or craniotomy and microsurgical excision.

Conclusion Endoscopic transaqueductal cysto-ventriculostomy is a safe, effective and minimal invasive modality in the hands of an experienced neurosurgeon for the management of fourth ventricular and juxta ventricular arachnoid cysts.

Arachnoid Cyst: A Sudden Deterioration

Arachnoid cysts are relatively rare and usually asymptomatic. It can only be diagnosed through radiological imaging modalities. Some patients may develop symptoms such as seizures, headache, dizziness, or psychiatric symptoms. We present a case of a 25-year-old male, previously healthy, who presented with sudden, repetitive episodes of seizure without regaining his consciousness. Computed tomography (CT) head scan showed a large cystic lesion that showed a rightward midline shift. Treatment was done surgically via endoscopic fenestration, and the patient remained symptom-free for one year. Most arachnoid cysts tend to remain asymptomatic throughout a patient's life span, allowing them to lead everyday normal lives; however, when these symptoms surface, they tend to be of a sudden nature requiring urgent surgical intervention. Our report follows the case of a young patient whose symptoms appear suddenly with triggers that led to status epilepticus. Our patient continued to suffer from multiple seizure attacks despite being on multiple anti-convulsive medications, and his symptoms eventually subsided via surgical intervention.

Intracranial cysts: incidental or neurodevelopmental?

OBJECTIVES

Intracranial cysts are fluid-filled sacs within the brain. There is a diversity of intracranial cysts with different incidences in addition to the growing awareness about comorbidities and the consequences. The present study aimed to evaluate cystic findings in children who were admitted to the department of pediatric neurology.

METHODS

Children who were admitted to the Clinic of Pediatric Neurology and who had an MRI between 2016 and 2021 were evaluated. The MRI examination was performed with the pediatric epilepsy protocol. Children with primary intracranial cysts were enrolled in the study. Demographic and clinical findings were evaluated from the hospital's database and patients' files.

RESULTS

Among the 78 patients, 36 (46.2%) were male and 42 (53.8%) were female. The mean age was 7 ± 5.4 years. The most frequent presenting complaint was a seizure (47.4%). Approximately one-quarter (28.2%) had mental and/or motor retardation. Nine (11.5%) of the children had a neuropsychiatric diagnosis. Most of the cysts were located at the midline (41%) with the majority located extra-axial (71.8%) and supratentorial (78.2%). Arachnoid cysts were observed most frequently with a percentage of 64.1%, followed by pineal cysts (15.4%). The history of seizure, epilepsy, presence of mental retardation, and neuropsychiatric problems were evaluated according to the population ratios based on z approximation in which significantly higher rates were observed among cases with intracranial cysts.

CONCLUSION

Intracranial cysts should be taken into consideration for comorbid pathologies, especially in the childhood period. Early evaluation in patients with intracranial cysts for developmental delay and neuropsychiatric problems is important.

Controversies in the Treatment of Arachnoid Cysts with Special Emphasis on Temporal Arachnoid Cysts

Intracranial arachnoid cysts (ACs) are benign lesions. The incidence in children is 2.6%. ACs are often diagnosed incidentally. Because of the broad use of CT and MR imaging, the frequency of AC diagnosis has increased. In addition, prenatal diagnosis of ACs is becoming more common. This places clinicians in a difficult situation with regard to the optimal treatment, since the presenting symptoms are often vague and operative management includes not negligible risks. It is generally accepted that conservative management is indicated in cases with small and asymptomatic cysts. In contrast, patients with definite signs of raised intracranial pressure should be treated. There are however clinical situations in whom the decision about the preferred treatment is difficult to make. Unspecific symptoms such as headaches and neurocognitive or attention deficits can be challenging to evaluate, whether they are related to the presence of the AC or not. The treatment techniques intent to establish a communication between the cyst and the normal cerebrospinal spaces or consist of a diversion of the cyst fluid by a shunt system. Which surgical method (open craniotomy for cyst fenestration, endoscopic fenestration, or shunting) is preferred differs between neurosurgical centers or the pediatric neurosurgeon in charge. Each treatment option has a unique profile of advantages and disadvantages which should be considered when discussing treatment with the patients or their caregivers.

Seizures and Postictal Psychosis in a Patient With Retrocerebellar Arachnoid Cyst: A Case Report

Retrocerebellar arachnoid cysts are uncommon intracranial tumors, especially rare in adults. Although asymptomatic in the majority of cases, they may cause a variety of symptoms including convulsions. The causal involvement of these cysts in postictal psychosis, however, remains a topic that is not well-explained in the literature.

An 85-year-old Asian man presented with recurrent episodes of convulsions for the last seven months along with preceding headaches and postictal psychotic symptoms. MRI of the head revealed a retrocerebellar arachnoid cyst. He was commenced on symptomatic pharmacological therapy after he refused surgical intervention and remained symptom-free till his discharge from the hospital before being eventually lost to follow-up.

This case report focuses on the rare occurrence of a retrocerebellar arachnoid cyst with seizures and postictal psychosis and illustrates the necessity of further case studies and research to identify and explore the potential causal relationship between arachnoid cysts and psychosis.

Arachnoid cyst alone causes hemifacial spasm: illustrative case

BACKGROUND

Hemifacial spasm (HFS) due to an arachnoid cyst at the cerebellopontine angle is rare. Here, the authors reported such a case and analyzed the mechanism of facial nerve hyperactivity by reviewing the literature.

OBSERVATIONS

A 40-year-old man presented with right HFS for the past 3 years. Preoperative magnetic resonance imaging revealed a right cerebellopontine angle cystic mass with high intensity on T2-weighted images, low intensity on T1-weighted and diffusion-weighted images, and no contrast effects. Cyst excision and decompression of the facial nerve using a lateral suboccipital approach to monitor abnormal muscle response (AMR) resulted in permanent relief. The cyst was histologically compatible with an arachnoid cyst.

LESSONS

In the present case, when the cyst was dissected, the AMR disappeared and no offending arteries were detected around the root exit zone. Therefore, the cyst itself was responsible for HFS, for which AMR was useful. Limited cases of HFS due to arachnoid cysts without neurovascular compression have been previously reported. The authors suggested that pulsatile compression by the cyst results in facial nerve hyperactivity and secondary HFS.

Reversible hearing loss after 3D video-assisted marsupialization of several posterior fossa arachnoid cysts: A case report

Very few pediatric cases of arachnoid cyst of ponto-cerebellar angle are described in the literature. Only 4 are described with hearing loss. It is a pathology which poses especially a problem of early diagnosis. In this paper we describe the management of a 16-year-old patient with an arachnoid cyst of the cerebellopontine angle with an isolated auditory deficit that was treated surgically. The follow up was marked by a Full recovery of hearing after surgical treatment. Arachnoid cyst of the cerebellopontine angle is rare in the pediatric population. early surgical management help to increase the chances of recovery.

[Endoscopic fenestration of arachnoid cyst of posterior cranial fossa through third ventriculostomy]

Arachnoid cysts (AC) are spaces with cerebrospinal fluid covered with arachnoid membrane. Most cysts are supratentorial and only 10-12% of ACs are found in posterior cranial fossa. This disease is usually diagnosed in childhood. In adults, ACs make up 1.4% of all focal lesions. ACs of posterior cranial fossa are often localized behind the cerebellum or in cerebellopontine angle. Most patients with cysts do not have permanent symptoms and should be followed-up. Surgery is indicated for cysts complicated by focal and hydrocephalic-hypertension symptoms. Microsurgical or endoscopic procedures are used. Surgical approach is determined by the closest location of cyst to brain surface. The authors report non-standard surgical approach for giant AC of posterior cranial fossa complicated by obstructive hydrocephalus, intracranial hypertension and visual function impairment. Endoscopic third ventriculostomy was followed by AC fenestration through ventriculostomy. Symptoms disappeared within 6 months after surgery.

Is there any gender difference in epidemiology, clinical presentation and co-morbidities of non-functioning pituitary adenomas? A prospective survey of a National Referral Center and review of the literature

PURPOSE

Gender differences in patients diagnosed with non-functioning Pituitary Adenomas (NFPA) in a National Referral Center for Pituitary Tumors at the Federico II University of Naples, Italy.

METHODS

Patients newly diagnosed with non-functioning sellar masses found on pituitary Magnetic Resonance Imaging from January 1st 2016 to December 31th 2018 underwent anthropometric measurements, basal evaluation of pituitary function, and metabolic assessment. Fatty live index (FLI) and visceral adiposity index (VAI) were calculated.

RESULTS

Seventy-three patients (35 males, 51.1 ± 17.0 years; 38 females, 41.8 ± 18.1 years) presented with NFPA. Lesions > 1 cm (85.7% vs. 47.3%; χ² = 10.26, p = 0.001) and hypopituitarism (77.1% vs. 7.9%; χ² = 33.29, p = 0.001) were more frequent in males than females. The highest sizes of pituitary adenomas were significantly associated with male gender (OR = 1.05, p = 0.049; R² = 0.060; IC 1.00-1.10). Headache (62.8% vs. 31.6%; χ² = 5.96, p = 0.015) and visual field deficits (57.1% vs. 26.3%; χ² = 5.93, p = 0.015) were significantly more frequent in males than in females. There was no sex difference in obesity prevalence, but the metabolic syndrome was more common among males than females (60.6% vs. 26.3%; χ² = 7.14, p = 0.001). FLI was also higher in males (69.6 ± 27.3 vs. 49.2 ± 31.3; p < 0.001), while there were no differences in VAI.

CONCLUSIONS

Apart from the possible delay in the diagnosis induced by the gender differences in symptom presentation, the higher prevalence of macroadenomas amongst NFPA in males compared with females let to hypothesize a key role of the sex hormone profile as predictive factors of their biological behavior and metabolic profile. Further studies are, however, mandatory to better support the influence of gender differences on onset, progression, and metabolic consequences of NFPA.

Interhemispheric arachnoid cyst

Background

Interhemispheric arachnoid cysts are uncommon and typically associated with other midline neurodevelopmental disorders, such as complete or partial agenesis of the corpus callosum.

Case Description

We report a case of a 27-year-old woman with worsening headache, memory deficit, and radiological progression of an interhemispheric arachnoid cyst. The treatment consisted of craniotomy for interhemispheric cyst fenestration into both the interhemispheric cistern and lateral ventricle. The postoperative course was unremarkable, with considerable clinical improvement and significant reduction in cyst size.

Conclusion

We successfully treat a patient with an enlarging arachnoid cyst and associated progressive symptoms with microsurgical fenestration.

Objective improvement in adults with cerebellopontine angle arachnoid cysts after surgical treatment

BACKGROUND

Intracranial arachnoid cysts are extra-axial benign lesions mainly found in the middle cerebral fossa. Rare case series report various cranial nerve dysfunctions associated with cerebellopontine angle (CPA) cysts and there is no consensus with regard to their surgical management; some reports claiming that subjective improvement in adults with intracranial arachnoid cysts cannot justify surgical treatment.

METHODS

This retrospective study included all 12 consecutive adult patients treated by microsurgical fenestration for symptomatic CPA arachnoid cysts between 2010 and 2019 and using a retrosigmoid approach. Demographic, clinical, surgical, and radiological data were collected from medical files.

RESULTS

The main symptoms were audiovestibular in 9 patients (75%) complaining of dizziness and 6 patients (50%) with hearing loss. In addition, 3 patients (25%) reported tinnitus, 3 patients (25%) presented vasovagal syncope, and 1 patient (8.3%) reported facial pain. Surgery improved 5 patients (83%) with pre-operative hearing loss, 7 patients (78%) reporting dizziness, and all patients with vasovagal syncope. All of the patients recovered from at least one symptom. No recurrence was observed with a mean follow-up of 5.5 years.

CONCLUSION

Although most arachnoid cysts are asymptomatic, the CPA location may lead to cranial nerve impairments. Microsurgical fenestration seems to be a simple, safe, and effective technique.

Paediatric arachnoid cysts: Surgical outcomes from a Singapore children's hospital

Arachnoid cysts (AC) are reported to have a prevalence of up to 2.6% in children. Most AC remain indolent, but others may expand or rupture to cause life-threatening symptoms of raised intracranial pressure. Currently, there are 2 controversial topics with regards to the management of ACs: the indications for surgery and the choice of surgical procedure. We therein report our institution's neurosurgical experience for symptomatic AC over a 22-year period and corroborate our results with published literature. This is a single institution, retrospective study conducted at KK Women's and Children's Hospital from 01 January 1998 to 31 December 2019. A total of 38 patients with ACs that required surgery were recruited. The 3 most common anatomical locations were in the middle cranial fossa (40.5%), posterior fossa (24.3%) and interhemispheric (13.5%). Typical clinical presentations included symptoms of raised intracranial pressure (34.2%), obstructive hydrocephalus (28.9%) and AC rupture (21.1%). Surgical approaches included 17 craniotomy-based procedures, 7 endoscopic fenestrations, 11 cystoperitoneal shunts, 2 burrhole drainage operations and 1 excision of spinal AC. Thirteen patients (34.2%) underwent either another operation due to the lack of resolution of their AC-related symptoms or secondary to complications directly related to their initial surgery. Average length of followup from time of first operation was 84.1 months. Overall, our results demonstrate similarities in epidemiology, clinical presentation and surgical experience, in comparison to larger cohort studies. We advocate collaborative efforts to better understanding of the pathophysiology of paediatric ACs, particularly for deciding between the various surgical treatment modalities.

Arachnoid cysts on magnetic resonance imaging: just an incidental finding?

Objective

To determine the clinical significance of arachnoid cysts.

Methods

The scans of 6978 patients undergoing magnetic resonance imaging of the internal acoustic meatus for unilateral cochleovestibular symptoms were retrospectively reviewed. We identified the scans with arachnoid cysts, and assessed the statistical associations between the laterality, location and size of the arachnoid cyst, the laterality of symptoms, the patients’ age and gender.

Results

In a total of 37 arachnoid cysts identified in 36 patients (0.5 per cent), no associations were identified between the laterality of symptoms and the laterality of the arachnoid cyst, regardless of its size or location. There were no significant associations between the location of the arachnoid cyst and the age (p = 0.99) or gender of the patient (p = 0.13), or size (p = 0.656) or side of the cyst (p = 0.61). None of the cysts with repeat imaging scans (17 cysts) demonstrated growth.

Conclusion

Our results suggest that most, if not all, arachnoid cysts are of no clinical significance. Given their indolent behaviour, even serial imaging is not essential.

Familial arachnoid cysts: a review of 35 families

INTRODUCTION

Arachnoid cysts are commonly considered congenital lesions, but this has not been proven. With the development of neuroimaging and DNA testing technology, more cases of familial arachnoid cysts have been reported. Herein, we review such cases.

MATERIALS AND METHODS

The PubMed, Embase, and Web of Science databases were searched for case reports of arachnoid cysts published through April 2018. Case reports were included only if two or more related patients were diagnosed with an arachnoid cyst by neuroimaging or intraoperatively. For each report, the following data were extracted: first author name, date of publication, number of families, number of patients, location of the arachnoid cysts, patient age, patient sex, and genetic mutations and associated disease.

RESULTS

Our searches identified 33 case reports involving 35 families and 115 patients. The locations of arachnoid cysts were similar in 25 of the 35 families. Spinal extradural arachnoid cysts were reported most often, followed by arachnoid cysts in the middle fossa and posterior fossa. A left-sided predominance was noticed for arachnoid cysts of the middle fossa. Mutation of the FOXC2 gene was reported most often, and arachnoid cysts may be associated with mutations on chromosome 16.

CONCLUSIONS

Although the origin of arachnoid cysts is believed to have a genetic component by some researchers, the genes associated with arachnoid cysts remain unknown. Unfortunately, the evidence remains insufficient.

Familial intracranial arachnoid cysts with a missense mutation (c.2576C > T) in RERE: A case report

RATIONALE

Arachnoid cysts are relatively common intracranial space-occupying lesions; nevertheless, familial intracranial arachnoid cysts are extremely rare, with only a few cases having been reported.

PATIENT CONCERNS

The proband was a 7-year-old girl who had experienced generalized tonic-clonic seizures 5 times in the 8 days prior to admission. Nine months later, her 6-year-old younger female cousin presented to us with a 3-day history of headache.

DIAGNOSES

Brain magnetic resonance imaging (MRI) confirmed the diagnosis of arachnoid cyst for both of the girls.

INTERVENTIONS

A cyst-peritoneal shunting and cyst fenestration were performed for the 7-year-old girl and her cousin separately. Sanger sequencing revealed a heterozygous missense mutation (c.2576C > T) in the Arginine-Glutamic Acid Dipeptide Repeats gene (RERE).

OUTCOMES

The outcome was favorable and the follow-up was uneventful.

LESSONS

We hypothesize that the mutation in RERE may be associated with the pathogenesis of familial intracranial arachnoid cysts.

Neurodevelopmental outcomes in children with large temporal arachnoid cysts

OBJECTIVE Management of children with large temporal arachnoid cysts (TACs) remains controversial, with limited data available on their neurodevelopmental outcome. The aim of this study was to examine neurodevelopmental outcomes in children with large TACs. METHODS In this medical center-based cohort study, 25 patients (19 males) who were diagnosed in childhood with large TACs (9 patients [36%] with a Galassi type II and 16 patients [64%] with a Galassi type III TAC) were examined. The mean ± SD age at assessment was 11.1 ± 5.6 years (range 2.7-22 years). Twelve patients (48%) had right-sided, 12 (48%) had left-sided, and 1 (4%) had bilateral cysts. Nine patients (36%) underwent surgery for the cyst. The siblings of 21 patients (84%) served as control participants. Neurodevelopmental function was assessed using the Adaptive Behavior Assessment System (ABAS), Vanderbilt Behavioral Rating Scale (VBRS), and Developmental Coordination Disorder Questionnaire (DCDQ), and quality of life was measured using the treatment-oriented screening questionnaire (TOSQ). The results of all instruments except for TOSQ were compared with those of the sibling control participants. RESULTS The mean ± SD ABAS score of the patients was 93.3 ± 20.09 compared with 98.3 ± 18.04 of the sibling control participants (p = 0.251). Regarding the incidence of poor outcome (ABAS score < 80), there was a trend for more patients with TAC to have poor outcome than the sibling controls (p = 0.058). Patients who underwent surgery scored significantly worse with regard to the VBRS total score compared with those who did not (p = 0.020), but not on ABAS, DCD, or TOSQ. The mean score of the cognitive and psychological items on TOSQ was lower than that for the physical items (p < 0.001). CONCLUSIONS Children with a large TAC performed similarly to their sibling control participants in neurodevelopmental function. However, a subgroup of those with cysts did have an increased risk for poor outcomes in general function. Neurodevelopmental assessment should be part of the management of all patients with TAC.

Prepontine arachnoid cyst presenting with headache and diplopia: A case report study

Background:

Arachnoid cysts are found everywhere in cerebrospinal axis, most often in the middle cranial fossa. They are very rare in prepontine location.

Case Description:

In this study, we report a 26-year-old female presenting with a 3-month history of headache and diplopia. On physical examination, she had clinical manifestations of sixth cranial nerve palsy. Magnetic resonance imaging revealed a prepontine arachnoid cyst with extension into interpeduncular and suprasellar cisterns. Computed tomography scan demonstrated no evidence of hydrocephalus. The patient was treated surgically by endoscopic fenestration of the cyst with endonasal transsphenoidal approach. The cyst was opened to prepontine, interpeduncular, and suprasellar cisterns.

Conclusion:

Endoscopic endonasal fenestration of the cyst to adjacent cistern may be safe in prepontine arachnoid cysts with sellar and suprasellar extension; it may be effective and less invasive compare to transcranial approach.

[Relevance and therapy of intracranial arachnoidal cysts]

Intracranial arachnoidal cysts (AC) are relevant due to their space-demanding character. The pathophysiological sequelae are dependent on the size and location of the cyst and the patient's age. Direct pressure on surrounding tissue causes headaches (meninges) or rarely seizures (brain tissue). Cerebrospinal fluid (CSF) circulation disturbances resulting from brain mass displacement with occlusion of, for example, the foramen monroi or the aqueduct cause occlusive hydrocephalus, which can lead to an increase in intracranial pressure. Depending on age, the typical primary clinical symptoms or findings differ. In adults and older children, headaches are usually the first clinical symptom. Children, in whom skull growth is not yet complete, present with a head circumference above the 97th percentile. An abnormal one-sided deflection of the calotte in the region of the underlying AC may also be present. Cranial magnetic resonance imaging (cMRI), the first-line diagnostic tool of choice to demonstrate size and location of the cysts and the surrounding intracranial structures, is of utmost importance for therapy planning. In addition, further malformations can be detected. Moreover, cMRI may also be useful for a rough assessment of increased intracranial pressure (ICP). In most symptomatic AC, surgical treatment is unavoidable. The primarily goal is to establish communication between the CSF and the cysts' content in order to effect pressure equalization. If the CSF reabsorption capacity is insufficient, it may also be necessary to implant a CSF shunt. Asymptomatic arachnoidal cysts should be strictly followed clinically and by cMRI over time. The reasonable frequency for follow-up depends on the size and location of the cyst.

Ophthalmological symptoms in children with intracranial cysts

The purpose of this study was to perform an ophthalmological assessment in children with intracranial cysts and to assess the correlation between the occurrence of cysts and visual disorders. The documentation of 46 children with intracranial cysts, monitored by the Children’s Outpatient Ophthalmology Clinic, Poznan, Poland was analysed. The best corrected visual acuity (BCVA), the alignment of the eyes, visual evoked potentials (VEP), comprehensive eye examination were performed in all patients. Additional ophthalmological tests were conducted to eliminate other causes of decreased visual acuity.Included in the final analysis were 26 children (52 eyes). The average age at the last visit was 10.3 years. Sixteen children (61.5%) had arachnoid cysts located in the posterior cranial fossa, 3 children (11.5%) in the middle cranial fossa, while 7 children (27%) had a pineal cyst. Decreased BCVA was found in 13 children, abnormal VEP in 13, strabismus in 14 patients (53.9%), nystagmus in 5 patients (19.2%), and double vision in 2 patients (7.7%). Numerous visual disorders in children with intracranial cysts suggest the necessity to carry out enhanced ophthalmological diagnostics in these patients. In the examined patient group, visual disorders occurred mostly in the case of arachnoid cysts of the posterior fossa.

Neuropsychological improvement after posterior fossa arachnoid cyst drainage

PURPOSE

Posterior fossa arachnoid cysts (PFAC) are mostly considered as benign lesions of the cerebellum. Although many studies have shown the major role of the cerebellum in modulating movement, language, cognition, and social interaction, there are few studies on the cognitive impact and surgical decompression of PFAC.

METHODS

We present the cases of two brothers successively diagnosed with PFAC and neuropsychological delay. After multidisciplinary discussion with the boys' parents, it was decided to drain these lesions. Clinical signs, cerebral images, and neuropsychological status were assessed on admission and then 1 and 3 years after surgery.

RESULTS

At presentation, both children had mild cerebellar signs, associated with cognitive and visual-motor impairments and academic regression. CT scans revealed retrovermian cysts, which were shunted. Post-operatively, both brothers demonstrated improved visual-motor skills and behavior. At follow-up, we observed disappearance of dysarthria and academic delay and significant improvement in cognition especially at the intelligence scale and in language. Fine motor skills had improved but remained slower than the average and writing skills appeared limited.

CONCLUSION

Except for PFAC which impair cerebrospinal fluid circulation or which are responsible for a significant mass effect, most PFAC are usually considered as "asymptomatic" and do not require surgical treatment. The two cases reported herein suggest that these lesions might be responsible for some associated but potentially reversible neuropsychological impairment. In the future, clinical assessment should include neuropsychological evaluation to help inform decision for surgical decompression in these children with PFAC.

Neurological Fallacies Leading to Malpractice: A Case Studies Approach

A young woman presents with an intracranial arachnoid cyst. Another is diagnosed with migraine headache. An elderly man awakens with a stroke. And a baby delivered vaginally after 2 hours of questionable electronic fetal monitoring patterns grows up to have cerebral palsy. These seemingly disparate cases share a common underlying theme: medical myths. Myths that may lead not only to misdiagnosis and treatment harms but to seemingly never-ending medical malpractice lawsuits, potentially culminating in a settlement or judgment against an unsuspecting neurologist. This article provides a case studies approach exposing the fallacies and highlighting proper management of these common neurologic presentations.

Transaqueductal trans-Magendie fenestration of arachnoid cyst in the posterior fossa

BACKGROUND

Neuroendoscopy is currently recommended as the first choice to treat posterior fossa arachnoid cysts. It has proven to be effective, providing improved outcome, and safe, having a low complication rate. Compared to craniotomy and shunt placement, it has lower surgical morbidity, minimizing or avoiding risks of subdural fluid collections, shunt infection, malfunction, overdrainage, and dependence. Usually, rigid scopes maneuvered through a suboccipital approach are used. When symptomatic obstructive hydrocephalus develops, CSF diversion is the first aim of surgery.

METHODS

In these patients, a flexible scope introduced through a frontal burr hole allows not only immediate and efficient management of hydrocephalus with endoscopic third-ventriculostomy, but in selected cases also direct cyst inspection and fenestration. Navigation of an enlarged cerebral aqueduct is actually safe when performed by experienced neurosurgeons.

RESULTS

We describe the cystocisternostomy of a cisterna magna arachnoid cyst using a transaqueductal trans-Magendie approach.

CONCLUSIONS

This minimally invasive technique gives the possibility of performing both endoscopic third-ventriculostomy and cyst fenestration, which alone may not be enough to efficiently treat hydrocephalus.

Prevalence and symptoms of intracranial arachnoid cysts: a population-based study

To investigate the prevalence of intracranial arachnoid cysts in a large population-based sample. We also aimed to assess the association between arachnoid cysts and cognitive impairment, depression, epilepsy, headache, dizziness, previous head trauma, hip fractures, and mortality. A population-based cohort and nested case-control study. The sample comprised representative populations (n = 1235) aged ≥ 70 years. All participants underwent baseline neuropsychiatric examinations, including computed tomography (CT) of the brain, between 1986 and 2000. All CT scans were examined for arachnoid cysts. Headache, dizziness, history of head trauma, dementia, depression, epilepsy, and hip fracture were assessed using data from clinical examinations, interviews and the Swedish hospital discharge register. Cognition was assessed using the Mini-Mental Status Examination, and depressive symptoms using the Montgomery-Åsberg Depression Rating Scale. Date of death was obtained from the National Swedish Death Registry. The prevalence of arachnoid cysts was 2.3 % (n = 29), with no significant difference between men and women. Probands with and without cysts had the same frequency of headache, dizziness, previous head trauma, cognitive impairment, and depressive symptoms. Furthermore, there were no differences regarding the prevalence of dementia, depression, epilepsy, or previous hip fracture. Arachnoid cysts were not associated with increased mortality. Arachnoid cysts are common incidental finding, with the same rate in men and women, and are probably asymptomatic. The lack of relation with symptoms like headache, dizziness and cognitive impairment suggest caution in ascribing symptoms to incidentally discovered arachnoid cysts and a restrictive attitude to treatment.

[Rare location of arachnoid cysts. Extratemporal cysts]

The therapeutic management of arachnoid cysts depends largely on its location. Almost 50% of arachnoid cysts are located in the temporal fossa-Sylvian fissure, whereas the other half is distributed in different locations, sometimes exceptional. Under the name of infrequent location arachnoid cysts, a description is presented of those composed of 2 sheets of arachnoid membrane, which are not located in the temporal fossa, and are primary or congenital.

Surgical Decompression of Arachnoid Cysts Leads to Improved Quality of Life: A Prospective Study

BACKGROUND

There is no previous prospective study on the outcome of surgical decompression of intracranial arachnoid cysts (AC).

OBJECTIVE

To investigate if surgical fenestration for AC leads to change in patients' health-related quality of life.

METHODS

Prospective study including 76 adult patients operated for AC. Patients responded to Short Form-36 and Glasgow Benefit Inventory quality of life questionnaires, and to visual analogue scales, assessing headache and dizziness pre- and postoperatively. Patient scores were compared with those of a large sample of healthy individuals.

RESULTS

Preoperatively, 84.2% of the patients experienced headache and 70.1% dizziness. Mean pre- versus postoperative Visual Analogue Scale scores for headache and dizziness dropped from 45.6 to 25.7 and from 35.2 to 12.2, respectively. Preoperative Short Form-36 scores were significantly below age norms in all subscales, but improved after surgery into normal range in 7 out of 8 subscales for middle-aged and older patients. Younger patients' scores remained lower than age norm in 6 out of 8 subscales. A significant postoperative improvement was seen in 3 out of 4 Glasgow Benefit Inventory subscales. Improvement in headache and/or dizziness, but not preoperative cyst size or reduction in cyst volume, correlated with improvement in 6 out of 8 Short Form-36 subscales and 3 out of 4 Glasgow Benefit Inventory subscales. Only 1 patient experienced a severe complication causing permanent invalidity.

CONCLUSION

Surgery for AC can be performed with a fairly low risk of complications and yields significant improvement in quality of life correlated to postoperative improvement in headache and dizziness. These findings may justify a more liberal approach to surgical treatment for AC.

Gradually Progressive Symptoms of Normal Pressure Hydrocephalus Caused by an Arachnoid Cyst in the Fourth Ventricle: a Case Report

BACKGROUND

Arachnoid cysts in the fourth ventricle are extremely rare, with only 13 cases having been described in the literature. Especially, only 1 case of a patient older than 70 years has been reported. Arachnoid cysts in the fourth ventricle may cause obstructive hydrocephalus. Here, we report the case of a 72-year-old man who presented with an arachnoid cyst in the fourth ventricle that caused gradually progressive symptoms of normal pressure hydrocephalus.

METHODS

A 72-year-old man complaining of persistent dizziness and gait difficulty was admitted to our hospital due to a gradual worsening of his symptoms and apparent cognitive impairment. Computed tomography scan of the head showed symmetrically dilated third, fourth, and lateral ventricles.

RESULT

Though we performed a ventriculoperitoneal shunt operation, his trunk ataxia persisted. We finally diagnosed an arachnoid cyst in the fourth ventricle by direct ventricular infusion of enhanced material. We performed direct surgical fenestration of the cyst and achieved a good outcome.

CONCLUSION

Arachnoid cysts of the fourth ventricle are exceedingly rare, but it is important to recognize them because they cause normal pressure hydrocephalus symptoms and cerebellar or brainstem deficit. We propose detailed neurologic and radiologic examinations of patients with normal pressure hydrocephalus symptoms to avoid unnecessary shunt.

Disequilibrium in patients with posterior fossa arachnoid cysts

BACKGROUND

Arachnoid cysts (AC) are benign, congenital malformations of the leptomeninges. In our experience, dizziness and vertigo are common complaints in patients with such cysts.

OBJECTIVE

To quantify dizziness and imbalance in patients with arachnoid cysts in the posterior fossa using the Dizziness Handicap Inventory (DHI), Vertigo Symptom Scale Short-Form (VSS-SF) and Computerized Dynamic Posturography (CDP). We also wanted to investigate whether any dizziness and imbalance are reversible after surgical cyst decompression.

METHODS

The study includes four patients with AC in the posterior fossa (two in the cerebellopontine angle and two supracerebellar in the midline) and 15 control subjects undergoing ENT surgery for benign lesions of the larynx (n = 10) or the parotid glands (n = 5). All participants answered the DHI and VSS-SF and underwent CDP the day before, and at follow-up after surgery. The AC patients also graded their dizziness through the use of a Visual Analogue Scale (VAS).

RESULTS

Preoperatively, cyst patients scored higher than controls on subjective symptoms (DHI, VSS-SF A and VSS-SF V) and had a lower score on postural sway (CDP). Symptom scores decreased after surgery; the cyst patients improved in the subjective tests (DHI, VAS and VSS-SF), and three of the patients improved their CDP scores. In the controls, symptom and CDP scores were unchanged after surgery.

CONCLUSION

Patients with fossa posterior cyst had a significant preoperative impairment compared with the controls, and they exhibited post-operative improvement in their subjective dizziness.

Growth of arachnoid cysts in patients with autosomal dominant polycystic kidney disease: serial imaging and clinical relevance

Background

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder that results in the growth of cysts in the kidneys and other organs. Multisystemic involvement is common including affection of the central nervous system with cerebral aneurysms and arachnoid cysts.

Methods

This is a prospective cohort study to investigate the prevalence and growth rate of arachnoid cysts in ADPKD patients. Participants enrolled in the SUISSE ADPKD cohort were offered cranial imaging for the detection of intracranial alterations. In the case of identified arachnoid cysts, patients were suggested to undergo follow-up imaging to assess the growth rate of the cysts. Volume of arachnoid cysts at the baseline and at follow-up visits was assessed by manual segmentation on a dedicated workstation.

Results

A total of 109 ADPKD patients agreed to undergo cranial imaging. In 14 (12.8%) patients (9 males and 5 females), 18 singular arachnoid cysts were identified. The baseline volumes of individual cysts ranged from 1.8 to 337.6 cm³. During a mean follow-up period of 24 months, the volume changes of 12 individual arachnoid cysts of nine patients ranged from −3.1 to 3.7 cm³. Cystic lesions were mostly localized in the middle fossa. All affected patients were clinically asymptomatic.

Conclusions

We found a higher prevalence of arachnoid cysts in ADPKD patients with more advanced disease. There was a large variability in size and growth. These arachnoid cysts were clinically silent and their growth pattern was subtle and unpredictable, in contrast to the much more foreseeable growth of the renal cysts.

Incidental findings on brain and spine imaging in children

In recent years, the utilization of diagnostic imaging of the brain and spine in children has increased dramatically, leading to a corresponding increase in the detection of incidental findings of the central nervous system. Patients with unexpected findings on imaging are often referred for subspecialty evaluation. Even with rational use of diagnostic imaging and subspecialty consultation, the diagnostic process will always generate unexpected findings that must be explained and managed. Familiarity with the most common findings that are discovered incidentally on diagnostic imaging of the brain and spine will assist the pediatrician in providing counseling to families and in making recommendations in conjunction with a neurosurgeon, when needed, regarding additional treatments and prognosis.

A boy with arachnoid cyst, a fall, and temporary and reversible visual impairment

BACKGROUND

Temporal arachnoid cysts have been shown to interfere with the function of nervous structures, both cerebral cortex and cranial nerves.

METHODS AND RESULTS

In this case report we describe a boy with a left temporal arachnoid cyst with a sudden onset of visual impairment 4 days after a mild trauma to the head. A perimetry test revealed a complete nasal hemianopia of the left eye, which normalized rapidly after an emergency craniotomy with cyst fenestration 3 hours after the patient experienced the reduced vision.

CONCLUSIONS

The observed, reversible effect on vision is most probably caused by pressure exerted by the medial part of the cyst on the left optic nerve. We believe this is the first time such a case has been described.

Arachnoid cysts in tuberous sclerosis complex

OBJECTIVE

Some clinical findings in tuberous sclerosis complex (TSC), such as hypomelanotic macules or angiofibromas are related to problems in development of the neural crest, which is also the origin of cranial leptomeninges. Arachnoid cysts have been reported in two TSC patients to date. The purpose of this study was to assess the prevalence and characteristics of arachnoid cysts in a large cohort of TSC.

MATERIALS AND METHOD

We performed a review of brain MRIs of 220 TSC patients searching for arachnoid cysts.

RESULTS

Arachnoid cysts were found in 12 (5.5%) (general population: 0.5%), including ten males (83.3%). Four patients (33.3%) had also autosomal dominant polycystic kidney disease (ADPKD) due to a contiguous deletion of the TSC2-PKD1 genes. Three patients (25%) had two or more arachnoid cysts, of whom two also had ADPKD. One patient with an arachnoid cyst did not have tubers, subependymal nodules or white matter migration lines.

CONCLUSION

Our study suggests that arachnoid cysts are part of the clinical spectrum of TSC and may be also present in TSC patients without other typical TSC brain lesions.

Pre- and post-operative dizziness and postural instability in temporal arachnoid cyst patients

OBJECTIVES

Arachnoid cysts (AC) are benign, congenital malformations of the leptomeninges, with a predilection for the temporal fossa. In our clinical experience, patients with temporal AC often complain of dizziness and imbalance. However, these symptoms and the effect of surgery on them have not been studied before.

MATERIALS AND METHODS

Dizziness and imbalance in patients with temporal AC were quantified before and after surgical cyst decompression, using the Dizziness Handicap Inventory (DHI), Vertigo Symptom Scale - Short-Form (VSS-SF) and computerized dynamic posturography (CDP). The study includes 16 patients with temporal AC and 15 control subjects undergoing surgery for benign lesions of the larynx (n = 10) or the parotid glands (n = 5). All participants answered the DHI and VSS-SF and underwent CDP the day before and 3-6 months after surgery. The patients with AC also graded their dizziness through the use of a visual analogue scale (VAS).

RESULTS

Preoperatively, cyst patients scored higher than controls on subjective symptoms (DHI, VSS-SF A and VSS-SF V), but not on postural sway (CDP). Symptom scores decreased after surgery; the cyst patients improved significantly in the subjective tests (DHI, VAS and VSS-SF), while CDP scores did not. In the controls, symptom and CDP scores were unchanged after surgery.

CONCLUSIONS

Patients with temporal AC have a significant preoperative impairment and post-operative improvement in their subjective dizziness, but not in postural sway as measured by CDP.

Intracranial arachnoid cysts: impairment of higher cognitive functions and postoperative improvement

Background

Intracranial arachnoid cysts have been shown to yield cognitive impairment over a range of basic mental functions, and these functions normalize after surgical cyst decompression. We wanted to investigate whether such cysts may also impair executive cognitive functions, and whether surgical cyst decompression leads to an improvement.

Methods

This study included 22 patients with arachnoid cysts and 13 control patients scheduled for low back surgery. All subjects were tested with Delis-Kaplan Executive Function System (D-KEFS) tests, assessing executive function 1 day before surgery and a minimum of 3 months after surgery. The data were analyzed according to scaled score computations based on raw scores provided by D-KEFS, adjusted for age, gender, and educational norms.

Results

Preoperatively, the patients with cysts group performed worse than the control group in verbal knowledge, mental flexibility, inhibitory capacity, problem solving, and planning skills. Postoperatively, the patients with cysts group significantly improved performance and were no longer different from the control group in the following subtests: inhibition, inhibition/switching, letter fluency, category switching, and total switching accuracy. The patients with cysts group also significantly improved performance in color naming, category fluency, and in the Tower test, but nevertheless remained impaired at follow-up compared with the control group. The control group did not show a similar improvement, except for the Tower test. Cyst size or postoperative volume reduction did not correlate with cognitive performance or postoperative improvement. Patients with left-sided temporal cysts performed poorer than patients with right-sided cysts on a complex verbal task demanding mental flexibility.

Conclusions

Arachnoid cysts seem to impair not only basic cognition, but also executive functions. Most of this impairment appears to be reversible after surgical cyst decompression. These results may have implications for future preoperative considerations for patients with intracranial arachnoid cysts.

[Ocular manifestations of arachnoid cysts in children: report of two cases]

Arachnoid cysts are congenital benign intracranial collections of cerebrospinal fluid. Most arachnoid cysts are small and asymptomatic. They are usually located in the temporal fossa. Classically described complications result from compression of adjacent structures and include neurologic involvement, headaches and seizures. There are few cases of arachnoid cysts with ophthalmic manifestations reported in the literature. We describe two pediatric cases of arachnoid cyst with ocular complications. A 12-month-old girl with a history of acquired nystagmus and enlarged head circumference was referred for ophthalmologic examination. An MRI study showed a 7cm×7cm arachnoid cyst in the left temporal fossa. Six months after cystocysternostomy, the nystagmus resolved. A 2-year-old girl with esotropia and severe amblyopia of the left eye was referred for ophthalmologic examination. Optic nerve hypoplasia was detected on left fundus examination. MRI demonstrated a supracellar arachnoid cyst with mass effect on the optic chiasm as well as hydrocephalus. She was referred to neurosurgery for shunt surgery. In the case of clinical signs such as nystagmus, optic nerve hypoplasia, papilledema and oculomotor palsy, an arachnoid cyst may be a probable cause.

Maze learning in patients with intracranial arachnoid cysts

BACKGROUND

The temporal lobe is of importance for visuospatial orientation. Intracranial arachnoid cysts have a predilection for the temporal fossa, and might therefore affect visuospatial orientation. The aim was to find out whether temporal cysts affect maze learning and if surgical cyst decompression improves maze performance.

METHODS

Forty-five patients with a temporal arachnoid cyst and 17 control patients with cervical disc disease were tested in a labyrinth route in the hospital corridors the day before surgery and at least 3 months postoperatively.

RESULTS

Thirty-five cyst patients (78 %) experienced postoperative improvement of their preoperative complaints. The cyst patients spent significantly longer time than the controls navigating through the maze in the preoperative test, 161 s and 127 s, respectively, but there was no difference in number of errors between the two groups. However, the cyst patients improved significantly in the postoperative test, both with regards to number of errors they made and time spent, contrary to the control patients, whose postoperative performance equalled that of the preoperative test. For the cyst patients, postoperative improvement in the labyrinth test correlated with the clinical outcome-but not the neuroradiological outcome-after the operation.

CONCLUSIONS

Thus, temporal arachnoid cysts may affect visuospatial orientation and learning in a reversible manner.

Prevalence and natural history of arachnoid cysts in adults

Object

Arachnoid cysts are a frequent finding on intracranial imaging. The prevalence and natural history of these cysts in adults are not well defined.

Methods

We retrospectively reviewed the electronic medical records of a consecutive series of adults who underwent brain MRI over a 12-year interval to identify those with arachnoid cysts. The MRI studies were reviewed to confirm the diagnosis. For those patients with arachnoid cysts, we evaluated presenting symptoms, cyst size, and cyst location. Patients with more than 6 months' clinical and imaging follow-up were included in a natural history analysis.

Results

A total of 48,417 patients underwent brain MRI over the study period. Arachnoid cysts were identified in 661 patients (1.4%). Men had a higher prevalence than women (p < 0.0001). Multiple arachnoid cysts occurred in 30 patients. The most common locations were middle fossa (34%), retrocerebellar (33%), and convexity (14%). Middle fossa cysts were predominantly left-sided (70%, p < 0.001). Thirty-five patients were considered symptomatic and 24 underwent surgical treatment. Sellar and suprasellar cysts were more likely to be considered symptomatic (p < 0.0001). Middle fossa cysts were less likely to be considered symptomatic (p = 0.01. The criteria for natural history analysis were met in 203 patients with a total of 213 cysts. After a mean follow-up of 3.8 ± 2.8 years (for this subgroup), 5 cysts (2.3%) increased in size and 2 cysts decreased in size (0.9%). Only 2 patients developed new or worsening symptoms over the follow-up period.

Conclusions

Arachnoid cysts are a common incidental finding on intracranial imaging in all age groups. Although arachnoid cysts are symptomatic in a small number of patients, they are associated with a benign natural history for those presenting without symptoms.

Fenestration methods for Sylvian arachnoid cysts--endoscopy or microsurgery

INTRODUCTION

Two different approaches to fenestration, endoscopic and microsurgical, are in use for Sylvian arachnoid cysts (SACs), the most frequent among intracranial arachnoid cysts. We presented the clinical data and compared our results, with regard to technique and clinical success, with either microsurgical or neuroendoscopic fenestration of SACs.

MATERIALS AND METHODS

Twenty-nine patients who subjected to cysto-cisternostomy by the same team, using either of the two methods, were studied retrospectively.

RESULTS

Thirteen patients underwent microsurgery, and 16 had endoscopic cysto-cisternostomy. No reoperation was needed in either of these groups, i.e., full clinical and radiological success was achieved in both. The complication rate was 23% in the microsurgery patients and 47% in the endoscopic surgery group, with no statistically significant difference.

CONCLUSIONS

No relevant differences between the two methods are seen either in the published data or in our results. Adding our results to the published data, both techniques were reviewed in a discussion of the one that allows a better controlled or safer fenestration. We conclude that endoscopic fenestration of SACs is not superior to microsurgical cyst fenestration, and the latter seems safer.

De novo suprasellar arachnoid cyst: case report and review of the literature

PURPOSE

We present a case of a 4-year-old child who was incidentally found to have a suprasellar arachnoid cyst (SAC) after initial CT imaging at 6 weeks of age but who demonstrated no anomalies. This is only the sixth case of intracranial de novo ACs documented in the English literature and only the second case of SAC to arise de novo.

METHODS

Case review after an SAC was found on an MRI scan at 4 years of age which had not been present on a previous CT of the head.

RESULTS

Apparent de novo SAC formation in a healthy 4-year-old female without a history of intracranial infection, surgery or trauma.

CONCLUSION

The pathophysiology leading to the formation of the cyst might well be congenital, although there is some question as to how early in development the cysts are formed as our child was a 32-week GA preemie with an initial scan at 38 weeks GA. With the use of fast MRI scans instead of CT scans and the continued neuroimaging of premature infants, we can take a better look at the anatomy and better determine the timing of development of the SAC.

Arachnoid cysts

Arachnoid cysts are fluid-filled duplications or splittings of the arachnoid layer with a content which is similar but not equal to the cerebrospinal fluid. Arachnoid cysts are not actual neurodegenerative disorders, rather the underlying defect of the texture of the arachnoid layer is probably congenital in nature. They can occur sporadically or can be associated with other malformations or diseases. Arachnoid cysts may be discovered in early childhood. However, they can develop de novo, grow or decrease in size. They may be diagnosed by ultrasound screening in the fetal period or be discovered during childhood or adulthood. Many arachnoid cysts are asymptomatic.Treatment strategies are discussed controversially. If they are diagnosed incidentally or are correlated with only very mild symptoms, a conservative management with follow-up imaging may be favored. If they grow, they can cause headaches, seizures or other neurological symptoms and require neurosurgical treatment. This chapter addresses aspects of pathogenesis, clinical symptoms, indication for neurosurgical treatment and treatment options.

Presentation of a minimally symptomatic large extradural hematoma in a patient with an arachnoid cyst: a case report and review of the literature

Introduction

Hemorrhagic complications of arachnoid cysts have been reported, extensively presenting with subdural or intracystic hematoma after trauma, but presentation with extradural hemorrhage is very rare. In this paper, we report the case of a patient with an arachnoid cyst who developed an extradural hematoma after a subtle head injury. Our patient presented with very mild symptoms in spite of the very large size of the hematoma.

Case presentation

Our patient was a 23-year-old Iranian man who complained of diffuse progressive headache and vomiting after mild head trauma. A brain computerized scan showed a very large extradural hematoma in the left frontotemporoparietal convexity over a large arachnoid cyst.

Conclusion

Brain parenchyma containing an arachnoid cyst is vulnerable to trauma and increases the risk of serious hemorrhagic complications. We also suggest that the abnormal shape of the head should be considered as an indication for a computerized tomography scan in cases of mild head injury.